Jiangcheng No. 7 High School, Li Dong

The following afternoon, Chengdu.

At Huaxuan Technology's Sichuan branch, in an office where papers were being graded.

The grading panel for this semifinal consisted of three Department of Physics professors from top universities and four senior engineers from Huaxuan Technology's R&D department.

For a high school competition to have such a lavish grading lineup, all one could say was that Huaxuan was damn impressive.

The conference room was silent at the moment, with only the occasional yawn faintly audible.

Zhang Mo, a senior engineer from Huaxuan Technology's lithography R&D team, sat before a student's test paper with a lifeless expression.

He had not really wanted to do this boring job.

The company's Extreme Ultraviolet Light Source Stabilization System project was at a critical stage. They could barely finish their work even with daily overtime, yet he had to make time to grade papers for a bunch of high school students?

But the higher-ups had made their intentions clear: rather than poaching talent later, it was better to identify and nurture it early.

This is such a waste of time.

Zhang Mo grumbled inwardly.

How could talent possibly be discovered just because someone wanted to find it?

Besides, the third part of this experimental question was based on a technical route their R&D team had only cracked half a year ago. They were using it in a high school competition to discover talent?

Wasn't that a joke?

Zhang Mo had already been grading for an hour straight.

Eighty percent of the papers had left this question blank.

Of the remaining twenty percent, some were impractical fantasies, while others were complete nonsense that defied engineering logic.

"Gamma-Ray Lithography," Zhang Mo said, shaking his head helplessly.

Gamma rays had high resolution, but the engineering challenges involving the light source, radiation protection, and compatible photoresists made practical implementation impossible in the short term.

A few answers occasionally hit the mark, but they all reflected typical "laboratory thinking," with no consideration for cost or yield rate.

"Immersion Lithography... using pure water as a medium to increase the numerical aperture..."

Zhang Mo looked at the paper in his hand and curled his lip.

This was the most mature standard answer currently used in mass production. It was safe, but utterly boring.

Although it was still widely used commercially, to engineers seeking technological breakthroughs, this sort of answer was like plain water—it quenched thirst but did nothing to wake one up.

"Students these days may read plenty of books, but they're lacking a bit of spark."

"Still, it's understandable. They've never worked on a production line, so they don't know how to spell the word cost..."

Zhang Mo casually awarded the paper full marks.

Just as he yawned and wondered whether to order mildly spicy or medium spicy hotpot that evening, one paper made him pause.

[Proposal Name: Dual-Beam Laser Interference Maskless Lithography]

He rubbed his eyes and checked again. He was not seeing things.

It really was Dual-Beam Laser Interference Maskless Lithography.

His previously drowsy mind instantly snapped awake.

This was the exact core approach his team had used half a year ago to solve that low-cost micro-nano fabrication problem!

He hurriedly read on.

"Let two coherent beams with wavelength λ strike the photoresist surface symmetrically..."

"Using spatial geometric constraints, the interference fringe period is d = λ/(2sinθ)..."

"Subwavelength resolution verification..."

The more Zhang Mo read, the more alarmed—and energized—he became.

Although this student's solution used high school physics formulas for the superposition of simple harmonic waves rather than the complex Fourier Optics transformations and vector diffraction theory used in their engineering work.

But!

There was not a single flaw in its logic.

And the note at the end made his eyes light up even more.

[Note: This approach can eliminate the need for high-precision mask fabrication and does not require a projection objective lens assembly. Although it places higher demands on source coherence and phase stability, it offers a tremendous cost advantage in the small-batch, high-precision production of periodic micro-nano structures.]

"Hiss."

Zhang Mo swallowed and could not help taking a sip of coffee from the table.

"He's got real talent. He actually knows what he's talking about."

This student had accurately identified the two key factors for reducing costs and improving efficiency: "maskless" processing and eliminating lenses.

Zhang Mo quickly ran some estimates in his head.

If they followed this student's simplified approach and built a pilot line for a specific process.

They could eliminate projection objective lenses that cost tens of millions, as well as mask sets costing millions.

"Even if the cost of a high-coherence frequency-stabilized light source doubles, the overall BOM cost... could drop by at least 40%!"

Even he was beginning to doubt himself.

"Is this for real?"

He quickly pulled out an A4 sheet of paper and began calculating at top speed.

ΔCost≈ Cost_Laser_Stable -(Cost_Projection_Lens + Cost_Mask_Set)

He drew several simple module diagrams on the paper, muttering to himself.

"If we use the beam-splitting prism he mentioned in the question for coherent beam splitting, then combine it with plane mirrors to fold the optical path, the machine's size could be reduced even further..."

If they built an experimental setup according to this student's simplified approach, it would cost at least another 10% to 15% less than the equipment they were currently using.

"No, I need the team to run a simulation first! Follow this high school physics approach and see if we can simplify that damned phase-locking module!"

At that point, Zhang Mo no longer cared about grading discipline. He grabbed the paper, stood up, and headed outside.

One of the professors beside him asked in surprise.

"Engineer Zhang, where are you going? You haven't finished grading the papers."

Zhang Mo acted as if he had not heard him. Well, he genuinely had not heard him—his mind was completely occupied with cutting costs.

The other graders were left staring at one another.

"What's gotten into him?"

"No idea..."

After chatting briefly, everyone continued grading the papers in their hands. Who had not reached the point of despair while grading papers?

At that moment, another professor picked up a test paper.

"Hey, I've got a pretty good one here. It uses Phase-Shift Mask Technology. It's a little overloaded with theory, but for a high school student, understanding this much is already very impressive."

The paper was passed around among several graders.

After taking a look, the engineers nodded.

"Mm, solid theoretical foundation. Give it full marks."

But that was all.

This sort of answer only demonstrated the level of an excellent student. It was still far from the kind of talent they wanted—someone who could bring new ideas to practical engineering applications.

Outside in the corridor.

Zhang Mo immediately tore open the sealing strip on the side of the paper.

[Candidate Number: SC-2022-001]

[School: Jiangcheng No. 7 High School]

[Name: Li Dong]

"Jiangcheng No. 7 High School? Li Dong?"

Zhang Mo repeated the name under his breath.

He took out his phone, photographed the experimental question section, and added the company's encrypted watermark.

Then he wrote an evaluation.

[The "Maskless Double-Beam Interference" proposal put forward by the candidate (Candidate Number SC-2022-001) aligns with our team's current research direction.

Using high school simple harmonic wave superposition principles, he fully derived the resolution formula for interference lithography, identified an optimization route involving large-angle oblique incidence, and clearly noted the proposal's applicable scenarios and engineering limitations.

The simplified optical-path concept he proposed was something we had overlooked. I have conducted preliminary calculations, and if we build an experimental setup following this approach, overall costs are expected to decrease by 15%-20%.

I recommend that our team immediately conduct optical simulation and verification based on this approach!]

Click. Sent.

Recipient: Lin Wei, Director of Huaxuan Technology Lithography R&D Center.

At the same time, at Jiangcheng High-Speed Rail Station.

Li Dong and Zheng Hua dragged their suitcases along.

The two had properly "worked through their emotions" in Chengdu yesterday, only leisurely taking the high-speed rail back that afternoon.

As soon as they exited the station, Zheng Hua patted Li Dong on the shoulder.

"All right, Li Dong. Go home and get some proper rest today. Come back to school tomorrow."

Zheng Hua wore a smile.

"You've exhausted yourself during this training camp. No matter the result, your teacher is proud of you."

Feeling Zheng Hua's concern, Li Dong asked emotionally.

"Um... Teacher Zheng."

"I wanted to ask, if... I mean, if I make it into the finals, when will that twenty-thousand-yuan prize money probably arrive?"

The air suddenly fell silent for two seconds.

Then Zheng Hua suddenly laughed.

In his eyes, this was called confidence!

If he was not sure of himself, who would ask about prize money?

"Don't worry!"

"As soon as your results come out and it's confirmed that you've made the finals, I'll personally go see Principal Wang!"

"This money won't go through the regular reimbursement process. That's too slow."

"I'll apply through the school's Special Exceptional Talent Reward Fund."

After thinking for a moment, Zheng Hua gave him an approximate time.

"Once the approval process is complete, probably... half a month! It will definitely be in your account in around half a month!"

"Half a month?"

Li Dong calculated it in his head.

Half a month later would be right at the end of the month. He could still make it in time to buy his mother a new phone for her birthday.

"That's great! Thank you, Teacher Zheng! Take care, Teacher Zheng! Stay safe, Teacher Zheng!"

Li Dong treated him even more warmly than he would his own father.

After seeing Zheng Hua off, Li Dong called his mother.

"Hello, Mom. I finished the exam and came back."

"Huh? Didn't you say you were going for two days?"

Li Qin's voice came from the other end of the call.

"I came back after the exam. There wasn't anything else to do."

Li Dong answered casually.

"Mom, where are you? I'm a little hungry."

"Oh, I'm at your uncle's house."

"Your uncle's factory has been busy these past few days, and there are some accounts he can't sort out, so he asked me to come help."

"Just come over. We'll eat here tonight."

"All right, I'll head over now."

Li Dong pondered it.

It did not seem right to go to his uncle's house empty-handed.

Teacher Zheng had covered all the expenses for this trip, so he had not touched the money his mother had given him.

"Maybe I should buy some fruit?"

There was a fruit stand not far away. Li Dong walked over and was about to pick out some apples.

"Boss, these apples..."

Before he could finish speaking, he noticed that the figure sitting in front of the fruit stand looked very familiar.

"Mi Xia?"