At about half past ten in the evening, Chen Zhou sent Zhang Yifan out of the room.

Zhang Yifan had to hurry back to school, and according to him, their dormitory manager aunt was simply not too fierce.

If you are locked out, writing a review is light.

If you don't know it, you will be notified and criticized.

Seeing that what he said was so serious, Chen Zhou naturally didn't dare to delay his time.

It's just that he's very strange, aren't the dormitory aunts all amiable?

If you come back late, don't you let you in quickly, for fear of delaying your rest?

Helped Zhang Yifan call a taxi, watched him get into the car, and Chen Zhou returned to the room again.

As soon as I went back, I saw Shen Jing yawning.

Chen Zhou couldn't help but smile, he actually got up quite early today, and he didn't make up for sleep on the high-speed train, which would be a little sleepy.

"Senior, let's go back and rest first, tomorrow the experiment of the forty-third institute will officially begin. ”

"It's okay, I'll sort out two more articles. After Shen Jing finished speaking, he yawned again.

He was really a little sleepy, if you count it according to the day's activity time, then he has not rested for nearly 16 hours in a row.

"Okay, there's no hurry to do this, I'll do it tomorrow. Chen Zhou said that he went over to help Shen Jing turn off the computer and urged him to go to bed quickly.

Shen Jing glanced at Chen Zhou, packed up his things, and walked towards his room.

When he was about to go out, he suddenly stopped, turned his head and asked Chen Zhou, "Do you stay up late reading literature?"

Chen Zhou laughed softly: "No, I'll fall asleep after watching it for a while." ”

Shen Jing left suspiciously, but after returning to the room, he felt that something was wrong, what kind of concept was this kid for a while?

After thinking for a while, Shen Jing turned the computer back on.

Work, work with concentration, will counteract that tired sleepiness!

After cheering himself up, Shen Jing began to continue.

Chen Zhou's side, after Shen Jing left, he sat back at the table and continued to read the literature.

There are two left, the DC arc plasma injection CVD method and the microwave plasma CVD method.

The direct current arc plasma injection CVD method is also called the DAPCVD method.

This is a DC arc plasma deposition method that is implicit in the discharge zone.

The advantage of this method is that it has a very fast deposition rate.

It's extremely fast, not ordinarily fast!

In the 90s of the last century, there was a laboratory that used a reactor with the cathode and anode at right angles to achieve a high-speed growth of 930m/h.

That's 930 m/h, not 930 μm/h!

Moreover, even if it is 930 μm/h, it is much higher than the 40 μm/h of diamond film prepared by the current 43 institutes.

Not to mention 930m/h.

In contrast, the speed of one is a rocket, and the other is a bicycle.

Maybe not even a bicycle.

It is also because of this rate of growth that this method once became a hot method.

The preparation process is not complicated.

The main thing is to apply a direct current voltage between the rod cathode and the annular anode, and when the gas passes through, an electric arc is triggered, the gas is heated, and the gas expanded at high temperature is ejected from the anode nozzle at high speed to form a plasma jet.

The gas of arc initiation is usually argon, and after forming a plasma jet, the reaction gases methane and hydrogen are introduced, and the methane and hydrogen are ionized and reach the substrate of the water-cooled deposition table, on which the nucleation and growth of diamond films are formed.

Moreover, this method of preparing diamond film can not help but be fast, and the quality is high, and there is no electromagnetic pollution.

However, due to the uneven temperature field of the velocity and occasion of the injection plasma, the film thickness is uneven in the deposition range, and it will be distributed in a trapezoidal shape.

When the deposition rate is too fast, the surface of the film is uneven, which greatly reduces the density of the film.

Seeing this, Chen Zhou smiled strangely: "It seems that it's not good to ...... if it's too fast."

But overall, this approach has a lot of research potential.

Chen Zhou took notes on scratch paper and jotted down his thoughts.

After reading the relevant literature of the DAPCVD method, Chen Zhou slid the mouse with his right hand and clicked on a new PDF file.

The last preparation method.

Microwave plasma CVD method, also known as MPCVD method.

It is the method adopted by the forty-three.

It is also the purpose of Chen Zhoucha's literature.

There was only a year between the time when the DAPCVD method was reported.

It is also currently the most widely used method for depositing diamond films.

This method first uses an axial antenna coupler to convert a rectangular microwave of 2~5W to form a plasma at atmospheric pressure.

The high-pressure plasma is then sprayed through the "pinhole" of the coupler onto the water-cooled sample stage, where a diamond film is formed.

The gas source used in the DAPCVD method is the same, mainly argon, and the reaction gases are methane and hydrogen.

Today, this approach has taken many forms.

However, whether it is a quartz tube type, a quartz bell type and a metal cavity type with a microwave window according to the formation of a vacuum chamber, or a surface wave coupling type, direct coupling type and antenna coupling type according to the coupling mode of microwave and plasma.

Their deposition rate is related to microwave power.

For example, with the MPCVD method with 5 kW of microwave power, it is possible to deposit tool-grade diamond films at a rate of 10 μm/h, heat sink grade diamond films at a rate of 8 μm/h, and optical grade diamond films at a rate of 3 μm/h.

With 10 kW of microwave power, the deposition rate can reach 25 μm/h.

In other words, by increasing the microwave power, the deposition rate of the diamond film can be increased.

In addition, the deposition rate of the diamond film is also related to the gas pressure.

At high microwave power, high methane-to-hydrogen volume-to-flow ratio, and 160 Torr gas pressure, 150 μm/h polycrystalline diamond film can be prepared.

Under the same conditions, if the pressure is increased to 310 Torr, a single crystal diamond film of 165 μm/h can be prepared.

"Gas Pressure ......"

"Weibo Power ......"

Chen Zhou wrote these two words on scratch paper.

I took the pen and clicked twice, and I made two circles casually.

That's the point.

Putting down the pen, Chen Zhou slid the mouse and continued to read the content of the literature.

The MPCVD method is the most widely used method because it provides better quality of diamond films than the DAPCVD method.

It solves the problem of low density of the film and can produce a large volume of diamond film.

In addition, this method enables the deposition of diamond films on curved or complex surfaces.

Moreover, the MPCVD method does not have an internal electrode, which can avoid electrode discharge pollution and electrode corrosion.

It can be said that the conditions for the preparation of high-quality diamond films are met.

But, like the setup of forty-three laboratories, the deposition rate of the MPCVD method is a hard hit.

After reading this literature detailing the MPCVD method, Chen Zhou couldn't help but think.

"If you had half the speed of the DAPCVD method and the quality of the preparation of the MPCVD method, wouldn't that be the case?"