"Samples are out!"

"Purity 11N!"

At ten o'clock in the morning on September 20, Mu Yang was reading information in the office when he suddenly received news from the silicon factory (wafer fab). His face, which had been staring at the information without any waves, was filled with joy.

Semiconductor silicon wafers suitable for the integrated circuit industry have extremely high requirements for product quality. The purity must reach 99.99999999% (nine nines, referred to as 9N). The most advanced process needs to reach 99.999999999% (11 nines, or 11N).

.

Export requirements generally must reach 9N.

Nowadays, there are domestically produced silicon rods that can reach 11N, but the production is extremely unstable and the cost will be much higher.

Muyang's requirement is that it must reach 12N stably, and the production cost cannot be too high.

Of course, the silicon rod indicators are not only purity, but also crystal structure, flatness, etc., and must also meet various parameter index requirements such as resistivity, carbon residue, thickness, warpage, and surface metal residue.

But purity is the core, and size is the cost. This is a bit one-sided, but it’s not wrong.

"Okay, I'll come over and take a look."

Mu Yang put down the information and called the driver to prepare the car.

The silicon factory is not here at the headquarters base, but in the Xinghai Group Industrial Park No. 2, which is the Yangfu District Industrial Park.

Three minutes later, Mu Yang got into Future 01 and drove towards the silicon factory.

Half an hour later, Mu Yang came to the experimental workshop, put on white dust-free clothes and rubber gloves, and put on a mask, covering his whole body except for his eyes.

After pressing your fingerprint at the entrance to verify your face, you can truly enter the experimental workshop.

The weather in September is very hot. Fortunately, the workshop is a constant-temperature workshop and the temperature is only 20 degrees Celsius. Otherwise, it would be very uncomfortable to wear tightly wrapped clothes.

But even so, Mu Yang still felt a little unaccustomed, especially after not wearing a mask for several years, and felt that breathing was not very smooth.

In later generations, if you are used to wearing a mask, you will feel fine if you don't take it off for a day. It will just hurt a little from the strangulation at the base of your ears.

Walking in the workshop, no one recognized Mu Yang.

An employee passing by saw that he was not wearing an employee badge and there was no personal name tag on the back of his clothes. He quickly walked back to block him and said, "Hello, who are you? How did you get in? Why didn't you wear an employee badge?"

At this time, Mu Yang remembered that he was not angry, but smiled. However, the employee in front of him could not see his smile.

"Asking you? Otherwise I will call the police!"

"It's okay, I'm Mu Yang." Mu Yang took off the mask, showed a smile, and then put the mask back on

When he said this, the young employee in front of him panicked and bowed deeply to Mu Yang: "Ah, you are the chairman, I didn't recognize you, I'm sorry, I'm sorry!"

"It's okay, you did a good job and were very vigilant. Several colleagues I passed by didn't notice this. In the final analysis, it's my problem, I didn't make my own sign." Mu Yang waved his hand and smiled.

"Thank you, Chairman, I really didn't recognize it."

"Don't worry, just go and get busy."

"Okay, bye." After saying that, the employee left quickly, feeling too embarrassed. Fortunately, the chairman didn't care and praised him.

Mu Yang came to an XH1200 single crystal furnace. At this time, seven or eight employees were communicating outside the equipment. When they saw Mu Yang, these employees still didn't recognize him.

Technical manager Xiang Hai had met Mu Yang many times and knew that Mu Yang was coming. He recognized him through his figure and eyes, and then walked over to say hello:

"Chairman, you are here."

When Xiang Hai shouted this, the blood pressure of other employees instantly spiked. The person in front of him turned out to be the chairman!

"Well, let's talk about the specific situation." Mu Yang nodded.

Xiang Hai said: "The equipment in front of us started trial production yesterday. The theoretical maximum melting capacity reaches 1,200 kilograms, and we put 1,000 kilograms.

The equipment can draw single crystal silicon rods from 12 inches to 14 inches, and is currently in production.

It's a 12-inch silicon rod, how about trying the full length size.

Yesterday, we trial-produced two one-meter-long monocrystalline silicon rods. Judging from the test results, various indicators have met the silicon material requirements for high-end mobile phone chips. The production efficiency is twice as fast as the conventional lifting of 10 centimeters per hour.

about.

Of course, there are still some gaps from the requirements we set, and there are many small flaws. For example, the silicon purity has reached 11N, but no matter how we debug it, it cannot reach 12N. We are looking for the reason, but we haven’t found it yet.”

The silicon refining method currently used by Xinghai Group is the pulling method.

First put the molten Si in a graphite crucible, use induction heating, and then put it in a quartz container, using pure hydrogen gas as a clean atmosphere. Then put the seed crystal as a seed at the front end of the vertical rod, and then put it into the melt

Inside the Si.

Because the surface of the seed crystal will absorb melt, in the process of continuous slow rotation and pulling of the vertical rod, a bulk material crystal with a diameter much larger than that of the seed crystal can be grown.

It's a bit like inserting two chopsticks into a pot full of noodles. The noodles clamped by the chopsticks are like "seed crystals", adsorbing other noodles in the pot. As the chopsticks rotate and then lift, more and more noodles appear.

Got caught in the chopsticks.

Moreover, the rolled noodles are arranged relatively neatly. In fact, the pulling method also takes advantage of the rotational gravity to evenly distribute the molten silicon. At the same time, the temperature and geometric structure of the silicon are controlled through the rotation of the shaft (chopsticks).

of unevenness.

Mu Yang said, "Take me to see the trial-produced sample first."

Xiang Hai nodded and walked to an uncut single crystal silicon rod, which was about one meter long and 12 inches in outer diameter. This silicon rod also weighed more than a hundred kilograms.

Mu Yang squatted down to observe, touched the surface of the silicon rod with his hand, and praised: "The outer diameter is very straight and the diameter is uniform. However, it is only one meter long. After pulling a furnace of 1,000 kilograms, it can theoretically be pulled four to five meters."

long."

After Mu Yang inspected the uncut single crystal silicon rod, he then checked another cut silicon rod sample. It had been cut in half.

The monocrystalline silicon rod is first cut off with tapered ends at both ends using a wire cutting machine. If the silicon rod is very long, it is segmented. Otherwise it will be too heavy to move and process, and then the outer diameter is cut using a real slicing machine.

Cut wafers.

Slicing with a microtome will be much faster, the cutting planeness will be better, and it will not break easily. If it is wire cutting, it will be rough.

The thickness of the newly cut wafer is less than one millimeter, and it needs to be polished and ground until it meets the designed thickness requirements.

The thickness of the slice mainly depends on the toughness of the material and the performance of the slicer. If it is easy to cut, then cut it thicker. And the larger the diameter, the more difficult it is to slice, so the cutting thickness of 12 inches must be thicker than that of 8 inches.

.

This can't be helped, the toughness of single crystal silicon is very poor, and it is actually a brittle material.

The thickness of the final chip is generally less than 0.3 mm, and if it is thin, it can reach about 0.1 meters thick.

Mu Yang picked up a piece of wafer. From the appearance, the flatness was good.

"How many pieces did you cut, and what is the probability of it breaking?"

"I tried cutting dozens of slices, and a few slices were cracked at the beginning. I found that the cooling system of the slicer was not working properly, and the subsequent slices were not cut."

"Just purity 11N"

Xiang Hai said, "Well, we randomly inspected 9 wafers and they all have this data."

Mu Yang nodded. He understood the difficulty. Even if every component was produced according to the drawings and the process was as he did, there would definitely be errors in the assembly of the equipment. The production environment would also have an impact, as well as other factors, which would ultimately affect the single crystal.

Silicon purity and other properties.

If we can achieve the current situation, we can indeed start mass production, even if it is still far from the theoretical value of his design.

His request is just to make better chips based on this. For example, the purity requirements of chips used in high-end mobile phones and high-end computers are so high, no matter how poor they are, they must reach 10N.

Moreover, other indicators of silicon rods have reached the world's top level.

It can be said that Xinghai Group has produced the world's top silicon rods. It depends on what happens next.

Mass production status.

"A single crystal rod is not representative. It may be accidental. We need to produce more samples in the early stage and test more to collect data."

Mu Yang stated his request. Next, he personally checked the root cause of the problem and eliminated it one by one from the purity and flow rate of hydrogen, silicon raw materials, operating temperature and humidity of the single crystal furnace, etc.

He is familiar with all the equipment and processes, but has no practical experience in this area. During the process of instilling the technology, the "familiar experience" given to him in his brain is still somewhat different from the reality. He needs to go through it again and integrate it better.

It's like the brain says: "I know it."

The hand said: "I don't know how to do it yet!"

The principle is the same, Mu Yang has no practice and no muscle memory.

He worked for an hour and didn't find any problems. When it was time to get off work in the morning, he had lunch and took a rest. He continued to work on it in the afternoon and didn't find any problems.

"It's really weird!"

Mu Yang asked the equipment assemblers in the laboratory to assemble new equipment, and he had to watch them assemble it from the beginning until it was put into production.

In the next few days, Mu Yang was directly involved in the production of monocrystalline silicon rods. During this period, he also personally assembled and debugged the equipment.

Two days before the National Day holiday, another set of equipment was assembled and put into equipment debugging to prepare for trial production.

During this period, the purity of the single crystal rods produced by the first two sets of equipment assembled was still 11N.

The energy consumption and production efficiency of the equipment that Muyang attaches great importance to have all reached the expected goals, but the silicon purity still does not meet the design requirements.

It’s September 30th.

Mu Yang is obsessed with the work of silicon purity. If the newly installed equipment still fails to meet the requirements, he will take a break and cannot continue to compete.

The reading system helped Mu Yang quickly master knowledge, but it could not help him analyze the problem, let alone find the root cause of the problem.

After testing, the purity of the monocrystalline silicon rods produced by a new set of equipment is still the same and has not improved.

Mu Yang frowned when he saw the result, "It's weird, we just can't find out the problem. Manager Xiang, please stop now and sort out your thoughts when you get back from the National Day holiday."

Xiang Hai nodded, but after thinking for a moment, he said, "Chairman, how about we work overtime and do more inspections."

Mu Yang shook his head and sighed: "In this case, if you can't figure things out, even working overtime will be useless. Maybe we have jumped into a dead end these days.

You can successfully assemble the equipment, achieve continuous crystallization successfully, and the yield and other indicators have reached the world's top level. This is considered a success, but I am a bit competitive."

These days, they have eliminated operational problems, raw material problems, and crucible quality problems. There are no problems with the thermal cycle, and there are no problems with the speed.

That is, the cause of the problem cannot be found.

A test engineer said, "Chairman, our industrial park consumes a lot of electricity during the day, and the current and voltage are unstable. Will it cause power jump changes and affect the temperature in the furnace to become unstable?"

"Huh? Wait, let me think about it."

Mu Yang seemed to understand the reason after this employee's reminder, and said to the test engineer: "You reminded me well. It may be an electrical control problem, but it may also be other reasons. Check the current and voltage meter and the stability of the test engineer."

Pressure gauges, these measuring instruments, might have been wrong when they left the factory."

It is normal for instrument errors to exist. For example, if it displays 220V, it may actually only be 215V. Most people don't care too much about this, but it may have an impact on the production of monocrystalline silicon rods.

Soon, the electrical engineer found out that the current and voltage were slightly unstable, and the sensitivity of the voltage regulator was not adjusted appropriately.

Although the temperature in the furnace meets the requirements, it is sometimes high and sometimes low, which has an impact on production.

"Although it has been found that there is a problem with the voltage regulator meter of the voltage stabilizing system, we don't know yet whether it has affected the purity of the monocrystalline silicon rods. We will test it again after the holidays are closed during the National Day."

After Mu Yang finished speaking, he left the experimental workshop.

More than two dozen R&D personnel in the experimental workshop saw the chairman leaving and looked at the new equipment that had just been assembled.

There was no time for trial production.

An employee said, "During this period, the chairman was very tired, and he personally assembled and debugged the equipment with us, which is really rare."

Xiang Hai said, "The production of monocrystalline silicon ingots is very important to our company. Chip manufacturing is the chairman's dream, and it is also our dream.

Whether domestic high-end chips can be realized, to be honest, depends on our company in China as a whole.

Now, we have produced qualified monocrystalline silicon rods, but the chairman is not satisfied yet and cannot meet his requirements. This spirit of striving for excellence and climbing to the top is worth learning. We must not have any achievements.

We feel proud and complacent because we have reached the first place in the world.

Although the chairman praised us, he was also under a lot of pressure, but he just didn't tell us. Otherwise, he wouldn't have personally debugged the equipment and spent time in the laboratory with us. You would think he was very idle.

If you look at this period of time, even if you abandon the identity of the chairman, his operational abilities are much better than those of us, and we have too much to learn."

"Well, the chairman's ability is extraordinary. I heard that there are very few problems that trouble him. But what I admire more is his research spirit."

Everyone admired Mu Yang from the bottom of their hearts. Looking at the newly assembled equipment, the problem of silicon purity was like a thorn stuck in the throat. If it couldn't be solved, they felt uneasy and didn't want to leave the laboratory.

"If this problem is not solved, I won't be able to sleep even if I have a holiday."

"The chairman won't let us work overtime."

"How about we secretly work overtime without overtime pay?"

"That's a matter of overtime pay. The company doesn't lack overtime pay."

Technical manager Xiang Hai said, "I don't force everyone to work overtime, and the company doesn't encourage overtime. This holiday is voluntary. There is no overtime pay. You don't have to come if you have something to do. If we are found to be working overtime, we will be criticized."

"It's better to criticize than to think about it all the time. I feel like I've found the problem, but I haven't tried to verify the conclusion. I really can't sleep at night."

"A test run takes a long time. Even if we only produce a one-meter-long monocrystalline silicon rod, cutting and testing will still take time. It will definitely take two days."

Xiang Hai heard that everyone agreed to work overtime voluntarily and said, "Well, since everyone has no objections, if it's okay, let's have dinner and continue tonight. If there is something urgent at home, you really don't need to come."

"It's nothing urgent. There's nothing better than the problems we encountered." One of the R&D staff said with a smile.

"What about you, didn't you say you want to go shopping and watch a movie with your girlfriend tonight? You don't have to come."

"Cancel it. Actually, I don't want to watch that kind of romance movie. Now I have an excuse not to go. I don't have the passion for scientific research."

"Romance movies are okay, wouldn't they be more passionate?"

A few R&D staff joked and I felt much more relaxed.

In the next two days, these R&D personnel began to verify the production situation after the current and voltage stabilized.

It was five days later, October 8th.

Not long after he started working, Mu Yang came to the silicon rod experimental workshop again, found Xiang Hai, and asked him to start verification.

Xiang Hai was a little embarrassed and said, "Chairman, actually, we have already verified it."

Mu Yang was a little confused, "Oh, have you verified it? When did it happen?"

After I finished speaking, I probably understood and asked seriously, "During the National Day, did you secretly work overtime?"

Seeing Mu Yang's expression, a R&D staff member quickly explained: "Chairman, I don't blame Manager Xiang. We asked him to work overtime. I really couldn't sleep at night."

Mu Yang smiled happily, "I don't blame you either. What's the result?"

When he said this, Xiang Hai and the surrounding R&D staff breathed a sigh of relief. They were really afraid that the chairman would scold them.

Xiang Hai said, "We produced two monocrystalline silicon rods more than one meter long. After verification and testing, the silicon purity was stable above 12N. It was indeed caused by unstable current and voltage."

"Okay, okay, the design goal has been achieved! We are officially ready for mass production!"

Mu Yang was very happy when he heard this, "You are very good, you should be rewarded."
Chapter completed!