Chapter 103

Gu Lu's brows furrowed slightly.

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

According to Master Huang, the silicon wafer they obtained after polishing through this equipment has the highest accuracy of 1.06 nanometers.

The difference between the two is tenfold.

This data is not right, it is very wrong!

There must be something wrong with the link.

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

But the disciplines are interrelated.

When Gu Lu studied 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 quite a lot of professional books and literature on the entire production process of silicon wafers.

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

It's just that the situation in front of him really made Gu Lu a little puzzled.

Or, there is a problem with the equipment itself, and the batch of equipment imported by Haiyue Company from the United States is a fake!

But this is unlikely.

Or, in the process of operation, where did the link go wrong.

In a book, Gu Lu saw the structural drawings of the Buehler Phoenix Bets polisher.

Gu Lu compared the equipment in front of him with the structure described on the drawings in his memory, and found that it was completely consistent.

That shouldn't be buying a fake.

Gu Lu got up, patted the dust on his hands, and said with a smile to Master Huang, "Master Huang, actually operate the machine, I'll see the effect." ”

Master Huang nodded, and returned a few minutes later with an unpolished silicon wafer.

Master Huang came back with a few young employees in overalls.

With a curious gaze, he looked at Gu Lu, who was standing tall beside Manager Zhang.

"Master Huang, let's get started. Under the gaze of several people, Gu Lu was calm and calm, and his eyes looked at Master Huang.

The operation of the polishing machine is simple.

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

Press the red button to start the machine.

The polisher starts working.

Gu Lu surrounded the polishing machine and observed in all directions.

Everyone around them held their breath and waited quietly.

As a result, in this area, in addition to the sound of machines turning, only the sound of Gu Lu pacing on the ground remained.

Time is ticking by.

The polishing time of this new type of polishing machine is 30 minutes.

"It shouldn't be!" Gu Lu touched his chin and muttered.

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

Although the position of the silicon wafer placed by Master Huang leads to an increase in the cutting depth during the polishing process to a certain extent, it is not enough, and the accuracy will increase tenfold compared to the expected value.

Gu Lu looked at the working process of the machine and did not find anything abnormal.

It stands to reason that a tenfold difference in accuracy is impossible.

Is it going to overturn today?

Towards the end of the polishing time, Gu Lu glanced behind Master Huang, and then locked his gaze tightly on the blue plastic liquid bottle.

That's right, polishing slurry!

A flash of inspiration flashed in Gu Lu's mind, and he instantly understood the crux of the problem.

In the polishing process, in addition to the polishing machine and the object to be polished, the polishing slurry used to assist in polishing can also greatly affect the accuracy of the object to be polished.

Often, the most suitable polishing slurry is different for different types of polishing machines and different objects to be polished.

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

"Uh......" Master Huang was stunned for a moment and replied casually, "The nano aluminum oxide powder polishing slurry we are using now." ”

Manager Lin looked at Gu Lu with a nervous expression, "Mr. Gu, is there any problem?"

There is a problem, a big problem!

Nano aluminium oxide powder is used as an abrasive and added to the Buehler Phoenix Bets polishing machine to carry out precision polishing of single silicon wafers, which is itself an extremely unwise move.

Because aluminum oxide is too hard!

Even nanometer aluminum oxide powder does not reduce its hardness. During the polishing process, damage to the silicon wafer is sure.

On the other hand, according to the Preston 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 already knew why the polished silicon wafers with the new equipment had not been up to the mark in terms of accuracy, he thought.

"The polishing fluid was used incorrectly. Gu Lu glanced at Manager Zhang with a flat look in his eyes and said.

"Isn't it using aluminum oxide powder polishing liquid, I have always used 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, of course it is no problem to use nano aluminum oxide powder, because the preparation is simple and the cost is low, but for high-precision polishing machines, this kind of high-hardness polishing abrasive is obviously not applicable." ”

"Then Mr. Gu, which kind of nano abrasives should we use?" asked Manager Zhang.

"Cerium dioxide. Gu Lu, please spit out four words.

"Cerium dioxide?" Manager Zhang frowned.

"You don't have this kind of polishing liquid?" Gu Lu asked.

"Uh...... No. Manager Lin replied honestly.

To be honest, this kind of polishing slurry is not common in China.

"Then did you buy this bottle of aluminum oxide polishing liquid from outside, or did you prepare it yourself?" Gu Lu then asked.

Manager Lin spoke, "We do it ourselves, we have a special production line. ”

In addition to selling some semiconductor materials, polishing slurry is also one of their products, but the volume is not large.

Except for some self-produced and self-sold, not much enters the market.

Gu Lu was not surprised.

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

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

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

Gu Lu shrugged his shoulders and said in a relaxed tone, "There's no need to make such a fuss, this thing has no technical content, as long as the materials are available, people with a little chemical knowledge will get it." ”

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

"Then ...... over here," Manager Lin hesitated as he pointed to the equipment that was about to end the polishing process.

"Don't look any further, the result will be the same as what you got before. There's no need to waste time. ”

"Okay, then Mr. Gu, please here. ”

The polishing slurry production line is located on the top floor of the factory's small five-storey building.

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

Gu Lu came to the experimental table, glanced at the pile of chemical reagents on the table, and then glanced at the general equipment in the entire room, and smiled faintly.

"Luckily, the materials and equipment for preparing cerium dioxide are basically available, and then just leave it to me. ”

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