Hand rubbing nuclear fusion live in the wilderness

Chapter 409 The Tragic Small Island Country
Negative-tone photoresists are also known as 'photoresists' in silicon-based chips.

After this material is applied on the wafer, photocuring reaction can quickly occur in the exposure area, so that the physical properties of the single crystal silicon wafer, especially the solubility and affinity, will change significantly.

These areas are thus preserved during the subsequent development process.

Therefore, negative photoresist is a main photoresist used in the manufacture of high-precision integrated chips.

And because of the characteristics of graphene single crystal material, when it faces positive photoresist, the exposed area will not be easily etched, so we can only find ways to strengthen the exposed area, and then carry out the subsequent development process .

The main components of negative photoresist for silicon-based chips are photosensitive resin, sensitizer and solvent group.

The same is true for carbon-based chips, which are also composed of these three main components.

Among them, the photosensitive resin has not changed much, while the sensitizer and solvent group have undergone considerable changes.

After all, you can't take a sensitizer and solvent set that is suitable for a silicon-based chip and treat a carbon-based chip.

The properties of single crystal silicon and graphene can be quite different.

In addition, the optical properties of the two materials, graphene single crystal wafers and single crystal silicon wafers, are also different.

Graphene, a material with very good optical properties, has an absorption rate of about 2.3% in a wide wavelength range, and within a fixed number of layers, the absorption rate increases by 2.3% for each additional layer of thickness.

This also makes it very sensitive to light sensitivity. When the intensity of incident light exceeds a certain critical value, the absorption of graphene will reach saturation.

Therefore, although graphene wafers are also processed by photolithography machines, the exposure process is different from that of carbon-based chips.

In the chemical laboratory, Han Yuan dug out the photoresist used to prepare the [-]-nanometer integrated chip and the corresponding materials for configuring the photoresist from the storage room.

Among them, there are three kinds of photosensitive resins, which he used to configure mixed photosensitive resins.

Compared with a single photosensitive resin, the mixed photosensitive resin is more excellent in performance, and the prepared photoresist has higher precision and can be used to etch low-nanometer chips.

At the beginning, Han Yuan was thinking of deploying a photoresist with higher precision so that Huaguo could also produce it himself, but now it is better, it is more convenient for him.

These three kinds of photosensitive resins are mixed according to different proportions, and the complex photosensitive resins prepared can be applied to carbon-based chips.

He is now going to prepare negative photoresist, in fact, there are only two materials, sensitizer and solvent group.

But it is said that there are two kinds, but they are actually composite materials.

Among them, the sensitizer is composed of two different photoinitiators mixed, not to mention the solvent group, which is known from the name, and its composition materials are various.

For example, part of it is a glue remover suitable for glue removal, and its raw materials are a mixture of acetone, methyl acetate, and ethyl acetate.

The raw materials for the preparation of the sensitizer and the solvent set have a part in hand.

These are left over from the previous processing of silicon-based chips, and they are pure enough to be used directly, which saves a lot of energy.

As for most of the remaining materials and solvents, they need to be redeployed.

The properties of graphene single crystals are more stable than those of single crystal silicon, so a solution with stronger corrosiveness and plasticity is required for processing.

It is not difficult for Han Yuan, an aging worker, to chemically configure various solvents when he has the required basic materials in hand. He has already kept various chemical reactions in mind, and it can even be said to be engraved in his genes.

From easy to difficult, chemical solvents appeared in his hands one by one, and these solutions contained in glass containers or polyester containers were the raw materials for the final composition of the solvent group.

Compared with sensitizers suitable for carbon-based chips, various mixed solvents in the solvent group are easier to prepare.

These solvents are among the simplest of photoresist manufacturing materials.

They serve as the medium of the polymerization reaction, which can ease the reaction between the photoresist and the corresponding coating, facilitate temperature control, prevent gelation and increase storage stability, etc.

Although the solvent group is composed of a variety of different chemical solvents, most of the solvents can find alternative materials.

Unlike sensitizers, those materials are always used.

After processing the various chemical solutions required by the solvent group, Han Yuan tested them first to confirm that the solvent group meets the requirements before starting to process the sensitizer.

After preparing the materials, he went into the storage room and found a set of glass containers.

Looking at this group of glass containers covered with some dust, Han Yuan felt a little embarrassed. This was the equipment he used to refine and prepare plasticizer three years ago.

Because the composition of the overall container is relatively special, subsequent chemical experiments have not been used after use.

If it weren't for the preparation of sensitizer today, this group of glass containers with special structure won't even remember its existence.

Cleaning up the turned-out glass container group, Han Yuan checked the glass tubes and special materials at the connection of the container, found that some were old and replaced them.

The state of the new glass and the old glass of the reassembled equipment is very clear, and the newly replaced glass is bright and transparent, which can be seen through at a glance, with a faint reflection.

After the test of time, the old glass that occupies the main part of the container has a matte feel. Although it is also transparent, the difference can be clearly seen.

Of course, the existence of these old glass does not affect the use.

After assembling the container, Han Yuan pulled over the camera and said, "The photoresist used for carbon-based chips is different from the photoresist used for silicon-based chips, as I just mentioned."

"And of these, the biggest difference is the 'sensitizer' used in the two photoresists."

"Sensitizer, also known as photoinitiator, is a material that can absorb radiation energy, undergo photochemical changes after being excited, and produce active intermediates, free radicals or cations with the ability to initiate polymerization."

"In short, it absorbs the radiant energy of 'extreme ultraviolet light' in the photolithography machine, and then chemically changes the photoresist as a whole."

"And this chemical change will cause changes to the wafer under the photoresist. Some may cause the wafer to solidify, and some may cause the wafer to corrode."

"This is the main reason why photoresists are divided into 'positive and negative' genders."

After a pause, Han Yuan turned around and picked up the materials he had just prepared from the table, and continued: "It's different from using benzoin and its derivatives, acetophenone derivatives, and aromatic ketones as photoinitiators for silicon-based chips."

"Because the carbon-based chip uses graphene single crystal material as the wafer material, it is quite resistant to materials that could have been used as photoinitiators for carbon-based chips."

"So it is not acceptable to use the photoinitiator of silicon-based chips as the sensitizer of carbon-based chips. I need to reconfigure one."

"After thinking and practice, according to the characteristics of graphene single crystal materials, there are not many materials suitable for use as photoinitiators."

"The most suitable of these is a 'mixture of 4-trimethylpentylphosphine oxide and 75% alpha-hydroxyketone in acetonitrile'."

"This mixture is what I call a 'carbon-based UV photoinitiator.'"

"Compared with traditional photoinitiators such as benzoin and its derivatives, acetophenone derivatives, and aromatic ketones, carbon-based ultraviolet photoinitiators are more sensitive to ultraviolet light and are suitable for ordinary ultraviolet light and extreme ultraviolet light."

"In addition, its adaptability is quite high. It can be used not only to prepare photoresist for carbon-based chips, but also for silicon-based chips."

"If there is any disadvantage, it is that its manufacturing process is quite complicated, and part of the preparation process is not suitable for intelligent mechanical production, and requires quite experienced workers to control it."

[Small photoresist is so troublesome to manufacture. 】

[I just recorded that the photosensitive resin is made of three materials, the brightening agent is two kinds, and the solvent group is the most. There are thirteen different materials in total. 】

[I always thought that photoresist was an ordinary liquid colloid, but I didn't expect the structure of this thing to be so complicated. 】

[Photoresist, hey, the good days of the small island nation are over. 】

[Why upstairs?Shouldn't it be the end of America's good days? 】

[Let me tell you, because the photoresists in the world are mainly supplied by small island countries, accounting for about 60.00%, and more than 90.00% of the extreme ultraviolet photoresists suitable for EUV lithography machines are small island countries. supplied by the island nation. 】

[In the field of photoresist, the top five companies in the world account for nearly 90% of the market. Except for Rohm and Haas, the rest are from small island countries. What is dominance is what dominance is. 】

[It's too loud! 】

[Good guy, the photoresist companies in the small island country are about to be wiped out. I like this, I love it. 】

[Good news, good news, I'm going to buy and hang firecrackers to celebrate. 】

[Upstairs, a firecracker is not enough, at least there are fireworks! 】

[It's too small, the layout is too small, so I'll go straight to the four-foot jade! 】

[The four-foot jade was developed by the small island country. 】

[That's even better, wouldn't it be beautiful to celebrate with their own research_]

In the live broadcast room, barrages continued, nearly twice as much as usual.

Things involving small island countries always make people excited.

The main reason is that the big revenge has not been reported, which cannot make people calm.

And the fact is just like the audience routine in the live broadcast room. In the area of ​​photoresist, the stock prices of related companies have already jumped like jumping off a building.

If there is no circuit breaker mechanism, it will directly fall below the offering price in one day.

Choose this 'carbon-based UV photoinitiator', won't do anything.

It's not that he doesn't have photoinitiators suitable for carbon-based chips, but that different photoinitiators have different requirements for photosensitive resins and solvent groups.

Some photoinitiators that are easy to manufacture and can be mechanized and controlled throughout the production process have high requirements on the solvent group, and the overall photoresist will be more complicated to manufacture.

The most critical thing is that the precision of the photoresist is insufficient and cannot reach the level of ten nanometers.

The photoresist that can reach the nanometer scale is more complicated in the manufacturing process, and it is not suitable for the materials he has now.

However, the precision of the photoresist is too high, which is not only more difficult to manufacture, but also not suitable for Huaguo.

No matter how high the precision is, there is not much benefit except for those Western countries to quickly master the preparation of photoresist technology to monopolize the market again.

After all, Huaguo was far behind in the technology of photoresists and lithography machines. Ten nanometer-level photoresists are enough for Huaguo to study for a long time.

After comprehensive consideration, Won finally chose the 'carbon-based UV photoinitiator'.

Although a certain amount of manual assistance is required in the manufacturing process, what Huaguo lacks most is people.

In the chemistry laboratory, Han Yuan explained and then began to process the materials in his hand.

The sensitizer, that is, the photoinitiator is the core material in the photoresist, and it is also the core factor for the photoresist to be divided into positive and negative. The manufacturing process will not be simple.

Although the 'carbon-based ultraviolet photoinitiator' he chose is composed of two materials, the manufacturing difficulty of these two materials is not low.

Whether it is 4-trimethylpentylphosphine oxide or α-hydroxyketone acetonitrile solution with a concentration of 75%, the preparation steps are very complicated, and there are many places that need to be controlled and paid attention to.

The α-hydroxyketone acetonitrile solution in particular has a rather unexpected point in the manufacturing process.

It needs to combine α-hydroxy ketones at a high temperature of 170 degrees, and then rapidly cool down to minus ten degrees when building acetonitrile groups.

And that's not all, after the acetonitrile group is linked to the α-hydroxy ketone main chain, the temperature needs to be quickly adjusted to about [-] degrees to keep it stable.

Although the temperature is too low, the acetonitrile group can be linked to the α-hydroxy ketone main chain to form an α-hydroxy ketone acetonitrile compound, but after a long time, the acetonitrile group can also be released from the α-hydroxy ketone main chain. .

It sounds contradictory, but this sort of thing happens so often in chemical processes that it's not uncommon.

On the contrary, the audience in the live broadcast room listened to his explanation in a daze.

[What the hell, build at low temperature, fall off at low temperature?Repeatedly jump? 】

【True · Repeated horizontal jump】

[Chemistry is so interesting, it's a pity that I didn't choose this major in college. 】

[Upstairs, you should be glad you didn't choose, otherwise it would be miserable now. 】

[Biochemical ring material, I advise you to run away, anyway, most of them are doing other things——]

[For those who don’t understand, majors such as biochemical and environmental materials are actually very important to the country, and they are the pillars of the country’s scientific and technological progress.But this has nothing to do with finding a job, because you can't be at the forefront, so it's not easy to find a job at all. 】

[Materials people pass by, change careers, unless you are really good at academic and professional level and can walk in the forefront of the world, otherwise it is really not very interesting, big investment and small output.Biochemical ring material is not a joke. 】

[The key is that there are a few teachers in the school who teach something that is really useful, the training is unreasonable, masters and Ph. 】

[Biochemical ring materials · four major tiankengs. 】

[The two major tiankengs of mechanical civil engineering, the four major guardians of biochemical environmental materials, and the five major minions of agriculture, forestry, mining, animal husbandry and fishery, even if they are promoted to research, they will not have the effect of changing lives against the sky.It is recommended that the younger generation switch to IT, 360 lines, and turn to IT. 】

[To put it bluntly, I can't settle down, and I'm impetuous and unwilling to be an honest person. 】

[Honest man, have you eaten your rice? 】

(End of this chapter)