Xueba starts with change

Chapter 241 MPCVD
Chen Zhou glanced at Dr. Wu who was looking at him with a smile, but was not in a hurry to answer the question.

He didn't think Dr. Wu would ask himself, a mathematics student, about the research of semiconductor materials for no reason.

In Chen Zhou's mind, he was constantly filtering information related to this topic.

"The key to this project is the preparation and doping of single crystal diamond, and the main problem we both help solve should be the problem in the doping process."

Hearing Chen Zhou's words, Dr. Wu's eyes lit up. The young man is a bit interesting and has a strong ability to grasp key points.

"That's right." Dr. Wu nodded, "The two of you mainly use mathematical methods to help analyze and solve the problems of p-type doping, n-type doping and co-doping."

Shen Jing heard the conversation between the two, and looked at Chen Zhou in surprise. Why are the documents we read different?
This doping, what are the doping things?
Just when Shen Jing was puzzled, Peng Fei brought Pan Shiyan over.

"Dr. Wu, Shiyan is here."

Pan Shiyan glanced at Chen Zhou and the two first, and then focused on staying on Chen Zhou for two seconds before saying to Dr. Wu: "Teacher, let me get them acquainted first."

Dr. Wu nodded: "Okay, I'll go to another research group to take a look first. Shiyan, you can show them the environment, and Peng Fei, you can prepare for the experiment in the afternoon."

"Okay, Dr. Wu (teacher)." Several people responded at the same time.

After explaining the matter, Wu Xinyue left the laboratory.

She is in charge of two subjects at the same time, and one is about a new type of bulk dilute magnetic semiconductor.

"Shiyan, then I will go to work first, and Chen Zhou and the others will leave it to you." After Peng Fei finished speaking, he smiled at Chen Zhou and the others, and then went to work on his own.

Originally, he thought Wu Xinyue would hand them over to him, but he didn't expect to call Pan Shiyan over.

But it's not surprising, Pan Shiyan is Wu Xinyue's favorite disciple, and it's obviously more appropriate for her to lead Chen Zhou and the others.

Pan Shiyan looked at Chen Zhou and the two, and introduced herself, "I'm your senior sister, from the Chemistry Department of Yan University."

"Chen Zhou, from the Mathematics Department of Yanda University, hello, senior!" Chen Zhou said.

"Hello, senior, my name is Shen Jing, and I'm also from the Mathematics Department of Yanda University." Shen Jing also said.

Pan Shiyan nodded and looked at Chen Zhou: "Chen Zhou, I know you, Yanda's new generation of genius mathematicians have proved the hail conjecture."

Chen Zhou smiled and said, "Senior sister is too much for the prize."

Pan Shiyan was noncommittal, and said instead: "Let's go, I'll show you."

Hearing this, Chen Zhou and Shen Jing followed.

Pan Shiyan didn't talk much, she just briefly introduced various instruments and equipment, as well as the experimental content of this project along the way.

Other than that, he didn't say a word.

Chen Zhou and Shen Jing looked at each other, and both felt that the senior was quite cold.

And Chen Zhou and Shen Jing followed silently, not daring to speak more.

After walking for a long time, Pan Shiyan asked when she came to the experimental area for the preparation of single crystal diamond: "The technological innovation speed of semiconductor materials and devices has always followed Moore's Law, making contributions to the development of the information industry."

"With the continuous development of the semiconductor industry, more and more semiconductor materials are used in electronic devices. Do you know why we use diamond for this project?"

Chen Zhou and Shen Jing looked at each other again, Shen Jing gave Chen Zhou a look, I leave it to you, I don't understand this...

And Chen Zhou just felt puzzled, why do both master and apprentice like to ask people questions?

It's such a simple question, why is it difficult to ask?

If you think so, Chen Zhou will definitely not say it, in case this high-cold senior sister...

Withdrawing his thoughts, Chen Zhou said softly: "Ordinary semiconductor materials are constrained by their own performance, and their application under high temperature conditions will be greatly restricted."

"The diamond semiconductor device has excellent electrical properties such as high carrier mobility, high thermal conductivity and low dielectric constant, and can operate in very harsh environments such as high frequency, high power, high temperature and high pressure."

"Diamond can exhibit n-type conductivity and p-type conductivity through doping, and its performance will far exceed materials such as gallium arsenide, gallium nitride and silicon carbide. It is currently the most promising wide-bandgap high-temperature semiconductor material."

Pan Shiyan glanced at Chen Zhou in surprise, but she didn't expect this person to know a lot.

"That's right. But not only that," Pan Shiyan added, "Due to the wide band gap of diamond, in the field of semiconductors, it can be used not only as an active device material, such as field effect transistors and power switches, but also as a Schottky diode. Such passive device materials."

After a pause, she looked at Chen Zhou and asked again: "You just said that diamond is a wide-bandgap high-temperature semiconductor material, how did you know that?"

Chen Zhou took a look at Pan Shiyan and thought about it, since you opened the topic, I'm not going to be polite.

Chen Zhou said: "The bandgap width of diamond is 5.5eV, its high carrier mobility is 4500cm/(V s), the hole is 3800cm/(V s), and its high thermal conductivity is 22W/( cm K), the high breakdown electric field is at 10MV/cm."

“而其电子载流子饱和速率在1.5×10^7到2.7×10^7cm/s之间，空穴载流子饱和速率在0.85×10^7到1.2×10^7cm/s之间，低介电常数是5.7。”

"Based on these excellent performance parameters, diamond is considered to be the most promising material for the preparation of next-generation high-power, high-frequency, high-temperature and low-power-loss electronic devices."

After saying this, Chen Zhou paused for a moment, and continued: "Although the reserves of diamonds are very scarce, in the 50s, people had synthesized artificial diamonds from graphite."

"Moreover, artificial diamonds and natural diamonds have the same structure and similar performance, which solves the problem of diamond sources very well."

"In addition, in the 80s, through the establishment of a hot-wire chemical vapor deposition device, that is, the HFCVD method, it was possible to prepare diamond films on non-diamond substrates. By the mid-90s, the theory of diamond film deposition had been relatively perfect."

"Although the research on diamond films was not smooth due to the constraints of the preparation method from the end of the 20th century to the beginning of the 21st century, the emergence of the repeated growth method, three-dimensional growth method and mosaic method promoted the development of large-scale diamond preparation. develop."

Following Chen Zhou's narration, Shen Jing beside him was already dumbfounded.

Guys, are you really our math major?

No, are you really our physics and mathematics major?

How is this chemical method so familiar?
Of course, what surprised Shen Jing even more was why he didn't see these contents in the literature?
Whether it is the project materials sent by 43 or the project materials sent to him by Chen Zhou, there is no...

Except for Shen Jing, the researchers who were doing the experiment looked back at Chen Zhou in surprise.

Didn't you say that you are looking for someone from the Department of Mathematics of Yanda University to help?
How do I see this looks like it's from the chemistry department?

And Pan Shiyan who asked the question was also surprised by Chen Zhou's fluent narration.

She originally wanted to teach the two newcomers, but she didn't expect to be taught by Chen Zhou again.

Chen Zhou glanced at everyone, then slowly set his eyes on the experimental device, and said softly: "The method you use to prepare the diamond film should be a microwave plasma chemical vapor deposition device, that is, the MPCVD method."

(End of this chapter)