Tech Giants: Starting from Bankrupt Companies

168: Chapter 168 The ”Dawn” of PhotoresistJanuary 18th, 2:17 PM, Huizhou, Spark Materials Industrial Park.

This is one of the highest security areas within the xinghuo system—the Photoresist R&D Center. The exterior of the building looks ordinary, but the walls are 30-centimeter-thick concrete reinforced with lead plates, and the electromagnetic shielding level reaches military standards. Entry requires passing through three security checkpoints: fingerprint, iris, and DNA saliva testing.

Chen Wei stood in front of the observation window of the cleanroom, wearing a Class 10 cleanroom suit, with only her eyes exposed. At 38, she is the head of this project, a Ph.D. in Chemistry from the Chinese Academy of Sciences, and a student of the late Academician Zhang, a titan of semiconductor materials. At this moment, her eyes were fixed on the critical experiment taking place inside.

Inside the laboratory, the 37th batch of KrF photoresist was being coated onto a 300mm silicon wafer. The robotic arm’s movements were precise to the micron level, and the colloid spread out at a uniform speed, with the thickness controlled within the range of 200 nanometers ± 1 nanometer.

”Vacuum level stable.”

”Temperature 23.5°C, humidity 35%.”

”Coating complete, entering soft bake stage.”

The operator’s report came through the walkie-talkie. Chen Wei’s palms were sweating; she could feel the dampness even while wearing gloves.

This was the 37th attempt in two years. In the previous 36 attempts, some failed due to excessive metal impurities, some due to too many particles, and others because the line edges were rough after development... Every failure meant the burning of millions in R&D funds and another month of staying up late for the team.

Photoresist, this chemical that sounds ordinary, is the ”blood” of modern semiconductor manufacturing. Its performance directly determines the line width, yield, and reliability of the chip. The global market is monopolized by the Japanese ”Big Three”—JSR, Tokyo Ohka Kogyo (TOK), and Shin-Etsu Chemical—who hold over 85% of the market share. Chinese enterprises import over 2 billion USD worth of photoresist annually, but for the most advanced ArF and EUV grades, the Japanese say they won’t sell, and they cut off supply just like that.

”Soft bake complete, entering exposure.”

The silicon wafer was sent into the UV exposure machine. The KrF laser (wavelength 248 nanometers) passed through the photomask, carving the designed pattern onto the photoresist. This process is like photography, only the precision is at the nanometer level.

The exposed wafer entered the developer solution. Chen Wei held her breath.

Through the transparent window of the development tank, she could see the colloid slowly dissolving in the chemical liquid, with the unexposed parts remaining to form fine line patterns.

”Development complete, ready for inspection.”

The silicon wafer was taken out and sent to the adjacent inspection room. The lens of the Scanning Electron Microscope (SEM) slowly descended.

The display screen next to the observation window lit up. Zoom in, zoom in again.

1000x, 10000x, 100000x...

The lines appeared.

Straight, smooth-edged, uniform-width lines were neatly arranged on the surface of the silicon wafer. The measurement data was displayed in real-time next to it:

Line width: 16.2 nm

Line Edge Roughness (LER): 1.8 nm

Defect density: 0.08 / cm²

Critical Dimension Uniformity (CDU): ± 0.5 nm

Chen Wei’s breathing stopped.

These data... all reached or even exceeded the level of similar products from Japan’s JSR. Especially the defect density, 0.08 / cm², which meant less than 0.1 defects per square centimeter, a standard already for large-scale mass production.

”Dr. Chen...” the young engineer next to her said with a trembling voice, ”Did we... did we succeed?”

Chen Wei did not answer. She took off her goggles—this was a violation of cleanroom regulations, but she couldn’t care less at this moment—rubbed her eyes, and looked at the screen again.

The data hadn’t changed.

16.2 nm line width, 0.08 defect density.

She suddenly turned around, walked quickly out of the observation area, and arrived at the changing room next door. Taking off her cleanroom suit, she rushed to the sink, turned on the faucet, and splashed her face with cold water over and over again.

Water droplets slid down her cheeks; it was impossible to tell if it was tap water or tears.

Two years.