Hand rubbing nuclear fusion live in the wilderness

Chapter 186 N-Drift Layer

High-energy ion implantation is a requirement for modern integrated chips.

For him, currently, it is enough to implant aluminum ions into the silicon carbide crystal to form a transition layer.

And the technique he used was not pure ion implantation, as the barrage said before.

He uses ion doping, and it is the 'infiltration doping method' in ion doping.

Because he does not have such a high-tech thing as an ion implanter, but this kind of transistor is inseparable from the N-drift layer.

So he can only find a way to replace it.

Ion doping is the way he thought of.

This is a technique in alloying process.

One metal is plated on another metal surface by corresponding chemicals.

In fact, it first appeared in the smelting of alloys, and was later widely applied to materials such as ceramics, glass, composites, and polymers.

However, compared with modern ion doping technology, Won has made some improvements.

For example, conduction in a glass container does not have this step in the original ion doping.

In the glass container, the solution based on dilute sulfuric acid and dilute nitric acid forms an electrolyte, and the aluminum ions in the solution can form a thin and relatively uniform doped layer on the silicon carbide crystal by heating and electrifying.

The doped N-drift layer can also play a sufficient role, but it needs to be repeated many times.

Although the doping method requires multiple electrolytic doping and quenching, it is far from being comparable to ion implantation in terms of uniformity and depth.

But for him at present, this is the most suitable and easiest way.

With the continuous heating of the alcohol lamp, the water in the solution is continuously evaporated, and the aluminum ion solution in the container gradually becomes viscous.

When the solution could no longer cover the silicon carbide crystal substrate, Han Yuan cut off the power supply, took out the silicon carbide crystal material in the glass container, and poured out the electrolyzed aluminum ion solution.

The silicon carbide crystal is cleaned, then blown dry, repainted with a layer of paraffin wax coating, and injected again with doping.

According to the standard process, the concentration of the aluminum ion solution he produced required six repetitions of doping implants to form a usable N-drift layer at the bottom of the silicon carbide crystal.

So he needs to repeat five more doping implants, which will take at least five hours.

In the afternoon, Han Yuan stayed in the chemical laboratory, repeating the process of doping aluminum ions continuously.

Of course, for most ordinary people, it is enough to read this kind of thing once and see it fresh.

But what the scientists squatting in the live broadcast room were interested in was actually this.

Although the ion doping technology is already very mature at present, the Korean Won's improved 'electro-thermal ion infiltration method' is a brand new way.

And it seems to be a way that can be applied to implant the ion layer on the chip base.

Unlike Won, who does not have key instruments in his hands, countries and laboratories capable of reviewing his experiments basically have corresponding experimental instruments and identification instruments in their hands.

More importantly, they also have enough manpower.

On the one hand, the re-engraving experiment can be carried out completely according to the live broadcast, and on the other hand, the staged results can be obtained on professional inspection instruments for identification.

In Huaguo, Beijing, the door of a laboratory was hastily pushed open, and a young man rushed in with a stack of A4 papers in his hand.

Before he had time to catch his breath, the young man raised the information in his hand and shouted loudly.

"Group leader, the penetration test of aluminum ions in silicon carbide crystals. The results are out. This result. The results are incredible."

Judging from the shortness of breath, this young man ran all the way here.

In the brightly lit laboratory, after hearing the sound, another middle-aged man who was re-doping aluminum ions according to the live broadcast quickly got up and walked over, took the information from the young man and started to read it.

"The primary permeability is 1.01325×10-15mD."

"The secondary permeability is 1.78314×12-15mD."

"."

"DPA of 18.3 for a single penetration of carbon atoms."

"The DPA of the secondary penetrating carbon atom is 32.1."

"This is impossible!"

Seeing the final DPA injury result, the middle-aged team leader blurted out instantly, his face full of disbelief.

The data on this set of materials is really shocking.

How is it possible that the DPA damage of carbon atoms once infiltrated is only 18.3?

Even with the most advanced ion implantation in the windmill country, the carbon atom damage in the silicon carbide crystal material will reach more than three digits.

More importantly, the secondary penetration of this method has only low double-digit DPA damage.

Such a low penetration damage rate, if applied to the manufacture of chips.

The middle-aged team leader of the laboratory no longer dared to think about it anymore.

Just like in a certain laboratory in the capital of Huaguo, such scenes are repeated all over the world.

In the simulated space, the afternoon passed quickly.

After a full six osmosis treatments, the sun went down too.

But today's live broadcast can't stop until now.

The silicon carbide crystal material after the infiltration treatment needs to be further processed to stabilize the newly implanted aluminum ions and form a usable N-drift layer.

As for the method of stabilization, it is an annealing treatment by high temperature.

After the cleaned silicon carbide crystal material was blown dry, it was placed neatly upside down in a dry glass container, and Won took out a transparent plastic bag from the materials on the side.

Inside was fine black powder, and there was a paper label on it that said 'toner'.

Open the bag, take out the toner inside and put it into the groove filled with aluminum ions, covering the whole groove.

Thirty silicon carbide crystals were all processed and loaded into metal trays, and then sent into a high-temperature furnace.

The temperature in the furnace is controlled between [-] and [-] degrees.

This step is very important. By adding carbon powder at high temperature to form a protective film on the N+ drift layer of the silicon carbide crystal, it can stably and effectively control the loss of electrons in the N- drift layer.

The process of high temperature annealing is about three hours.

From the time the sun went down until the moon came up, Han Yuan took out the silicon carbide crystals from the furnace and cleaned off the excess toner after cooling.

After the treatment, the N-drift layer of the silicon carbide crystal is cleaned by concentrated sulfuric acid to remove the stubborn carbon residue.

After this step was completed, Han Yuan heaved a sigh of relief.

He has already prepared the most difficult N-drift layer in silicon carbide transistors.

The rest can be dealt with tomorrow.

After saying hello to the audience in the live broadcast room, he stopped the live broadcast.

After the N-drift layer is processed, the remaining work is relatively simple.

Of course, this is only for the silicon carbide transistors he made.

If it is a modern integrated chip, a series of steps such as P well, P+ contact area, N+ contact point, and P- area need to be implanted later.

Trouble is not limited to 01:30.

(End of this chapter)