シャドーイング練習: The Closest Thing We Have to Alien Technology - 動画で英語スピーキングを学ぶ

練習モードを選ぶ

各モードは全画面の練習ルームで開きます。

738 文

文が短すぎたり長すぎる場合は、Editをタップして調整してください。

This is a microchip.

When you zoom in, you find a nanoscopic computing city.

Skyscrapers, hundreds of layers tall, with hundreds of kilometers of wires connecting everything.

And at the very bottom is this.

Transistors.

Billions of them.

They are the ones and zeros of our computer.

The chip works by whizzing electrons from transistor to transistor.

And the smaller you can make those transistors, the less the signals have to travel, so the faster they can compute.

Plus, you can fit more transistors into the same area, resulting in a much more powerful chip.

So for over 50 years, transistors got smaller and smaller, and the number you could fit on a chip doubled every two years.

This became known as Moore's Law, named for Intel's co-founder Gordon Moore after he noticed the pattern back in 1965, and it's been one of the main drivers of the the tech industry.

But around 2015, progress came to a screeching halt.

And we might have never gotten past it if it wasn't for a single company that makes these machines, the machines that saved Moore's Law.

Holy.

This is a video about the most complicated commercial product humanity's ever built.

That's insane.

It costs a whopping $400 million and it is so bizarre that I want to introduce it to you with a thought experiment.

Imagine you are shrunk down to the size of an ant.

And you're given a laser that's strong enough to melt through metal like butter.

Next, a tiny droplet of molten tin, roughly the size of a white blood cell, is shot out in front of you around 250 kilometers per hour.

And your task is to hit this not once, not twice, but three times in a row in 20 microseconds with your little laser.

Well, that is exactly what this machine does.

It hits one tiny tin droplet three times in a row, heating each one up to over 220,000 Kelvin.

That's roughly 40 times hotter than the surface of the sun.

And it doesn't just hit one droplet.

It hits 50,000 droplets every single second.

How often do you miss a laser shot?

We don't miss them.

What?

You do 150,000 laser shots a second, and you don't miss one.

Exactly.

The same machine also contains mirrors that might just be the smoothest object in the universe.

If you scale one up to the size of the earth, then the largest bump would be no thicker than a playing card.

On top of

that, it is able to overlay one layer of a chip perfectly on top of another

and never be off by more than five atoms.

And this is all happening while parts of the machine whip around at accelerations of over 20 Gs.

For 30 years, almost everyone thought that actually building this machine was impossible.

And yet it exists.

There is only one company in the world that can make it.

So what is this company?

And what is this impossible machine they've built?

This video is sponsored by Brilliant.

More about them at the end of the show.

Now, just as a quick aside, the makers of this machine didn't actually sponsor this video.

We just thought that the science and engineering here were so cool that we had to make a video about it.

So let's jump straight in.

To make a microchip, you start by taking silicon dioxide, usually from sand, and purifying it into ultra-pure,

nearly 100% silicon chunks, which is then melted down in a special furnace.

Next, you lower a small seed crystal into the vat, silicon atoms attached to the crystal, extending its structure.

Then you slowly raise the seed crystal while rotating it, and this results in a large single crystal silicon ingot.

This is where the seed crystal would be, and then you pull it out.

Can I touch it?

Yeah, you can.

It seems like you would not be able to hold this from here.

Yes.

It even feels fragile, like if you kinda...

Looks not good.

Yeah, I'm scared to break it.

Yes.

He's using more force.

The ingot is then cut into wafers with diamond wire saws, up to 5,000 of them, after which each wafer is carefully polished.

Next, it's coated with a light-sensitive material called photoresist.

There are different kinds, but in a positive photoresist, the areas exposed to light become weaker and more soluble.

So if you shine light through a patterned mask, you can selectively weaken parts of that coating.

Then you rinse the wafer with a basic solution to wash away the exposed photoresist, leaving the design imprinted.

So now you can actually turn this pattern into physical structures.

This is often done by etching into the uncovered silicon by using either chemicals or plasma.

And then you deposit a metal like copper to fill in those etched lines.

As a last step, you wash away the remaining photoresist, and now you've made a single layer of the chip.

We've simplified this cycle down to the main steps, coat, expose, etch, and deposit.

It repeats for every single chip layer, and depending on the chip, there could be anywhere from 10 to 100 layers.

The bottom layer is the transistors.

This is the most complicated layer requiring hundreds of steps that all need to be perfect.

The higher layers are a little easier.

These are the metal wires that carry signals and power.

By the end, the completed wafer can have hundreds of chips, which are then cut into separate pieces, packaged and put into products.

But by far the hardest

and most crucial step in the process is where you shine light through the mask and onto the wafer.

This is photolithography.

And that's because this step determines how small you can make the features.

At first, it seems simple.

Light passes through the openings and it gets blocked by all the rest.

But as you try to print smaller and smaller features, the gaps in the mask start to approach the wavelength of the light.

And that causes problems.

And we can actually show it because I happen to have a...

This is a mask, this is a reticle.

A reticle or a mask carries the design of one chip layer.

This reticle is filled with microscopic lines and gaps around 670 nanometers across.

And if I take like a laser pointer, so this is a red laser.

If I shine it through it, then you see this here.

The laser has a wavelength of around 650 nanometers.

When light hits the reticle, its wave fronts bend as they pass through each gap.

So each gap sends out waves that spread out and overlap.

Now, let's just look at the light from these two gaps.

When the peaks of one wave line up with the troughs of the other, we say that the two waves are outer-face and they cancel each other out.

So you get dark spots.

And when the peaks line up with the peaks, the two waves are in phase.

100

They add up and you get bright spots.

101

You get interference, right?

102

And you get a diffraction pattern.

103

Now diffraction is inevitable.

104

So instead of fighting it, designers actually use it to get the patterns they want.

105

They kind of work backwards from the eventual pattern they want on the wafer

106

and they design the slits so that diffraction will occur in such a way that it creates the pattern that they want.

107

You see three dots.

108

The middle dot, that's the original one, that's the zero order, and then on the left and the right you can see the first and the minus first.

109

Now in order for us to have this image resolved on the wafer, you need to capture the zero and the first and the minus first order.

110

The smaller you make the features, the larger this angle alpha between the zero and first orders becomes systems, so the larger your lens needs to be to capture the light.

111

The size of the lens is described by the numerical aperture, or N-A for short, which is just the sign of this angle.

112

So the larger that is, the smaller the features you can print.

113

But there is a hard limit to how large your lens system can be.

114

When this angle is 90 degrees and your numerical aperture is 1, well your lens would have to be infinite.

115

Fortunately, there is one other thing we can change.

116

This is a red laser.

117

Yeah.

118

And a red laser has a wavelength of 650 nanometers-ish, I would say.

119

Something like that, yeah.

120

And if I take the green laser, and this one has a wavelength of 532,

121

then you can see that the green dots are closer spaced than the red dots.

122

That's because the light from the two different gaps doesn't have to travel as far to match up in phase again.

123

So the orders end up closer together.

124

So with a smaller wavelength you can print smaller patterns using the same lens.

125

All of this is captured by the Rayleigh equation, which determines the smallest feature size or critical dimension.

126

But since there's a limit to how much you can increase the numeric aperture, I mean to one, over time the only way to keep making smaller

127

and smaller features is by using shorter and shorter wavelengths.

128

So this is exactly what happened up until the late 1990s when the industry settled on 193 nanometer deep UV light.

129

This was the light that was used to make all of the most advanced chips right until around 2015.

130

But by that point scientists had reached the limit to how small they could make the features

131

and Moore's law was about to run into a brick wall.

132

So a radical change was needed.

133

A change that had been brewing for around 30 years.

134

All the way back in the 1980s, Japanese scientist Hiroki Yoshida came up with a crazy idea.

135

Why not use much shorter wavelengths, like X-rays of around 10 nanometers?

136

In theory, that should allow you to print much smaller features.

137

But you quickly run into a problem.

138

X-rays at these wavelengths have enough energy to eject electrons from their atoms, so most materials absorb them.

139

But unlike medical x-rays, which have wavelengths shorter than one nanometer, these are still long enough to interact with air, so air absorbs them too.

140

That meant that Kinoshita's setup had to be in a vacuum.

141

But even worse, he couldn't use lenses to focus the light, because the lenses would absorb it too.

142

So it seemed like this idea would never work.

143

But around 1983, Kinoshita stumbled on a paper by Jim Underwood and Troy Barbie.

144

Their work focused on special mirrors that could reflect X-rays with a wavelength of 4.48 nanometers.

145

So Kinishida was intrigued.

146

Curved mirrors can focus light just like lenses do.

147

If he could figure out how to make these special mirrors for the wavelength he was using, then this could be another way to do photolithography.

148

The mirrors work something like this.

149

When light crosses from one medium to another, say from air to glass, it bends or refracts.

150

Some of it goes through and part reflects back.

151

How much gets reflected depends on things like the angle, the light's polarization, and most importantly for us, the difference between the refractive indices of the two media.

152

The larger that difference, the more light is reflected.

153

And Underwood and Barbie used that principle.

154

They made a super thin layer of tungsten, less than one nanometer thick, thin enough that X-rays could pass through without immediately being absorbed.

155

When X-rays hit the layer at a specific angle, the tungsten reflected less than 1%.

156

Then they carefully tuned the layer thickness so the path length of the transmitted x-rays was only one quarter of its wavelength.

157

Then they added another layer, this time out of carbon.

158

It has a higher refractive index than tungsten for wavelengths of 4.48 nanometers.

159

The x-rays hit the boundary and a little bit more reflects.

160

But this time the phase is inverted or it's changed by half a wavelength.

161

This happens when any light moves from a lower refractive index to a higher one.

162

Now, by the time this new reflected wave reaches the tungsten boundary, it has traveled another quarter of its wavelength for a half wavelength in total.

163

So the two phases line up and the waves interfere constructively.

164

Underwood and Barbie kept doing this trick for a total of 76 alternating layers, so that in total, they could reflect back much more of the x-rays.

165

Now, they only managed to reflect around 6% of the light, but it was a proof of principle that you could reflect X-rays.

166

So, Kinoshita saw the possibilities.

167

He got to work, and after around two years, his team designed and built three tungsten carbon curved multilayer mirrors to reflect 11 nanometer light.

168

And with it, he managed to print lines four microns, or 4,000 nanometers thick, proving that,

169

at least in theory, X-ray lithography was possible.

170

A year later, in 1986, he went to present his findings to the Japanese Society of Applied Physics.

171

Proud and excited, he explained his setup and showed his image.

172

But to his horror, the audience refused to believe it.

173

Unfortunately, the audience was highly skeptical on my talk.

174

Kinoshida was devastated.

175

He later said, people seemed unwilling to believe that we had actually made an image by bending x-rays, and they tended to regard the whole thing as a big fish story.

176

Nobody believed that this was a viable way forward and unfortunately the reaction was at least somewhat justified.

177

First, this light isn't naturally produced by anything on Earth.

178

The closest natural source is the Sun.

179

We had to basically build an artificial Sun here on Earth.

180

Most scientists including Kinoshita produced x-ray light using a particle accelerator or a synchrotron.

181

It gives an enormous amount of power.

182

It's as big as a soccer field.

183

You can fuel the whole feb.

184

The problem is if the light goes out, the whole feb goes out.

185

So each machine needed its own power source.

186

But even if you could produce the light, you'd need to make incredibly smooth mirrors to actually focus and print those tiny features.

187

You would need the smoothest objects in the universe.

188

Okay, so I got a football and I've got a bouncy ball and a cobblestone street.

189

Now, what do you think is gonna happen when I drop them?

190

The football basically bounces straight up, but for the bouncy ball, it just shoots up to the side.

191

And that's because the surface is relatively flat for the football, which is much larger, but it's super rough for the bouncy ball.

192

And a similar thing happens with mirrors.

193

If the surface is super rough compared to the size of the wavelength, then the light scatters randomly.

194

Now, it might look smooth, but if you zoom into a mirror, you find something that looks like this.

195

You find all these crazy bumps.

196

And now to measure the roughness, what you do is you take the average of these bumps, and that will give you your mean line.

197

Now, for a normal household mirror, the average height is about 4,000 silicon atoms.

198

But for Kinoshita's mirrors, which not only needed to reflect x-ray light, which has a hundred times shorter wavelength, but also needed to minimize scattering,

199

you know, so that all the photons make it onto the wafer, it needed to be way more smooth.

200

It needed to be atomically smooth.

201

In fact, the average bump could only be about 2.3 silicon atoms fig.

202

If one mirror would be the size of Germany, the biggest bump would be about a millimeter high.

203

But Kinoshida refused to give up.

204

However, my belief did not change.

205

And soon help would come from an unlikely place.

206

Across the Pacific, around 70 kilometers east of San Francisco, is Lawrence Livermore National Lab.

207

A lab that was born out of the Cold War, heavily funded by the US government, and built for one purpose and one purpose only, nuclear weapons.

208

The lab was founded by the inventor of the cyclotron, Ernest Lawrence, and the father of the hydrogen bomb, Edward Teller.

209

And over its lifetime, they designed over 10 fusion-type nuclear warheads.

210

So part of their research focused on what happens inside nuclear fusion reactions.

211

Fusion reactions released a lot of x-ray light, light that they had never been able to capture and analyze.

212

But now, using those special multi-layer mirrors, there was a chance.

213

One of the scientists tasked with making this work was Andrew Hoverluck, and within a few years, he and his team used multi-layer mirrors to reflect some x-ray light.

214

But then in 1987, Andy got a visit from a professor from Cornell.

215

very impressed with the technologies that we developed

216

and he looked at me at the end of the day

217

and said this is all very interesting and very neat

218

and stuff but his words

219

and I'll remember it to the day I died was can you do anything useful with this stuff?

220

This was the day before a Christmas shutdown in 1987

221

and I was so inflamed by that comment that I went home

222

and for the next 10 days I wrote up a multi-page white paper.

223

He applied these mirrors to lithography to print chips using x-rays.

224

Around five months later, Andy presented his findings at a conference.

225

But like Inoshita, it was not the response he was hoping for.

226

It was extremely negative.

227

That was the low point in my career.

228

I was literally laughed off the stage and I kid you not.

229

Every person who I looked up to in the field,

230

they were listening to my talk and they came up to the microphone and told me basically why it wouldn't work, how stupid an idea it was.

231

Later that week I flew back

232

and the following Monday my boss asked me how did it go

233

and I looked at him and I said I will never speak of it again.

234

But then three days later he gets a phone call from someone named Bill Brinkman from from Bell Labs.

235

So I walked over to my boss and I said, I just got this phone call from a guy named Bill Brinkman, you know who he is?

236

And my boss's eyes popped open and said, yeah, he's the executive vice president of AT&T.

237

And I said, well, he just called me and asked me to fly out to New Jersey and give a talk.

238

The response from my boss said it all.

239

He basically said, well, you gotta go.

240

At Bell Labs, Andy found fellow believers, and it couldn't have come at a better time.

241

Over the past 30 years, the US government had invested billions of dollars into national labs to maintain the country's technological edge during the Cold War.

242

But by the late 1980s, the Cold War was slowing down.

243

And all these labs were sitting on research that had commercial potential.

244

So the government encouraged the labs to partner with US companies to turn that research into products and to stimulate the economy.

245

And the government would then supply seed money.

246

And so Bell Labs partnered with Andy's Labs and two others to keep developing X-ray lithography.

247

And by 1993, the first international conference for X-ray lithography was held in Japan, near Mount Fuji.

248

In the opening address, Kinoshita said that as long as we do not lose the desire that has sprung from within us, technology will steadily advance from the micro,

249

to the nano, to the pico.

250

They even gave the technology a new name, Extreme Ultraviolet Lithography, or just EUV.

251

But then in 1996, the US government cut funding for the project.

252

This spelled disaster for the big chip companies like Intel.

253

The industry estimated that the 193 nanometer lithography tools would fall behind Moore's law by 2005.

254

But there were no other alternatives.

255

So Intel, Motorola, AMD and other companies got together and invested $250 million to keep it going,

256

making it the largest investment ever by private industry in a Department of Energy research project.

257

By the year 2000, the labs had produced this, the engineering test stand.

258

It was the first fully functioning EUV prototype.

259

It produced 9.8 watts of 13.4 nanometer EUV light, which was then reflected by eight mirrors from the source to the mask to the wafer.

260

It could print 70 nanometer features and it proved that EUV could work.

261

It was a milestone to get the engineering test stand to work.

262

It demonstrated to people like Intel that, you know, good engineering will get us there.

263

And it seems like you've got the prototype.

264

Shouldn't be too hard to then commercialize it.

265

That's what they thought.

266

But the prototype had a major flaw law.

267

It could only print about 10 wafers per hour.

268

And to make EUV economically viable, it would have to print hundreds of wafers per hour, 24-7, 365 days a year.

269

The main reason output was so slow was because the light reflected off of eight mirrors and the reticle, which is also a mirror, just with the design imprinted.

270

Traditional masks that allow light to pass through don't work because, well, they absorb all the light.

271

Each mirror had a reflectivity of around 70%, which is close to the max, but after 9 bounces, you're only left with 4% of the light.

272

Which means that out of every 100 photons, only 4 make it to the waver.

273

So you might think, just use way fewer mirrors.

274

But that only works up to a point.

275

When you focus light with any optical system, you always get some distortion.

276

For example, rays that pass through the outer edges of most lenses focus light slightly different from those near the center.

277

This is called spherical aberration.

278

And normal cameras correct for this and other aberrations by using multiple lenses.

279

And a mirror system is no different.

280

You need to have a certain amount of mirrors before you can say I have my aberrations under control.

281

In reality, the systems of today have six mirrors.

282

That helps a little, but after reflecting off six mirrors and the reticle, you're still only left with around 8% of your light.

283

So they needed to drastically increase the source power to at least 100 watts.

284

Now to most companies, that tenfold increase seemed impossible.

285

Even people who worked on the engineering test tent noted that while EUV technology itself is a done deal,

286

there were six zillion engineering challenges to make it a fab-line reality.

287

And so one by one, American companies walked away from developing a full UV lithography machine.

288

That left just one company, ASML.

289

ASML, which used to stand for Advanced Semiconductor Materials Lithography, is located in a small, nondescript town in the Netherlands.

290

It spun off from Philips back in the 80s with little more than a shed

291

and a barely working wafer stepper to its name.

292

But Philips also gave them people, Jos Benshoop, ASML's first researcher, and Martin van den Brink,

293

who would eventually become ASML's CTO and EUV's greatest champion.

294

And he's really like the Steve Jobs of lithography.

295

And he saw EUV coming.

296

ASML had joined the US EUV consortium earlier, and now it became their task to find a way to commercialize EUV.

297

They would work together with their German partner Zeiss, where Zeiss would take care of the mirrors, and ASML would focus on the light source.

298

One of the first decisions when making any lithography system is deciding which wavelength to use.

299

In the early days, anything between 5 and 40 nanometers was explored.

300

The thing is, you need to find a source, and you need to find optics that reflect the wavelengths.

301

So you have to look for the combination.

302

Underwood and Barbie had already made mirrors that could reflect light of around 4 nanometers.

303

And since that wavelength is so small, it seems like the obvious choice.

304

But the maximum reflectivity for those mirrors was only around 20%.

305

So after hitting six mirrors and the radical, you're just left with 0.00128% of the light, which is way too low.

306

Fortunately, further researchers also looked at two other pairs.

307

Silicon and molybdenum, which had a theoretical maximum reflectivity of 70% for wavelengths around 30 nanometers,

308

and molybdenum and beryllium, with a theoretical maximum reflectivity of 80% for wavelengths around 11 nanometers.

309

So the choice seemed obvious, right?

310

I mean, pick the shorter wavelength and the higher reflectivity.

311

But it turns out that beryllium is extremely toxic and it's also difficult to handle.

312

So scientists focused on silicon and molybdenum instead.

313

To make the mirrors, Zeiss used a process called sputtering.

314

A target of coating material is bombarded with either plasma or ions, causing atoms to be ejected, fly off, and stick to the mirror.

315

This is a messy process, so the layers end up having bumps and gaps.

316

That was a nice trick that actually the team in the Netherlands perfected.

317

With iron beam, you just shake it a little bit until the atom falls in the hole where it needs to be, and then it's all flat.

318

With the mirror design locked in, ASML needed a source for that specific wavelength.

319

So it was 13.x.

320

Yeah.

321

The next good question is, what's the x?

322

Now you look for the source.

323

So there are basically three ways to generate the UV, to build a sun on Earth.

324

The first method, which early researchers used, was the synchrotron.

325

But it was quickly rolled out because each machine needed its own source.

326

The other two methods are based on the same principle.

327

When an electron recombines with an ion, the ion drops to a lower energy level, and it releases that excess energy as a photon.

328

And if you choose the ion just right, then that photon will have exactly the wavelength you need.

329

Now, there are two ways you can create those ions.

330

The first is you take a metal, heat it up until you get a metal vapor, and then you apply a strong electric field across it.

331

This causes three electrons to knock into nearby atoms and ionize them.

332

If you then turn off the electric field, the electrons recombine with the ions and produce light.

333

This is discharge-produced plasma.

334

That's the concept we used first because of its relative simplicity.

335

And we quickly got it to a few watts.

336

We wanted to get 100 watts and we struggled forever.

337

So you couldn't scale it?

338

We could not scale it.

339

They needed a drastic change.

340

So they switched to the second method.

341

This method uses a high-powered laser to hit a target material, creating a plasma that's more than 220,000 degrees Celsius hot.

342

The electrons have so much energy that the nucleus can't hold on to them anymore.

343

And up to 14 electrons escape their orbits.

344

After the laser shuts off, the electrons and ions recombine to produce light.

345

This is laser-produced plasma, and it was the only method that seemed scalable.

346

In fact, this was the same method that the engineering test stand used.

347

A 1700-watt laser fired into a stream of xenon gas to produce 13.4 nanometer light.

348

But Xenon had a big problem.

349

The conversion efficiency, that is the ratio of usable light to the amount of power you put in, was terrible.

350

It was only around 0.5%.

351

That's because while Xenon does emit light in the 13 to 14 nanometer range, there's much more light released around 11 nanometers.

352

So most of the energy went into making light that the mirrors couldn't reflect.

353

Plus, the laser didn't ionize all the atoms, so leftover neutral Xenon atoms would strongly reabsorb some of that 13.4 nanometer light.

354

So, ASML started looking at another material, tin.

355

Now, tin has a much higher emission peak, around 13.5 nanometers, which results in a 5 to 10 times higher conversion efficiency than Xenon.

356

But just like Xenon, neutral tin atoms also absorb EUV light.

357

So they came up with a crazy idea to shoot one tiny tin droplet at a time.

358

But to get the required power, you would have to make and hit thousands of droplets every second, all of which have to be the exact same shape and size.

359

But it turns out that you can't instantly make thousands of tin droplets that are the exact same.

360

So they found a workaround.

361

To make the droplets, extremely pure tin is melted and pushed through a microscopic nozzle by high-pressure nitrogen.

362

This nozzle vibrates at a high frequency, breaking the stream into tiny droplets.

363

These droplets are irregular in size, shape, velocity and distance, and the whole process is chaotic.

364

That's like our magic sauce, is how do you modulate that tin jet so it forms the droplets we want and that they're stable.

365

I think we found some paper that described this process, and it was sort of eye-opening to me

366

that it seems like all the droplets actually come out irregular out of the nozzle.

367

But then before they reach the site where they get hit by the laser, like the little irregular droplets come together to form these perfectly spaced,

368

perfectly regular droplets that are about the same size and shape, and all traveling at the same velocity.

369

That feels like magic to me, Jason.

370

Yeah, it's exactly that.

371

It's how do you take a long stream of a tin jet

372

that wants to break up into all these irregular droplets

373

and like force onto it that it's going to collapse into a single droplet and then happen again and again and again.

374

You also don't have that many variables to play with.

375

You've got the pressure with which you push out the tin and the frequency of the nozzle.

376

Yeah, it seems like a hard problem to solve.

377

There's not a whole lot of variables to play with and

378

so mastering that modulation of the jet is how we make the droplets.

379

But these droplets not only have to be identical, they have to be moving incredibly fast.

380

What will happen is if the next droplet that's coming down the line is too close, then it'll actually get disturbed and mess up the next plasma event.

381

So we have a requirement which is both that we make 50,000 droplets per second, but also that they're traveling extremely fast.

382

By 2011, their laser produced plasma source reached 11 watts, which was more than double what they managed with their previous source.

383

But they were still limited to just 5 wavers per hour.

384

So they needed to increase the power and fast, because they promised they'd hit 60 wavers per hour by the end of 2011.

385

Unfortunately, this new method had a major flaw.

386

Now the problem with the tin issue, you hit the droplet, you generate EUV with a very decent conversion efficiency, where does the tin go?

387

Because like you know 30 centimeters away you have this atomically flat, very beautiful, very expensive mirror from our friends at Zeiss.

388

And in the early days we would coat the thing within like this.

389

These machines need to run for a year.

390

You're putting liters of tin through this plasma event and a single nanometer of tin, if it was to land on that collector mirror,

391

you'd You have to take the collector out of commission.

392

We need to keep it almost perfectly clean for a year.

393

Yeah, how do you even approach that?

394

So our main tool here is the hydrogen gas, actually.

395

They filled the chamber with low pressure hydrogen.

396

This slows and cools the tin particles down.

397

And even if something makes it to the collector, the hydrogen pulls it off to form a gas called stannane.

398

This way, the machine cleans the collectors while it's running.

399

But that hydrogen gas also gets hot from all those tin explosions.

400

So they need to keep flushing new, cooler hydrogen into the system while flushing out the stinane and hotter gas.

401

But they had to get the pressure and the flow rate just right.

402

I mean, too little hydrogen and the mirrors would get too dirty, but too much hydrogen would not only absorb too much EUV light, but it would also cause the system to overheat.

403

But the question is, how much heat is there?

404

How much energy is being deposited into the gas? and we were stumped for quite some time.

405

If you look at an EEV light source, what you'll see is that it's kind of like a globe of like purplish red light.

406

And you kind of ask yourself like, why is that happening?

407

So we bought an ultra fast camera.

408

What we realized is that after every plasma event, there's a shockwave that goes propagating out into the hydrogen gas.

409

And it's extremely repeatable.

410

And you think to yourself, there must be like an explanation for this.

411

And there's this formula, the Taylor van Neumann-Ziddow formula, that explains point source explosions in an environment,

412

like say, a nuclear blast out to supernova.

413

So I took this formula, it exactly describes the data.

414

It's just fantastic that we're seeing these tiny little supernovas happening in our vessel 50,000 times a second.

415

And is that a fair way to think about this?

416

Like creating mini supernovae?

417

Yeah, it's actually pretty similar.

418

It's almost like very similar to a Type 1a supernova, it turns out, where you kind of have an object that just fully evaporates and explodes apart.

419

And when all that energy goes into the hydrogen gas, it produces a shockwave, a blast wave that comes flying out, which is basically the same thing if you look up in the night sky.

420

There are these like remnant supernovas that you can see coming from space.

421

Using those energy calculations, they discovered they needed to flush the hydrogen at incredibly high speeds, around 360 kilometers per hour.

422

That's more than a category 5 hurricane, even if those speeds are at low density.

423

But 2012 came and went, and they still didn't have enough power.

424

In fact, by 2013, ASML just reached 50 watts by shooting 50,000 thin droplets per second.

425

But this increased power came at a price, because more power means more heat.

426

Heat that ends up slightly shifting the mirrors, resulting in misaligned light and misaligned chip layers.

427

So SAIS built a nervous system directly into the optics.

428

Robot guided sensors that constantly measure the exact position and angle of each mirror,

429

down to the nanometer and the picoradiant, which is absolutely insane.

430

So how accurate do we need to control this mirror?

431

Now one of the things you can do a thought experiment and I can place a little laser

432

on the side of this mirror.

433

And we go all the way to the moon and we put a dime here.

434

So then this light travels all the way here and then with the accuracy I can control this mirror.

435

I can decide whether I point to this side of the dime or whether I point to this side of the dime.

436

What?

437

That's crazy.

438

So you can see that the pointing accuracy is also in picoradiance.

439

That is something very extreme.

440

This allowed them to control the light even when the power increased.

441

While Zeiss was doing a stellar job with the optics, ASML was still struggling with the power source.

442

The problem was that the thin droplets were too dense, meaning

443

that most of the emitted EUV light was still getting reabsorbed

444

by the neutral atoms before it could ever reach the collector mirror.

445

The way we blasted the droplet was so not enough light, too much debris.

446

To make matters worse, they could see that about 10 years from now, they would need a new generation of machine.

447

A high NA EUV machine.

448

Essentially one with a larger optics system that could print smaller features.

449

So what did they do?

450

They decided to double down and invest in the next generation before they even got the current one to work.

451

The most doubtful period was in the beginning.

452

So I started to work on this in 2012.

453

By that time, EUV was not working.

454

And there was this crazy idiot working on the next generation

455

where we could not even make the EUV light in the first place.

456

Not only are you all in on EUV, you're doubling down even before you know if EUV is going to work.

457

Yes.

458

But to keep funding the development, they needed money and lots of it.

459

So they turned to the very people who needed this technology.

460

ASML reached out to its main customers, okay, you want this technology for the next generation of chips,

461

well you need to make us able to invest more by investing in us.

462

Intel invested around 4.1 billion dollars and Samsung and TSMC invested another 1.3 billion combined.

463

So they can keep the research going, but with no product to show, customers were running out of patience.

464

We were crucified at every conference.

465

That promises we made last year we were unable to live up to.

466

And they said this is what you showed two years ago, this is what you showed last year, this is what you're telling me this year, so why would I believe you?

467

They were getting desperate.

468

But this was I think about 2012 or 2013.

469

We were struggling to get the EV power up.

470

And Kinoshita visited us, I took him to dinner in a small town nearby

471

and across from the The restaurant was a Maria Chapel.

472

And now, you know, science, we have come to the limits of science.

473

Let's go for defined interventions.

474

So we went to the chapel.

475

So Kinoshita, just to be safe, lit three candles for the three suppliers that were pursuing EV technology at the time.

476

And lo and behold, and I have the data to prove it, there is a very strong correlation between us lighting the candle and power going up.

477

It's not a causal effect, but there is a strong correlation.

478

The big idea was instead of hitting the droplet once, hit it twice.

479

One shot to hit the droplet and it expands in like a pancake shape.

480

And then, only then, have the second shot, the more powerful main pulse, where you evaporate the pancake and turn it into a plasma.

481

This was a major breakthrough.

482

By changing the target from a droplet to a pancake, you got a larger surface area for the laser to vaporize but without the cost of adding more debris or neutral atoms.

483

Because now the tin is vaporized all at once.

484

By 2014, they finally managed to hit that coveted 100 watts mark.

485

But improvements in multi-patterning with 193 nanometers now meant

486

that EUV would only be useful if the source reached at least 200 watts and made 125 wavers per hour.

487

The source went from 100 to 200, but as the industry moved on, nobody waits for you.

488

They find other solutions.

489

We had to catch up, so it was a moving goalpost.

490

One of the problems was how do you perfectly time the laser so you hit each of these droplets?

491

So the analogy is a bit like a golf ball that you need to land in the hole 200 meters away.

492

Not like land on the green, not bounce and then get in the hole, but like land in the hole every time.

493

That's the level of precision that we need to deliver the droplets.

494

Those droplets are traveling through this maelstrom of hydrogen flow.

495

The speeds are tremendously high, it's like shoot golf balls through a tornado.

496

And then right when it lands at the hole, that's when it needs to get hit by the laser.

497

So in order to basically track the droplets, for that we use laser curtains and we can sort of look at when does the droplet pass through a laser curtain.

498

Those scattered photons tell us basically when and where is the droplet.

499

And then importantly tells us when to fire the laser.

500

So we actually have to take into account how long will

501

it take for the light pulse to hit the droplet after we send the pulse.

502

Now by 2015 they were getting closer and closer to that coveted 200 watt mark.

503

When all of a sudden the ASML board members got summoned.

504

This was one of these decisive moments where our customers were really thin on patience

505

and Martin and other board members were summoned to Korea to show 200 watt.

506

They were really fed up with it.

507

You either show it now or you go away.

508

When they entered the plane, the experiment was still running.

509

When they exited the plane, they had the first result demonstrating to the other.

510

This is how close we came.

511

With the source power up, there was one final problem that had to be solved before they could begin manufacturing their machine.

512

See, while the hydrogen gas did protect the collector mirror from debris, it wasn't perfect.

513

All the intense high-energy photons and hydrogen ions zipping around deteriorated a very special top coating on the collector.

514

So they still had to clean the mirrors every 10 hours, which is terrible for productivity.

515

Martin van den Brink asked for updates every day on their progress.

516

But then one of the engineers noticed that every time they opened up the machine, the mirrors suddenly seemed cleaner.

517

He kind of chimed in and said, oh, wait a second.

518

Whenever we open up the machine, oxygen comes in and our problem is solved.

519

Couldn't we think of a way to add just a little oxygen to our system

520

and make sure that the collector stays clean longer?

521

And so they started experimenting with the amount of oxygen that was needed in the vacuum.

522

And then finally got to this point, okay, if we add so much oxygen, we'll keep the collector clean for longer.

523

With this fix, ASML's machine could run continuously for much longer.

524

And it finally became commercially viable.

525

By 2016, orders started pouring in, and now all of the most advanced chips need ASML's machine,

526

making them perhaps the most important tech company in the world.

527

ASML's first commercial machines had a numerical aperture of 0.33 and could print 13nm lines.

528

These are called the Loename machines, and ASML still makes them.

529

But the machine that Jan's team started working on back in 2012 was the next generation, which had a larger optic system so they could print even smaller features.

530

This is the Hi-NA machine with a numerical aperture of 0.55, and we get to see their latest version up close.

531

How much is the machine?

532

Eh, we always say north of 350 million euros.

533

And you can actually buy it, right?

534

You can if you want, yeah.

535

If I had the money, I could buy it.

536

Yes, you could.

537

How many people have seen this before?

538

We really limit the amount of people that get to go inside the clean room.

539

ASML's machines are built in a super strict clean room.

540

In any cubic meter, there can be no more than 10 particles, only 0.1 microns large.

541

And nothing bigger than that.

542

A speck of pollen is around 20 microns, and extremely fine sand is around 10 microns.

543

To put all of this in perspective, hospital operating rooms, which have to be extremely clean,

544

only allow a maximum of 10,000 particles per cubic meter that are 0.1 microns wide.

545

It's so unfair how much better Mark looks though.

546

In his light suit, I feel like a little nerve.

547

Okay, so we're gonna go through the air showers.

548

So you're gonna have to do as I do.

549

So this is brushing down all the particles that are still on us.

550

Yeah, so this is like super clean air blowing us clean.

551

This place is huge.

552

It's huge.

553

It's insane.

554

I've been in a clean room a couple times before, but it's nothing compared to this.

555

Are there any secret areas here where almost no one has access to?

556

Uh...

557

I can't tell you.

558

Great answer.

559

Okay, so this is the total system.

560

This is it.

561

That's crazy.

562

Look how big it is.

563

This is the most advanced machine humanity's ever built.

564

It's taken many, many years, decades of development, many billions of dollars, all to get this humongous beauty.

565

So this is the first H&A machine?

566

Yes.

567

So if you saw pictures on the internet or whatever, Yeah.

568

that's this machine.

569

So the very first lines ever printed at 8 nanometers and stuff, that was this machine.

570

The smoothest object on earth?

571

Yeah, it's all in here, yeah.

572

Wait, so let me see if I can figure this out.

573

This is the light source.

574

This is where they make the extreme ultraviolet.

575

Yes.

576

And then the laser must come in from there.

577

In fact, we got to see just how the laser and light source work.

578

I think we're entering the laser system here.

579

Mark's just making sure I think that we can actually film here.

580

We're not catching anything we're not supposed to.

581

Oh, wow.

582

This looks dangerous.

583

Now, the laser system is covered by all of these brown cabinets, but here is a model version.

584

A carbon dioxide laser of just a few watts enters this amplifier, it bounces around until it's roughly five times its original power.

585

It then goes through a total of four different amplifiers to bring the final laser up to 20 000 watts, which is four times stronger than lasers that cut through steel.

586

Over here we have the amplifiers that generate this powerful laser beam.

587

And then it basically comes out and this is part of the beam transport system where it's brought to the machine.

588

So this pipe here has the big laser beam.

589

And this has a mirror?

590

Yes.

591

Then the pulses travel to the light source module.

592

It kind of looks like a transformer or like a...

593

I don't know, like a spaceship.

594

There's so many wires going everywhere.

595

Don't twitch this.

596

Holy crap.

597

This is pretty big, huh?

598

This is insane.

599

And this is just a light source.

600

This is just a light source.

601

Are you getting this comparison, Sean?

602

So you need all of this just to make the UV light.

603

Just to make the light?

604

Yes.

605

That's incredible.

606

Can we do a little walk around?

607

You can do a little walk.

608

Let's go.

609

So basically this is the heart of the source.

610

Can I stand on here?

611

If you're below 137 you can.

612

I think I am.

613

And so the tin droplets are coming in from the left.

614

Yes.

615

Then we're shooting a laser from here?

616

Yeah.

617

Okay, it explodes.

618

And then the light goes out there.

619

One improvement from ASML's first EUV machine to their newest one is the number of pulses that hit the droplet.

620

The first prepulse still flattened the droplet into a pancake.

621

But now there's also a second prepulse that further reduces the density.

622

It basically turns it into a low-density gas.

623

It verifies it.

624

And then the final pulse essentially ionizes all of it.

625

So for basically the same power coming from the drive laser, they get even more EUV light.

626

Now, if they want even more light, then the only way to do that is by hitting more droplets.

627

And that's exactly what they did.

628

Our most recent EUV light sources that we're shipping right now, which are around the 500 watt level, we increased the rep rate up to 60,000 times per second.

629

And then we have a roadmap that's going to go to 100,000 droplets per second.

630

We've actually now already demonstrated this 100,000 droplets per second in the lab, so it's not an if, but a win.

631

Crazy.

632

The three pulses that we use to make the pancake, to blow up the pancake a little bit, and then to evaporate the pancake.

633

Yeah.

634

The first two pulses, they would be coming in through this pipe here.

635

And then the main pulse with the big laser, the laser beam would be delivered through this pipe here.

636

Both the high and low NA machines shipping out right now use three pulses, and eventually they will hit more droplets per second.

637

But the light source is just one small part of the full machine.

638

After bouncing off the collector mirror, the EUV light moves to the illuminator.

639

A set of mirrors shape and focus the light before it hits the reticle.

640

The reticle is the top half, and this module is built in a separate facility and installed later.

641

Next, the light goes into the projection optics box, which is a set of mirrors that shrink the light down.

642

The Hyenae machine can shrink the pattern eight times in the vertical direction and four times in the horizontal direction.

643

The mirrors are also much smoother still.

644

If the low NA's mirrors were the size of Germany, the tallest bump would be about a millimeter.

645

But if the high NA mirrors were the size of the world, the tallest bump would be about the thickness of a playing card.

646

By the combination of both of these improvements, ASML was able to increase the numerical aperture from 0.33 to 0.55.

647

And finally, the light hits the waver.

648

In order to print around 185 wavers per hour, the reticle whips back and forth at accelerations of over 20 Gs.

649

That's over five times the acceleration of a Formula One car.

650

And this is some actual footage of what that's like inside this machine, and notice that this is not sped up.

651

But the crazy thing to me about this machine isn't how fast the reticle moves, or even how small it can print, but it's just how insanely accurate it needs to be.

652

The most any two layers can be off, which is called the overlay, is one nanometer.

653

That's five freaking silicon atoms of precision.

654

That's insane.

655

So typically what we do as system engineers is that we make a budget.

656

So we say, hey, you get, let's say, a nanometer.

657

And we divide then the nanometers to smaller fractions.

658

The nanometers total.

659

It's not like your group gets a nanometer.

660

You get a nanometer.

661

You get no. No, you get a nanometer in total.

662

Yes.

663

So you have to fight for your part of the nanometer.

664

It's kind of cool to realize that every smartphone nowadays has a chip

665

that is made with the machine that was actually put together here.

666

So that's a cool thought.

667

Take a look at this.

668

It's pretty massive, huh? So big.

669

So do you cover it up?

670

Yes.

671

At a customer fat, it will be looking like a big white box.

672

I like it better like this.

673

Yeah, me too.

674

It's funny, you need such a big machine, so much infrastructure to make the tiniest things we can make at scale.

675

It's inversely proportional.

676

Yeah, the smaller you want to go, the larger everything around it becomes.

677

After the machines are assembled, tested and approved, they are disassembled to ship all around the world.

678

5,000 companies supply 100,000 parts, 3,000 cables, 40,000 bolts and two kilometers of hosing.

679

ASML ships their H&A machine in 250 containers, spread out over 25 trucks and seven Boeing 747s.

680

Despite all the doubt and setback, EUV finally made it to manufacturing level three decades after Kinoshita's first images.

681

But even when almost the entire world didn't believe it would work, there were some people at ASML who knew that it was going to work all the way back in 2010.

682

Around 2001 we said let's do EUV.

683

And then we run into many challenges.

684

2010 we installed the first system at a customer.

685

So it was installed in Korea.

686

There it was.

687

This thing I had been pursuing for 13 years was now standing at a customer producing wafers.

688

This for me was a moment I realized, yes, we made the right bet.

689

Years later, Jas ran into the man who helped install that first machine.

690

He's now a professor at the Renown Institute.

691

And I shared the story about my relief and how great we made the decision.

692

And Hanko said, yeah, yeah, yeah.

693

He said, when you left, when you flew out after Christmas, the thing broke down.

694

And it took two months to get back up again.

695

And they almost fired me for making the wrong decision.

696

We had some ups and downs along the way.

697

But again, once I saw the system installed at a customer, in a customer fab, I knew we had done the right thing.

698

This was 2010, the first phone that came out was 2019, so we still had some hurdles to resolve, but we kept going.

699

Now, I have spent several months working on this video and thinking about it, and it still feels absolutely impossible.

700

And the more I think about it, the more I think, you know, those people 40 years ago that said it was impossible, they had a point.

701

But it's completely unreasonable to think that you could make this artificial sun in a lab, that you could make these mirrors that are this smooth,

702

and that you could get the required overlay accuracy.

703

The reasonable thing is to think that none of that is possible

704

and to point out all the problems with each of them.

705

Which reminds me of this quote, the reasonable man adapts himself to the world.

706

The unreasonable one persists in trying to adapt the world to himself.

707

Therefore, all progress depends on the unreasonable man.

708

Imagine if Andy and Kinoshita and all the others had been reasonable.

709

We would have none of this.

710

In fact, imagine what the world would be like if everyone on it was reasonable.

711

It would probably be extremely boring.

712

Probably most of the technology, most of the things you enjoy on a daily basis wouldn't be here.

713

In fact, you probably wouldn't be watching this video.

714

Because just about all the technology we have nowadays would seem completely unreasonable even just 200 years ago.

715

And so I really think that to a large extent we owe our lives to those unreasonable people.

716

And maybe, at least to me, it's a reminder that it's good to be a little unreasonable.

717

At least in some of the big parts of life.

718

Changing the world is difficult.

719

It took overcoming thousands of obstacles and over 30 years to get EUV to work.

720

But big breakthroughs usually start in the same way.

721

That is, you learn, you explore some related ideas, you try to apply them in some new ways, and then you build skills to take on bigger and bigger challenges.

722

Bit by bit, you gain knowledge.

723

And that's where today's video sponsor Brilliant comes in.

724

Brilliant helps you excel in math, science, and computer science with visual interactive learning that's personalized for you.

725

It's an incredibly powerful way to reach big learning goals.

726

Mastering math for class or contributing to the next big technological breakthrough.

727

On Brilliant, you learn by doing, a method that research has shown to be far more effective than just passive learning.

728

It starts you at the right level based on your background, designs practice sets and reviews customized for you, and then it helps you advance at your ideal pace.

729

There is always something new to discover on Brilliant.

730

Want to better understand optics after watching this video? well, their scientific thinking course is a great place to start.

731

It helps you think like an engineer by showing you how to break down large concepts into smaller, more understandable pieces.

732

Whether you're conquering fundamental math, algebra, or calculus, diving deep into algorithms,

733

exploring material science, or understanding the physics that will take us beyond EUV, Brilliant will help you get there.

734

And if, like me, you've resolved to learn more in the new year, then Brilliant is a great way to actually make that resolution stick.

735

So to learn for free, go to brilliant.org slash Veritasium, scan the QR code on screen, or click the link in the description.

736

Brilliant's also given our viewers 20% off an annual premium subscription, which gives you unlimited daily access to everything on Brilliant.

737

So I want to thank Brilliant for sponsoring this video, and I want to thank you for watching.

738

Thank you.

アプリをダウンロード

流暢に話すために必要なすべて

AI発音採点文ごとに採点

IPA練習すべての音をマスター

単語学習自分の単語帳を作る

単語ゲーム遊びながら覚える

QRをスキャン

Download on theApp Store Get it onGoogle Play

📺 同じチャンネル

✨ おすすめ動画

76 文

The Limitless AI Lie. The Bubble Is Slowly BURSTING.

Business EnglishDaily ConversationUniversity Students

306 文

Deep Dive: Investigating Thermal Cycling Failures Cracked MSOP Solder Joints

Business EnglishUniversity StudentsWorking Adults

230 文

Starship - Test Like You Fly

Business EnglishUniversity StudentsWorking Adults

265 文

How are Microchips Made? 🖥️🛠️ CPU Manufacturing Process Steps

Business EnglishUniversity StudentsWorking Adults

249 文

My Puzzle Robot is 200x Faster Than a Human

Business EnglishUniversity StudentsWorking Adults

208 文

What If a Needle Hit The Earth At The Speed Of Light?

Daily ConversationUniversity StudentsWorking Adults

195 文

What is This $3BN Machine Under New York?

Business EnglishUniversity StudentsWorking Adults

124 文

How to Make Anything - Learn to Think Like an Engineer

Business EnglishUniversity StudentsWorking Adults

450 文

I bought the most SATISFYING TECH on the internet.

Business EnglishDaily ConversationUniversity Students

138 文

10 weird OSS projects you need right now...

Business EnglishUniversity StudentsWorking Adults

1043 文

I Wrote a NEW Sci-Fi with Project Hail Mary Author Andy Weir

Business EnglishUniversity StudentsWorking Adults

このクリップで鍛えるスピーキング力

科学技術に関する説明は、英語のスピーキングで重要な「複雑な情報を明快に伝える」能力を養うのに最適です。このビデオではマイクロチップの製造過程や最先端技術について語られていますが、その中で使われる専門用語の発音や長文のリズムを覚えることで、IELTS スピーキング対策にも役立つ実践的なスキルが身につきます。特に「shadowspeak」（シャドースピーク）という方法で繰り返し練習すれば、自然な発音と流暢さが急速に向上します。

実践的なフレーズバンク

「whizzing electrons from transistor to transistor」（トランジスタ間を電子が素早く移動する）- 技術的な説明で使える動詞句
「the number you could fit on a chip doubled every two years」（チップに搭載できる数が2年ごとに倍増する）- 傾向を表す表現
「progress came to a screeching halt」（進展が急停止した）- 変化を強調するイディオム
「overlay one layer of a chip perfectly on top of another」（チップの層を完璧に重ねる）- 製造工程の説明に有用

これらのフレーズを「shadowspeaks」の練習で覚えれば、同じような文脈ですぐに使えるようになります。

弱点を克服するポイント

このビデオの最大の特徴は、速いスピードで語られる長文のリズムと専門用語の発音です。例えば「nanoscopic computing city」（ナノスケールのコンピューター都市）のような複合語は、発音が難しいですが、「shadow speak」の方法で何度も追いかけることで、正確な発音が身につきます。また、「220,000 Kelvin」（22万ケルビン）のような数字の読み方も、スピーキングで重要です。これらのポイントを集中的に練習することで、英語の発音を良くするだけでなく、聴解力も向上します。

少しずつ繰り返し練習して、自然な発音と流暢さを手に入れましょう。「shadowspeak」は短期間で効果が現れる方法なので、毎日10分でも取り組めば、大きな進歩が見込めます！

この動画の文法

話し手がよく使っている文型を、動画の実際の表現とともに紹介します。

文型	動画での表現
条件文 if + 節, will/would + 動詞 — 条件とその結果	if you could produce the light, you'd need · If one mirror would be · if we add so much oxygen, we'll keep
現在完了形 have/has + 過去分詞 — 過去の出来事が今も関係している	it's been · they've built · you've made
受動態 be + 過去分詞 — 誰がするかより、何が起きるかに焦点を当てる	are shrunk · is shot · is sponsored
関係詞節 who / which + 節 — 人や物について情報を加える	chunks, which is · chips, which are · short, which is

シャドーイングとは？英語上達に効果的な理由

シャドーイング（Shadowing）は、もともとプロの通訳者養成プログラムで開発された言語学習法で、多言語習得者として知られるDr. Alexander Arguelles によって広く普及されました。方法はシンプルですが非常に効果的：ネイティブスピーカーの英語を聞きながら、1〜2秒の遅延で声に出してすぐに繰り返す——まるで「影（shadow）」のように話者を追いかけます。文法ドリルや受動的なリスニングと異なり、シャドーイングは脳と口の筋肉が同時にリアルタイムで英語を処理・再現することを強制します。研究により、発音精度、抑揚、リズム、連音、リスニング力、そして会話の流暢さが大幅に向上することが確認されています。IELTSスピーキング対策や自然な英語コミュニケーションを目指す方に特におすすめです。

シャドーイングのやり方: ステップ別の完全ガイドを読む →

シャドーイング練習: The Closest Thing We Have to Alien Technology - 動画で英語スピーキングを学ぶ

練習モードを選ぶ

アプリをダウンロード

Something is jamming GPS over Europe. Here's what we found

The Absurd Engineering Behind the Internet

Why It Was Almost Impossible to Make the Blue LED

You've (Likely) Been Playing The Game Of Life Wrong

We're trying something new...

How does light 'know' the shortest path?

The CIA's new tech doesn't make sense

Why does every mammal get 1 billion heartbeats in their life?

Why Cold Drinks Were Deadly Before 1914

Exposing The Flaw In Our Phone System

Our Greatest Delusion

The Most Controversial Problem in Philosophy

Why Are 96,000,000 Black Balls on This Reservoir?

We've Been Using The Wrong Science In Court For 50 years

Explaining Pi With Pizza

5 Fun Physics Phenomena

The Most Misunderstood Concept in Physics

Falling ladders - why does this happen?

How a slinky falls in slow motion #shorts

We're 99.9% sure this pattern is true, but no one can prove it

The Limitless AI Lie. The Bubble Is Slowly BURSTING.

Deep Dive: Investigating Thermal Cycling Failures Cracked MSOP Solder Joints

Starship - Test Like You Fly

How are Microchips Made? 🖥️🛠️ CPU Manufacturing Process Steps

My Puzzle Robot is 200x Faster Than a Human

What If a Needle Hit The Earth At The Speed Of Light?

What is This $3BN Machine Under New York?

How to Make Anything - Learn to Think Like an Engineer

I bought the most SATISFYING TECH on the internet.

10 weird OSS projects you need right now...

I Wrote a NEW Sci-Fi with Project Hail Mary Author Andy Weir

このクリップで鍛えるスピーキング力

実践的なフレーズバンク

弱点を克服するポイント

この動画の文法

シャドーイングとは？英語上達に効果的な理由