This was no longer the experimental cleanroom of the Stringlight Research Institute, but the main plant area of China's largest chip manufacturer—"Huaxin International"—located at the edge of the vast desert. Extreme dryness and geographical distance from seismic sources provided natural advantages for chip manufacturing. Xiuxiu stood on the observation corridor above the grand main passage of the Fab (wafer fab), gazing through thick specialty glass at the fully automated chip mass production line below, which was about to receive its soul from "Stringlight One."
The air here flowed slowly downward in meticulously calculated laminar fashion; constant temperature and humidity were strictly confined within fluctuations of mere thousandths of degrees, cleaner than an operating room by thousands, tens of thousands of times. There was no clamor, only a nearly sacred silence, accentuated by the low operating sounds of automated equipment and the faint airflow stirred by robotic arms moving with precision in the distance.
Today was the day when the first mass-produced High NA EUV lithography machine "Stringlight One" officially entered the customer's production line and underwent its first full-process production ignition. It was no longer merely an exhibit proving its capabilities in the laboratory, but a heart about to integrate into this massive industrial organism, beginning to pump computational power blood day and night for the market.
Behind Xiuxiu stood Huaxin International's chairman, general manager, technical director, and her own core team members. Everyone's gaze was focused on the production line below; the atmosphere was so tense it could be wrung out like water. She took a deep breath; the air, filtered through countless layers and carrying the unique scent of chemical cleaning agents, slightly calmed her turbulent emotions. A decade-long technological Long March, countless sleepless nights, near-collapse despair and ecstatic relief from the brink—all ultimately converged upon today, upon "Stringlight One" standing quietly below in the lithography area, massive and complex.
"Dr. Xiu, all silicon wafers from pre-process stations are ready, wafer carriers fully calibrated, environmental parameters stable within specification range." The calm voice of the site commander reached her ear through bone conduction headphones, crystal clear.
"Acknowledged." Xiuxiu's voice was calm, but only she knew her fingers gripping the railing were slightly white from exertion. Her gaze swept over the fully automated production line that "Stringlight One" was about to integrate into—a silent industrial epic, the ultimate embodiment of human wisdom and manufacturing craftsmanship.
The starting point of the production line was the **wafer input station**. Raw silicon ingots, polished to mirror-like surfaces like black vinyl records, were sliced by precision cutting equipment handling them like precious diamonds into thin slices of standard size—wafers. These wafers underwent rigorous cleaning and inspection, then were loaded into standard Front Opening Unified Pods (FOUP)—enclosed, self-contained microenvironment purple or black boxes, like exclusive "space capsules" protecting them from contamination throughout the entire manufacturing process.
Next, the wafers began their long journey through the maze-like production line. They were precisely grasped and lifted by automated overhead hoist transport (OHT) systems, silently gliding at astonishing speeds along the overhead track network, like spirits guided by invisible hands, accurately delivered to the next processing station.
Before entering "Stringlight One," wafers needed to undergo a series of pre-processing steps. First were **oxidation furnace tubes**; silicon wafers reacted with oxygen or water vapor at high temperatures, growing a thin, dense silicon dioxide insulating layer on their surfaces. This oxide layer would be the foundation for subsequent transistor construction. Next were **chemical vapor deposition (CVD)** equipment; by introducing specific reactive gases, various functional thin films were deposited on wafer surfaces, such as polysilicon gates, silicon nitride etch-stop layers, and barrier layers for metal interconnects. There was also **physical vapor deposition (PVD)**, depositing conductive layers through sputtering in vacuum environments for subsequent metal interconnects.
Each step was followed by **chemical mechanical polishing (CMP)**. This was the key process for achieving nanometer-level planarization. Through combined chemical corrosion and mechanical grinding, uneven thin films on wafer surfaces were flattened, like preparing an absolutely flat canvas for subsequent "micro-carving." Cleaning after CMP was crucial; any residual abrasive particles could become fatal defects.
These pre-processes, like laying foundations and constructing frameworks for a grand building, made complete preparations for the final **lithography** step performed in "Stringlight One"—defining transistor and circuit patterns.
"FOUP 001, arrived at lithography area buffer zone." The system alert sounded again.
Xiuxiu's heart seemed to skip a beat. She knew the FOUP carrying the first batch of official production wafers had arrived at "Stringlight One's" entrance. Next would be the decisive steps.
Through monitoring screens, she saw "Stringlight One's" interface unit slowly open, like a giant beast opening its mouth. Robotic arms gently yet precisely extended into the FOUP, extracting a 300mm diameter silicon wafer. The wafer was vacuum-adsorbed and secured on a special chuck, then sent into the lithography machine's interior.
The internal process, Xiuxiu could recreate in her mind with eyes closed. First was dispensing **photoresist** on the rapidly spinning wafer—a photosensitive polymer sensitive to EUV light. Centrifugal force spread it uniformly, forming a film only tens of nanometers thick, requiring extremely high uniformity. This resist layer was the "photosensitive plate" awaiting carving.
Next, the wafer was sent into the **alignment system**. Using infrared or visible light, by recognizing **alignment marks** pre-etched on the wafer, nanoscale precise positioning was performed between patterns needing exposure in the current layer and already-formed patterns in lower layers—this was **overlay accuracy**, key to whether multilayer circuits could stack correctly. Any minute deviation could cause entire chip functional failure.
Alignment completed, the wafer was moved into the **exposure chamber**—the lithography machine's core battleground. Here, vacuum environment had long been established. The **reflective mask** bearing circuit design information (unlike DUV's transmissive type, EUV masks themselves were also complex multilayer reflective structures) was already in position.
"Light source activated, power stabilized at 285 watts." The report came.
Xiuxiu could almost "see" the microscopic miracle occurring deep within the vacuum chamber: high-power carbon dioxide lasers precisely bombarding tin droplets, generating high-temperature plasma, radiating 13.5nm extreme ultraviolet light. These photons, arduously collected by collector mirrors (each reflection losing nearly thirty percent energy), passed through the illumination system, illuminating the mask. The mask's patterns, via reflection, carrying circuit information, passed through the **projection objective system** composed of over a dozen aspheric mirrors, with accuracy reaching picometer levels, finally projecting the reduced image precisely onto the photoresist-coated wafer surface.
The exposure process was not completed in one go, but followed the **step-and-scan** pattern. The wafer stage carried the wafer in high-speed uniform linear motion beneath the projection objective, while the mask stage performed synchronized movement in the opposite direction, ensuring the entire chip area was scanned and exposed stripe by stripe. This motion had to achieve extreme smoothness; any micro-vibration could cause pattern blurring.
Exposure completed, the wafer entered the **development station**. Here, a specific developer solution was sprayed onto the exposed photoresist. The developer reacted chemically with resist that had been exposed to EUV light (undergoing "acid-catalyzed chemical amplification"), dissolving it away, revealing the circuit patterns "carved" onto the resist layer. Unexposed resist remained, forming protective film for subsequent etching processes.
After development, the wafer underwent **inspection**. Automated optical or electron microscopy scanned the wafer surface, identifying and classifying potential defects: missing patterns, bridging, foreign particles, edge roughness... Any serious defect could render the chip partially or completely failed. Only wafers passing this inspection could proceed to the next stages—**etching**, **ion implantation**, **metallization**—layer upon layer building the microscopic electronic city.
Yet today, at this moment, Xiuxiu's focus wasn't on those subsequent complex processes. Her entire being was concentrated on the exposure process currently underway within "Stringlight One."
Exposure time: precisely 72 seconds per wafer.
These 72 seconds, condensed with humanity's decades of accumulated wisdom in physics, materials, optics, mechanics, control, and software, encapsulated countless trials and errors, failures and breakthroughs, despair and hope, by generations of scientists and engineers.
These 72 seconds, also carried the heavy expectations of a nation's technological independence and industrial security.
Xiuxiu's gaze didn't leave the monitoring screen for a moment. Every subtle data fluctuation—light source power stability, wafer stage motion error, overlay error feedback, chamber vacuum level... each data point was like the pulse of this giant machine, conveying its operational status.
Tension permeated the entire observation corridor. No one spoke; even breathing seemed deliberately controlled. The immense investment behind this production line—hundreds of millions in equipment, years of planning and construction, the efforts of thousands of workers and engineers—now hinged on the proper functioning of this machine's core.
Time ticked by second by second.
Xiuxiu's hands, placed behind her back, clenched tightly. Nails dug into palms, the slight pain helping maintain alertness. She repeated a silent mantra in her heart: "No anomalies, no anomalies..."
The scene before her eyes and the data flow reminded her of the countless test runs in the laboratory. The difference was—those were trials, while this was true battlefield.
Suddenly, a subtle fluctuation appeared on the light source power curve—a slight dip of about 2 watts, lasting less than 0.5 seconds, then recovering.
Xiuxiu's heart tightened instantly.
Her mind raced. What caused it? Tiny deviation in tin droplet generation? Transient fluctuation in laser energy? Or minor instability in plasma? This tiny fluctuation wouldn't cause fatal exposure quality issues, but...
Before she could think further, the system issued a warning: "Power fluctuation detected. Exposure quality monitoring activated."
Almost simultaneously, quality monitoring sensors installed within the exposure chamber began real-time analysis of the exposure stripe just completed, comparing it with standard values.
Xiuxiu's breathing unconsciously paused. Her entire team leaned closer to the monitoring screen.
Time seemed to stretch.
Five seconds passed.
The monitoring system's indicator light turned from yellow to green.
"Exposure quality within specification. Process continues."
A collective sigh of relief filled the observation corridor, though still restrained.
Xiuxiu closed her eyes briefly. The tiny fluctuation was just a minor hiccup, like a healthy person's momentary arrhythmia, quickly self-corrected.
Yet this incident made her deeply aware: The true test of industrialization was not how perfect the machine could be under ideal laboratory conditions, but how many such minor fluctuations it could endure in continuous operation, and how to handle them without human intervention, ensuring production continuity and quality stability.
After 72 seconds of exposure, development, and initial inspection, the first wafer completed all "Stringlight One" processes and was sent to the next station.
Data appeared on the screen: "First wafer complete. Overlay accuracy: 1.2nm (target: ≤1.5nm). Critical dimension uniformity: 0.8nm (target: ≤1.0nm). Defect density: 0.05/cm² (target: ≤0.1/cm²)."
The targets were all met, even exceeded.
Yet Xiuxiu knew this was just the beginning. This first wafer had received extreme attention; every parameter was monitored. The true challenge was after mass production started, when the machine needed to maintain such precision and stability day after day, month after month, year after year, amidst repeated start-stop cycles, routine maintenance, minor environmental changes...
Industrialization was a marathon requiring not just momentary peak performance, but enduring, unwavering long-term reliability.
Subsequent wafers continued being processed, one after another, smoothly entering "Stringlight One," being exposed, developed, inspected...
Time passed, batch after batch.
No further anomalies occurred. The machine's performance remained stable.
The tense atmosphere in the observation corridor gradually eased. Conversations started softly.
The customer's technical director turned to Xiuxiu, a smile finally appearing on his face: "Dr. Xiu, so far, everything is perfect. This machine's performance has exceeded our expectations."
Xiuxiu nodded gently. "The machine is performing its duty. But the real test is sustained operation."
"Yes," the director said sincerely, "But this start is more than perfect. You and your team should feel proud."
Proud?
Xiuxiu looked down at the machine below. At this moment, "Stringlight One" was processing a new wafer with calm, precise movements, like a master artist carving on the most exquisite canvas.
She didn't feel pride, but a more complex emotion—a mix of relief, gratitude, and an even heavier sense of responsibility.
Relief, because the hardest first step had been taken.
Gratitude, to the countless companions who fought alongside her, to Mozi who supported her without reservation, to Yue'er whose theoretical wisdom inspired her, and to every failed attempt and every successful breakthrough.
Responsibility, because this was only the beginning. The machine needed to operate stably for years; it needed to continue evolving to meet future higher demands; it needed to cultivate more technical talent; it needed to empower more innovative applications...
There was still a long, long road ahead.
Yet today, at this moment, watching those wafers being precisely "carved" by extreme ultraviolet light, becoming carriers of future computational power, she felt that every hardship, every sleepless night, every moment of despair—was all worth it.
The first ignition had succeeded. The heart had begun beating.
And she knew, this was not an end, but the beginning of a new chapter.
Outside the fab, the desert sun shone brightly, casting the massive building's silhouette long across the land.
Inside, the light continued.