Chapter 94: Lithography Is Easier than You Think

Lithography machines are difficult.

It's really, really hard.

The difficulty factor is ten times that of the hydrogen bomb.

Even with all the efforts of the country, it is impossible to win it in the short term.

These are the words that often fill Wei Ming's ears, making him almost have calluses on his ears.

Is it really that difficult?

These days, I personally entered the R&D factory and understood the working principle of the photolithography machine. In the "boss workshop", I used the little black in my body to easily polish dozens of qualified high-precision parts, as well as a 20-yuan "pot". "Lid" lens - Each "pot lid" lens is made of forty layers of glass, and the surface protrusions must not exceed 1 nanometer.

"It's very simple. It doesn't seem to be difficult."

Looking at the batches of parts with fully qualified precision in front of him, Wei Ming curled his lips and said.

"What's the problem?"

"Light generators are very difficult."

Pu Weicai said: "To create extreme ultraviolet light with a wavelength of 13.5 nanometers, we must use deep ultraviolet light with a wavelength of 193 nanometers to hit free-falling metal tin droplets, and we must hit two tin droplets continuously in a very short period of time. Repeated 50,000 times per second to produce extreme ultraviolet light of sufficient intensity.”

You must know that the diameter of metal tin droplets is only twenty microns.

During the free fall process, not only does it have to be hit by a laser, it must be flattened from the shape of a water drop into a round cake, and then hit a second time to emit the most intense extreme ultraviolet light... The entire process takes place completely dynamically. It's like hitting a fly with an embroidery needle, twice in a row.

And repeat this operation 50,000 times in one second.

"Didn't you say that the light source problem has been solved? And the energy utilization rate has reached 5%?" Wei Ming said in confusion.

"The light source has been solved because the impact light source we use is 132-nanometer light emitted by a special crystal. The energy utilization rate is definitely much higher than that of 193-nanometer light. However, if we want to produce extreme ultraviolet light with sufficient intensity of 13.5 nanometers, Light still has to be achieved by hitting tin drops, this is the only feasible way.”

"In other words, you only solved the problem of hitting the light source, and then you said you solved the light source...these two are not the same thing, right?"

Wei Ming frowned.

"Minister of Health, it's not that we like to engage in false propaganda, but if there are no results in long-term scientific research, who will pay attention to us, and how will the higher authorities provide us with funding? So even if it is just a partial breakthrough, we must focus on publicizing it."

Xiang Guanglin on the side explained.

"The last technical problem we are overcoming is the frequency of tin droplets striking."

Pu Weicai also said: "We have solved the problem of continuous hitting, but the maximum repetition rate is 5,000 times per second. However, our energy utilization rate is higher. We only need to repeat 20,000 times per second to have enough light intensity. ”

"So our energy utilization is not meaningless. 20,000 times per second is obviously much easier to achieve than 50,000 times per second."

"20,000 times per second..."

Wei Ming pondered for a moment and said, "What conditions are missing to prevent you from reaching this frequency?"

"Accuracy, the accuracy of the control system."

Pu Weicai said: "It is like a clock that accurately controls the free fall of 20,000 tin drops and 40,000 hits at the same time. In terms of time, the error within each second must not exceed one billionth of a second; in terms of distance, each time Seconds cannot exceed 1 nanometer, and a 'bias correction' system must be designed. As long as the error accumulation is too large, it will be automatically corrected to allow the system to operate stably for a long time."

"Currently we are working hard to conquer the control system, and the correction system is a little behind, but we have also arranged a team to tackle the problem."

"Of course, if the relevant parts imported from the island countries can be in our hands soon, we may be able to achieve a hitting frequency of more than 20,000 times within three months."

Island country?

Three months?

Wei Ming shook his head and smiled, and said: "If there are any missing parts, just leave them to me and I will fiddle with them for you."

Then he tinkered for three days straight.

Laser frequency controller.

Highly sensitive distance sensor.

There are also devices like this, devices like that, and things that Wei Ming cannot name by professional name.

He did a dozen in three days.

Then let Pu Weicai and others insert these devices into the control system and assemble them together with extremely high precision requirements.

The trial run was started again.

"Release tin drops, the initial frequency is 1 drop per second." Pu Weicai gave the command.

"Start releasing."

"Two hits are successful, the flattening shape is perfect, and the stimulation effect is perfect!"

"Increase release frequency."

"50 successful trials per second."

"500 successful tests per second!"

"5150 tests per second were successful! Tying the highest record." The operator said with a slightly trembling voice.

"Keep increasing! Make it higher!"

Pu Weicai also started to get excited. This was just his first debugging, and it actually tied the previous set of parts that had been debugged hundreds of times, setting a record?

"5500 tests per second were successful, setting a new record!"

"More!"

7000 per second

9000 per second

10,000 per second

…

Keep increasing to 20,000 per second to meet the frequency of use requirements.

Everyone was shocked to the point of numbness, but they still succeeded!

"Add more, add more!"

30,000 per second

40,000 per second

45,000 per second

50,000 per second!

"The release frequency of tin drops has reached the upper limit, and it's still a success!" The operator shouted without any image.

"The converted light intensity is 2.5 times the rated light intensity!"

Xiang Guanglin shouted with red eyes: "This means that the efficiency of this lithography machine in processing wafers is at least twice that of ASMC EUV. One of us can replace two of them!"

"Don't shout!"

Pu Weicai waved his hand high, staring at the data after the duration, and said with all his strength: "Look at 50,000 tin drops per second and 100,000 hits per second. How long can this system work stably? Don't make noise, your noise may affect its performance."

Everyone fell silent.

Holding their breath.

All eyes were fixed on the duration.

5 minutes

15 minutes

29 minutes and 38 seconds

Due to the increasing cumulative error, there was no correction system to correct it, and the entire system finally stopped running automatically.

Snap!

Pu Weicai hit his left palm with his right fist, and said with a flushed face: "3 minutes is enough. With only 3 minutes, there is no need to design a very complicated correction system. I didn't expect it to last for half an hour! We only need to design a very simple correction system to make it work stably for a long time. The complexity of the whole system is reduced by at least 10%, saving us a lot of time!"

"It's amazing, it's amazing!"

As the project leader, he also shouted: "The light source problem has been completely solved, the duplex table is ready, the lens can be used, and our EUV lithography machine has a completion rate of at least more than 90%!"

"We can see the hope of victory!"

As he said, his tears burst like a dam, and he almost cried with his face in his hands.

He has persisted for more than ten years! This time, he really saw hope, right in front of him, already within reach.

Seeing him like this, other members of his team also wiped their eyes and made a whimpering sound.

"It hasn't really succeeded yet, so it's better to save your tears for the celebration banquet."

A slightly disappointing voice came.

But Wei Ming said: "Dr. Pu, you were so resistant just now, doubting that the things I polished could not be used. What about now? Believe what I said, right? The parts problem is not a problem for our company, and the technical difficulties you mentioned are not that difficult."

"That's right."

Pu Weicai wiped his tears quickly and showed a childlike smile: "Mr. Wei, you are right. As long as Mr. Wei takes action, there will be no difficulties in the lithography machine. I believe that under the leadership of Mr. Wei, we can solve all technical problems!"

He was really convinced this time, with only admiration in his eyes.

"That's right, it's all thanks to Mr. Wei."

"Mr. Wei has worked hard, give Mr. Wei a pat on the shoulder."

"Mr. Wei's god-level polishing can create industrial miracles!"

"Mr. Wei is the biggest contributor, thank you Mr. Wei."

Another wave of flattery came.

This time, Pu Weicai not only did not cough to stop it, but was the one who flattered the most.

Of course, it was enough to listen to the flattery for a while. Wei Ming asked them to get back to work immediately, continue to find problems, and solve problems until there were no problems.

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