Morning light pierced through the misty vapor over the East Sea, casting golden rays onto the ultra-precision manufacturing park affiliated with the String Light Research Institute. At the center of the park, a massive cleanroom stood silently in the dawn, constructed entirely from microporous sound-absorbing materials and low-thermal-expansion composite building materials, like a silent giant. Here, the air cleanliness exceeded that of the highest-grade medical operating rooms by ten thousand times, temperature fluctuations were strictly controlled within ±0.01°C, and the foundation was completely decoupled from the building structure, isolating even the most minute tremors from the earth. Today, the doors of this cleanroom would open for the 'giant's child' nurtured within.
Inside the cleanroom, lights shone brightly, yet an unusual silence prevailed. Only the high-precision air circulation system emitted a near-inaudible hiss. In the central area, a colossal machine was shrouded under a transparent multi-layer polymer dust cover, its streamlined silver-gray shell reflecting a cold, sharp gleam. This was 'String Light No. 2,' one of humanity's closest approximations to the physical limits of industrial equipment--the first fully commercialized, mass-produced High NA EUV lithography machine.
Xiuxiu stood in the isolated observation corridor, gazing through thick specialized glass at the machine poised to change the world. She wore a light-blue cleanroom suit, her long hair meticulously tied up under a protective cap. Her face showed little expression, only a sharpness and calmness settled deep in her eyes from years of weathering storms. Her gaze, like the most precise sensor, slowly swept over every critical module of 'String Light No. 2.'
Finally, her eyes fixed on the most core and awe-inspiring component--the optical imaging system, particularly the signature **large-aperture lens assembly**. It was not a single lens in the traditional sense, but an incredibly complex composite imaging system comprising over twenty aspherical lens elements. Each lens was made of special high-purity glass-ceramic material, with internal impurity content controlled below one part per billion, and surface shape error required to be less than fifty picometers--equivalent to controlling the height fluctuation error across the entire map of China within the diameter of a single human hair. And now, to achieve higher numerical aperture, the largest lens in this assembly had reached unprecedented dimensions in both diameter and curvature. It hung silently on precise electromagnetic suspension mounts, like a profoundly deep **giant eye**, about to **gaze into the microscopic universe of silicon**, etching there the circuit patterns that would define the boundaries of future computational power.
'Numerical aperture, NA value...' Xiuxiu silently recited in her mind, one of the most core parameters in lithography. It was not merely a number, but the physical cornerstone determining lithography resolution. The formula NA = n * sin θ, deceptively simple yet imbued with profound physical meaning. n is the refractive index of the medium between the lens and the silicon wafer; in air n≈1, while in immersion lithography water (n≈1.44) was used to enhance NA. The revolutionary breakthrough of High NA technology lay precisely in drastically increasing sin θ, i.e., **enlarging the aperture angle θ**. This meant the lens needed to collect and converge more obliquely diffracted light, thereby transmitting finer circuit pattern information onto the silicon wafer.
The direct transformation this brought was disruptive. **Single-exposure resolution enhancement**. Recall previous technology nodes: to etch circuits finer than the light source wavelength, engineers had to rely on complex **multiple patterning** techniques. Like a painter unable to draw an extremely thin line in one stroke, they decomposed the pattern into several parts, drawing and overlaying them in multiple steps, ultimately combining them into the target graphic. This method vastly **increased the complexity, cost, and cycle time of the process flow**. Each additional patterning step came with risks of mask alignment errors, cumulative process variations, and defect rate accumulation--like dancing on a knife's edge, where **yield** improvements were painstakingly slow.
Yet High NA EUV, with its higher resolution, enabled many complex chip designs that previously required triple, quadruple, or even more patterning steps to be achieved with just **single exposure or significantly reduced exposure counts**. This was nothing short of a simplification storm. It **greatly simplified the process flow**, directly leading to shorter production cycles, significantly lower costs, and most crucially--**substantial improvement in chip yield**. Because fewer steps meant fewer opportunities for errors and defects, and greater controllability of the manufacturing process. For chip manufacturing, this was a critical leap toward higher performance, lower power consumption, and broader application scenarios. It meant that from smartphones to AI clusters, from autonomous driving cores to cloud data centers, the computational foundations supporting modern civilization would undergo a qualitative leap.
'Light source power stable, plasma density maintained above threshold.'
'Vacuum system operational standard achieved, residual gas analysis normal.'
'Dual-stage synchronization calibration completed, positioning accuracy meets specification.'
'Reticle transfer system ready, defect inspection system self-check passed.'
...
Calm, clear reporting voices from subsystem leads came through the internal comm channel. Behind every 'ready,' 'stable,' and 'meets spec' lay countless days and nights ofovercoming difficulties, Xiuxiu leading the team across the chasm between proof-of-concept prototype and commercial mass production--a gap seemingly short but actually fraught with thorns.
She recalled the polishing of that **large-aperture lens assembly**: collaborating with domestic top optical material factories and machining centers, iterating over a hundred grinding and polishing processes, developing AI-based online compensation ion beam figuring technology, only to finally control the mirror surface morphology to that breathtaking picometer level. Any minute residual stress, temperature gradient could induce nanometer-scale distortion in the lens, enough to make the converging extreme ultraviolet light deviate from target, scrapping an entire wafer.
She recalled optimizing **imaging contrast** under High NA. Higher NA also brought shallower **depth of focus**, imposing near-harsh demands on wafer surface flatness and photoresist thickness uniformity. They had to redesign chemical mechanical polishing (CMP) processes, develop new photoresist material systems more sensitive to EUV exposure with wider development windows.
She also remembered the battle to increase **throughput**. High NA meant more complex optical paths, finer control; how to boost wafer processing speed without sacrificing precision was another key to commercial success. The team pushedultimate optimization on laser pulse frequency, stage motion trajectories, data bandwidth, finally pushing 'String Light No. 2' throughput to levels meeting mass production demand.
These technical details, like countless hard foundation stones, built up today's tower named 'Pinnacle of High NA.' And she, Xiuxiu, was the core architect and supervisor of this tower.
'Chief Xiuxiu, the reception team from Global Chip Electronics has arrived at the external reception area. The handover ceremony begins in half an hour.' Her assistant's voice came through the headset, breaking her contemplation.
Xiuxiu gave a slight nod, taking one last look at the silent 'String Light No. 2.' It was about to be disassembled, packaged, transported by a specialized constant-temperature, constant-humidity, anti-vibration convoy to the world's largest chip foundry--'Global Chip Electronics'--where it would be installed, calibrated, and begin producing the world's most advanced 2-nanometer and below process chips.
The handover ceremony was held in the park's main auditorium. No dazzling light shows, no noisy song-and-dance performances; the venue was arranged simply yet solemnly. Executives from Global Chip Electronics, industry partners, government representatives, and top global tech media journalists packed the hall, the air thick with historic anticipation.
Xiuxiu, as head of the String Light Research Institute's lithography division and chief designer of the 'String Light No. 2' project, stood before the podium. She still wore that light-blue cleanroom suit, as if it were her most familiar and confident battle garb. Camera flashes burst likea dense burst of starlight, yet she seemed in another dimension, her gaze calmly sweeping the hall.
She had prepared no lengthy speech, only using a clear, steady tone to briefly review the team's journey from deciding to tackle High NA to today's mass-production delivery. She didn't overly dramatize the hardships, merely objectively stated several key technical nodes and breakthroughs. When the large screen behind her lit up with a close-up of 'String Light No. 2' signature **large-aperture lens assembly**, the audience erupted in suppressed gasps of awe.
'...High NA EUV is not merely about resolution enhancement; it represents chip manufacturing processes moving toward higher degrees of integration, determinism, and economic efficiency,' Xiuxiu's voice amplified through microphones filled the hall. 'It simplifies complexity, enhances reliability, paving a broader, smoother road for the entire electronic information industry's next decade. Today, the delivery of 'String Light No. 2' is not an endpoint...'
She paused, her gaze seeming to pass beyond the auditorium dome toward more distant horizons.
'It is but one step in our understanding of light, harnessing light, exploring the creative potential of the material world. The physical limits of silicon-based chips may be in sight, but **the possibilities of light are far from exhausted**.'
Her voice wasn't loud, yet carried an irrefutable force. The hall fell silent for a moment, then erupted in thunderous applause. They understood--this wasn't just a machine delivery, but the opening of an entirely new technological era, a declaration of limitless future possibilities.
During the subsequent ribbon-cutting and symbolic button-pressing ceremony, Xiuxiu's face maintained that faint, professional smile. When Global Chip Electronics' CEO excitedly grasped her hand, offering congratulations and thanks, she politely responded, yet her heart remained like deep ocean waters, unrippled.
No wild elation, no tears ofexcitement. What she felt was a **mission-accomplished** **calmness**.
Yes, mission. From the moment she resolutely returned from the Netherlands, determined to build China's own high-end lithography machine; from leading the team stumbling forward, conquering DUV, breaking through immersion, mastering EUV light sources, to today standing atop the pinnacle of High NA... this path had taken hera full decade. This decade, her life had completely merged with this endeavor. Every failure, every breakthrough along the way had long diluted and sedimented the joy of success, transforming into a deep-seated sense of responsibility and forward momentum.
Now, standing under the halo of the handover ceremony, she seemed merely an executor who had completed aphased mission. Task completed, delivered, and then... then what?
Her gaze involuntarily turned again toward the distance, past the bustling crowd, past the park boundaries, toward the direction of the String Light Research Institute main building, toward that vast landscape carrying Mozi's capitallayout, Yue'er's mathematical fantasies, and her own future blueprints.
High NA was a pinnacle, but not the absolute peak. In her heart, the contours of the next technological summit were already faintly emerging--that might involve exploration of even shorter-wavelength light sources, perhaps paradigmstranscend silicon-basedcarbon-based or even biomolecular computing, possiblyentirely new path pushing lithography precision toward quantum limits. **The instinctive gaze toward the next technological summit**, as natural as breathing, had long become part of her life.
After the ceremony concluded, amidst the crowd'ssurrounded by the crowd and media pursuit, Xiuxiu quietly withdrew. She declined all interview requests, returning alone to that office overlooking the entire ultra-precision manufacturing park.
The setting sun cast a warm golden hue over the park. The specialized convoy transporting 'String Light No. 2' was undergoing final checks before departure, like giant beasts poised forexpedition, steady and solemn.
Xiuxiu stood by the window, watching quietly. In her hand, she unconsciously rubbed a small, smooth-edged silicon test wafer sample. On it, etched by the earliest DUV lithography machine, were the team's logo and a motto--'**Those who chase light will eventually become one with light**.'
She didn't know what the next challenge would specifically be, but she knew it was certainly there, waiting for her and her team to once again ignite the flame of exploration, to once againharness that unyielding beam of light.
The pinnacle of High NA was merely away station on the journey. And light still lay ahead.