In the chip manufacturing workshop of the radio factory, 30 engineers from the Nanyuan Electronics Factory are still working hard to learn the skills of the lithography machine with Liu Gong.

Maybe when you look at the steps of using the lithography machine, you will think that it is very simple, nothing more than gluing, exposure, processing, and finally etching, what is so difficult about this? But when Liu Gong explained to them step by step, they understood how deep the doorway was.

Take the first step of gluing, which literally means to coat a layer of photoresist on the silicon wafer, because photolithography is actually the engraving of these photoresists, not silicon wafers.

These photoresists are dissolved and removed by specific wavelengths of light, and then soaked in specific chemical solvents to finally obtain the silicon wafer you want, and the photolithography is completed.

It sounds simple, but gumming is not about spreading the pancake fruit, and it doesn't allow you to take a small spatula to smooth out the photoresist, in fact, it won't be even at all.

Generally, it is completed by high-speed rotation using centrifugal force, although most of the photoresist will be thrown out and wasted during the period, but it can ensure the absolute uniformity of the photoresist.

"But even then you still can't guarantee that the photoresist will be applied well, because the colloid can easily accumulate around the silicon wafer and even flow to the back side under the action of centrifugal force, so in order to avoid this, we have to carry out continuous blowing while applying the photoresist, and finally we have to remove the edges."

Listening to Liu Gong's lectures, most engineers are very confused, they haven't studied so intensively for a long time, and their attention is a little unable to keep up.

In addition, they really didn't expect lithography to be so complicated, this is only the first step of gluing, and it has not yet started lithography, so it is so complicated?

Liu Gong can understand their state very well, after all, interlacing is like a mountain, especially the cutting-edge precision technology of chip manufacturing, if they can learn it once, it will be really against the sky.

At this time, a person raised his hand in confusion: "Liu Gong, I remember that you said before that coating photoresist is equivalent to putting a film on the silicon wafer, but now you say that you want to blow the wind, isn't this a contradiction?" Even if there is no dust in the clean room, it is still troublesome if there are bubbles inside, right? ”

When someone raised his hand to ask a question, Liu Gong was not only not annoyed, but was very happy, which showed that he really listened.

He looked over, and sure enough, it was their leader, Zhang Bensong.

"You're right, once a bubble is formed in the photoresist, it can cause a series of problems such as excessive etching, but you also need to blow the air, and the key to all of this is the rotational speed."

Liu Gong told Zhang Bensong that whether it is the spread and diffusion of the photoresist or the smoothing out, as well as the final blowing, it needs to be matched with the speed, Liu Gong wrote a few numbers on the blackboard: "This is my own summary of the matching figures, of course, this can only be used as a reference, you need to explore by yourself in the actual operation." ”

"In fact, at the end of the blowing, we need to bake the silicon wafer for the first time, and baking should also be used as an important step in gluing, because only baking can make the liquid photoresist completely adhere to the smooth silicon wafer, and also make the photoresist finalized, so as not to affect the next step of lithography."

"At the same time, more importantly, baking is also an important means of repair when the lithography is not in place......

Regardless of whether Zhang Bensong and the others understood their previous explanation, Liu Gong directly skipped the gluing and entered the baking step, which was not Liu Gong's going through the motions, but Zhang Bensong's request.

After all, half of the time has passed now, and if they all wait for them to understand and listen to the next step, they will not be able to fully master the lithography technology in the remaining half a month.

Therefore, Zhang Bensong found Liu Gong and asked him to talk to himself, as for whether he can listen to and master these things, it is his own ability.

That's what Liu Gong is doing now.

……

It wasn't until dark that Liu Gong gave Zhang Bensong and his party a complete set of professors for the gluing process.

I don't know if they can understand it, but they must write it all down, and then they have to go back to discuss and review, and strive to deepen their understanding, and if they have any questions that they don't understand, they will come back to ask themselves in class tomorrow.

After sending Zhang Bensong away and the engineers of Nanyuan Electronics Factory, the door of the workshop was knocked on again after a while.

"I'm not saying that you all go back and think about it yourself, and whatever the problem is, you will unify tomorrow...... How are you? ”

Liu Gong thought that someone had forgotten something, or that there was something wrong, but when he looked closely, it was actually the deputy director of the radio factory: "Lao Li, what wind blew you here?" ”

The deputy factory director surnamed Li looked at Liu Gong and stopped talking, and hesitated for a while before speaking: "Liu Gong, do you know what happened in the factory recently?" ”

Liu Gong fell into a long silence, and only nodded with a wry smile after a long time: "If Lao Li is referring to a new product, I think I probably heard the rumors." ”

"Liu Gong, you are the chief engineer of the radio factory, the development of this new product should be handed over to you, he actually promoted the surname He at will and started to do it, where does this put you, the chief engineer?"

Liu Gong waved his hand to stop Director Li: "After all, I am now teaching my brother unit, and I don't have time to develop new products." ”

"That's exactly what I'm trying to say." Director Li emphasized, "What do you do with these guys from Nanyuan Electronics Factory? I don't know if the factory director is very angry about this, is this what is done for you now? If you go on your own way, beware of your position as chief engineer! ”

"It's not that I have to go my own way, but the craft of lithography really needs to be passed on, if it is lost, then who will make chips in the future, will it all be imported abroad? What if when those foreign devils will not be sold, or will we be forced to sign some treaty that will lose power and humiliate the country? It's better to keep a little spark for this line. ”

"Zhang Bensong, these engineers, I can see that they all really want to learn, I will take them well, although the time is short, but as long as one can really learn, then even if I did not teach in vain."

As for themselves......

Liu Gong smiled freely: "I'm so old, I'm not the same as the factory director, and it's okay to retire early." ”

"Liu Gong, you are a person!" Director Li said with a little hatred that iron does not become steel.

At this time, the door of the workshop was pushed open again, and it was Zhang Bensong and his thirty engineers standing at the door.

"Liu Gong, Teacher Liu, please rest assured, we will not let you down, we will learn all the lithography skills, and we will not embarrass you!" Zhang Bensong said that the thirty of them collectively bowed to Liu Gong.

Chief Engineer Liu Zhenguo also smiled freely, and the last rays of the sunset outside the window sprinkled on his face, like a young man......