Mask (1)

The tenth floor of the JH Research building.

In a room furnished like a lecture hall, a man in a suit wrote something across the blackboard.

One instructor. One student.

The student was me.

I nodded along to the instructor's explanation.

"Dr. Han Woo-seok. So when you transfer a mask onto a silicon wafer, the pattern shrinks by means of lenses."

"Exactly. That is why the lens technology for manipulating light must be exceptional. Fail to master the lenses and you fail to master light; fail to master light and you cannot manufacture semiconductors at all."

A schematic of semiconductor architecture lay open on the desk, while the bold characters for Mask still remained on the whiteboard.

Dr. Han Woo-seok was both an employee of our company and my private tutor.

He came from a modest background yet possessed a brilliant mind. While studying semiconductor engineering at Hankook University he had spent years teaching academy classes in Daechi-dong to cover tuition and living expenses. I had scouted the hardworking student who managed to balance study and livelihood, and brought him in.

His sole duty was to teach me. He had not yet finished his degree, but claimed that writing the dissertation was all that remained and that he could manage it even while tutoring me.

"Representative. That concludes today's material on the mask."

For several months I had been learning semiconductors from Dr. Han Woo-seok. I had now more or less completed a full circuit of the eight major processes of semiconductor fabrication. It would have been absurd for the representative of a semiconductor research institute to remain ignorant of semiconductors. Moreover, semiconductor knowledge was foundational to the path I intended to walk.

"The more you study semiconductors, the more they resemble a high-rise apartment building."

A building had to raise its foundation first, then stack floor upon floor. Each story required careful consideration of doors, walls, plumbing and the rest before steel and concrete could be poured. Semiconductors were the same. Onto the foundational silicon wafer one stacked, story by story, transistors, electrodes and intricate electrical circuits. The stack had to reach at least a hundred layers; in the latest processes of five nanometers or below, some chips climbed as high as two hundred. A semiconductor was tens of billions of transistors wired into more than a hundred stories of circuitry. Each layer was deposited, etched, filled with copper, and etched again. When the next story was raised, it had to connect with the one beneath it according to an exact plan—and all of it at a scale almost too small to imagine.

Of the production sequence, today's lesson had been the mask.

"It's fascinating that making a semiconductor is so similar to printmaking."

"Without it, mass production would be impossible."

"I suppose so. Carving such tiny circuits one by one would never be easy. So the mask is like the printing plate that stamps out semiconductors?"

"In a sense, yes. How much does a mask cost?"

"For the latest processes, a full mask set runs into the hundreds of billions of won."

"Wow. Expensive."

"Yet with that set you can stamp out hundreds of millions of chips. Make it well and you more than recover the cost."

"Makes sense. Creating the mask itself is the core technology, then?"

"Yes. The hardest part is the design. Mask design technology can be called the pinnacle of semiconductor art."

"That's what places like Nvidia do, right?"

"Correct. Nvidia produces the ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠design blueprints for the mask. Those blueprints go to foundries such as TSMC or our own Ohsung, which then fabricate the actual masks and stamp out the chips."

"Hmm… Dr. Han, what makes a design house trust a foundry enough to simply hand over the blueprints?"

"Ah—I see what you mean. You're asking what happens if the foundry simply copies the design."

"Exactly."

"Of course the risk exists. But there are only a handful of foundries worth mentioning. The big three are TSMC, Ohsung and Intel, and the trustworthy ones worldwide number barely more than a dozen. Steal a customer's design? That would be suicide."

"Still, the temptation must be there. Copy it quietly and sell it—money in the bank."

"TSMC is number one in foundry work, and their motto is that they never compete with their customers."

"So… they promise never to pilfer a client's design and will quietly manufacture only what they're given?"

"Precisely. And far from stealing the design, if they spot a flaw they actually work to improve it."

"What?"

"TSMC has manufactured so many products that when a design problem surfaces they sit down with the designer, put their heads together and solve it. That is how they became the top supplier."

"So instead of copying, they fill in whatever the design house lacks? A first-rate foundry has to go that far."

I thought I understood. America's finest talents designed the complex logic circuits that would become real silicon. Then, in places with lower labor costs—Korea, for example—those designs were turned into masks and stamped out like prints. And a computer contained more than one kind of chip. A design house that held the copyrights could farm out its CPUs and various memories to several different foundries, reducing the risk of any single partner absconding with the entire body of knowledge.

Dr. Han Woo-seok wrapped up the lecture.

"Representative, you worked hard again today. Be sure to review."

"Of course."

Once he left I closed my eyes for a moment and let the flow of the lesson settle.

Review right away.

I took out the smartphone linked to the Nano World. The moment the screen lit up, Illys answered shyly from the other side.

"Illys. Today we're going to learn about masks."

Teaching Illys what I had just learned was my review. Teaching was the highest form of study. As I explained things to her, the material sank cleanly into my own mind.

There were two additional reasons for tutoring her. First, the ones who actually built the semiconductors were the people of the Nano World. I had simply handed them finished chips with no explanation and said, "Try this," and the results they returned had already been extraordinary. If I transmitted foundational knowledge as well, what monstrous creations might they produce? Second, it was fun. Confucius had spoken of the joy of teaching—hearing one thing and knowing ten. I had never truly understood the phrase until now. Illys seemed to grasp ten things for every one I taught. Dr. Han Woo-seok, who taught me, would never know: instructing a genius was pure delight.

Illys's eyes sparkled.

I had thought of printmaking; Illys compared the relationship between mask and semiconductor to a seal. The analogy was perfect. After offering that neat comparison she tilted her head again.

Sharp as ever. Asking the right question at exactly the right moment. Without Dr. Han's tutoring I could not have answered.

"Illys. Do you know what a magnifying glass is?"

"Yes. A device that gathers light."

"Exactly. That is how we shrink the image."

I continued the explanation while sketching a simple diagram on the classroom board.

"We do not print the mask pattern onto the ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠silicon as-is. We use light. Light reflected from the mask passes through a series of lenses that reduce the image many times over before it is burned onto the wafer."

Illys's pupils glittered.

I laughed.

"That's it exactly. We reduce it dozens of times and carve circuits too fine for the naked eye. The mask itself is already small, yet what we etch is far smaller still."

Illys clasped her hands in admiration.

Building a skyscraper the size of a fingernail—that was semiconductor fabrication. Work of such extreme difficulty that ordinary companies could never manage it alone.

"Illys. Did you solve yesterday's logic-circuit problem?"

"Yes."

She produced her notebook with proud readiness. Complex circuit diagrams of symbols and lines filled the pages.

"Good. Today's a new problem."

I sketched a simple circuit on paper as I spoke.

She calculated at speed, lifting her pen to sketch npn and pnp transistors and arrange them in rows.

After only three months of study the problem was still a little hard for me. I stole a glance at the answer key.

"Oh, Illys! Well done. You really are amazing!"

"Next question. What material is a mask made of?"

"Bingo."

Nano World.

These days Illys's daily routine consisted of two main tasks. One was her lessons with the Constellation. The other, once class ended, was visiting the building the Constellation had sent.

That building was a semiconductor.

Illys sought out Ralph, who was silently transferring diagrams, and asked:

"Ralph. While you dismantle, you're keeping thorough records, yes? Every single layer, without omission."

Ralph raised the pen in his hand and nodded.

"Of course. CPU building, GPU building, DRAM building. I've recorded the order in which every floor of each structure is demolished. The wiring of every layer, the patterns of every inscription, the paths the current travels—not a single detail left out."

"Thank you. These are artifacts used in the Constellation's own world. Opportunities to take such things apart are rare."

"Indeed. It feels like dismantling a grand mage's magic tower piece by piece. My hands are trembling as I work."

"Good. Keep it up."

"Understood."

Beside the dismantling site stood a log cabin that served as the command post for the semiconductor deconstruction. Inside, Illys spread out the circuit records and related materials she had accumulated. These were reverse-engineering blueprints of the semiconductors Ralph was carefully copying down. The results of dismantling the CPU, GPU and RAM the Constellation had sent were being ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠reborn as design schematics.

Illys examined the already completed drawings one by one. The CPU's arithmetic circuits, the GPU's parallel architecture, the cells of the DRAM—all intertwined and overlapped into endlessly complex patterns. A small light kindled in her eyes.

"Oh? This is what I learned today! If I feed a 1 here the output becomes 0. That is why the transistors had to be arranged exactly like this."

Inside her mind the separate design sheets began to fuse into a single building.

Illys was a mage. A 4-Circle Mage, no less. That title meant a genius among geniuses. On Earth, the accumulated scientific knowledge of humanity had produced objects that bordered on magic; in the Nano World a mage was someone who, with nothing but the knowledge and calculation inside her head, could manifest magic itself.

"The first-floor wiring rises to the second story and distributes this way, so the logic circuit goes like this…"

And now, inside this small log cabin, knowledge of semiconductors that bordered on magic met a true mage.

Illys slowly sank deeper into the semiconductor blueprints.

Hummmmmm.

A vibration filled the cabin. It was neither the building's tremor nor the noise of machinery.

"Ah…!"

The vibration began inside Illys's body—the trembling of mana within her heart, within her circle.

"View Image."

In midair she constructed a virtual semiconductor according to the blueprints. Line by line she connected circuits. A hundred-story edifice. A composite structure woven with perfect logic. The instant the building was complete, she understood.

"This is… space. Space overlaid with pure logic."

The highly complex three-dimensional architecture of a semiconductor locked into place inside her mind. The moment of enlightenment.

"Marvelous!"

Dazzling light bloomed behind her. A vast wave of mana exploded outward.

Outside the cabin, Knight Commander Carlton, who was on guard duty, and Ralph, still at work, both felt the surge of mana.

"This is…!"

"Mana is pouring out!"

Commander and dwarf sprinted toward the log house. Peering carefully through a crack in the door, they saw their lord floating in midair, wrapped in coiling mana.

"This is… an awakening?!"

The Knight Commander stood at the absolute peak of the Expert realm. He recognized Illys's state at once. He signaled sharply to Ralph.

"Hush!"

Ralph nodded. Though not on the Commander's level, he too was sensitive to mana. All work halted. Everyone except the guards withdrew from the cabin. This was their lord's moment of enlightenment. It had to be protected.