The Millennium Semiconductor Survival Guide.

Chapter 4 Optimizing the MOSFET Model
A large part of the reason why many people are confused when they arrive at university is that the evaluation criteria have changed from one-dimensional to multi-dimensional.

Before high school, from the city to the school and then to the class, I often organized exams, which allowed you to have an accurate positioning of your grades in the whole school and even the whole city.

One-dimensional evaluation criteria plus repeated tests make it easy for people to improve themselves.

At the university level, the evaluation system has become multidimensional, and the requirements for students are no longer limited to test-taking ability.Teachers in high school never taught students what they can do and what they need to do in college.

At this time, most people will fall into confusion.

For example, Cao Yongluo's family has arranged for him early in the morning, and he only needs to follow the route planned by the family step by step.

Zhou Xin came back from the era of information explosion and knew exactly what he was going to do.

As for Wang Wei and Li Li, after entering Yanda University, they found that their exams were not as good as this group of exam kings. There were only midterm exams and final exams a year, and they didn't know how much they had to learn to rank high.

Pure open blind box.

When they first entered the freshman year, the two also studied hard for a period of time, but the problem was that it had no effect, and their grades were only in the middle of the class.

Zhou Xin has a certain understanding of these, but he doesn't care.

For him, he intends to contact his former supervisor, Professor Hu Zhengming, as soon as possible.

After collecting materials and information for a period of time, Zhou Xin made it clear that this time and space is exactly the same as the time and space before he came.

He also found Hu Zhengming's information on the Internet. If his guess is correct, then Hu Zhengming's mailbox is still the same as before.

Because he followed Hu Zhengming for four years as a Ph.D. student, Zhou Xin had either read most of his papers or learned about them through references to other papers.

This is not an easy task. You must know that Hu Zhengming has more than [-] papers.

The reason why I went to find Hu Zhengming was not only to value the other party's status in the academic world, but more importantly, the other party's contacts in the industry.

"Dear Professor Hu Zhengming:
While reading your improved paper on the degradation model of hot electron sensing MOSFETs, I have some new ideas that can be used to improve your optimized mathematical model."

Zhou Xin's plan is very simple. He still has to find Hu Zhengming, go to Berkeley to get a doctorate, and then use the leading edge of technology to start a business in Silicon Valley.

After the success of the business, return to China.

With this identity, it is too difficult to start a business in China.

In other words, it is too difficult to engage in semiconductors.

After a little preparation, Zhou Xin sent a paper on the further optimization of the MOSFET model to Hu Zhengming's email address.

Hu Zhengming has been teaching at Berkeley since 1976, and his mailbox has never changed.

Starting from the actual MOSFET transistor, deducing the mathematical model in the field of complex physics is the proud work of Hu Zhengming.

This paper, published since 1985, has been cited nearly 2000 times, which is his achievement second only to the FinFETch architecture.

In this era, the mathematical model was selected as the first and only international standard for designing chips by the Transistor Model Council in which 38 large companies participated in the world.

Since the paper was published in 1985, various studies have attempted to improve the model.

In 94, there was an attempt to optimize the model by thin nitride oxides, and in 95, there was an optimization by thermal re-emission of electrons.

But these studies are all through the material level, by changing the transistor material, to achieve the purpose of optimizing the MOSFET transistor.

It has not been a long time to start from the mathematical model level to optimize the results of Hu Zhengming's MOSFET model.

You must know that 1985 years have passed since 13.

Professor Hu Zhengming, who is far away in the San Francisco Bay Area, checks his mailbox every morning as usual.

E-mail has a history of more than ten years. In the past ten years, thanks to e-mail, scientists from all over the world have communicated more frequently.

For Hu Zhengming, the first thing he does when he comes to the office every day has changed from checking paper mails to checking e-mails.

An email called MOSFET model optimization quickly attracted his attention.

After all, as the creator of the model, Hu Zhengming also hopes to further optimize it.

It is a pity that neither he nor other scientists can optimize MOSFETs from the perspective of mathematical models.

". This critical energy and the observed time dependence can be explained by a physical model involving =Sis H bond breaking. The device lifetime is proportional to I-2sub 9 I1d9ΔV15t. If Isub changes due to small L or large Vd, etc. τ becomes smaller if τ is large. Therefore, Isub (and possibly light emission) are strong predictors of τ.

The constant of proportionality has been found to vary by a factor of 100 for different technologies, which offers the hope of significantly improving reliability through future improvements in dielectric/interface technology.A simple physical model can relate the channel field Em to all device parameters and bias voltages.Its use in explaining and guiding thermal electron scaling is described. "

Because the mathematical model built by Hu Zhengming is very simple, it simply depicts the essence of MOSFET degradation.

The simpler the model, the harder it is to optimize.

But this email provided Hu Zhengming with a new perspective to think about this issue.

The optimized mathematical model can explain more phenomena, so as to better monitor the phenomenon of thermal electron scaling.

In order to read this email, Hu Zhengming completely forgot about coffee.

After he finished reading the core part, he went back to see who sent him the email.[email protected], an email from Yanda University.

"Zhou Xin? I've never heard of such a number one person in Yanda's semiconductor field? And logically speaking, shouldn't he publish papers?" Hu Zhengming was very puzzled.

Generally speaking, those who can make this level of innovation are not unknown people.

Hu Zhengming read the last part of the email again, and the last part of the email expressed his hope to come to him to study for a Ph.D.

Only then did Hu Zhengming understand why the other party sent him this email.

It turned out that this was the way to attract his attention.

He had also received similar emails from Huaguo students before, and tried to get a recommendation letter from him by expressing his views on scientific research and thoughts after reading some papers.

After 20 years, this is called magnetism.

It's just that the cross-border emails of these Huaguo students are at best an idea.

However, Zhou Xin sent it over, adding a little summary, it can be called a complete paper, but a paper that can be published in the top journal.

Hu Zhengming planned to reply an email to the other party, make a phone call, and talk in detail.

It is rare for such a high-quality thesis to come from a college student.

Hu Zhengming hopes to further confirm the level of the other party through direct calls.

(End of this chapter)