Chapter 426 Mercury Telluride Cadmium Can Be Used
"CVD? Chemical vapor deposition?" Although he had never done it, Yu Yuncheng had some impression of it.

Gao Zhendong nodded. In addition to CVD, thin film crystal manufacturing also includes LPE (liquid phase epitaxy) and MBE (molecular beam epitaxy) technologies, but they are slightly ahead of the times and cannot be used in this environment, especially MBE. In the current environment, this thing is a bit too advanced.

CVD is a very versatile technology, not just for semiconductors.

The resources at Factory 1274 are limited, and if they want to engage in CVD, they may not be able to do it.

Yu Yuncheng is a more suitable place because he is engaged in this field and has theoretical foundation and practical research experience in crystal growth and forming. He is much more suitable than Factory 1274.

However, Gao Zhendong currently had nothing to help him in this regard, to see if he could find a way out on his own. It seemed a bit of a waste to search for information specifically for this matter. Gao Zhendong couldn't even remember whether he had any CVD-related materials, as he had downloaded too many things in the past.

After listening to Gao Zhendong's words, Yu Yuncheng thought about it carefully and felt that this was indeed an avenue worth studying. There had been some theoretical results and practical realizations, but overall the road had not been exhausted.

It's probably because everyone is at the same starting line, and if you can really make it, it will be very fulfilling.

"Well, Chief Engineer Gao, I've taken note of your idea. I'll go back and look up the information carefully before making a decision." Anyway, it will take some time for the mercury cadmium telluride crystal to grow, so he is not in a hurry to start a new mine now.

Let’s do some research and preparation first. The suggestions put forward by Chief Engineer Gao can be the focus.

I invited Yu Yuncheng to have lunch at noon, and Yu Yuncheng ran away in the afternoon. Haihekou is not too far from the capital, so it is quite convenient. Moreover, this time I asked comrades from the army to escort the mercury cadmium telluride crystals over, and they have a car.

After Yu Yuncheng left, Gao Zhendong looked at the tightly packed box in front of him with a look of joy on his face.

Although they were said to be escorted, there were actually not many things. The escort vehicles were mainly used to carry people rather than things.

Gao Zhendong picked up the phone and called Engineer Lu from the Guidance Research Institute. He was in charge of the infrared air-to-air guidance system and was now also the person in charge of the guidance system for the modified Thunder-1 that Gao Zhendong suggested.

Engineer Lu picked up the phone, and after listening to Gao Zhendong's words, he took Lin Lianwei and others to the third rolling mill without saying a word. Chief Engineer Gao had already produced the new infrared sensitive material!

Don’t forget that Gao Zhendong is also the deputy chief designer of the Raiden-1 modified.

In less than an hour, they were sitting in Gao Zhendong's office, and Gao Zhendong showed them a copy of the test results of the mercury telluride cadmium material.

For this batch of materials, Gao Zhendong asked Yu Yuncheng to make them into the 8-14 micron band, which is more suitable for their use in infrared guidance heads.

Engineer Lu took the test results and laughed as he looked at them, with a smile on his face.

"Intrinsic excitation, high quantum efficiency, high absorption coefficient, good, good!"

"It has a high operating temperature, a wide operating range, and a low dielectric constant, which is interesting."

"It's even more interesting to be able to adjust the infrared band, but the 8-14 micron range is suitable for us now."

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After reading the inspection results, Engineer Lu looked up at Gao Zhendong and said, "Chief Engineer Gao, you said that this material already has a finished product?"

Gao Zhendong nodded: "Yes, we have it. Although the output is not high and the price is expensive, there is no problem in mass production. You can take a look here."

After saying that, Gao Zhendong took out a mercury cadmium telluride crystal and handed it to Engineer Lu.

Engineer Lu admired the crystal while examining it. The appearance of mercury cadmium telluride crystal and silicon crystal was quite different, and it looked more like a piece of metal.

Looking at this tiny crystal, Engineer Lu was calculating its size in his mind.

"Engineer Lu, this crystal has very good consistency, so you can consider cutting it into pieces to ensure that the materials of the four infrared photoelectric tubes of each orthogonal four-element detector come from the same crystal."

These crystals are a few millimeters thick and about 10 millimeters long, which is enough to meet Gao Zhendong's suggestion.

Although the infrared seeker looks more than 100 mm thick, in fact, apart from the optical part of the orthogonal quaternary detector, the actual infrared detector body is not that thick, and is just a small piece in the middle of the seeker.

Engineer Lu smiled and said, "Well, Chief Engineer Gao, your suggestion is good. Can the current production technology ensure that every crystal meets this specification?"

Gao Zhendong nodded and took out more than ten tightly packed mercury cadmium telluride crystals from the safe: "Yes, as long as it is a qualified finished product, it will at least be of this specification. This is the minimum requirement for mass production technology."

In fact, the total amount that Yu Yuncheng brought was more than this, but the Institute of Research and Development is not the only one that needs to use this thing. For the Institute of Research and Development, this amount should be enough now.

Sure enough, seeing Gao Zhendong take out such a pile at once, Engineer Lu was overjoyed. He originally thought that he could just get a few and start the research first. After all, this thing was just made.

But I didn't expect there would be more than ten. This way, more things can be done at the same time, and I don't need to be so careful when using them.

Engineer Lu was afraid that Gao Zhendong would take it back again, so he quickly signaled his men to put the things away, and said with a smile: "Chief Engineer Gao, then I won't be polite, haha."

Strictly speaking, Gao Zhendong just showed him the crystals and hadn't said he would give them to him yet, so he gave full play to his subjective initiative and took action directly to secure the prize. The person in charge of the action was Lin Lianwei. Look, every time I come to Chief Engineer Gao's place, it's always a good idea to bring him along.

Gao Zhendong was a little amused when he saw the actions of these two people.

"Wait!"

After hearing what Gao Zhendong said, Lin Lianwei's hands froze and he felt uncomfortable.

"You guys can count first, go through the formalities, and then take it away. Why are you in such a hurry? Haha."

Foreman Lu breathed a sigh of relief. Chief Engineer Gao was quite good at making jokes.

After Gao Zhendong made a small joke with them, he got down to business: "Mr. Lu, when you are making infrared photodiodes, please do me a favor."

"Okay, you tell me." Engineer Lu didn't ask what the favor was. Since Chief Gao had spoken, he had to agree to it regardless of whether he could do it or not. The main reason was that the other party had given him so much over such a long time, not to mention that he was the deputy chief engineer of the Thunder-1 modification.

"Do some research and find out how many infrared photodiodes can be made from a single mercury cadmium telluride crystal while ensuring the yield and performance."

The linear array of line scan thermal imaging has a requirement for consistency. When there was no thin film crystal growth technology, the simplest way to solve the consistency problem was to use the same crystal.

The solid-state recrystallization method was originally chosen because it has a simple process and good crystal consistency.

However, Gao Zhendong was not sure how many diodes could be made from one crystal. If the number was not enough, he would have to add a selection process.

This matter can only be confirmed by letting the Research Institute do some research first.

Engineer Lu agreed immediately, as this was their job.

Before leaving, Gao Zhendong remembered something else.

"If you have any questions about the manufacturing process of mercury cadmium telluride infrared photodiodes, you can consider contacting Factory 1274. They are working on semiconductor manufacturing processes and have some new equipment and processes that were not available before. They may be able to help you. I will give them a call and cooperate with your work when needed."

To make mercury cadmium telluride into a photodiode, it does not require steps such as photolithography, but necessary passivation, substrate, ion implantation or diffusion are still required. This is a new material and there may be some differences from the previous process, so Gao Zhendong reminded them about Factory 1274.

When Engineer Lu heard this, he thought that Deputy Chief Engineer Gao's arrangement was really thoughtful and even took the process into consideration. He happily took note of the matters concerning Factory 1274.

Gao Zhendong grabbed Lin Lianwei and made an appointment with him for dinner on Saturday. He was going to visit his wife on Sunday, so Saturday was still possible.

To help an old classmate, you don't have to do too much. Don't interfere in his internal work arrangements unless necessary. Just make a dinner appointment with him in front of other people in a calm manner.

After work, Gao Zhendong ran to the cafeteria to have dinner.

Lou Xiao'e was at school, so it was meaningless to go home for dinner alone, so Gao Zhendong temporarily returned to his bachelor life.

When Sha Zhu saw Gao Zhendong, he laughed at him: "Wow, Zhendong, your wife is not at home, so you are completely free? Eat in the cafeteria."

In the back kitchen of the cafeteria, Liu Lan looked at the silly man outside and curled her lips: "Master He's mouth will suffer sooner or later. Chief Engineer Gao of the Third Factory is the only one who calls by his name."

Another canteen chef smiled and said, "You don't have to worry about him. He and Chief Engineer Gao live in the same courtyard and they have a very good relationship. Didn't you see who Chief Engineer Gao asks to cook whenever he invites guests? That's just his habit. Chief Engineer Gao doesn't care. Why are you so anxious?"

When you invite someone to cook for a dinner, it's a good job, which means he can get some of the food on the table. This is an unspoken rule, and everyone understands it.

At this point, Sha Zhu's new apprentice Ma Hua smiled quietly. Chief Engineer Gao treated them to a meal and his master was the chef, so he got a lot of money.

Outside, Gao Zhendong smiled and said, "You have to work, so I can't help it. If you were off work today, I would go to your house for dinner."

Ma Hua glanced at Liu Lan and said, "Look, look."
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Talking about this matter, it is really a series of things. Just as the mercury-cadmium-telluride issue was over, comrades from the Institute of Communications came over again.

They came here after learning the basic knowledge of switches given by Gao Zhendong thoroughly and sorting out the relevant ideas.

In fact, the original research institute obtained the materials for the laser gyroscope earlier than them, but they have not yet fully digested them.

As usual, the team leader is Chief Engineer Feng, and this matter is the top priority for their Institute of Communications recently.

"Boss Gao, although the traffic data has not yet been fully returned, we do have a preliminary idea. We want to develop large-scale, medium-scale, and small-scale programmable space-division switches."

As expected of a large research institute directly under the ministry, it did something big right from the start.

(End of this chapter)