The World's Most Important Machine

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. Billions of them.

They are the ones and zeros of our

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

>> 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 2 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 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

Next, a tiny droplet of molten tin, roughly the size of a white blood

cell, is shot out in front of you around 250 km/h.

And your task is to hit this nut once,

not twice, but three times in a row in 20 microseconds

with your little 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

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

>> The same machine also contains mirrors that might just be the smoothest

objects in the universe.

If you scale one up to the size of the Earth, then the largest

bump would be no bigger

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 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 >> 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

Next, you lower a small seed crystal into the vat.

Silicon atoms attach 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.

>> It even feels fragile don't if you kind >> It'll snap thing?

>> Uh, yeah, I'm I'm scared of the break it. Yes.

>> Uh, 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

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 nm across.

And, if I take like a laser pointer,

so this is a red laser. Yeah.

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

The laser has a wavelength of around 650 nm.

When light hits the reticle,

its wavefronts 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 out of phase 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.

They add up and you get bright

>> You get interference, right?

And, you get a diffraction pattern.

>> Now, diffraction is inevitable.

So, instead of fighting it, designers

actually use it to get the patterns they want.

They kind of work backwards

from the eventual pattern they want on the wafer

and they design the slits

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

>> You see three dots.

Uh 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.

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.

>> The smaller you make the features, the larger this angle alpha between the zero

and first orders becomes.

So, the larger your lens needs to be to capture the light.

The size of the lens is described

by the numerical aperture

or NA for short,

which is just the sine of this angle.

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

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

when this angle is 90°

and your numerical aperture is one,

well your lens would have to be infinite.

Fortunately, there is one other thing we can change.

>> This is a red laser.

>> And a red laser has a wavelength

of 650 nm, something like that I would say.

And if I take

a green laser, and this one has a wavelength

of uh 532, then you can see that the green

are closer spaced than the red dots.

>> That's because the light from the two different gaps doesn't have to travel as

far to match up in phase again.

So, the orders end up closer together.

So, with a smaller wavelength, you can print smaller patterns

using the same lens.

All of this is captured by the Rayleigh equation,

which determines the smallest feature size or critical

>> But since there's a limit

to how much you can increase

the numerical aperture, I mean to one,

over time the only way to keep making smaller and smaller features

is by using shorter and shorter wavelengths.

So, this is exactly

what happened up until the late 1990s,

when the industry settled on 193

nm deep UV light.

This was the light that was used to make all of the most advanced

chips right until around 2015.

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

make the features, and

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

So, a radical change was needed,

a change that had been brewing for around 30 years.

All the way back in the 1980s,

Japanese scientist Hiroki Kinoshita came up with a crazy idea.

Why not use much shorter wavelengths,

like X-rays of around 10 nm?

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

But you quickly run into a problem.

X-rays at these wavelengths have enough energy to eject electrons

from their atoms, so most materials absorb them.

But, unlike medical x-rays,

which have wavelengths shorter

than 1 nanometer, these are still long enough to interact with air.

So, air absorbs them, too.

That meant that Kinoshita's

setup had to be in a vacuum.

But, even worse, he couldn't use lenses

to focus the light because the lenses would absorb it, too.

So, it seemed like this idea would never

>> But, around 1983, Kinoshita

stumbled on a paper by Jim Underwood and Troy Barbee.

Their work focused on special mirrors that could reflect

x-rays with a wavelength of 4.48 nanometers.

So, Kinoshita was intrigued.

Curved mirrors can focus light just like lenses do.

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.

The mirrors work something like this.

When light crosses from one medium to another, say from air to glass,

it bends or refracts.

Some of it goes through and part reflects back.

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.

The larger that difference, the more light is reflected.

And Underwood and Barbee used that principle.

They made a super thin layer of tungsten,

less than 1 nanometer thick.

Thin enough that x-rays could pass through without immediately being absorbed.

When x-rays hit the layer at a specific angle,

the tungsten reflected less than 1%.

Then, they carefully tuned the layer thickness so the path length of the transmitted

x-rays was only 1/4 of its wavelength.

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

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

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

But, this time the phase is inverted,

or it's changed by half a wavelength.

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

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.

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

Underwood and Barbee 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.

Now, they only managed to reflect around 6%

of the light, but it was a proof of principle

that you could reflect x-rays.

>> So, Kinoshita saw the possibilities.

He got to work and after around 2 years his team designed and built

three tungsten carbon curved multilayer

mirrors to reflect 11 nanometer light.

And with it he managed to print lines 4 microns

or 4,000 nanometers thick,

proving that at least in theory

x-ray lithography was >> A year later in 1986

he went to present his findings to the Japanese

Society of Applied Physics.

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

But to his horror, the audience

refused to believe it.

the audience was highly

skeptical of my talk. >> Kinoshita was devastated.

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

>> Nobody believed that this was a viable way forward,

and unfortunately, the reaction

was at least somewhat

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

The closest natural source is the sun.

>> We had to basically

build an artificial here on Earth.

>> Most scientists, including Kinoshita,

produced x-ray light using a particle accelerator or a synchrotron.

>> It gives an enormous amount of power.

It's as big as a soccer field.

You can fuel the whole fab.

The problem is if the light goes out, the whole fab goes

>> So, each machine needed its own power source.

But, even if you could produce the light, you'd need to make incredibly

smooth mirrors to actually focus

and print those tiny features.

You would need the smoothest

objects in the >> Okay, so I got a football

and I've got a bouncy ball and a cobblestone street.

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

The football basically bounces straight up.

But, for the bouncy ball,

it just shoots up to the side.

And that's because the surface is relatively

flat for the football, which is much larger,

but it's super rough for the bouncy

And a similar thing happens with mirrors.

If the surface is super rough compared to the size of the wavelength,

then the light scatters randomly.

>> Now, it might look smooth, but if you zoom into a mirror, you find

something that looks like this.

You find all these crazy bumps.

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.

Now, for a normal household

mirror, the average height is about 4,000 silicon atoms.

But, for Kinoshita's mirrors,

which not only needed to reflect X-ray light, which has a 100 times shorter

wavelength, but also needed to minimize scattering,

you know, so that all the photons make it onto the wafer,

it needed to be way more smooth.

It needed to be atomically smooth.

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

>> If one mirror would be the size of Germany,

the biggest bump would be about a millimeter high.

>> But, Kinoshita refused to give up.

>> However, my belief did not change.

>> And soon, help would come

from an unlikely place.

>> Across the Pacific, around 70 km

east of San Francisco,

is Lawrence Livermore National Lab,

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.

The lab was founded by the inventor

of the cyclotron, Ernest Lawrence,

and the father of the hydrogen bomb, Edward Teller.

And over its lifetime,

they designed over 10 fusion-type nuclear warheads.

So, part of their research focused on what happens

inside nuclear fusion reactions.

>> Fusion reactions release a lot of x-ray light,

light that they had never been able to capture and analyze.

But now, using those special multilayer

mirrors, there was a chance.

>> One of the scientists

tasked with making this work was Andrew Hawryluk.

And within a few years,

he and his team used multilayer

mirrors to reflect some x-ray

But then, in 1987,

Andy got a visit from a professor from Cornell.

>> He was very impressed with the technologies

that we developed, and he looked at me at the end of the day

and said, "This is all very interesting and very neat and stuff, but

and that his words, and I'll remember it till the day I die, was,

"Can you do anything useful with this stuff?"

And this was the day before

a Christmas shutdown in 1987.

And I was so inflamed

by that that comment

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

>> He applied these mirrors to lithography

to print chips using x-rays.

Around 5 months later,

Andy presented his findings at a conference.

But like Inoshita, it was not the response

he was hoping for.

>> It was extremely negative.

That was the low point of my career.

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

Every um person who I looked up to

in the field, 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

Later that week, I flew back, and

the following Monday, my boss asked me, "How did it go?"

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

>> But then, 3 days later, he gets a phone call from someone

named Bill Brinkman from Bell Labs.

>> So, I walked over to my boss and said,

um "Just got this phone call from a guy named Bill Brinkman.

Do you know who he is?"

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

And I said, "Well,

he just called me and asked me to fly out to New Jersey and give a talk."

The response from my boss said it all.

Um he basically said, "Well, you you got to go."

>> At Bell Labs, Andy found fellow believers,

and it couldn't have come at a better time.

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.

But by the late 1980s,

the Cold War was slowing down,

and all these labs were sitting on research

that had commercial potential.

So, the government encouraged

the labs to partner with US companies

to turn that research into products

and to stimulate the economy.

And the government would then supply seed money.

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

>> And by 1993, the first international

conference for X-ray lithography

was held in Japan near Mount Fuji.

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

to the nano to the pico.

They even gave the technology a new name, extreme

ultraviolet lithography, or just EUV.

>> But then, in 1996,

the US government cut funding for the project.

This spelled disaster for the big chip companies like Intel.

The industry estimated that the 193

nanometer lithography tools would fall behind Moore's law by 2005.

But there were no other alternatives.

>> So, Intel, Motorola, AMD,

and other companies got together and invested

$250 million to keep it going,

making it the largest

investment ever by private industry

in a Department of Energy research project.

By the year 2000,

the labs had produced this, the engineering test stand.

It was the first fully functioning EUV prototype.

It produced 9.8 W of 13.4

nm EUV light, which was then reflected

by eight mirrors from the source to the mask to the wafer.

It could print 70 nm

features, and it proved

that EUV could work.

>> It was a milestone

to get the engineering test stand to work.

It demonstrated to people like Intel

that, you know, good engineering will get us

>> And then it seems like you've got the prototype.

Shouldn't be too hard

to then commercialize it.

>> That's what they thought.

>> But the prototype had a major flaw.

It could only print about 10 wafers per hour.

And to make EUV economically

viable, it would have to print hundreds

of wafers per hour,

24/7, 365 days a

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.

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

Each mirror had a reflectivity

of around 70%, which is close to the max,

but after nine bounces,

you're only left with 4% of the light.

Which means that out of every 100 photons,

only four make it to the wafer.

So, you might think, just use way fewer mirrors.

But that only works up to a point.

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

For example, rays that pass through the outer edges of most lenses focus light

slightly different from those near the center.

This is called spherical aberration.

And normal cameras correct for this and other aberrations

by using multiple lenses,

and a mirror system is no different.

>> You need to have a certain

amount of mirrors before you can say I have

my aberrations under control.

In reality, the systems of today have six mirrors.

>> That helps a little,

but after reflecting off six mirrors

and the reticle, you're still only left with around 8% of your light.

So, they needed to drastically

increase the source power to at least 100 watts.

Now, to most companies,

that tenfold increase seemed impossible.

Even people who worked on the engineering test that noted that while EUV technology

itself is a done deal, there were six

zillion engineering challenges to make it a fab line reality.

And so, one by one, American companies walked away

from developing a full UV lithography machine.

That left just one company, ASML.

>> ASML, which used to stand for advanced semiconductor

materials lithography, is located

in a small, nondescript

town in the Netherlands.

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

shed and a barely working wafer stepper to its name.

But, Philips also gave them people.

Jos Benschop, ASML's first researcher,

and Martin van den Brink, who would eventually

become ASML's CTO and EUV's greatest champion.

>> And he's really like the Steve Jobs of lithography,

and he saw EUV coming.

>> ASML had joined the US EUV consortium

earlier, and now it became their task to find a way to commercialize EUV.

They would work together with their German partners Zeiss, where Zeiss would take care

of the mirrors and ASML

would focus on the light source.

One of the first decisions when making any lithography

system is deciding which wavelength to use.

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

The The thing is, you need to find a source,

and you need to find optics that reflect the wavelength.

So you have to look for the combination.

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

And since that wavelength is so small,

it seems like the obvious choice.

But the maximum reflectivity

for those mirrors was only around 20%.

So after hitting six mirrors

and the reco, you're just left with a

of the light, which is way too

Fortunately, further researchers also looked at two other pairs.

Silicon and molybdenum, which had a theoretical

maximum reflectivity of 70%

for wavelengths around 30 nanometers,

and molybdenum and beryllium

with a theoretical maximum reflectivity

of 80% for wavelengths around 11 nanometers.

So the choice seemed obvious, right?

I mean, pick the shorter wavelength

and the higher reflectivity.

But it turns out

that beryllium is extremely

toxic and it's also difficult to handle.

So scientists focused on silicon and molybdenum instead.

To make the mirrors,

Zeiss used a process called sputtering.

A target of coating material

is bombarded with either plasma

or ions, causing atoms to be ejected,

fly off, and stick to the mirror.

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

>> There was a nice trick that actually

the team in the Netherlands perfected.

With ion beam, you just

shake it a little bit until the atoms falls in the hole where it

needs to be, and then it's all flat.

>> With the mirror design locked in, ASML

needed a source for that specific

>> So it was 13.x. >> Yeah, okay.

>> next good question is what's the x?

Now you look for the Now you look for the source.

So there are basically three ways to generate EUV.

To build an a sun on Earth.

>> The first method, which early researchers

used, was the synchrotron.

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

The other two methods are based on the same principle.

When an electron recombines

with an ion, the ion drops to a lower energy level and it releases

that excess energy as a photon.

And if you choose the ion just right,

then that photon will have exactly

the wavelength you need.

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

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.

This causes free electrons

to knock into nearby atoms and ionize them.

If you then turn off the electric field, the electrons

recombine with the ions and produce light.

This is discharge produced plasma.

>> That's the concept we used first

because of its relative simplicity.

We quickly got to do a few watts.

We wanted to get 100 watts

and we struggled forever.

>> So, you couldn't scale it.

>> We could not scale it.

>> They needed a drastic change.

So, they switched to the second method.

This method uses a high-powered

laser to hit a target material,

creating a plasma that's more than 220,000° C hot.

The electrons have so much energy

that the nucleus can't hold onto them anymore

and up to 14

electrons escape their orbits.

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

This is laser produced plasma

and it was the only method that seemed scalable.

In fact, this was the same method that the engineering test didn't use.

A 1,700 W laser

fired into a stream

of xenon gas to produce 13.4 nm light.

But xenon had a big problem.

The conversion efficiency, that is, the ratio of usable light to the amount of

power you put in, was terrible.

It was only around 0.5%.

That's because while xenon does emit light in the 13 to 14 nm range,

there's much more light released around 11 nm.

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

Plus, the laser didn't ionize all the atoms.

So, leftover neutral xenon atoms

would strongly reabsorb some of that 13.4 nanometer light.

So, ASML started looking at another material, tin.

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.

But, just like xenon,

neutral tin atoms also absorb EUV light.

So, they came up with a crazy

idea, to shoot one tiny

tin droplet at a time.

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.

But, it turns out that you can't instantly make thousands of tin droplets that

are the exact same.

So, they found a workaround.

To make the droplets,

extremely pure tin is melted and pushed through a microscopic

nozzle by high-pressure nitrogen.

This nozzle vibrates at a high frequency,

breaking the stream into tiny droplets.

These droplets are irregular

in size, shape, velocity,

and distance, and the whole process is chaotic.

>> That's like our magic sauce is

how do you modulate

that tin jet so that it forms the droplets we want and that they're stable.

>> I think we found some paper

uh that described this process,

and it was sort of

eye-opening to me that it seems like all the droplets

actually come out irregular

out of the nozzle.

But, then before they reach the side where they get hit by the laser,

like the little irregular

droplets come together to form these

perfectly spaced, perfectly regular droplets that are about the same size

and shape, and all traveling at the same velocity.

That feels like magic to me, Jason.

>> Yeah, it's it's exactly that.

It's how do you take a long

stream of a tin jet

that wants to break up into all these irregular droplets

and like force onto it that it's going to collapse

into a single droplet

and then happen again and again and again.

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

You've got the pressure

with which you push out the tin and at the frequency of the nozzle.

Yeah, it seems like a hard problem to solve.

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

and so mastering that modulation

of the jet is

is how we make the droplets.

>> But these droplets not only have to be identical,

they have to be moving incredibly fast.

>> What will happen is if

the next droplet that's coming down the line is too close,

then it'll actually get like disturbed

and mess up the next plasma event.

So, we have a requirement

which is both that we make 50,000

droplets per second, but also that they're traveling extremely fast.

>> By 2011, their laser produced plasma source reached 11

watts, which was more than double what they managed with their previous source.

But they were still limited to just five wafers per hour.

So, they needed to increase the power

and fast because they promised

they'd hit 60 wafers per hour by the end of

Unfortunately, this new method had a major flaw.

>> 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?

Because like uh you know, 30 cm away, you have this

atomically flat, very beautiful,

very expensive mirror from a French inside.

And in the early days,

we would coat the thing within like this.

>> These machines need to run for a year.

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,

you'd have to take a collector out of commission.

We need to keep it

almost perfectly clean for for a year.

>> Yeah, how do you even approach that?

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

>> They filled the chamber with low-pressure hydrogen.

This slows and cools the tin particles down,

and even if some tin makes it to the collector,

the hydrogen pulls it off to form a gas called stannane.

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

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

So, they need to keep flushing

new, cooler hydrogen into the system

while flushing out this stannane and hotter gas.

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

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.

>> But, the question is how much heat is there?

How much energy is being deposited into the gas?

And, we were stumped for quite some time.

If you look at a EV light source,

what you'll see is that it's

it's kind of like a

globe of like purplish red light.

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

So, we bought an ultrafast

What we realized is that after every plasma event, there's

a shockwave that goes propagating

out into the hydrogen gas.

And, it's extremely repeatable.

And, you you think to yourself, there must be like

an explanation for this.

And, there's this formula, the Taylor-von Neumann et al.

formula, that explains point source explosions

in an environment, and like say, a nuclear blast

out to like supernova.

So, I took this formula,

and it like exactly describes the data.

It's just fantastic that

we're seeing these like little tiny little supernovas

happening in our vessel

50,000 times a second.

>> And, is that a fair way to think about this, like creating mini supernova?

>> Yeah, it's actually pretty similar.

It's almost like very similar to a like a type 1a supernova, it turns

out, where you kind of have an object that just fully evaporates and explodes apart.

And, when all that energy goes into the hydrogen gas, it produces a a

shockwave, a blast wave that comes flying out, which is

basically the same thing you can look up in the night sky.

There are these like remnant supernovas

that you can see coming from space.

>> Using those energy calculations,

they discovered they needed to flush the hydrogen at incredibly

high speeds, around 360 km/h.

That's more than a category 5 hurricane,

even if, you know, those speeds are at low density.

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

In fact, by 2013,

ASML just reached 50 W by shooting 50,000

tin droplets per second.

But this increased power came at a price, because

more power means more heat.

Heat that ends up slightly shifting

the mirrors, resulting in misaligned

light and misaligned chip

So Zeiss built a nervous system

directly into the optics.

Robot-guided sensors that constantly

measure the exact position

and angle of each mirror,

down to the nanometer

and the picoradian, which is absolutely insane.

>> So how accurate do we need to control this mirror?

Now, one of the things

you can do a thought experiment,

>> and I can place

a little laser on the side of this mirror,

then we go all the way to the moon,

and we put a dime here.

So, then this light travels all the way here,

and then with the accuracy

I can control this mirror,

>> I can decide whether I

point to this side of the dime,

or whether I point to this side of the That's crazy.

>> So you can see that the pointing

>> is that's also in in picoradians.

That is something very extreme.

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

>> While Zeiss was doing a stellar job with the optics,

ASML was still struggling with the power source.

The problem was that the tin droplets

were too dense, meaning that most of the emitted EUV light

was still getting reabsorbed

by the neutral atoms

before it could ever reach the collector mirror.

>> The way we blasted

the droplet was so not enough light, too much debris.

>> To make matters worse, they could see that about 10 years from now they

would need a new generation

of machine, a high NA EUV machine.

Essentially, one with a larger

optic system that could print smaller features.

So, what did they do?

They decided to double down and invest in the next generation

before they even got the current one to work.

>> The most doubtful period was in the beginning.

So, I started to work on this in 2012.

By that time, EUV was not working

and there was this

crazy idiot working on the next generation

where we could not even

make the EUV light in the first place.

>> Not only are you all in on EUV,

you're doubling down even before you know if EUV is going to work.

>> But to keep funding the development,

they needed money and a lots of it.

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

>> ASML reached out to its main customers,

you want this technology

for the next generation

of chips, well, you need to make us able to invest

more by investing in us.

>> Intel invested around $4.1

billion and Samsung and TSMC

invested another $1.3 billion combined.

So, they can keep the research going, but with

no product to show,

customers were running out of

>> We were crucified at every conference

that the promises we made last year we

we were unable to live up to.

>> And they said, this is what you showed 2 years ago, this is what

you showed last year, this is what you're telling me this year, so why

would I believe you?

>> They were getting desperate.

>> But this was, I think, about 2012 or or 13.

We were struggling to get the EUV power up.

And Kinoshita visited us.

I took him to dinner in a small town nearby.

And across from the restaurant was a Maria Chapel.

And now you know, science

we have come to the limits of science.

He said let's go for divine intervention.

So we went to the Chapel.

So Kinoshita, just to be safe, lit three

candles for the three suppliers

that were pursuing EUV technology at the time.

And low and behold

and I have the data to prove it.

There is a very strong correlation

between us lighting the candle power going up.

>> It's not a causal

effect, but there is a strong correlation.

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

>> One shot to hit the droplet

and it expands in like a pancake shape.

>> And then, only then have the second

shot, the more powerful

main pulse, where you evaporate

the pancake and turn it into a plasma. >> This major breakthrough.

>> 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.

Because now the tin is vaporized all at once.

By 2014, they finally

managed to hit that coveted 100-W mark.

But improvements in multi-patterning

with 193 nm now meant that EUV

would only be useful if the source reached at least 200

W and made 125 wafers per hour.

>> The source went from 100 to 200,

but as the industry moved on, nobody waits for you.

You know, they find other solutions.

We had to catch up.

So it was a moving goal post.

>> One of the problems is how do you perfectly

time the laser so you hit each of these droplets?

>> So the the analogy is a bit like a golf

that you need to land

in the hole 200 m

Not like land on the green, not bounce and then get in the hole,

but like land in the hole every time.

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

Those droplets are traveling

through this like maelstrom of hydrogen flow.

The speeds are tremendously high.

It's like shooting golf balls through a tornado.

And then right when it lands at the hole, that's when it needs to

get hit by the laser.

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?

Those scattered photons tell us

basically when and where is the droplet.

And then importantly tells us when to fire the laser.

So, we actually have to take into account how long will it take for

the light pulse to hit the droplet after we send the pulse.

>> Now, by 2015, they were getting closer

and closer to that coveted 200 W mark.

When all of a sudden,

the ASML board members got summoned.

>> This was one of these

decisive moments where our customers

were really thin on patience.

And Martin and all the board members were summoned

to Korea to show 200 W.

And they were really fed up with it.

You know, yeah, you either show it now or you you go away.

And when they entered the plane, the experiment was still running.

>> When they exited the plane,

they had the first result demonstrating 200 W.

This is how close we came.

>> With the source power up, there was one

final problem that had to be solved

before they could begin manufacturing their machine.

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

All the intense high-energy

photons and hydrogen ions zipping around

deteriorated a very special

top coating on the collector.

So, they still had to clean the mirrors

every 10 hours, which,

you know, is terrible for productivity.

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

But then one of the engineers noticed that every time they opened up the

machine, the mirrors suddenly seemed cleaner.

>> That he kind of chimed in and said, "Oh, wait a second.

Whenever we opened up the machine,

oxygen comes in and our problem is solved.

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

to our system and make sure that the collector stays clean longer?"

And so they started experimenting

with the amount of oxygen

that was needed in the vacuum.

And then finally got to this point, "Okay, if we add so much oxygen,

we'll keep the collector clean for

>> With this fix, ASML's machine could run continuously

for much longer, and it finally became commercially viable.

By 2016, orders started pouring in, and now all of the most advanced

chips need ASML's machines,

making them perhaps the most important

tech company in the world.

ASML's first commercial machines

had a numerical aperture of 0.33

and could print 30 nanometer lines.

These are called the low NA machines,

and ASML still makes them.

But the machine that Young'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.

This is the high NA machine

with a numerical aperture of 0.55,

and we get to see their latest version up close.

How much is the machine?

>> Uh we always say

north of 350 million

>> And you can actually buy it, right?

>> You can, if you want.

>> If I had the money, I could buy it. >> Yes, you could.

>> How many people have seen this before?

>> We really limit >> the amount of people

>> to go inside the clean room.

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

In any cubic meter, there can be no more than 10 particles

only 0.1 microns large,

and nothing bigger than that.

A speck of pollen is around 20 microns,

and extremely fine sand is around 10 microns.

To put all of this in perspective,

hospital operating rooms, which have to be extremely

clean, only allow a maximum

of 10,000 particles per cubic meter that are 0.1 microns wide.

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

>> It is light suit.

I feel like a little

>> Okay, so we're going to go through the air showers.

So you're going to have to do it as I do. Okay.

>> So this is brushing down all the particles

that are still on you.

>> this is like super clean air blowing us

>> This place is huge. >> It's huge. >> It's insane.

I've been in a clean room a couple times before,

but it's nothing compared to this.

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

I can't tell you. >> Great answer.

>> Okay, so this is the total system. >> This is crazy.

Look how big it is.

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

It's taken many, many years,

decades of development, many billions of dollars

all to get this humongous beauty.

So this is the first high NA machine.

>> So if you saw pictures

on the internet or whatever, >> that's this machine.

So the very first lines ever printed at 8 nanometers and stuff,

that was this machine.

>> This is the smoothest object on Earth.

>> Yeah, it's all in here. Yeah.

>> Wait, so let me see if I can figure this

This is the light source.

It's where they make the extreme

>> And then the laser must come in from

>> Let's take a look at the laser.

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

Think we're entering the laser system here.

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

We're not catching anything we're not supposed to. Oh, wow. This looks dangerous.

Now, the laser system is covered by all of these brown cabinets,

but here is a model version.

A carbon dioxide laser of just a few watts enters this amplifier

where it bounces around until it's roughly five times its original power.

It then goes through a total of four different amplifiers

to bring the final laser up to 20,000

W, which is four times stronger

than lasers that cut through steel.

>> Over here, we have the the amplifiers

>> that generate this this powerful laser

>> And then it basically comes out and this is part of the beam transport

system >> where it's brought to the machine.

>> So, this pipe here has the big

laser >> And this this is a mirror?

>> Then the pulses travel to the light source module.

>> It kind of looks like a transformer

or like a I don't know, like a spaceship.

There's so many wires going everywhere. >> Don't touch this. >> Holy crap.

>> This is pretty big, huh? >> This is insane.

>> And this is just a light source.

>> This is just a light source.

Are you getting this comparison shot?

And so, you need all of this

just to make EUV

>> Just to make the light. >> That's incredible.

Can we do a little walk around?

>> You can do a little walk. >> Let's go.

>> So, basically this is the heart

of the >> Can I stand on here?

if you're below 137, you can.

>> I don't I think I am. Ooh.

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

>> Then we're shooting the laser from here? >> Okay, it explodes.

>> And then the light

>> the light goes out there.

>> One improvement from ASML's first EUV machine to their newest one is the number

of pulses that hit the droplet.

The first pre-pulse still flattens the droplet into a pancake,

but now there's also a second

pre-pulse that further reduces the density.

It basically turns it into a low-density gas. It vaporizes it.

And then the final pulse essentially

ionizes all of it.

So, for basically the same power coming from the drive laser,

they get even more EUV light.

Now, if they want even more light, then the only way to do that

is by hitting more droplets.

>> And that's exactly what they did.

Our most recent EUV light sources that we're shipping right now, which are around

the 500 W level,

we increased the rep rate up to 60,000 times per second.

And then we have a road map that's going to go to

100,000 droplets per second.

We've actually now already demonstrated

this 100,000 droplets per second in the lab, so it's not an if, but a when.

>> The three pulses that we use to make the pancake,

to blow up the pancake a little bit, and then to evaporate the pancake.

>> The first two pulses,

they would be coming in through this pipe here.

>> And then the main pulse,

with the big the laser beam would be delivered through this pipe here.

>> Both the high and low NA machines shipping out right now use three pulses,

and eventually they will hit more droplets per second.

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

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

A set of mirrors

shape and focus the light before it hits the reticle.

The reticle is the top half, and this module is built in a separate

facility and installed later.

Next, the light goes into the projection

optics box, which is a set of mirrors that shrink the light down.

The high NA machine can shrink the pattern eight times in the vertical direction

and four times in the horizontal direction.

The mirrors are also much smoother still.

If the low NA's mirrors were the size of Germany, the tallest bump would

be about a millimeter.

But if the high NA mirrors were the size of the world,

the tallest bump would be about the thickness

of a playing card.

By the combination of both of these improvements,

ASML was able to increase the numerical aperture from 0.33

to And finally, the light hits the wafer.

In order to print around 185

wafers per hour, the reticle whips back and forth at accelerations

of over 20 Gs.

That's over five times the acceleration

of a Formula 1 car.

And this is some actual footage of what that's like inside this machine.

And notice that this is not sped up.

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.

The most any two layers can be off, which is called the overlay, is >> 1 nanometer.

That's five freaking silicon atoms of precision.

That's >> So, typically what we do as system engineers

is that we make a budget.

>> So, we say, "Hey, you get,

let's say, a uh and we divide

then uh the nanometers

uh to to smaller >> The nanometers total.

It's not like you your group gets a nanometer.

>> you get No, no, you get a

a nanometer in total. Yes.

>> So, you have to

to fight for the

for your part of the nanometer.

>> It's kind of cool to realize that like every smartphone nowadays

has has a chip

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

So, that's a cool thought.

>> Take a look at this.

>> It's pretty massive, huh? >> So big.

So, do you cover it up? >> Yes.

At the customer fab, it will be

looking like a big white box.

I like it better like this. >> Yeah, me too. >> It's funny.

You need such a big machine,

so much infrastructure to make the tiniest

things >> we can make at scale.

>> It's uh inversely proportional. >> Yeah.

Smaller you want to go,

the larger everything around it becomes.

After the machines are assembled,

tested, and approved, they are disassembled

to ship all around the world.

5,000 companies supply 100,000

parts, 3,000 cables, 40,000

bolts, and 2 km of hosing.

ASML ships their highly advanced machine in 250

containers spread out over 25

trucks and seven Boeing 747s.

Despite all the doubt and setback,

EUV finally made it to manufacturing

level three decades after Kinoshita's first images.

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.

>> Around 2001, we said, "Let's let's let's do EUV."

And then we run into many challenges.

2010, we installed the first system at a at a customer.

So, it was installed in >> There it was.

This thing I had been pursuing

for, you know, 13

years was now standing

at a customer producing wafers.

This for me was a moment

I realized, "Yes, we made the right bet."

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

>> He's now a professor

at a renowned institute,

and I shared the story about my relief

and how how how great he made the decision.

And uncle said, "Yeah, yeah, yeah."

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

And it took two months to get back up again, and they almost fired

me for making the wrong decision.

That we had some ups and downs along the way.

But again, once I saw the system installed

at a customer in a customer fab,

I knew we had done the right thing. This was 2010.

The first phone that came out was 2019.

So, we still had some hurdles to resolve,

but we kept going."

>> Now, I have spent several months working on this video and thinking about it,

and it still feels absolutely impossible.

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.

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,

and that you could get the required overlay accuracy.

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

and to point out all the problems

with each of them.

Which reminds me of this quote,

"The reasonable man adapts himself to the world.

The unreasonable one persists

in trying to adapt the world to himself.

Therefore, all progress depends

on the unreasonable man."

Imagine if Andy and Kinoshita

and all the others

had been reasonable, we would have none of this.

In fact, imagine what the world would be like if everyone

on it was reasonable.

It would probably be extremely boring.

Probably most of the technology,

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

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

because just about all the technology

we have nowadays would seem completely

unreasonable even just 200 years ago.

And so, I really think

that to a large extent we owe our lives

to those unreasonable people.

And maybe, at least to me, it's a reminder

that it's good to be a little unreasonable,

at least in some of the big parts of life.

Changing the world is difficult.

It took overcoming thousands of obstacles

and over 30 years to get EUV to work.

But big breakthroughs usually start in the same way.

That is, you learn, you explore some related ideas,

you try to apply them in some new ways, and then you build skills

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