Xueba starts with change

Chapter 259 P-type n-type co-doping

Chen Zhou first summarized the 10 sets of experimental data compiled by Shen Jing, and then began to refer to the research method of thin film preparation process.

First, through a large amount of literature, put out all the problems and find solutions.

Combined with these 43 sets of experimental data from the 10rd Institute, trial and error was carried out through the wrong question set.

As for Shen Jing, Chen Zhou assigned the same task as Zhang Yifan.

That is, he needs to work with Fang Jieming to build an analytical model for the doping experiment.

"The choice of boron source for p-type doping is B(CH3)3, which should be no problem."

"Because B(CH3)3 acts as a boron source, it is beneficial for boron atoms to be incorporated into alternative positions in the diamond lattice, which can improve the efficiency of boron incorporation..."

"...Effect of different diamond substrate facets on the carrier mobility of boron-doped diamond prepared..."

"...From the experimental data and literature information, when boron-doped diamond layers are prepared on (100), (110), (111) plane single crystal diamond substrates respectively..."

"...the lattice defects of (111) and (110) facet diamond substrates trap a large number of boron atoms, which reduces the incorporation efficiency of boron atoms, and there is strong impurity scattering, making the mobility lower than that of the (100) facet Diamond substrates..."

"so……"

The thoughts in Chen Zhou's mind were very clear.

All the content about p-type doped diamond is constantly being filtered and screened in his mind.

He was turning his train of thought into a definite direction.

At the same time, the pen in Chen Zhou's hand was constantly writing on the draft paper.

In the eyes of outsiders, the content he wrote on the draft paper may not have any rules.

But in Chen Zhou's eyes, he is approaching his goal step by step.

11 o'clock in the morning.

Peng Fei came to this small office.

The excited expression on his face has not completely faded, and the mental state of the whole person is still extremely excited.

When Chen Zhou saw his appearance, he was a little worried. Will this person suddenly... fall down?

But before Chen Zhou could speak, Peng Fei had already said: "The task you entrusted to me is all done! I have sent all the information to the computer in front of you through the intranet!"

Chen Zhou minimized the page on the computer, searched on the computer, and saw the information compiled by Peng Fei.

Chen Zhou raised his head and said to Peng Fei, "I saw it."

Peng Fei walked up to Chen Zhou at this moment, just looked at Chen Zhou without saying a word.

Chen Zhou looked up at him strangely: "What's wrong?"

Only then did Peng Fei say, "Is there anything else I can help with?"

Seeing the flickering look in Peng Fei's eyes, Chen Zhou couldn't help but smile. Can this guy be addicted to help?
Shaking his head lightly, Chen Zhou said, "Not for the time being."

Hearing Chen Zhou's words, Peng Fei felt lost for a moment.

Noticing the change in Peng Fei's expression, Chen Zhou thought for a while and added: "I suggest you go to rest first, there will be a lot of things to come."

Hearing this, Peng Fei immediately looked at Chen Zhou, and quickly said, "No problem! I'll go to sleep after dinner!"

At noon, Chen Zhou and Shen Jing also had a simple lunch in the canteen of No. 43 Institute.

During the meal, Shen Jing couldn't help joking: "Chen Zhou, that Peng Gong is about to become your fanboy..."

Chen Zhou didn't say much about it.

It doesn't matter if you are a fan or not, the main thing is to feel like a helper, that's great~
After lunch, after a short 10-minute break, Chen Zhou sat in front of the computer again.

The problem of p-type doping is relatively simple, and his direction has been determined.

After thinking about it, Chen Zhou looked at Shen Jing and asked, "Senior, how is the analysis model you built?"

Shen Jing turned around and said: "It's not close. Because the model you require must be specific, we have fully considered all aspects of the experiment to construct the model of p-type doping, n-type doping, and co-doping. But it's coming soon."

"Okay." Chen Zhou responded and stopped talking.

Since Shen Jing and Fang Jieming have already caught up, let's start with the trial and error of p-type doping in the afternoon.

Put aside the issue of n-type doping and co-doping for a moment.

In the wrong question set, the theoretical research on p-type doping experiments has experienced a wave of parabolic trends.

In the morning, when Chen Zhou first started to study the problem of p-type doping, the set of wrong questions was as messy as a printing press.

They printed all the content that Chen Zhou had read until they reached a crest.

Later, with Chen Zhou's in-depth research on the problem, the content recorded in the wrong question set began to change.

Some old content is overwritten with new content, and some content disappears entirely.

Old content is covered by new content, which means that the research direction is clear.

The disappearing content means that Chen Zhou has solved the corresponding problem.

Now, there will be another wave of parabolic trends on the set of wrong questions.

"Crystal facet selection of diamond substrates..."

"Reaction pressure, temperature..."

"The doping concentration of the boron source..."

Combining the 43 sets of experimental data that 10 has completed, Chen Zhou started the trial and error of the p-type doping experiment.

An hour later, Chen Zhou took out a new draft paper and wrote down a series of experimental parameters on the draft paper.

Then he got up and walked to Shen Jing's side, and threw the draft paper to Shen Jing.

After receiving the draft paper, Shen Jing was slightly taken aback, and immediately began to communicate with Fang Jieming to conduct model analysis.

Chen Zhou returned to his seat and sat down again.

Next, it's the turn of n-type doping and co-doping.

The problem of n-type doping and co-doping is much more difficult than that of p-type doping.

"The first realization of diamond n-type doping was carried out on a (111) surface diamond substrate, and the samples showed n-type semiconductor transfer characteristics in a wide temperature range..."

"At a temperature of 500K, the Hall mobility is 23cm/(V s)..."

"However, compared with the (111) plane single crystal diamond substrate, which is difficult to polish, has many defects, and is small in size, the surface of the (100) plane oriented substrate has atomic level flatness, small defects, and the quality of the epitaxial film is better than (111) Surface-substrate diamond..."

"But this is not absolute, and the problem of the crystal plane is not the most critical factor..."

Thinking of this, Chen Zhou stopped the pen in his hand, and habitually tapped on the draft paper.

This is what Chen Zhou did when his thinking was blocked.

"Sort through the literature again..."

Thinking like this, Chen Zhou put down the pen in his hand, and turned his eyes to the computer screen again.

The scroll wheel of the mouse in the hand is constantly sliding, and the content on the screen is also constantly changing.

But Chen Zhou didn't blink his eyes.

He has already gone through these contents.

Look at it now, just to find out if you missed something.

In order to open up a gap for your blocked thoughts.

"Phosphorus doping concentration?"

"Electron scattering mechanism?"

"It's not about this part..."

"...1.7eV?"

"Why did you forget this data!"

When seeing this content, Chen Zhou's eyes brightened instantly.

N-type doping, or phosphorous doping diamond, is difficult.

This is because phosphorus atoms are larger than carbon atoms and are difficult to embed in the diamond lattice.

When phosphorus atoms enter the diamond lattice, it will cause lattice distortion and affect the configuration, bond type and charge distribution in diamond.

There are a large number of vacancies in phosphorus-doped diamond, which will also form phosphorus-vacancy defects with strong binding force with phosphorus atoms.

The energy level of this defect is located at the bottom of the diamond conduction band at about 1.7eV, which can compensate the donor and hinder the ionization of phosphorus atoms.

In turn, it is difficult to obtain high-quality phosphorus-doped diamond films.

Although the energy level of phosphorus is located 0.58eV below the bottom of the conduction band, this defect still exists.

"Filling of defects..."

The movement in Chen Zhou's hand accelerated, and the scroll wheel of the mouse kept sliding.

The content on the screen was dragged by Chen Zhou to the co-doping part.

[Nitrogen atoms are in the alternative position in the diamond lattice, which will form a deep donor energy level with an excitation energy of 1.7eV, which is non-conductive at room temperature...]

[In theory, phosphorus can be used as a shallow donor impurity, but the radius of phosphorus atoms is larger than that of carbon atoms, so it is difficult to incorporate into the diamond lattice...]

[Theory shows that the method of phosphorus-nitrogen co-doping may be an effective method to overcome the self-compensation of wide and ultra-wide bandgap semiconductors...]

【…】

Seeing this, the speed in Chen Zhou's hand slowed down unconsciously.

If the nitrogen atoms can fill the defect, there is room for the doping of phosphorus atoms...

Originally, I planned to solve the n-type doping problem first, but after thinking about it, the problem jumped to co-doping?

Because the n-type doping experiment in Institute 43 uses phosphorus doping.

So in co-doping, what they study is the method of phosphorus-nitrogen co-doping.

This also made Chen Zhou connect the two together.

Chen Zhou couldn't help but smiled in his heart, but immediately decided to solve the problems of n-type doping and co-doping together.

In co-doping experiments, PH3 was first used as a phosphorus source, and N2 was used as a nitrogen source.

However, when using these two gases to carry out experiments, the results obtained are not ideal.

The resistivity of the prepared doped diamond film is very high.

In subsequent experiments, the choice of phosphorus source and nitrogen source was constantly changed.

A single dopant source containing phosphorus and nitrogen, such as NH4H2P04, has also been applied to research.

However, the resistivity of the obtained diamond film is still high.

Chen Zhou glanced at the experimental data of Institute 43 again, and then began to sort out the substances that could be used as nitrogen and phosphorus sources on the draft paper.

When Chen Zhou was immersed in the research, the sky outside the room had gradually darkened.

"Chen Zhou."

Waking up by Shen Jing's voice, Chen Zhou looked up at Shen Jing suspiciously.

Shen Jing pointed to the computer: "The data analysis is complete."

"Oh." Chen Zhou responded, got up and walked to Shen Jing's side to take a look.

The results of the analysis were basically not much different from his expectations.

"Send it to me, and I'll do the final processing."

Shen Jing nodded: "OK."

Chen Zhou turned around and was about to go back to his seat, when Shen Jing grabbed him and pointed to the lower right corner of the computer screen.

Chen Zhou took a look, only to realize that it was already 06:30.

After thinking about it, Chen Zhou didn't plan to work overtime at the 43rd Institute, it would be more comfortable to go back to the hotel.

So, the two of them sorted out the materials, talked to Peng Fei, and left the 43rd Institute.

Chen Zhou was surprised that Peng Fei didn't come to see him all afternoon, and he realized it when he called.

Peng Fei is currently busy collecting finished diamond films.

The diamond film prepared by the improved process has been completed.

According to what Peng Fei said, Chen Zhou estimated that he would stay up late and work overtime again tonight.

And I don't know him alone...

After a simple dinner outside, Chen Zhou and Shen Jing returned to the hotel.

Shen Jing planned to follow Chen Zhou's room as before, but was stopped by Chen Zhou.

"Rest well tonight, you will be busy tomorrow." After leaving these words, Chen Zhou closed the door and entered the room.

Outside the door, Shen Jing looked at the closed door, and muttered: "Could this be retreat?"

In the room, Chen Zhou quickly turned on the computer, took out the draft paper and the collection of wrong questions.

"It's just tonight..."

After just a glance, the train of thought in the afternoon continued.

Chen Zhou once again immersed himself in the research of n-type doping and co-doping.

A stack of brand-new A4 draft paper that was originally specially prepared gradually became thinner as time went by.

And the pen refills that he has always loved are constantly passing on the draft paper at an unreasonable speed.

The content of the wrong question set is also constantly increasing and decreasing.

"No matter what nitrogen and phosphorus sources are used, there is only one purpose..."

"No matter what the system in the device is, it is always only for the preparation of doped diamond films..."

Chen Zhou's thinking became clearer, and his direction gradually became clear.

In the co-doping experiment of the 43rd Institute, no redundant system was used as an auxiliary in the device.

But in fact, if there are other systems to assist, the result may be better.

This is an inspiration to Chen Zhou from a foreign document.

Take the filled draft paper aside, replace it with a new draft paper, and replace the pen refill with a full one.

Chen Zhou wrote on the draft paper:
[In the NiMnCo-C system, P2N5, carbonyl ion powder and phosphorus powder are mixed under high temperature and high pressure to provide nitrogen source and phosphorus source, and this method is used to dope diamond...]

After writing this sentence, Chen Zhou suddenly laughed.

"Such a simple truth, why have I thought about it for so long?"

Compared with pure nitrogen-doped diamond, H atoms in the form of sp3-CH3 are more easily incorporated into the phosphorus-nitrogen co-doped diamond lattice, which improves the quality of co-doped diamond.

Because in the phosphorus-nitrogen co-doped system, many defects are generated after phosphorus atoms are incorporated, forming carbon atom dangling bonds, which help hydrogen atoms to be incorporated into the diamond lattice.

Hydrogen atoms can etch the sp2 phase, which is beneficial to the deposition of high-quality diamond films.

"After the system, nitrogen source, and phosphorus source are determined, the remaining problems of the co-doping experiment can be easily solved..."

As Chen Zhou said, he brought over a few pieces of draft paper that were put aside.

This is the parameter research done by Chen Zhou for different situations when studying nitrogen and phosphorus sources.

This will be just for verification.

General substrate temperature, doping concentration, working pressure, etc., through trial and error with the wrong set of questions, you can quickly get a rough range.

After the verification of the analytical model, go back to the wrong question set for further trial and error.

That's it!

Once the problem of co-doping is solved, the problem of n-type doping is the answer on paper.

(End of this chapter)