Now that the technical roadmap has been confirmed, the next step is how to implement it.

As the person in charge of the laboratory, Wang Zhongjun does not need to participate in everything in detail, but more to grasp the direction and coordinate and supervise the progress.

If you want to characterize the grating through atomic force microscopy, the biggest obstacle seems to be the problem of silicon probes.

Since the requirement is a grating with a resolution of 100 nm, the tip of the probe should be at least 50 nm.

A grating is actually a row of glass sheets of equal width alternating between transparent and opaque. Its resolution is the total width of a set of alternating transparent and opaque notches. If the width of this group is 100 nanometers, then the width of the opaque notch should be 50 nanometers.

To make a 50-nanometer-wide notch, of course, you need a 50-nanometer-thin needle tip.

"All of our requirements are focused on this probe, and we have a scoring of 50 nanometers, but we can't have a resolution of just 50 nanometers. ”

Wang Zhongjun had a somewhat disheveled hair, and his bloodshot eyes looked like he was a little sleep-deprived, but his voice was full of energy.

With a pen, he pointed to the projection on the screen, and then assigned the other researchers in the lab a task: "The probe material must be silicon, and our sample will not be absolutely smooth, so we must make sure that the probe does not break and contaminate the material." ”

"It should be a trapezoidal shape, with the tip of the needle being a plane 50 nanometers wide, which is the width of 500 silicon atoms. ”

Wang Zhongjun thought for a moment and added: "Before, I thought that it was inappropriate to use the tip of a needle to directly hit the material. Silicon knocks on silicon, and we cannot guarantee the integrity of the silicon on the probe, which means that the width of the knock is unpredictable. So it is not appropriate to tap the material directly, we also need to remove the photoresist with a probe, and finally implement the grating through etching and ion implantation. ”

"So what we need to solve now are three problems, tapping the probe, positioning the probe, and etching that satisfies the anisotropy. ”

"Tap the probe...... Old Zhong, you're in charge of this. Technically, based on the characteristics of silicon, you can try the monocrystalline silicon growth method first. ”

"I'll do the positioning probe, and I don't have any ideas for this for the time being. ”

"For etching and ion implantation, I consider the use of dry etching technology, and the related etching machine and PVD equipment are applied and retrofitted...... This can't be done by our laboratory alone, Qin Shi, you can connect with other relevant laboratories. ”

"Our laboratory is divided into three groups, one group with Lao Zhong, one group with me, Qin Shi, you will take a graduate student to do the coordination work for the time being. ”

......

Wang Zhongjun is in danger, and the laboratory has a backbone. Although it is inevitable that there will be great difficulties in developing technology by leaps and bounds, when we think about the meaning behind this scientific research project, everyone's hearts are filled with a sense of mission that we must do our best.

Zhong Dahua is an old researcher, after being seconded from the Institute of Optics and Mechanics to the new department, although he has not made any particularly outstanding contributions, he has never missed every experimental project he has handled.

In the past five or six years, Xinke has not only raised his salary for him, but also helped him take over his family in Changchun to arrange jobs and solve the problem of his children's schooling, and recently allocated him a 120-square-meter house.

This kind of treatment can be said to be not much worse than those who do business and officials in society.

"Well, I can't say much about the specific work, but I've probably been busy in the last two months. ”

Zhong Dahua opened the door of the computer room of the data room, and said apologetically with a mobile phone around his neck: "You tell the child that his birthday will be made up when I go back, and he can choose the birthday gift." If you have any trouble in life, you can go to Sister Huang, and you can always help in the organization. ”

"I won't say more, don't worry, I will pay attention to my body and ensure that I will call every day to report my safety...... You too, don't be too tired, don't always be angry with your son, I was like him when I was a child, maybe I will know how to ......study when I grow up."

"Okay, I'll get busy, let's not talk about it yet. ”

"Tut, Lao Zhong, you are a proper three-good man, 'I promise to call every day to report my safety', haha, is my sister-in-law so strict?"

Walking in with Zhong Dahua, Wu Mu was a young man, and he knew by looking at his appearance that he was homeless and light.

"You bachelor, what do you know? Why are you strict, obviously she can't do it without me!"

"You can pull it down, it's not like I haven't seen you kneeling on the washboard. ”

As he spoke, Wu Mu also patted the burden on his chest, and said with a grin: "Look at us, where the cover roll is, don't mention how comfortable it is!"

"Today I'm going to lay the floor in the reference room, and I'll add him to his class for a week!"

Jokes are jokes, after entering the working state, Zhong Dahua and Wu Mu are very serious personalities. However, after working for a while, they suddenly found that their computers could not be connected to the American database.

"What's going on, we can't connect to the public database in the U.S.?" U9 eBook

"Wait a minute, I'm searching for other areas. ”

Zhong Dahua thought about it, and then searched for a biological keyword, and the search results quickly appeared on the screen.

"I'll call the webmaster and ask if it's our problem. Wu Mu grabbed the landline next to him and dialed an internal number.

"Hey, is the network center? Yes, my semiconductor institute, what? You have also received a lot of feedback, suspecting that the US database has locked China's IP for semiconductor data? This is impossible, this is not in line with the academic spirit......

"Okay, I see, please let me know as soon as possible. ”

Wu Mu looked at Zhong Dahua with some dumbfoundedness, and said in disbelief: "The network center said that at present, it seems that the semiconductor database may have locked the Chinese IP and banned our account access. ”

Although Zhong Dahua had already guessed, he obviously looked like he had seen the hell about it. The blocking of open literature databases is too challenging for the current academic system.

"Americans are in a hurry, I knew there would be this day, but I didn't expect it to come so soon. ”

"We pose too much threat to Americans in the semiconductor field, and the rabbit skin can't be covered!" Wu Mu sat back in his position, thought for a while and pouted: "The recent situation is so tense, in the final analysis, it is not caused by the competition between us and the United States in the semiconductor field. ”

Zhong Dahua frowned, and said in a low voice: "Blocking IP makes us more troublesome at most, but it doesn't really play a role." But it's not about the actual effect, it's about the symbolism. Now that the academic community is still led by the Americans, if they want to sanction us, we will have to suffer like Iraq. ”

"Why should you bear it?"

Wu Mu jumped up instead and snorted: "I don't believe it, without Zhang Butcher, we would have to eat hairy pigs? Without the database of the Americans, we can still do a good job of the project! Blockade, it is better to blockade for ten or twenty years, and then we will have everything!"

Wu Mu jumped in the data room, but Zhong Dahua didn't say anything, but turned his head and began to continue working. It's just that the strength of his hitting the keyboard has obviously increased a lot.

The work is always endless, there is no American database, there are Chinese databases and European databases, and even some companies from other countries will soon come to the door to provide search services.

It's just that, as Zhong Dahua said, this is a disgusting attitude, as long as other countries can still query the US database, then the blockade is meaningless. Even a company that provides a search service doesn't make much money, because all it takes is a computer outside of China that can connect to academic institutions in other countries can log into the U.S. database. Such a business with no threshold will not be able to raise any price.

But for Zhong Dahua and Wu Mu in the data room at this time, it didn't make them feel much less humiliated.

"Old Zhong, I suddenly had an idea. ”

At half past eleven in the evening, Wu Mu suddenly raised his head from the monitor, looked at two dark circles under his eyes, and said in a daze.

"We have to go back, back to the original route. ”

"What?" Zhong Dahua was also stunned for a moment, not knowing why: "What is the original route?"

"Yes, wet etching. ”

Wu Mu nodded heavily: "Do you remember what was the biggest trouble when we used wet etching?"

"The biggest problem is the isotropy of wet etching, which can easily cause the scoring to lose accuracy. ”

"Yes, isotropic. ”

Isotropic, that is, the corrosive agent does not change due to the different directions in the process of eroding the material. At the same time as the downward erosion, the corrosive agent also erodes to the left and right. If the anisotropy is too good in etching, the part of the photoresist will be eroded away from the left and right sides. The parts that do not need to be eroded will also be eroded, and the natural accuracy cannot be guaranteed.

When Wu Mu said this, there was suddenly a hint of brilliance in his eyes: "But do you remember what kind of shape our wet etching will form if it fails, and the part that is finally blocked by photoresist?"

The drum does not need a hammer, and Zhong Dahua's mind quickly recalled the failed experiments he had experienced.

Isotropic corrosives erode left and right, eventually creating a slope on the side, like a small puddle.

Imagine if there were two "puddles" on the left and right under a photoresist, wouldn't the middle of them be a needle tip?

Wu Mu said excitedly: "If we use hydrofluoric acid and nitric acid to corrode monocrystalline silicon, because the corrosion rate of this corrosive agent can be controlled by proportion, we can get the needle tip width we want through ratio and time control!"

"This!"

Zhong Dahua's breathing suddenly became short, and he had a hunch that this should be a feasible route!

"It's just that in order to determine the ratio and precise timing of corrosive agents, we may have to look for a needle in a haystack!"