Cao Yunuan's continuous questions made the atmosphere in the conference room warm, and everyone felt that since Hu Yiting patiently answered the questions raised by a doctoral intern, it was not a shame to ask one or two more profound questions.

In this mentality, everyone also became relaxed, and one question after another followed, and Hu Yiting was not tired of it, and patiently answered them one by one.

After answering more than 20 questions, everyone had an intuitive understanding of Hu Yiting's technical background and depth of knowledge, and everyone finally understood that Hu Yiting's technical background could not be described as mature, and it could be called broad and profound!

Ma Jiaguang, director of Chengguang Institute, listened quietly at the conference table, his heart was amazed and inexplicable, after a series of questions, he clearly realized that Hu Yiting's level is completely comparable to the chief scientist of the top semiconductor laboratory in the West, without more than ten years of process and chip design skills, it is impossible to lift the weight of so many problems, and he can easily come to so many technical cases, his mastery of process technology and understanding of process equipment can be said to be higher than all the experts he has seen in China!

"Is that what genius is like? He's only 18 years old...... What was I doing when I was 18 years old...... Could it be that Hu Yiting grew up in the semiconductor laboratory since he was a child? It's really inexplicable......

Hu Yiting's mouth was dry, and seeing that everyone's problems were over, he lowered his head and continued to flip through the PPT he made.

"Well, let me tell you about it, it's a new technology that I invented. ”

As soon as they heard that another new technology was about to be born, the scientists and engineers in the audience immediately pricked up their ears, for fear of missing a trace of information.

Hu Yiting pointed to the projection screen and said: "This is a roadmap I have made about the development of memory technology, you can see that since the birth of memory, volatile memory and non-volatile memory have appeared, among which the position of non-volatile memory is becoming more and more important, from 1970 after the birth of the erasable read-only memory EPROM based on the floating polysilicon gate, the international memory semiconductor technology has not been stagnant, but is constantly accelerating.

EPROM needs to be removed from the system and exposed to ultraviolet light for erasure, and each erase completely erases all information, which is inconvenient to use, and has gradually been withdrawn from the market. Its replacement was the later advent of electrically erasable EEPROM, which enabled the memory to be flexibly programmed in the circuit.

Later, on the basis of EEPROM, a flash memory Flash-memory was developed, compared with EEPROM that can only operate a single byte erase each time, Flash-memory can allow the storage information of all array cells to be erased at the same time, so at present, around the development of Flash-memory technology, a trend has been formed in the world, the scientific and technological community is very optimistic about the future of this device, and major Western manufacturers are trying to make technological breakthroughs in this field.

At present, the international community believes that only by constantly making a fuss about the process linewidth can the flash memory be made larger, because it is very difficult to make the chip area bigger, and the cost rise curve brought about by the increase in area is steep and very undrawable, so only the most advanced line width can integrate more memory units on the same size flash memory particles.

However, we should understand that the improvement of process linewidth is very slow, according to the upgrade speed of Moore's Law, it takes 18 months for the number of transistors to double, that is to say, the capacity of flash memory chips is locked by Moore's Law.

This is unacceptable!

At least for those of us who are engaged in technology, it is unacceptable! We must not be bound by Moore's Law. ”

As soon as this remark came out, everyone was stunned, and said that you Hu Yiting is a cow, which we admit, but you want to challenge Moore's Law, this big talk is too outrageous, without increasing the line width of the premise, you are just to make the design flowers, the number of transistors is still so much, how can it be possible to increase the storage capacity?

Hu Yiting knew everyone's confusion and continued: "In fact, there are methods, and what I want to introduce today is a new technology that I have thought of to break through the upper limit of flash memory capacity. ”

Hu Yiting switched PPT pictures, "At present, some international experts have also elaborated on some technologies, and I have summarized that there are three kinds, one is proton non-volatile memory, the second is nano memory, and the third is single electronic memory.

What I want to say is that these are not reliable, at least for 30 years there is no prospect of commercial application, because whether from the perspective of materials science or engineering, these are currently science fiction technologies that can only be realized, a small number of transistor proton storage experiments in the laboratory, or one or two carbon nanotubes to verify the storable performance, or precision instruments to achieve single-electron manipulation, this is okay, but once it is in engineering, it will not work, large-scale engineering applications can not be done is equivalent to nothing, now no one knows what kind of equipment and technology to use for large-scale manufacturing, so we don't think about these concepts。 ”

Hu Yiting continued to switch PPT, "At present, all we can do is to continue to develop Flash-memory technology, continue to rely on the charge trapping principle of semiconductor devices, and develop new technologies compatible with ordinary logic processes by improving the traditional floating gate structure."

The new technology I personally invented this time is called Multi-Level-Cell, or MLC for short, while the traditional Flash-memory flash memory process is called Single-Level-Cell, or SLC for short.

As the name suggests, the difference between the two is that the traditional SLC is a single-tier storage, while the MLC technology I invented is a multi-tier storage. ”

After Hu Yiting finished speaking, the entire conference room was in an uproar, and everyone's interest was completely mobilized by him.

Zhao He said excitedly: "Mr. Hu, what is going on with this multi-layer storage? Is it to stack two chips together to make a package?

Hu Yiting said with a smile: "Don't worry, I'll just say, but it's not what you think, the pop stacking packaging process can't reduce the cost of flash memory, the two-piece particle superimposed packaging can only increase the capacity of a single chip, and the price will only be more expensive, and the MLC structure I said is two different things." ”

Saying that, Hu Yiting cut a self-made PPT and began to introduce the characteristics of MLC structure to the sketch he made like a ghost drawing last night.

"Look, under this polysilicon gate is three layers of insulating film, these three layers of film are tunneling oxide layer, silicon nitride, barrier oxide layer, of which silicon nitride has a very high density of electron traps, can capture electrons, to achieve the purpose of storing charge, charged is 1, uncharged is 0, this is common sense.

We all know that there are two kinds of carriers in semiconductors, one is electrons and the other is holes, and when we write to the cell, we use the hot electron injection method to inject hot electrons into silicon nitride at the edge of the channel, so that the writing process is completed. In the erasure, the holes between the valence bands are used to inject the holes into the silicon nitride at the edge of the channel to remove the charge, and the erasure is completed.

Next, I will talk about the key point, you look at the picture, due to the insulation of silicon nitride, the electrons generated by the thermal electron effect can only be injected and limited to the edge of the channel, so that once the two sides of the channel are all charged is 11, all uncharged is 00, but once we erase one side of the channel on both sides separately, there will be four situations, one is 01, the other is 10, so we can double the existing Flash-memory capacity without complex process changes!"

After Hu Yiting finished explaining the picture, there was an uproar in the conference room, the scientists and engineers first looked at each other, then they were at a loss, then they began to fidget, and finally they all began to applaud, and some even began to applaud.

Among them, Zhao He scratched his ears and cheeks with joy, he had lost his mind after being seduced by Hu Yiting, and hurriedly said: "Mr. Hu, you are too godly, how did you come up with this! This is a patent! It is a patent of Chongguang! We have to hurry up to experiment! Hurry up and write a paper and apply for a patent!"

Cao Yunuan also applauded happily: "Hu Yiting, your idea is too perfect! I think it's feasible! It's really feasible! Why didn't anyone think of this way before? You are really a genius! I know that you are the best!"

Hu Yiting looked at everyone's excitement, thinking that this is what I came up with, this is the SONOS-Falsh technology developed by the Israeli company saifun, which was officially announced and patented by Intel in September 97, and applied to the design of their flash memory products. In the future, I will come up with another MCL product with multi-voltage control gate multi-layer injection charge technology, and completely dominate the MLC flash memory patent market until the flash memory technology is pushed to the TLC and 3D-NAND processes!

At this time, Xi Longshan suddenly asked: "Mr. Hu, I have a question, you do this, you do it, so that a storage unit can carry four pieces of information, which is double the amount before, but how to read it next?"

Hu Yiting laughed: " The voltage of these four cases is different, we only need to design a set of decoding circuits, used to read and parse the data, according to my preliminary design, you can set 0.5V-2.5V to 11, 2.5V-4V to 10, 4V-5.5V to 01, 5.5V to 6V set to 00, the specific decoding circuit design I have a draft, the preliminary design of this chip I have been confident, last week I have completed the SLC chip design improvement, this week I will take out the MLC chip design, next week can carry out the design of the process flow, at the end of the month at the latest, we're going to do the first engineering tape-out of this MLC!"

After speaking, Hu Yiting was in high spirits, raised his right hand and pointed to the ceiling: "Let me tell you! Chongguang will become the world's first flash memory design company to adopt MLC technology! Chongguang's patent will forever be recorded in history! And this patent will definitely allow us to get rid of the shackles of Intel and Toshiba's flash memory patents, offset the patent fees we need to pay to the International Flash Technology Alliance! and very likely to make their money in turn!"

Xi Longshan couldn't close his mouth in surprise, his upper lip trembled, and he sighed softly: "Mr. Hu...... The man of God is also ......"