Chapter 384

At present, the well-developed wide bandgap semiconductors are mainly SiC and GaN.

At the Semiconductor Research Center of Yan University, the main research object of wide bandgap semiconductor is GaN.

In the field of GaN-based wide bandgap semiconductors, the research center has been in a leading position in China.

More than 20 invention patents related to GaN wide bandgap semiconductors have been registered.

Including large-area, low-power laser stripping method for GaN-based epitaxial layer, indium gallium nitrogen single crystal thin film MOCVD epitaxial growth technology, etc.

The third-generation wide bandgap semiconductor has good physical and chemical properties and can be used in many fields.

Now, according to the development of the third generation of semiconductors, their main applications are semiconductor lighting, power electronics, lasers and detectors, and four other fields.

The maturity of the industry varies from sector to sector.

However, in the field of cutting-edge research, wide bandgap semiconductors are still in the laboratory research and development stage.

At present, the mainstream semiconductors on the market are still dominated by first-generation semiconductors and second-generation semiconductors.

The reason for this......

Of course, there are still many technical problems that have not been overcome in the third generation of wide bandgap semiconductors.

The ongoing work of the Semiconductor Research Institute of Yanda is to make every effort to overcome these problems and realize the complete maturity of the third-generation semiconductor technology as soon as possible and apply it to the market.

............

In the wide bandgap semiconductor laboratory, Gu Lu and the three of them wore dark brown lab coats and walked in under the leadership of Director Zhang.

The area of the laboratory is large.

It's almost the size of half a basketball court.

At a glance, you can see that several researchers in the laboratory are busy in front of various instruments.

"Hello Director. ”

"Hello Director. ”

Several young research assistants greeted Director Zhang politely when they saw Director Zhang coming in.

Director Zhang nodded, then waved his hand, "You guys are busy, you guys are busy." ”

"Let's go to MOCVD first. Director Zhang lowered his voice and asked Gu Lu.

Gu Lu nodded and smiled.

Director Zhang took Gu Lu to a tall rectangular device.

"This is the MOCVD of our laboratory!" Director Zhang patted the iron shell on the outside of the equipment and introduced Gu Lu with a smile.

Gu Lu looked the device up and down.

The so-called MOCVD is a new type of gas-phase epitaxial growth technology developed on the basis of gas-phase epitaxial growth.

The equipment uses organic compounds of group III. and group II elements and hydrides of group V and VI. elements as crystal growth source materials, and carries out gas phase epitaxy on the substrate by thermal decomposition reaction to grow various third-V main group, II.-VI. secondary compound semiconductors and their multi-solid solution thin layer single crystal materials.

The above is a bit complicated.

To put it simply, this MOCVD device can be used to combine organic compounds and hydrides as GaN wide bandgap semiconductors required by the laboratory.

This is an instrument for growing wide bandgap semiconductors.

Gu Lu had seen this kind of equipment abroad.

However, there are some differences between domestic and foreign MOCVD systems.

Because the most critical problem of MOCVD system is to ensure the uniformity and repeatability of material growth, the main difference between domestic and foreign MOCVD systems is the reaction chamber structure.

In foreign countries, the reaction chamber structure mostly adopts the 'TurboDisc reaction', while in China, the 'planetary reaction' is used.

Both have their own advantages and disadvantages, and it is impossible to say which one is better.

However, the MOCVD presented in front of Gu Lu, although it still uses the domestic planetary reactor structure, should be deeply optimized in other components of the equipment.

Gu Lu simply glanced up and down at this device and came to such a conclusion.

"Director Zhang, this equipment of yours should have been modified to a certain extent, according to my speculation, this MOCVD can not only grow two 1.5-inch GaN wide bandgap semiconductors at the same time?" Gu Lu said his guess.

Director Zhang gave a thumbs up.

"You're right. Director Zhang patted the equipment and said in a slightly smug tone, "After I bought this equipment, I asked a few friends from the Mechanical College next door to modify it." ”

"You see, in this part of the source supply system, we have added a thermostat to ensure a balanced vapor pressure for the metal compounds. Director Zhang pointed to a thermostat installed on the front of the instrument to introduce Gu Lu.

"And this. Director Zhang led Gu Lu to the back of the MOCVD, "This is the gas transportation system, and there was originally only one pipeline here. ”

"But we've added another one, so that the reaction gas in the reaction chamber can be changed quickly, and it will not cause a change in the pressure in the reaction chamber yet!"

Director Zhang gave Gu Lu a detailed introduction to the modification of this equipment.

Except for the reaction chamber system, which still chooses planetary reaction, the rest of the systems have been modified and optimized to a certain extent.

"That ......"

Gu Lu asked the question he was most concerned about, "Now, what is the maximum output of this equipment?"

Director Zhang put up three fingers, "Up to three two-inch GaN wide bandgap semiconductors can be produced at the same time!"

"Hiss——!"

Gu Lu gasped.

This yield......

As far as Gu Lu knows, a new model of MOCVD developed by foreign Veeco companies has invested heavily in it, which is slightly higher than this output.

As Gu Lu was marveling, this equipment had just finished a round of work.

The researcher's assistant on the side was about to come over and pick up the finished product.

Director Zhang waved his hand and put on white gloves, indicating that he would personally take out the finished product this time.

After a period of busy work, Director Zhang took out two long, thick GaN wide bandgap semiconductors.

Director Zhang's hands rubbed on the long and thick object.

"You guys also come and touch it, it feels very good, it's hard, and it's a little hot. Director Zhang greeted Lawyer Gu and his apprentice with a smile.

Gu Lu tugged at the corners of his mouth, and then touched it with Director Zhang.

Next to it is a special instrument for cutting.

With a squeaky sound, the long, wide bandgap semiconductor is cut into many small segments.

Gu Lu picked up a piece and observed the cut section under the light.

"The condition is very good!"

Such semiconductors only need to go through a few simple steps to remove impurities, and they can be directly taken out and processed.

On the contrary, Director Zhang on the side shook his head not very satisfied, "It's still not good, only about 80% of the entire semiconductor can be used in the end, and the rest of the part is still too much impurities." ”

The section in Gu Lu's hand is located in the middle of the entire semiconductor, and the color is of course good.

But the part at both ends is because there are too many impurities.

In the actual production process, it needs to be melted and decomposed before being put into MOCVD for secondary production.

There's a lot of waste.

However, this is a fairly common phenomenon, and if you want to achieve 100% utilization, it is basically non-existent.

80% is a good number.