Chapter 103

Gu Lu's brows furrowed slightly.

As far as he knows, the polishing accuracy of this new American Buehler Phoenix Bets polishing machine should be about 0.1 nanometers.

According to Master Huang, the silicon wafer they polished with this equipment has the highest precision of 1.06 nanometers.

The difference between the two is ten times.

This data is wrong, very wrong!

There must be something wrong somewhere.

Silicon wafers, to be precise, belong to the field of materials science.

But the various disciplines are interrelated.

When Gu Lu was studying semiconductor physics in physics, he not only studied the atomic and electronic states in silicon wafers and the internal electronic processes of each device, but also consulted a considerable number of professional books and documents on the entire production process of silicon wafers.

Otherwise, he would not have taken over this matter in front of Academician Guo.

However, the situation in front of him really made Gu Lu a little confused.

Or, there is something wrong with the equipment itself, and the equipment imported by Haiyue Company from the United States is fake!

But the chances are slim.

Or, there is something wrong somewhere in the operation process.

Gu Lu once saw the structural drawings of the Buehler Phoenix Bets polishing machine in a book.

Gu Lu compared the equipment in front of him with the structure described on the drawing in his memory, and found that they were completely consistent.

Then you probably didn’t buy a fake.

Gu Lu stood up, patted the dust on his hands, smiled at Master Huang and said, "Master Huang, let's actually operate the machine and let me see the effect."

Master Huang nodded and came back a few minutes later with an unpolished silicon wafer.

Following Master Huang back, there were several young employees wearing work clothes.

Curious eyes looked at Gu Lu, who stood tall and tall next to Manager Zhang.

"Master Huang, let's start." Under the gaze of several people, Gu Lu looked at Master Huang calmly.

The operation of the polishing machine is very simple.

Plug in the power, place the silicon wafer on the corresponding fixture, and finally add polishing fluid.

Press the red button to start the machine.

The polishing machine started working.

Gu Lu surrounded the polishing machine and observed it from all directions.

Everyone around them held their breath and waited quietly.

Ever since, in this area, apart from the sound of the machine turning, the only sound left was the sound of Gu Lu pacing on the ground.

Time passes little by little.

With this new type of polishing machine, the polishing time is thirty minutes.

"It shouldn't be!" Gu Lu muttered, touching his chin.

What happened in front of him really touched his blind spot of knowledge.

Although the position of the silicon wafer placed by Master Huang will, to a certain extent, lead to an increase in the cutting depth during the polishing process, it is not necessarily so. The accuracy will increase ten times compared to the expected value.

Gu Lu watched the entire working process of the machine and found nothing unusual.

Logically speaking, an accuracy difference of ten times is impossible.

Is there going to be a crash today?

When the polishing time was about to end, Gu Lu glanced behind Master Huang, and then his eyes were firmly locked on the blue plastic liquid bottle.

By the way, polish!

An idea flashed in Gu Lu's mind, and he instantly understood the crux of the problem.

During the polishing process, in addition to the polishing machine and the object being polished, the polishing fluid used to assist polishing can also greatly affect the accuracy of the object being polished.

Often, different models of polishing machines and different objects to be polished have different polishing fluids that are most suitable for use.

"What kind of polishing fluid are you using?" Gu Lu asked in a deep voice.

"Uh..." Master Huang was stunned for a moment and replied casually, "We are currently using nano-alumina powder polishing fluid."

Manager Lin looked at Gu Lu nervously, "Mr. Gu, do you have any questions?"

There's a problem, it's a big problem!

Using nano-alumina powder as an abrasive and adding it to a Buehler Phoenix Bets polishing machine to perform precision polishing of a single silicon wafer is an extremely unwise move in itself.

Because aluminum oxide is really too hard!

Even if it is nano-level aluminum oxide powder, the hardness will not be reduced. During the polishing process, it will definitely cause damage to the silicon wafer.

On the other hand, according to Preston's formula, MRR=ρwNV.

The higher the hardness of the polishing abrasive, the greater the corresponding cutting depth, and the weaker the plastic grinding effect.

He thought he already knew why the silicon wafers polished using the new equipment could no longer meet the requirements in terms of accuracy.

"I used the wrong polishing fluid." Gu Lu looked at Manager Zhang with a flat look and said.

"Don't you use aluminum oxide powder polishing liquid? I used to use this in a large state-owned factory." It was Master Huang who spoke.

Gu Lu smiled and explained, "For those silicon wafers with low precision, it is of course no problem to use nano-aluminum oxide powder, because the preparation is simple and the cost is low, but for high-precision polishing machines, such high-hardness polishing abrasives

, it is obviously not applicable.”

"Mr. Gu, which kind should we use as nano abrasive?" Manager Zhang asked.

"Ceria." Gu Lu asked him to spit out four words.

"Ceria?" Manager Zhang frowned.

"You don't have this kind of polishing fluid?" the consultant asked.

"Uh... no." Manager Lin answered honestly.

To be honest, this kind of polishing liquid is not common in the country.

"Then you bought this bottle of aluminum oxide polishing fluid from outside, or did you prepare it yourself?" Gu Lu asked next.

Manager Lin said, "We make it ourselves. We have a special production line."

Haiyue Company, in addition to selling some semiconductor materials, polishing fluid is also one of their products, but the volume is not large.

Except for some that are self-produced and sold, not much has entered the market.

Gu Lu was not surprised.

Polishing fluid is not complicated to produce, and it is very simple to set up a production line.

"Take me over there and see if I can make a cerium dioxide polishing solution." Gu Lu looked at Manager Zhang and spoke slowly.

Manager Zhang was stunned for a moment, "You... made it yourself?"

Gu Lu shrugged and said in a relaxed tone, "There is no need to be so fussy. This thing has no technical content. As long as the materials are available, anyone with a little knowledge of chemistry can do it."

"Let's go, take me to see it." Gu Lu raised his eyebrows.

"This way..." Manager Lin pointed to the equipment that was about to finish the polishing process and said hesitantly.

"There's no need to read any further. The result will definitely be the same as what you got before. There's no need to waste time."

"Okay, then Mr. Gu, please come this way."

The polishing fluid production line is placed on the top floor of the five-story building of the factory.

When you walk into the room, you can see two employees working busy inside.

Gu Lu came to the experimental table, glanced at the pile of chemical reagents filled with bottles and jars on the table, then glanced at the general equipment in the room, and smiled lightly.

"I'm lucky. The materials and equipment for preparing cerium dioxide are basically available. Next, just leave it to me."
Chapter completed!