Chapter 276: Decided, Hand-Crafting an Integrated Circuit

Five chapters delivered today!

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"Small Scale Integrated Circuit, SSI," Li Mingyuan answered without lifting his head, his pencil moving rapidly across the paper. "If we use architecture as an analogy, Large Scale Integrated Circuit is a skyscraper, then this is a bungalow—simple in structure, easy to manufacture, but it can satisfy our current basic needs."

Lao Liu tried hard to identify the symbols and lines on the blueprint, but to him, these were a language from an entirely different world. "Are these all... circuits? They look like a maze."

"In a way, they really are like a maze," Li Mingyuan laughed. "Electrons flow through these lines to achieve specific functions. We will start with simple logic gate circuits, then move on to basic computing units, and the ultimate goal is to manufacture a 'Chip' that can truly perform mathematical operations."

Lao Liu scratched his head and said candidly, "I've worked in the factory for thirty years, but I still can't understand these things."

Li Mingyuan looked at the dense, crowded blueprints on the table, and a bold idea popped into his mind.

"Lao Liu, the Lithography Machine still needs at least quite a bit of time for debugging, but I can't wait." He suddenly pushed his chair back and stood up, his eyes flashing with a near-manic light.

"What do you mean?" Lao Liu was startled by his sudden movement. "If we don't wait for the Lithography Machine, then how do we make a Chip?"

Li Mingyuan grabbed the blueprints and strode toward the door: "Follow me, I have a crazy idea."

……

At three in the morning, the laboratory was brightly lit.

Li Mingyuan paced around a makeshift workbench, which was covered with all sorts of strange equipment—magnifying glasses, microscopes, ultraviolet lamps, a homemade robotic arm, and a pile of chemical reagents.

"Chief Engineer Li, what are you doing?" Laboratory Director Yang Laotou's eyes were wide open as he watched Li Mingyuan fiddling with those seemingly unrelated items on the table.

"Making an Integrated Circuit." Li Mingyuan answered briefly without looking up.

"Didn't you say we had to wait for the Lithography Machine?"

"I can't wait anymore." Li Mingyuan raised his head, his eyes bloodshot. "We must prove the concept is feasible; otherwise, everything that follows is just a castle in the air."

He summoned a dozen Technical Backbone members, stood before the workbench, and scanned everyone with a serious expression: "Today, we are going to do something unprecedented—we will hand-craft an Integrated Circuit without a Lithography Machine."

There was Silence in the laboratory, followed immediately by an outburst of whispering.

"By hand? Is that possible?"

"How wide are the circuit lines? Can the naked eye even see them?"

"Isn't this just wishful thinking?"

Li Mingyuan clapped his hands: "Quiet! I know this sounds like a fantasy, but it is not entirely impossible. The Lithography Machine is just a tool; its essence is using light to draw precise patterns on a silicon wafer. We can achieve this using homemade Photoresist, ultraviolet lamps, and precision mechanical methods."

Lao Liu raised his hand hesitantly: "But, how do we guarantee the precision?"

"It certainly won't compare to a professional Lithography Machine," Li Mingyuan said truthfully, "but we don't need the most advanced Chip; we only need to prove this path is feasible. I have designed a minimalist version of a logic circuit with the line width relaxed to 50 microns, which is theoretically possible."

"50 microns?" The electronics expert Xiao Wang scratched his head. "A human hair is 70 microns thick; how can we possibly draw lines thinner than a hair by hand?"

Li Mingyuan picked up a glass slide coated with black paint: "This is our photomask. I used a microscope and a precision robotic arm to engrave the circuit pattern onto it. Light passes through these patterns and shines onto the silicon wafer coated with Photoresist, which can form the pattern we want."

He picked up a small bottle: "This is the Photoresist I prepared—the main ingredient is cinnamate, which is sensitive to ultraviolet light. The parts exposed to light will undergo a chemical change, and then we use a developer to wash away the changed parts, and we can obtain the precise pattern."

Everyone looked at each other; although most were half-skeptical, Li Mingyuan's confidence and detailed explanation still gave them a glimmer of hope.

"Let's start!" Li Mingyuan rolled up his sleeves and took charge himself.

For the next seventy-two hours, the laboratory became a city that never slept.

Li Mingyuan took the lead, personally operating the most precise steps. His hands trembled slightly from continuous work, but his gaze was terrifyingly focused, like a surgeon performing a life-or-death operation.

They first cut high-purity silicon wafers into small squares, polished them to a mirror finish, and then coated them with a uniform layer of Photoresist. Li Mingyuan personally operated the ultraviolet lamp, irradiating the silicon wafer through the homemade photomask, precisely controlling the exposure time for every second.

"Develop!" Li Mingyuan carefully immersed the exposed silicon wafer into the developer, gently shaking it with tweezers, and the parts irradiated by the ultraviolet light gradually appeared.

"Etch!" A mixture of nitric acid and hydrofluoric acid began to corrode the silicon surface not protected by the Photoresist, forming tiny grooves.

Li Mingyuan's fingers were bleached white by the chemicals, and the edges of his fingernails were a sickly yellow. Lao Liu tried to persuade him to rest several times, but he waved him off each time.

"Lao Liu, I didn't come through time to enjoy myself. Every minute now could determine the future fate of Long Country." Li Mingyuan said in a low voice, his tone carrying a weight Lao Liu had never heard before.

"What did you say? Come through time?" Lao Liu asked suspiciously.

Li Mingyuan smiled and laughed it off: "I mean, once we pass through this technical bottleneck, Long Country will have hope."

The first attempt failed—the etching was uneven, and the lines were broken.

The second attempt failed—the exposure was excessive, and the pattern was blurred.

The third attempt failed—the development time was not controlled properly, and part of the pattern was washed away.

But Li Mingyuan constantly summarized his experience, adjusted the process parameters, and recorded every tiny change.

"Again!" His voice was hoarse, his eyes bloodshot. "0.5 seconds more precise, and dilute the Photoresist by another 3%."

At dawn on the fourth day, when most people were exhausted and could only rely on coffee and willpower to keep going, Li Mingyuan carefully removed the fourth silicon wafer from the etching solution.

He rinsed it repeatedly with pure water and then placed it under a microscope for careful inspection.

"Success!" He straightened up abruptly, his voice trembling with excitement. "The circuit pattern transferred perfectly! The line width is controlled within 60 microns!"

Everyone crowded around, vying to look through the microscope.

It was a silicon wafer less than the size of a palm, its surface covered with tiny lines and squares, forming a complex and precise geometric pattern. The details were almost invisible to the naked eye, but under the microscope, every line and every connection point was clearly visible.

"Next, there are still steps like doping, oxidation, and metallization," Li Mingyuan rubbed his sore eyes. "Let's stop here for today; everyone rest for four hours, then continue."

No one left.