Zhou Xin was a little surprised that he would receive a reply from Hu Zhengming the next morning.
You must know that twenty years later, Hu Zhengming checks his email only once a week.
"Does it mean that teachers in their youth read emails once a day?"
“I can’t tell that the teachers back then were so hardworking.”
Although Zhou Xin was following Hu Zhengming before, Hu Zhengming mostly only gave some directional advice at that age.
Of course, even so, Hu Zhengming published a paper in science that was cited more than a thousand times in 2016, when he was 69 years old.
"Professor Hu, hello, I am Zhou Xin, a sophomore majoring in microelectronics at Yanda University. Although Zhou was in an old country, his fate was restored."
Cross-border phone calls are very expensive, and after Zhou Xin came, he did not go to open source again.
Just relying on scholarships is still quite stretched.
"Zhou Xin, what a good name.
I originally thought it was the core of the chip.
I read the email you sent me, and I thought it was some professor who had new ideas on the MOSFET model.
Your results are enough to be published in IEEE or even Science. "
The two of them talked in English. Even though Zhou was trying to restore his old state, Zhou Xin still spoke in English.
After all, when he went to Berkeley to study for his PhD, he specially translated this sentence into English and said it when introducing himself to foreigners.
Zhou was a dynasty of China thousands of years ago. Adding this sentence instantly made the Americans with little history look at him differently.
This can be regarded as Zhou Xin’s little trick to quickly get familiar with foreigners abroad.
Talking about history and politics is one of the ways to quickly get closer to another strange man.
"Yes, I am currently a sophomore majoring in microelectronics at Yenching University. The reason why I sent this email is that I hope to study for your PhD.
Because my financial situation is not very good, I still need you to provide a full or half award. "
The difference between full scholarship and half scholarship in this era is that half scholarship can get less money, and half scholarship requires work, such as substitute teaching, correcting homework and the like.
Those with full scholarships will be asked to work by their instructors, but they can choose to refuse.
Generally speaking, it will not be refused.
"International phone calls are a bit expensive for me, so I made my request straightforward."
After Zhou Xin finished speaking, Hu Zhengming paused for a moment and asked:
"I will send you a paper later and you have five hours to answer it.
Reply to me via email after you answer.
If you have eighty points, I will help you arrange everything.
This paper is not too difficult, it is just the standard for the entrance examination for doctoral students in the Department of Electrical Engineering at Berkeley.
Although it will be a bit difficult for ordinary sophomores.
But the keen intuition about the model and the way you handle it showed in your email are not that of an ordinary sophomore.
Even many of the doctoral students I taught were not as capable as you in this area when they graduated. "
Hu Zhengming did not set too high a threshold for Zhou Xin regarding the difficulty of the doctoral entrance examination.
Of course, this level of difficulty would be impossible for a sophomore from Huaguo, except Zhou Xin.
This is not a level gap, but an all-round gap.
Regardless of the teaching materials, teacher level, depth of study, etc., there are thick barriers between the entrance exams for sophomores and doctoral students.
Not to mention having to answer in English.
"What if I fail the exam?" Zhou Xin asked on the phone.
Hu Zhengming smiled: "As long as you can prove that the email was written by you.
Then I will also help you with transfer and scholarship matters.
It just means that you need to come to Berkeley to complete the courses you have not completed in your undergraduate degree. "
As a godfather figure in the semiconductor industry, he has stayed at Berkeley for more than 20 years. It is no exaggeration to say that it is easy to help students obtain scholarships.
Hu Zhengming admired Zhou Xin very much, not only because of the email, but also because of the frankness shown in the communication and his fluent English.
Even some modal particles are the same as him.
During Zhou Xin's time at Amerikan, one of his main communication partners was Hu Zhengming, and his oral English improved by leaps and bounds during his time at Amerikan.
There are certainly similarities between the two in terms of oral expression.
Zhou Xin smiled on the other end of the phone: "Okay."
"The MOSFET model can relate Em to all device parameters and bias voltage, describing its use in explaining and guiding hot electron scaling. How did you come up with the idea of modeling MOSFET interconnects through the predictive power of circuit simulation? "
With telephone lines spanning thousands of kilometers, the distance between the two ends is not only geographical, but also distant in time.
The answer Zhou Xin sent to Hu Zhengming was Hu Zhengming's own paper in 2000, published in the 2000 IEEE Integrated Circuit Conference Proceedings, and ranked eighth among Hu Zhengming's more than 900 papers.
Although the ranking is not very high, it serves as a link between past and future.
Hu Zhengming's greatest contribution is to develop and optimize the 2D structure of semiconductors into a 3D structure, which is FinFET.
The basic planar (2D) MOSFET structure remained unchanged from 1960 until around 2010, until further increases in transistor density and reduction in device power consumption became impossible.
Hu Zhengming's laboratory at the University of California, Berkeley, saw this as early as 1995.
As the first 3D MOSFET, FinFET transforms a flat and wide transistor structure into a tall and narrow transistor structure. The benefit is better performance in a smaller footprint, much like the advantages of multi-story buildings over single-story buildings in crowded cities.
FinFETs are also known as thin-body MOSFETs, and this concept continues to guide the development of new devices.
It stems from the realization that current does not leak through transistors within a few nanometers of the silicon surface because the surface potential there is well controlled by the gate voltage.
FinFET keeps this thin body concept in mind. The body of the device is a vertical silicon fin covered by an oxide insulator and gate metal, leaving no silicon outside the range of strong gate control. FinFETs reduce leakage current by several orders of magnitude and reduce transistor operating voltage. It also points to a path for further improvement: further reductions in thickness.
Current does not leak through the transistor within a few nanometers of the silicon surface, because the surface potential there is well controlled by the gate voltage. This concept was discovered after the MOSFET interconnect modeling was replicated in the laboratory.
It is impossible for Zhou Xin to tell Hu Zhengming, you discovered this yourself.
However, because Zhou Xin had done intensive reading of Hu Zhengming’s most important papers, he had his own analysis of how he thought at the time.
During the exchange with Lao Hu twenty years later, these analyzes were also recognized by the other party.
