bookrandom Chapter 724 Come on, show us! Far ahead!
Chapter 724 Come on, show us! Far ahead!
Traditional contact lithography machines have always had only one silicon wafer stage. The alignment and pressing of the mask depends entirely on steady hand movements. The saying "a slight error means a wasted wafer" is a true reflection of the cruelty of this precision operation.
When Jiangxia was being designed, there was no "ghost hand" master like Master Weng to volunteer.
In order to overcome the precision bottleneck of contact lithography, Jiangxia came up with a clever dual-platform design!
One is a silicon wafer stage, used to support and hold silicon wafers coated with photoresist. It's specifically designed to carry photoresist-coated silicon wafers. The requirements are incredibly demanding; it needs to be able to perform nanometer-level drift in the X, Y, and Z directions while maintaining absolute horizontal alignment!
To achieve this, the Mirror Immortal put in a lot of effort, almost rubbing his hair down to the bone.
To achieve the desired effect, Jiang Xia originally planned to install four micrometer screw heads at the four corners of the platform. This would allow the operator to adjust the mask at the micrometer level by rotating these four fine-tuning knobs, just like adjusting a machine tool fixture, to counteract its own deformation or installation errors.
If the precision isn't enough, we'll make up for it manually!
The other is the photomask stage, used to hold and fix the photomask. This is quite impressive; it allows for precise fine-tuning in the X, Y, and θ directions, and also features precise lifting and pressure control in the Z direction!
Similarly, to achieve these functions, Jiangxia designed a mechanism with a precision lead screw and heavy-duty spring buffer. The operator performs coarse lifting and lowering using a large handwheel with a vernier scale, and switches to a fine-tuning handwheel connected to a high-precision dial indicator when approaching the mask! By observing the dial indicator's pointer reading, the distance the silicon wafer rises can be controlled with extreme precision.
Meanwhile, a set of calibrated pressure spring plates are installed below the platform. When the silicon wafer comes into contact with the mask, the tiny deformation of the spring plates is amplified by a lever mechanism and displayed on another dial to show the magnitude of the contact pressure!
The operator manually adjusts the pressure to a preset safety value based on the dial reading and a dial indicator. A thermocouple is also embedded inside the lower platform, connected to an old-fashioned pointer-type thermometer for monitoring the silicon wafer temperature.
Finally, with the addition of a high-magnification binocular microscope system, the prototype of the lithography machine was born!
Impressive, right?
This is not finished!
Little Ao Mao's ultimate dream is—fully automated photolithography!
Let the two platforms align and press together on their own, like a duet, completely replacing manual labor!
What do you rely on?
With precision servo motors as muscles, grating rulers as eyes providing real-time position feedback, and a control algorithm (PID, etc.) for the "Big Yellow Clone Runner" feature, it achieves closed-loop control—perfect!
but……
Yes, that's true, but there's always a "but".
The ideal is beautiful, but the reality is harsh!
Even when Little Da Mao was making empty promises, he knew that this kind of thing was just a pipe dream nowadays!
A qualified ultra-precision servo motor? No!
A high-resolution grating ruler feedback system? Absolutely not!
The complex collaborative control algorithm that allows "Big Yellow's clone" to run smoothly? Well, I guess that exists...
Although the "chubby kid" in the mental hospital, who had maxed out his programming skills, actually managed to write the program, "Big Yellow" (the program's name) lagged like a PowerPoint presentation when it ran!
God knows if it's right or wrong!
If it weren't for Master Weng's appearance, the researchers at the Academy of Sciences might still be struggling with servo systems composed of encoders and drives, hoping that they could achieve a closed-loop control process of "command-feedback-correction".
Because the series of compensation measures that Jiangxia designed to meet the parameter requirements for the two platforms are really too difficult to implement in practice!
Four micrometer screws + dial indicator + pressure gauge + microscope... Is this even humanly possible? One slip of the hand and the silicon wafer is ruined! The mental stress is comparable to defusing a bomb!
In the early stages of debugging the two tablets, the Academy of Sciences began to organize people to try operating the device. If one person can't do it, can two people do it?
The answer is of course no!
The final conclusion is: only a legendary level 10 worker with eight arms can operate it smoothly. Hands, eyes, brain, and resilience are all indispensable! A slight mistake, and the whole operation is lost!
Are there level 10 workers?
I already said it's legendary, how could it possibly exist... although in later generations, there really was such a title for professional and technical positions in public institutions.
The plan cannot be changed. Because this plan came from that guy who made empty promises and then ran away. Although that guy was a bit careless and didn't consider the bigger picture, the big shots reviewed it over and over and found that this was actually the most reliable one at the moment.
Fortunately, Jiangxia, who was incredibly lucky, managed to pull Master Weng out from among the labor camp inmates.
Only he could make Jiangxia's theoretically feasible but practically absurd transition plan work in a truly innovative way! He could turn "possibility" into "certainty"!
……
Watching Master Weng move his hands and feet in front of the lithography machine, some people couldn't keep their mouths shut.
"Hey, we're rushing things. We should train him on the basic operation of leveling the platform..." someone nearby worried.
"Did you explain the photoresist application technique to Master Weng? Engineer Jiang initially said to use spin coating, but later changed it to scraping..." another voice interjected.
Someone immediately responded: "I already said it! Engineer Jiang somehow managed to get someone to develop a pipette that can guarantee the consistency of the volume of each drop of liquid..."
Dr. Lan Ying stared intently at Master Weng's hands, while the researchers whispered anxiously and concernedly in her ears.
Actually, these operational details and precautions had already been explained to Master Weng repeatedly. His current nagging was simply a case of being overly concerned.
Shh! Look! Master Weng is moving!
All discussion came to an abrupt halt.
Instead of making simultaneous fine adjustments to both platforms as they had done before, Master Weng simply reached out and deftly pressed the "lock" button on the control panel of the mask platform!
The red lock indicator light is on.
"He...he locked the mask stage?" Xiao Guan's eyes widened in disbelief. "He only adjusted the wafer stage!"
"This...this violates the operating procedures?" someone frowned.
"The operating procedure was just a draft written by that kid; he never actually used it. Ultimately, it's a machine that's operated by a person!"
Dr. Lan Ying said in a deep voice, "Since our chief designer has chosen to trust Master Weng, then we shouldn't interfere with him!"
In fact, Dr. Lan Ying's heart was in her throat as she stared intently at Master Weng's hands, which had been praised by the project's chief engineer.
However, from the observation room, Master Weng looked like a pine tree, standing in front of the machine without moving an inch.
But, out of their sight, Master Weng's hands were operating the controller of the silicon wafer stage with extreme precision. The movements were so small that they were almost invisible, with only a few micrometer-level readings silently fluctuating on the control panel.
He didn't check the pressure gauge or frequently switch the dial indicator; all his attention seemed to be focused on the extremely subtle feedback of the silicon wafer stage itself.
The entire laboratory was so quiet you could hear a pin drop, with only the low rumble of the high-pressure mercury lamp ballast and the suppressed breathing of the people inside.
A moment later! Master Weng removed his hands from the stage, looked at the temperature display of the silicon wafer, raised his right hand, and said something into the microphone next to him.
Then, a slightly hoarse voice came from the external observation room: "The silicon wafer temperature has reached the set requirement! Request to proceed to the next step according to the procedure!"
"So fast!" Dr. Lan Ying looked at her comrades behind her in astonishment, subconsciously clenching her fists. The words she had just whispered seemed to echo in her ears: "Since we have chosen to believe... let's wait for the results."
"Agreed! Please proceed to the next step once the requirements are met!"
Open the bow without turning back the arrow!
Master Weng lightly tapped an inconspicuous button with his finger.
Om-!
At the top of the lithography machine, the high-pressure mercury lamp, representing "execution," suddenly burst forth with a blinding light! The light, like a fleeting flash of lightning, illuminated the entire laboratory in a ghastly white light before instantly plunging back into darkness, leaving only a lingering spot of light in the visual field.
The distinctive "smell" of a mercury lamp, carrying a hint of ultraviolet light, briefly filled the air.
Master Weng narrowed his eyes behind his sunglasses and sniffed: This smell... it smells like the printer that Xiao Jiang used to use.
Xiao Jiang is really amazing! He can design anything! It's just that his craftsmanship is a bit rough...
But the thought of having to memorize those printed documents is unbearable.
Master Weng's originally serious face fell down.
Development complete!
Dr. Lan Ying noticed that Master Weng's expression was off, and her heart skipped a beat. "Oh no!"