What excites Yu Zixian is that in Cai Junjie's research materials, he saw the manufacture of micron-scale masks corresponding to the electron beam exposure system of the most important process in the lithography process.

It sounds a bit tongue-twisting and difficult to understand, but to talk about the advancement of this micron mask technology, we have to start with the development of mask technology.

The production flow chart of the chip simply goes through several major links of IC design, plate making, chip processing, packaging, testing and packaging, if it is simply an analogy, if it is compared to the printing of a book, it is: writing, typesetting, printing, binding, inspection, packaging.

The mask mentioned above corresponds to the typesetting in the book printing, as long as the layout is typeset and printed against the layout, a neat and beautiful book can be printed. In the same way, before chip processing, the designed chip layout needs to be plate-made, and only by using this as a template for chip manufacturing lithography can the bare die be manufactured, and then the bare die is detected and selected from these bare die, and finally the chip is packaged, which can be regarded as a usable chip.

To put it more closely, the lithography process is one of the most important process steps in chip manufacturing. The main function is to copy the pattern on the mask onto the silicon wafer in preparation for the next step of etching or ion implantation.

In the lithography process of the chip fabrication process, it is usually necessary to go through multiple photolithography processes to cut various doping windows, electrode contact holes or etch metal interconnect patterns on the conductive layer of the dielectric layer on the surface of the semiconductor crystal.

The lithography process requires a complete set (a few to a dozen) of photocopy masks with specific geometries that can be accurately registered with each other, referred to as photomasks.

Photomask manufacturing technology was gradually developed with the birth of the plane process.

In 1963, the Republic of China had successfully developed planar transistors and silicon digital integrated circuits. At this time, the traditional photography technique was used, in which a layer of black paint was sprayed on coated paper, and then a scalpel was used to manually engrave and take screenshots, and a large camera was used to take pictures to make a mask.

In the 70s, the Republic of China introduced a batch of polyester red film engraving machines and E-line step-by-step repeated exposure machines that can be exposed on ultra-fine particle dry plates, which can be regarded as getting rid of the ability to manually enter the mechanical manufacturing of photomasks; and in the 80s, the mask technology and equipment were updated again, and while establishing the chromium plates required for the production of their own optical masks, they also took advantage of the honeymoon period between China and the United States to introduce a number of high-precision optical plate-making equipment, including variable diaphragm pattern generators, as well as the refining machine of the GCA company that matched it. At this time, the reticle plate-making capacity of the Republic has stepped up to a big step, and it is also the heyday of the photomask technology manufacturing industry, and the highlight moment closest to the international photomask manufacturing level.

It is gratifying that with the entry of the 90s, the international market has entered the practical application of sub-micron integrated circuits and sub-micron processing technology, and the photolithography technology and photomask technology of the Republic have once again reached the equipment happy cycle.

At this time, with the changes in the international political environment, the door to the introduction of the republic was completely closed by the Batumi embargo.

The mask technology being developed by Cai Junjie directly affects the quality of the mask, and the quality of the photomask not only directly affects the quality of the lithography process, but also affects the electrical performance, reliability and chip yield of semiconductor devices or integrated circuits.

It is better to say that the yield rate of the 3-micron process chip mentioned by Tong Ruoyu before is expected to increase from 59% to more than 70%, which is why.

The yield of the chip decreases sharply with the increase of the defect density of the reticle according to the negative exponential relationship. It is estimated that in order to achieve a yield of more than 95%, the defect density of the reticle must be controlled to less than 0.175 defects per square centimeter. If the defect density increases to 1.25 defects per square centimeter, the yield will drop to less than 65% due to the direct impact of defects. Therefore, according to Tong Ruoyu, Cai Junjie's mask technology should have made a breakthrough at this time.

And this breakthrough is very important to Yu Zixian, with this technology, this factory is worth the acquisition, Yu Zixian does not plan to mix around 3 microns all the time. A 4-inch wafer can process chips as small as 1.2 microns. Yu Zixian hopes to meet this standard in the 1-2 years after the acquisition is returned.

The 908 project, which the Republic planned to launch at this time, was only hit to 0.9 microns in 98 due to various reasons, and other domestic cooperation projects only crossed the threshold of 1 micron in 1995 and entered submicron technology.

Even if we can't be the world's leading technology, we can lead the development of domestic technology and strive for more right to speak for ourselves.

After thinking about this, Yu Zixian called Jiang Yuehua again and told him that he had decided to acquire Cai's wafer factory, so that he could start due diligence and loan procedures.

He has to go back to the inland to see if he can scavenge some money, he really doesn't want to drain the liquidity of the Golden Arches, that is all capital, a cash cow that will lay a cub!

After that, he signed an acquisition agreement with Boss Cai.

At this time, Yu Zixian felt that he had too few people available, and he had to run everything by himself!

He now has a trace of expectation, I don't know when Jiang Yuehua will officially leave HSBC, and he will have to find a way to dig it up when the time comes.

After the things were arranged here, Yu Zixian and Hao Meng returned to Yangcheng and prepared to make a plane back to Yanjing.

But there was no direct flight to Yanjing that day. In two or three days, there will be, but I can't wait!

Today is already February 2nd, according to the old man's plan, there seems to be a Yanjing citywide commendation conference around the 8th, and Yu Zixian has to go to participate, saying that there are surprises or something.

There are still five or six days left, first do your own things, and after you finish attending the meeting, before the Spring Festival, the game "Guess the Idiom by Looking at the Picture" will be launched again, and you will have to participate in it yourself, this is a bunch of things!

You have to leave today, otherwise there are too many things and there is too much time!

There was no way, so the two had to buy a ticket for the transit in Xialu City.

Hao Meng's matter here is over, and now he can spend a Spring Festival at home when he goes back.

Yu Zixian has a habit of not knowing whether it is good or bad, every time he takes the train or does the plane, he has to empty himself and clean it, otherwise he always feels too troublesome and uncomfortable to go to the toilet on the train or plane.

This time was no exception. Yu Zixian asked Hao Meng to go first, he went to the bathroom in the hall first, and when Yu Zixian boarded the plane, more than half of the people in front of him had already boarded the plane.

queuing up for the security check, there was a young man carrying a lockbox in front of Yu Zixian, who looked very irritable and looked a little flustered. Yu Zixian didn't care, thinking that the other party was not feeling well.

This young man is also in his 20s, very young, about 1.7 meters tall. Dressed in a suit, he holds a bouquet of plastic red roses in one hand, and looks like a rich man with a temperament.

However, everyone passed through the security check smoothly, and the two of them boarded the plane in turn.

The moment Yu Zixian boarded the plane and entered the cabin door, he suddenly had a palpitation, and he couldn't say that he was inexplicably irritable, but he just thought that he was waiting for a trace of fear in his heart, and he didn't care.