He stayed at the institute until evening. In the evening, Zhou Hong invited Li Xiucheng and Hu Yingmei to his home for dinner.
Both sons work out of town, leaving only an old couple at home.
The old lady was very hospitable, especially when she knew that Li Xiucheng was Zhou Hong's boss. She used her housekeeping skills to prepare a table full of dishes.
At the end of the meal, Li Xiucheng said: "I won't go to the institute tomorrow. Accountant Hu and I will go to Beijing for two days and then fly directly to Xingrong.
The institute needs you, Professor Zhou, to take more care and take care of things. "
Zhou Hong patted his chest and said seriously: "Don't worry, Mr. Li, as long as my old bones can still stand up, I will not let the research stop."
"Yes. I believe Professor Zhou!" Li Xiucheng smiled and nodded. He had considerable trust in the moral character of the old man, but it was also time to talk about the development route of the lithography machine.
What we are currently studying are old dry lithography machines, but the future will be dominated by immersion lithography machines. How can we make the old-timers accept this point of view?
This needs to be carefully considered.
After eating, Hu Yingmei helped the old lady clear the dishes. The two sat back on the sofa and drank tea to relieve their tiredness.
Li Xiucheng considered it and said, "I have a question to ask Professor Zhou."
"Lithography machine? If you have any questions, just ask." Zhou Hong just admired Li Xiucheng and didn't hold back if he didn't understand anything. Likewise, if you know you don't understand, you won't give indiscriminate instructions to others.
Such a boss who is generous, sensible and capable of delegating power is much better than the previous leaders who were laymen and experts in commanding.
“I know that the glue coating principle of a photolithography machine is actually similar to the exposure of camera film, and I have been supplementing my knowledge in this area recently.
I know that the production efficiency, yield and minimum resolution of photolithography machines are constantly evolving.
The minimum resolution of the lithography machine is controlled by a formula R=kλ/NA.
Among them, R represents the smallest size that can be resolved, which is the accuracy we are pursuing. Then the smaller the R, the better. K is the process constant representing our process technology, λ...λ....
What is λ? "
At this point, Li Xiucheng felt stuck and scratched his cheek.
Zhou Hong smiled with a teacher-like expression on his face: "λ is the wavelength of the light source used by the lithography machine. What we are currently studying is the G-line lithography machine with a wavelength of 346NM.
NA represents the numerical aperture of the objective lens, which is the key exposure system.
This is also the most difficult thing. What we are building now are products with parameters that are ten years behind others.
Anyway, the development of photolithography machine process technology has always followed the formula you mentioned.
Now the latest lithography machines in the United States can produce chips with an 800nm process, but we are still hovering at 1200nm, which is still far behind! "
At the end, Zhou Hong looked disappointed and lost interest in starting.
"Oh, it's so complicated!" Li Xiucheng made a confused expression, and then changed the topic: "But I roughly grasped the two key points, the light source and the refractive index of the objective lens!
In order to improve the production efficiency and yield of chips, it is necessary to develop the internal structure and working mode of the lithography machine at the same time.
So we can consider the overall factors, why not change a light source, and then change a refractive medium? "
"Huh?" Zhou Hong came back to his senses and said a little strangely: "Now there are two types of light: G line and I line. The wavelength is about three hundred to four hundred. It is indeed relatively large, and it is internationally recognized. The bottleneck will occur when the 193nm process is shortened to 157nm.
But what do you mean by refractive medium? "
Seeing Zhou Hong's interest, Li Xiucheng's lips curled up slightly and then quickly returned to their original state.
This is the biggest difference between today’s dry lithography machines and immersion lithography machines!
He deliberately made a face of uncertainty and said: "I think we can do more experiments with light, try XYZ rays, ultraviolet rays, and aurora, and we can always find the most suitable one.
As for the refractive index, the light waves of current lithography machines propagate in the air and are then exposed.
But didn’t we have a knowledge point when we were studying that the wavelength of light will change when it enters different media?
So can we refract the light source refracted by the objective lens through the medium again.
Such as water, such as other liquids! "
After saying the most important things in one breath, Li Xiucheng picked up the tea cup and looked at Zhou Hong.
At this moment, Zhou Hong sat on the spot blankly.
But a pair of slightly squinted eyes and furrowed brows showed that he was thinking intensely in his mind.
Li Xiucheng didn't rush, didn't even say a word, just waited quietly with his tea cup in hand.
Until Hu Yingmei and the old lady walked out, they saw how quiet the living room was and how Zhou Hong looked like a clay sculpture. They couldn't help but be very curious.
"What's wrong, old man?" The old lady called out in a moderate tone.
Um!
Zhou Hong came back to his senses with a jolt, and regardless of the old lady's curious expression, he leaned forward and looked at Li Xiucheng with bright eyes, and said with some excitement: "Mr. Li, the principle of your method is completely reasonable. of!
But there are also many difficulties.
I....I think we could give it a try.
If successful, this will be a new idea that is completely different from the current principles of lithography machines, and we may achieve great progress and success.
Even the theoretical 157NM bottle well problem will be solved. "
The more he talked, the more excited Zhou Hong became. He even stood up and danced with his hands, as if he wished he could go back to the laboratory and have a big fight right now.
Haha, it’s done!
Seeing him in this state, Li Xiucheng was extremely satisfied. He was worthy of being a popular advertisement protagonist, and his acting skills were simply amazing!
He smiled and said: "Since Professor Zhou also thinks it is feasible, of course we should study it carefully.
Let's do this, select a group of elite talents to sign a confidentiality agreement, and then start trying to develop it. "
Zhou Hong nodded: "Confidentiality is for sure, and I think we can give this method a new name to make it easier to call it.
What we are using now is air refraction medium. This method is that light propagates in liquid.
Or is it called wet? "
Li Xiucheng's mouth twitched: "Wet style? This is too difficult to pronounce."
"Oh, that's true. What suggestions does Mr. Li have?"
"Immersion, submersion is fine!"
"Immersion? Immersion..." Zhou Hong chewed the word repeatedly, and the more he thought about it, the more appropriate it became. He slapped his thigh fiercely and said, "Okay, let's call it this."
Li Xiucheng smiled slightly. The culprit who had troubled and hindered the development of China's chip industry in his previous life was finally revealed.
It's just that in this life, I started to catch up decades in advance, and I will definitely not let China fall into a passive position in the field of chips in the future!
The technological blockade of the United States will eventually be dismantled by the Chinese people bit by bit.
The current lithography machine is just the beginning, and there will be more in the future.
Next, Zhou Hong focused his attention on the three shots of the immersion lithography machine, while Li Xiucheng accompanied Hu Yingmei on a general tour of several scenic spots in the capital, and then flew back to Xingrong.
