[13] 반도체 기초_20

So, we have the introduction to the semiconductor system. We have the introduction to the end of the system. So, it's about the"Bando체 공정" and the"Fabrication" of the system. So, the"Fabrication" is the most important thing. If you have silicon, silicon is not possible to be able to use the system. So, what I'm saying is silicon.

So every fabrication I'm talking about the old electronics or something MEMS, all kinds of the fabrication for micro scale. micro scale even into the nano scale. fabrication. fabrication. based on silicon. so nothing but silicon. so backbone

material bases all the thing is a silicon. so top down or bottom-up all kinds of process based on this silicon. So most fundamental fabrication is lithography. This is a main tool for the chance for the smaller scale, micro-nano scale, that is lithography. So this is the most precise tool. the human-made, while the method to human fabricate is a smaller scale using the RISO.

RISO means light. The light fabrication is most precise and productive, which means repeatable process, stable repeatable process which means mass production.

As time is going on, the more processes stabilize, then cost reduction. So that is all regarding lithography. I'm going to first talk about lithography and many kinds of the fabrication process for semiconductor wall transistor. But this is the most fundamental thing. And then I want to talk about later on something. Etching.

Etching means take it out. Take it out means. which means cut it out something. And how about the other one is deposition. Deposition any kinds of material. Etching means take it out. Deposition means fire it up, which is the deposition process. So this is something kind of a metal, organic or inorganic, all kinds of material based on the patterning.

This patterning opens up the chance for etching or deposition, which is adding up, take it out. Take it out, adding up. Which is add up. Add up these kinds of materials. Metal, organic, inorganic. Adding up. Based on the two-dimensional. And adding up means I can make a three-dimensional structure.

Also etching means take it out which is also three-dimensional fabrication. And I want to talk about later on, one is the doping. Doping means some kinds of, first based on the silicon, okay, if you have some silicon, silicon is a 14 atom number and the outside electron is 4 and which means

fully occupied. Fully occupied that I talked about last time. The fully occupied means no free electron. Fully occupied. Qπ means no free electron. No free electron means what? Non-conductor. Not conductor. So the silicon is a backbone motor, non-conductor.

modify this property into the something conducting material. So conducting material makes something, some impurity atom into the silicon. Then gonna be changed to the conductor. So non-conductor changes to conductor by what? doping, which is by impurity atom. I'm going to talk more detail later,

so theoretically in the fabrication more. So doping. So I want to talk about here lithography first, and then etching is take it out, depositioning, adding up. And the other is doping. So doping is two kinds of method which is diffusion. Diffusion, I'm gonna talk about later. And then one is iron implantation. This is what I'm gonna talk about later.

So the main subject in fabrication is one lithography I'm going to talk about first, then etching, and deposition, and then doping. Doping is one kind of diffusion, the other is ion implantation. So like these kinds of fabrication is the most fundamental thing in fabricate micro nanoscale for the electronic. So then I'm going to cover this simple fabric. And this is fundamental the fabrication process. Then again I'm going to do whatever

electrical subject is going to be later on. So first I want to talk about it. So this is all about lithography. I want to overview of something about the semiconductor device. Semiconductor technology generated hundreds of billions of dollars. Productive in these recent years or now or maybe forever.

Without the silicon we cannot do anything. The F-silicon is made by a transistor. All kinds of things is made by a semiconductor. Manufacturing the plant costs several billion dollars. So I'm gonna talk about something device processing means fabrication process. So I'm gonna first lithography. Then I want to talk about the etching that I'm talking about it.

And then growth. Epitaxylography is something kind of a what I'm talking about something, deposition. The same thing, deposition. And which is doping. So this is the chemical method. This is the chemical method. This is why I put the doping and then this one. But I want to tell you later separately. This one first, growth first and then doping. And then iron implantation, the other way for doping. Okay, which is what I said, the diffusion, right?

Diffusion and epitaxyl are very much similar, that's why. So iron implantation, diffusion is for the doping. Okay, lithography, hatching. Okay, then deposition. So this is a major subject in semiconductor fabrication. This is the technological advanced challenge in processing become greater. Okay, so this is all kinds of subjects. These subjects fundamental things, this is the basic concept for the old,

even not electronic, something mem-stop, mem-stop, all kinds of micro nanoscale manufacturing, the fundamental. So I want to say this is a kind of nano manufacturing. It's all about it. So I want to talk about defabrication, nano manufacturing or micro. recently people talk about more nanotechnology nanoscale the micro scale

something this is like booming like 20 years ago not anymore something even more productive research is money in here and nano lithography so one thing is it So microscale, so optical lithography, what I'm going to talk about today, optical lithography, limited microscale. Then something is, we want to get into this something nanoscale, we definitely use for e-beam lithography, something few nanometerscale. So kinds of micro,

nano is barrier sorry this is micro millimeter whatever so meters okay so this is micrometer so one is the method is top down and then bottom one method top down is top to the bottom bottom one means bottom to the top top. So bottom to the top. So which is something vapor based, steam film, whatever. So this is the we separate. So which is top down method. Top down method is micro, nanoscale, both. Okay. And bottom up

method is only nanoscale. So that is different. Micronano is top-down method. Bottom-up is only nanometer scale, which is nanotube, nanowire, something graphene stuff. Graphene is a very fundamental subject, but this is a We can apply bottom-up method or top-down method both. So graphene is the CVD method huge scale, like a millimeter scale. It's huge in here.

The millimeter scale graphene is something. We do like a CVD method which is bottom-up. The top-down method is something transfer. Graphene is already made and then transferred into the vapor. It is bottom-up. The other method is top-down method. So I wanna ask you something. The two methods we can separate, which is top-down and bottom-up.

which is commercialized. So this TAPTA method is commercialized. commercialized, commercialized, which is already practical. but the Barma method is not commercialized which is you cannot use this process in industry okay so top down Barma is totally different so we do something research in school can use something Barma method this is not

commercialize. Okay, so this is two different things. The big difference is top down is something way of top to the bottom. Bottom up is the bottom to the top. So this is not commercialized yet. People develop it still. But top down method is already fully commercialized. There is also we can working on micro scale also nano scale but bottom-up method only nano scale.

Okay so more bottom-up method this is research focusing. Okay so this is research and practical. Practical means commercialized. Commercial means something making money. So still working on in industry. So this is something carbon nano2, nanowire, molecular level, something that is like a future semiconductor device maybe. People still working on it. That's starting to something, this is also the 20 years ago.

So nanotechnology boom, like people talk about the CNT or whatever. So WCNT, whatever, two different things. So this is something, future semiconductor. The substruring, Trang2D, silicon. So there was a high boom like 20 years ago. But people fail to do commercial lines. That is only problem. So lab scale, one chip device is working, is very good.

But millions of billions of same device productive method, then to get to something final product is not fully meet the good product ratio, which is something-- which is commercialized means 90% more than something positive. But something is a failure, weight is too much, it's going to be not commercialized. So this is people still working on it.

There is something too much failure ratio for in productive line. So this is only the problem. So the all the lithography or all kinds of deposition, etching, epitextural growth, all CBD methods, all kinds of like a fabrication, those kind of fabrication working in the clean room because no, this is

Dusty-free zone, which is a class like a 10,000, whatever. So number of the, this size 0.5 micrometer particle. cubic centimeter or cubic meter how many particles in there so this is all kind of dust free or all kinds of impurity free the very clean environment which is all the two things together in very nicely no led to anything

Okay, so those kind of things working on in the clinical. So the lithography. So I want to tell you the basic concept for lithography. So all this is smallest future allowed because if we want to do these some reduction lens here, the mask here. So this image transferred to the wave probe means sample. This is a sample. So this image is transferred to here by something this

optic tool, so lithography system. So this thing is lithography but this is a photolithography. Full name is photolithography. This is for microscale. So something nanoscale. with things we call it E-beam lithography.

This is something for nanoscale. I want to tell you more detail later. So even lithography is nanoscale, photolithography is microscale. So all CAD system. This image pre-made something mask making. So we just make what I deserve to shape the design of the some structure.

It patterned in mask imprint here and put things in lithography system. So these images transfer by lithography transfer to the vapor. So patterning. So all these patterning system. Patterning system. We do. Right. So smallest space is allowed. which is patterning, which is something penetrating, the other is

blocking. So this kind of pattern. So in there was nothing there. So penetrating light something pattern, the other one is black. So this feature transport to exactly the vapor. So all things together something smallest feature was spaced. Minimum overlap feature on this level which is another level. Minimum overlap is key point. The minimum spacing underline topology. So topology matter which is something

we insert paste something fabrication up and down up and down to minimum spacing in underlying with topology. This mask system has a high degree of the optical transparency, this is a key point. So that's why we usually made by not glass, which is a quartz,LAUGHTER. Quartz. Better transparency more than the glass. So small thermal expansion because this is high temperature so thermal involved.

So solid structure is going to expansion with the temperature, with the thermal energy. So we want to do small thermal expansion. flat should be this vapor vapor should be flat and reducing lighting scattering so all light going through through the lens here here but which is like passing to the mask into the sample but something is reflected to scatter all kinds of things

getting involved something, distortion image something. So we want to reduce something like scattering. So this is all basic concept for lithography. Okay. So lithography is a key functioning, nano patterning or micro patterning. But this system is recorded for lithography. Therefore, only micro scale.

So lithography, that is technology that developed as time is going on. And that light source, this is light source. As time is going, this wavelength is getting smaller, smaller. So 0.05 micrometer or something is getting smaller, smaller. Because this is the eye line, but next to the eye line, and then x-ray, whatever, e of v, is what the wavelength is getting.

then longer and smaller is this one. So smaller wavelength is much better something fine resolution. For smaller wavelength is finer resolution. So image transfer from mask to the semiconductor vapor. So semiconductor vacation. So these all things going to be the smaller wavelengths is better tool for the final image future.

So this will be how we can. major part is something we need photoreshography and even lithography. The photoreshography is fully commercialized. This is non-commercialized here. So photoreshography is good for the top-down process this is a top-down and bottom-up

but but this is here good suppose all of them we can operate this one but it's only top-down process and commercialize. And one thing I want to make sure is different things is photomask. This is the photomask we need. This is the non-need photomask. This is computerized CAD program. It's a software. This is pattern by

pattern by mask. This is pattern by mask. This is pattern by software program. Okay. So the photolithography, you can Separated contact plane which is fully contact with mask and target. So which is no gap here to this contact, fully contact.

This is better for final pattern. This is a possibility that residue may remain in photo mask. So something is good, something is bad. Approximately planning is not contact. No risk of PLA, non-contact. And limitation of a fine pattern. Something is a good thing, bad thing. Something happened. So trade off. So projection planning.

There is something dual lens. Two lens involved. Something projected. pattern into the something wave surface. So which is a higher resolution that is even riseropi. This is up to do something micrometer but this is a nanometer pattern. Atomic level is possible less than one micrometer. So direct step on the wafer technique. Okay so which is it this is photosensitive

this is electron sensitive with GST. Okay so as a photo mask photo mask here something using the CAD program that pattern generator into the something pattern generator to make a radical. Radical means part of the repeatable pattern. Then put into single step repeated camera and make a finalized master mask.

This is the photo mask process. This using further, this one. Okay. And even astrography. The comparison between contact printing, proximity printing, projection printing, this is all thing is here. Right. So regarding this, with the figure, more detail. The contact printing is, here is something is residue. P, R, P. residue in 2D in some mask. Approximately there is space here between the

peer actually this is peer. So here is fully contact. Here is the residue on here. But no contact. There is a separation with the space on it. So no contact. So this is something is in no residue here. But this is fully closed. Contact means fully contact means closed. So that's why final final imaging. This is less fine because there is a space here. The final means this is more

final than this is more final. Contact planning than proximity planning. So the project is planning is using the two lens here image transfer okay something is different so so that's why we can separate the two parts and the other one is your projection planning so something is there is a positive in or some negative

something is going on. So this is the whole optic lithography, like a photolithography.

So as I told you like a transfer image, transfer pattern image to the photosensitive material. So this image lights work and then mask some image in here with the lens. Something transfer this image into the wave pattern. This is pattern here. Okay, so we gotta do focusing exactly in plane. This is auto focusing, auto focusing, which is not a good resolution.

So we just focusing in place exactly. We deserve the height, which is radiation here, something there. Light is passing through the hole. This is a mask. And then radiation. And this substrate. Like a typically silicon. Silicon substrate. On top of that something photosensitive material. Which we call the PR. Photosensitive material with this one.

Okay, something exposure by light is only this portion right? Only this portion and then depends on the the PR the positive or negative. Get exposure to portion out of it. There is we call it something positive. The other is negative. I'm going to tell you later. So this is GAN which is positive PR.

Something lies on that is one remain like this. So this is the center is gone, but light exposure portion is a remain. The other is gone. That is the equal to negative. P.R. Okay. Now the positive. So this is what it is. Let's take a look. the photo register.

This is the before the light shot lithography. We need something coating uniformly. Coating in a vapor, silicon vapor. here, uniformity. So this is photoregist coding. In order to transfer image to vapor, the image transfer to the vapor, the surface of vapor have to be made sensitive to light.

That's why photo resist PR. We call photo resist. The make vapor, which is usually covered by thin oxide film, thermodur, direct classification material. which is sensitive to imaging. The photo register is spread on a wiper by processing by spin quarter, mostly uniformly depended by spin quarter. A certain rpm in here there is some dish

in top of the silicone piece of the silicone and then sucking this nozzle by air vacuum. So this is holding top of the dish and then certain RPM. Rotating and then spread pure and the uniform here. Something is nozzle deposits some registry vapor here and something drop in here top of there that is sucking into my vacuum

so then spindle, spin it and spread out start the spin which is spread out to PR which is something then spinning process then this is unified as time is going to southern RPM. So higher RPM means thinner. Higher RPM is thinner. Uniformly departs on top of the silicon vapor.

So which is coated vapor with PR. which is some uniformity in center point to the edge. So maybe in the edge we have some edge bit or something. So that edge portion does not really matter. The quality doesn't matter. But center point to the edge something is going to be some...

We control the uniformity. So here is something they have to say, the NOx or dielectric passivation material. It means something silicon vapor here, some vapor here, pure silicon, and top of that naturally coated by SiO2. So this is the NOx. or some dielectric investigation material that could be possible. So this is the whole thing about the photoregist coating.

Spread out uniformly on top of the silicon vapor. How? By rotating some mechanical RPM. So that is it. We control uniformity and something like that. So here is a control RPM. Rotation per minute. How fast rotating and time. Right. And viscosity.

PR. Okay, so this variable, this variable, this variable, which is a control parameter in thickness of the PR. So faster is going to be thinner, more time is going to be thinner, lower viscosity is thinner. Okay, the more sticky one higher viscosity is going to be thicker.

So this is working parameter control to the certain condition of the photoregist. So here is more going on. the mask generation and mask transfer, image transfer. So, resist to be reliable must verify three criteria. So PR resist must be good bonding to substrate, which is some silicon wafer here.

and maybe silicon dioxide on top of the SiO2. This is Si. Then PR should be good bonding to the substrate on top of the vapor. And its thickness should be uniform. This is the key point. Okay, the key point. Uniformity control is very important. Something that all the surface should be something light shot here. Some kind of a reflection may happen uncontrolled.

Non-uniformity may be scattered more. Many not good quality of the surface or something is not control all the mal functioning. Mal functioning may happen. So thickness should be reliably controlled over the different wave of a lot. So we have a 10 piece, thousand piece, million piece should be same thickness. control depends on the vapor. So which is it transfer image into the regist by

using mask. This image transfer from the mask. Okay so I want to tell you about some process about photoresolapy again here. So subject here some black is something This is silicon. So top of that is PR.

This is PR, exposure to the light through the mask in here. This is black, black, black. Block point. This is penetrating, penetrating, penetrating, penetrating. So that transfer image exactly from the mask to the PR. Exposure. This is exposure. This is a light shot. This is photorescope. So we can separate it depends on the PL which is positive PL and negative PL.

Positive PL and exposure to point is going to be take it out. which is something negative is light shot portion is remain. This is remain. This is moved away. Okay. So there is a totally opposite phenomena with different PR. Okay. So next step is fabrication. Etching or deposition.

Etching means something subtractive. Deposition is additive. We talked about before. additive move process. This is a subtractive process. Okay, so this is a change, subtractive process.

Then what? This portion is PR. PR is what? Sacrificial layer. Temporary state. So temporary state here but ultimately finally we should remove it by etcha which is a Asseton, using the Asseton, something is this is move move the take away. So this is nothing in here. So this is the final structure using the positive

resist. This is the final structure negative resist. So this structure is exactly our positive. Here is opposite here is opposite here is opposite all the things. So this is a patterned wiper Okay So I'm just questioning here What is this one? Dark blue is what? As I here is silicon. So light blue is what?

Silicon dioxide. So this is etched out perfectly only silicon dioxide. Here is it perfectly remain this silicon. So this is the etched out chemically active material with the silicon dioxide not silicon. This is the whole process for the etching process with the

photo result. Okay so this is a mask generation. The mask image transfer 2d1. It is a substrate which is silicon ray. So this is the final product of the selector. So this is again, we did before, but just showed again,

which is the same thing here. Wafer here, wafer here. So here, first, tell you about the substrate process and this is the additive process. It is a vapor top of the metal here. The depulsion pattern was resisted. So this is a photoregist. drop it here. Then etching some aluminum. This is here is aluminum.

This is aluminum, so which is wrapped over. Okay, so this is just simply present here, but many processes which is something we need to deposition and pattern. We need here something. Spin coding. Then what?

Lithography. Photo lithography. photoresorapy and then what? Almost there. spin coding, photoresorapy and what? develop. we just left over here photoregist. After develop we got a pattern of the photoregist.

So, which is this is what? Photoregist is what? Sacrificial layer. Temporary stain. Not permanent. Okay? facial layer. So when you do etched out, this is gone. This is called aluminum. Aluminum is gone. Then temporarily it follows this to the gone. So that's why here

no photoregister only remain aluminum. So this is only vapor and some pattern aluminum by photo through the photoregister and then film etching. So the other one is here compared with photoregister remain here. Exactly here same this situation. Patterned photoresistor. This is the same.

We exclude some prepattern. Spincoding photoresistor and develop. Then these things come up. with the photo register, patterned photo register after developing. So this process in here before. Then what? Here is etching. This part is etching but here is what? Formed position which is the deposition.

So this is what? This is photoregist here. The pattern photoregist here and then uniformly deposit some kind of material, any kind of metal. So this thickness, this thickness, this thickness is the same. The uniformly deposit in here. Once deposited, we need something lifted up. Photo resist here. Lift up photo resist is what? This one is gone. This one is gone. Two parts is gone. So this is gone. Lift up in this portion. Then this is

with whole thing is gonna be gone Out of the surface of the vapor. So this whole thing is gone. This whole thing is gone. Nothing is left over here. Nothing is left over here. So this is the column deposition only in here. So same geometry. This one and this one is the same geometry. This is what? Sun card of metal. This is metal, which is aluminum. So this makes pattern by two different methods.

One is subjective method or additive method. Once the cover is holding and then fold the solar beam and then lift up. This is the ground. Something is done here and then etched out here. So same final geometry. We can process two different ways. which is subjective way, which is the additive way. So this is the whole thing about it.

How we gonna be make something pattern with some metal layer. Okay so this is kind of a metal layer in top of the whip. So same final geometry product. But processor you can design anything you want. Okay so this process or this process you can choose to design some pattern and then product and with the silicon base.

So now I'm gonna get into the real actual process lithography process. So what it is? So I just mentioned about the what is the system of lithography. But I'm gonna tell you step by step what it is lithography system. what it is. So first, basic fundamental thing is to clean the vapor.

Vapor is a subject which is a silicon, right? Silicon vapor. And barrier layer deposition. So this is something optional. Okay, it is not mandatory. So now photoregist coding by spinning. Okay, then we gotta do some bait. Soft bait and then hard bait after. So this is before

exposure which is by light which is lithography system. Before exposure the light real process for lithography we do soft base. Okay and then which is a peer development which is something This is the key factor for developing PR. PR photosensitive or photo insensitive we just

separated negative or positive PR. So whatever photo developed after that something is here. here photoregist PR here with mask on it. This is blocked. This is right in here into the system which is a mask. This is transfer right. This is transfer. This is blocked. So what it is? After

Here is something light-sensitive chemical. Once light shot and then this portion is go away removed. So light shot portion is removed. positive PR. Something to remind that I told you before, negative. This is the positive PR.

So thing is gone and then this is remain PR. Right? So this is PR, photoregist. The PR is what is the purpose? The PR photo registry is not real actual material. This material needed system? No. This is temporary stain layer.

So, Once needed and then remove it. How? The final product is removed. Once photosensitive material is used for positive or negative pair, the remaining here and then here is etching. I'm going to tell you later. Etching is removed. This portion. So this is a barrier. This is no barrier. So etched out. So this portion is Next out of it. So this portion is out of it. That's why here nothing in here. So which means PR is temporarily staying layer not permanent.

Which is something functioning for what? Blocking something etching from the block. by etching effect. So which is another word sacrificial layer. Okay, sacrificial layer. So which is another word, temporally stained layer. So actually all the process is done PL is removal which means what? Exactly temporary stain or sacrificial deal.

So this is what it is. So this is the process for using image transfer for orthography using for or resist, final product coming up, constructive or destructive. So here is what? Etching means make it away, take away, which is

destructive okay constructive means something film the position like that is constructive this destructive because why just take it out break and take it out this is destructive so we need some align mark here I mentioned here is a line mark here what is that So every disorapi system is one two-dimensional vapor or system. Fabrication done or next fabrication done or next one.

Like three steps, four steps, five steps in manufacturing process. So we need the same thing. Exact portion alignment. So same or multiple steps. vertically aligned then could be working on exactly aligned structure which is to make three dimensional structure. 3D structure we need something alignment mark. okay so this is all result of this system.

So I want to step by step again. I want to repeat what it is. So CleanVapor, we need something photoresist. Okay, photoresist, which is a query with photoresist. This is optional. Okay, so optional. So process the photoresist here. soft bake here and end of it hard bake here. Align mask. Okay, so this is something very first time is not needed but second or third

whatever we need something. Align mask. Align. And then exposure the panel. So develop resist here. Okay. So align the mask, this is the lithography system here. Okay, develop what it is here. Develop the register here. And here something metallic position. Previously we learned about the etching. What it is, etching.

This is destructive, but this time it's metal deposition. It's constructive. Okay? The edge window in, field layer, remove the furrow edges, whatever. So this is kind of the metal deposition is constructive. Here is destructive. disruptive, constructive. But lift up is only needed for the deposition. Lift up process is for metal lift up.

So here, photoresist, which is we need something spin. So photoregistic coding thickness controlled by what? Time and RPM rotating. That is two main function and variable. Next, what is it? Lithography which is optical, which is non-optical.

So which is? dosage or time. How long exposure or how strong light that depends on. So dosage time is working variable. Next what is the development? After PR coding and lithography and then we need some development. Third step. The development, the working parameter is what temperature is and then time matter. Okay.

As time is more time is going to be more developed. Okay. So we need something precise, something vertical barrier. That is something is going to with desirable structure. It's a sharp and then vertical. Okay. So which is a temperature means here. So this is for the nano manufacturing process, something is lower temperature. Lower temperature is developing processes slow.

Slow means more precise. The higher temperature faster but not precise. So in manufacturing processes, time is money. So more time means more precise. more price which is cost more time more time means more cost like a temperature more cost means what more precise this is the fabrication process is more precise

we need more time okay so which is time is money so so metal deposition i'm gonna talk about later evaporator or spur there is a thickness or temperature they controlling quality and thickness metal deposition which is lift-off. Lift-off also is time and temperature. Lift-off is usually in acetone.

This is the whole basic fundamental lithography. system. So what it is? After lithography, before, after, what it is. Okay, it's the whole process. So lithography here, I'm gonna tell you the photorethography here, something I'm gonna compare positive and negative. Okay, this is the silicon.

And naturally, there exists silicon oxide here, top of there. Okay. And photoregist deposition here. And what? At top of the resist, or contact, or proximity, or transport or lithography, we need something mask. Mask means what? Microscale, something less or less of a system. The mask on it here. So which is the case is one is positive,

register. One is negative, register. Okay, register here is spin coding with soft base. Well, after exposure we need something developed and then hard base. So first we separated the positive and negative here. So here is mask is blocked area. So light shot here. So penetrating this part. So this is penetrating part. Okay.

I penetrate. This is like penetrating. This is a block. The light shot and then that part is gone is positive. Light shot in here that this light shot portion is remaining. Remaining is negative. We separate the positive and negative here. So once this is the peer, right?

The peer is here. This is the peer. Peer is what? For temporary staying, which means what? Sacrificial layer. Sacrificial layer. Once sacrificial layer remains and etched out, which means next is for example etching. So this portion is out. Then sacrificial layer remove it. This is remove it.

remove. So this is final product. So same lithography system, different pairs, different kinds of one is positive, one is negative. Positive is constructed, this kind of shape. Negative fabricate. I'm not going to use the constructive term. This is actually disruptive term but this is final verification prototype. This is final verification prototype.

Okay so this is we separate one is positive PR and one is negative PR. It depends on the PR. Kind of PR we can opposite structure we can make. Okay. Compare this product and this product. So here is also optic transfer. The single image projected directly on the surface of the vapor. The radical pattern may be ranged 10 times or whatever.

So this here, now let it go. Mask this image transfer with optical lens, transferred here. So two lenses here, this is what? Transfer, Resolupy System. Transfer. Okay. Two lenses here. This image transfer here. like reduce to 10 times here, like going to 10 times smaller images into the vapor, smaller image made. So, as you hear, say lithography here, for lithography, this is something opposite, which is subjective, kinds of

destructive, additive, it is constructive. Photolithography system we made here. Same PR, right? PR, this is PR. This is what? Some part is gone. Something is gone. Okay. Either way, positive or negative PR using exposure. Some portion is light shot or the other portion is black, whatever. this portion is gone and we cases it one is etched one is

the departure the constructive would constructive or destructive here they say something additive or subjective subjective okay so which is etched out here is a portion but etching Here some chemical or wet chemical is affected in here. This part, moving out, take away. And the portion process is was here, but was here, but adding up this portion.

Like the same thickness and this and this one. then what? Strip Regist means what? PL is gone here. So sorry, this is the PL. PL is gone. So this PL is gone. So this is gone means this metal layer is go away together. So this portion is whole thing is gone. This whole thing is gone. This is the remain. So that's why remain here. So this is actually here.

So this is This part is compared to the original shape. It's gone. This is additive. Something is into it on the vapor. The transfer image is Lift up by something. H. Okay, so pattern transfer from the pattern photo resist to underline layer by H. Okay, this is layer for by lift up. Lift up means metal deposition. Metal deposition.

Where? Here. This layer, this layer, this layer, metal deposition, right? Then what? Put in the acetone and then this sacrificial layer. PR layer is gone. Gone. So there is what we call the lift up. So lift off means lift off everything with PR, the metal is gone. Both of them is gone. We call it a lift off.

This is lift off. This is optical transfer. So process I just summarized here. What process is a technical word, hydration bake, which is to hydrate the water to something with addition. this kind of a bake okay the HMG' which is calling the vapor with surface adhesive promo this is optional okay this is optional optional it is not

necessary for all the surface okay the spin where is the spray calling the vapor with resist with either spinning or spray, but most of them is work done by the spinning process. It's a uniform coil. Okay, so PR surfaces should be uniform and thickness should be uniform. Non-uniform is no good. It's no quality work. This soft which is soft bake. Something I told you about soft-fake different thing and hard-based comparison.

So soft-fake lift-up-td, solve and resist, may result in something significant loss of mass of resist. Something different. So make resist more viscous. Okay. And alignment, that I told you before, the alignment pattern on the mask. with the feature on the web. All-line money is needed for something three-dimensional work, which is process, not just one layer.

One layer, two layer, two layer, deposition, constructiv, all the repeatable process working on based on the all-line money. That's why I needed alignment. Exposure is a projection of the image onto the register to cause the selective chemical property change. So exposure by light, some portion exposes the surface or part is something. chemical properties change.

Okay. So then we can fabricate constructive, destructive way of the structure. The post-bake, which is hard bake here, the baking resist drive of the further solvent content, which is more resistant to the action. more than develop. Okay, again, the possible with Haderbeck here. So Haderbeck, again here, something drive up a motor remaining solvent from the resist.

Make a concrete structure, okay? Concrete structure, which is harder. Harder header. So after... Develop is selective removal of resistive exposure itself as it is positive, unexpected resistive. Wet process although the dry process exists. Last part is DSGOM which is removal of a thin layer of

So, where this is gone? Okay. Should be O, include open region and pattern. It helps you open up the corner and pattern. Okay. So, sorry, this is include, open it. Okay, the process. So now we finished the basic fundamental process for optical lithography.

And so now take a look for the real application which is something not single layer. Layer process which means this is a silicon substrate. So pure silicon which is doped. Some doping. I'm going to tell you later more about the doping.

What is doping mean? Something. So this is P doped silicon. Okay. Then this is what the word means. means here. The P word is N word. Okay, so we need a doping process in here. Okay Then we have how many metal here? So this is N+ is high doping and this is somehow metal layer and this is somehow

the other metal layer, the one deposit and the other metal layer. So which is how many the process fabrication process like one here, maybe the other doping here, maybe metal here, this layer, or this layer. This layer. So like a multipool, like a minimum of five layers. More than five layers. So I'm gonna tell you more later. So like we can separate here. Because here is something P. Here is N+ which is what?

N+ I'm gonna tell you more theoretically later. So P, this is N+ and N+ the channel is gonna be P type. This is the channel M+ M+ and the channel gonna be anti which is PN which is PN diode. Okay, so I'm gonna take basic theory is gonna be later. Okay Later on I want a more process for now. I'm talking about just the fabrication. How are you gonna fabricate? We photorescography. We're using the mask.

How many process step by step here? One, two, three, four, five, whatever. It takes more than one layer. Okay so multiple layer, multiple multiple case, we need something, what? Aligner. We need something aligner because same position we're going to fabricate vertically aligned.

We need aligner. Okay. So dual purpose, which is to reproduce and then align layer to the previous one. because we need an aligner. So aligner needs something. All line mark. We need an align mark. That I talked about before. What is aligner? Mark. So the main process is design exposure to The chemical process, the radiation of the image to absorb the photoregist pattern and develop.

The photoregist which is a pillar and pattern is developed. Develop layer, we needed something. we finish through the optical lithography. So this is the real application case, the photolithography. Definitely it's a micro scale, typically. So primarily measure of the performance here. So what is the measure of the performance?

First we got the resolution here. Second registration means overlap the accuracy from layer by layer. Three is throughput. How efficiently product coming out the throughput layer. So this is measurable performance for what lithography system. So you get this is a typical sample for the lithography which is a multiple layer.

One, two, three, four, five maybe. Okay so this is the case whatever lithography system. This is the diode, but you know we can make a transistor all kinds of things together. Okay, transistor 2. So next is now I'm talking about the e-beam lithograph. Okay, what is e-beam lithography?

Same thing here. So this is a gun. Electron gun is much more powerful. Wow, something. Wavelength is shorter. Shorter wavelength, whatever. Okay. The electron beam result is maskless. No mask needed. Because the beam is focusing here shot into the sample specimen which is something electron scattering.

Then this is a kind of electron gun. This is no mask. This is only the computer program here. So this system is no mask. The software program here. So beam is shot here through the lens like two lenses here. one is here, one is here, something here, through the lens here and then shot the beam here. Okay so electron produced with some electron gun which is similar one of the television

like a CRT TV like a CRT TV with a big gun there. thermal gun, thermal tie. Thermal tie or we say field emission tie field emission emission tie So field emission tie So this is more quality.

So this is thermal type is something operation time is limited. Like an hour later some degradation power. But electron fuel type is very expensive. So we typically call FSM. Fuel Emission. secondary electron magnetically. This is one. Secondary electron detector or secondary electron microscope. So electron that then accelerate into the anode

and focus it in something magnetic lens. So using the anode here, accelerate electron and then focus something magnetic lens here. Then scheduling core that electron beam is rapidly start to entity out of specs. A specimen is with view and backscattered or secondary mode. It's monitor. So we just monitor how much electron field force

affected in this specimen. This is just I'll talk about what is the concept of the electron beam e-beam lithography. So now I'm talking about something to compare which is the optical lithography and then even with Soracha just compare. One major thing is the source is different. Source is different and then the other thing is something mask. This is mask on it. It is optical soropy. This is no mask on it. Just physical mode.

by the computer control. OK, so which is something-- same concept. The source is different, but something is pattern through the source and mask here. Right? This is something mask manufacturing, this operation, but this is physical and computer control.

So this is the RISO RP. So even RISO RP here, computer control. like the process system here, the same here, electron source here, spec span here, something. What is something stage moving? So we can, pixel by pixel, got the electrolithography, but they controlled by something computer. So these kinds of the computer program

transferred to the software program here. So same thing this CAD program transferred to the here. We do what? Vapor and then photolithography spin coring. So like a e-beam photolithography. e-beam resource which is different. This we call the peer. This is here something photoregist.

But e-beam is something different. Same polymer but this is more like an electron sensecape. We call it up something PMMA. something different. Okay. PR. So polymer is different. It's a coating on top of that. So even write something, we're writing by something. Software. Controlled by the computer. So stage control, software control, both of them, we just write it up something.

CAP-AMG transfer to the real sample on top of that. This is e-beam lessonography. This is typically, definitely nanoscale. Nanoscale. Okay. Then we control something spot-sized, like a smaller bigger bigger bigger something we just doing large area something we got to

something choose this one small in detail something spot size is smaller so which is a software programming well all system the writing we can choose depends on the scale size We choose the spot size, something bigger and bigger. So bigger means time is less consuming but quality is this one. So this choose this one is more time. This is less time, but quality is higher. Quality is less. So this is directly related to time. Less time is lower quality. More time is

more quality. Okay so quality and time, quality and time. This is even photography. So same thing. So we just drawing something like a two-dimensional drawing here. So CAD program E-beam generator, something that I transfer digital to analog system. Because this software is digital, this is analog system.

E-beam here, scheduling one by one, spot by spot size. Okay, so this is the moving is by stage moving here. Not beam is moving. Beam is just state. Okay, not moving but only state is moving so that's why working two-dimensional plotting or something bigger is generated.

So now that kinds of even lithography we can use the science more smaller region. Like one nanometer scale, carbon nanotube, or multi-wall nanotube, single-wall nanotube, all kinds of nanostructure we can fabricate. Like graphene stuff, layer by layer control, so we do something, metal deposition in sample. Like a few nanometer is done. possible and then this is like a fully suspended.

Okay, so I etched out. I'm going to talk about it later. So any kinds of lithographies, I just presented here, photolithography and then even lithography. One is microscale, one is nanoscale. So this is what black white figure. This is all. electron scattering figure which is SEM, which is nanoscale. Okay, it's totally different from the microscale.

So this is the whole thing about lithography. I just explained to you. in Microscale 2d, nanoscale. 감사합니다. 수고하셨어요.