The Science Fiction World of Xueba

Pang Xuelin stayed in the Biomedical Research Center for nearly an afternoon, and put forward many useful revision suggestions based on the dynamic APT parameters given by Shi Yi, Yang Heping, and Andrew White.

He basically uses dynamic APT technology every day in the world of Resident Evil, and he knows the performance and parameters of this device well, so it is not surprising that he gave various useful opinions.

Shi Yi, Yang Heping, and Andrew White didn't take it seriously either. With Pang Xuelin's reputation outside and frequent contacts with Pang Xuelin, they wouldn't be surprised that any miracle happened to this guy.

Of course, the three of them also have high hopes for dynamic APT technology.

If the cryo-electron microscope technology can win the Nobel Prize in Chemistry, then the dynamic APT technology, which is more realistic than the cryo-electron microscope technology, can undoubtedly be obtained.

Moreover, Pang Xuelin has already won the Nobel Prize in Chemistry once, and the three of them can just share a Nobel Prize.

Pang Xuelin stayed in the Biomedical Research Center for an afternoon to learn about the development of APT equipment. The next day, he went to the carbon-based chip research and development center led by Xu Xingguo.

At present, the development of global semiconductor materials is close to the physical limit. TSMC, the strongest in the field of integrated circuit foundry, has completed the commercial mass production of the 3nm process, and the 2nm process is also close to the completion of research and development.

SMIC, the strongest semiconductor manufacturer in China, is still stuck on the 7nm process, and there is still a two-generation gap with TSMC.

During the previous Sino-US trade war, the United States once launched a comprehensive technical blockade against Huawei, claiming that any company that uses American technology is not allowed to cooperate with Huawei.

It was not until the lithium-air battery was born that China, relying on the huge advantages of lithium-air batteries, was able to lift the technological blockade of Western countries, and the crisis facing Huawei was also easily resolved.

But even so, there is still a big gap between China and Western countries in the field of high-end integrated circuit manufacturing.

Among other things, ASML's extreme ultraviolet lithography machine (EUV) brings together the top manufacturing technologies of all Western countries and can be called the most sophisticated industrial product in human history.

Together with aero engines, it has become a jewel in the crown of industrial manufacturing.

In the era of silicon-based integrated circuits, Western countries have a huge first-mover advantage, and it is difficult for China to compete with Western countries in this field.

at this point,

Even Pang Xuelin had nothing to do.

It is possible for him to make a breakthrough in theory, and let him quickly improve the level of domestic industrial manufacturing. Pang Xuelin is also helpless.

The gap in the silicon-based chip manufacturing process makes it difficult for China to catch up with Western developed countries in a short period of time.

However, the inability to overtake in a corner in the silicon-based field does not mean that there is no other way.

Carbon nanotubes have been given high hopes by scientists.

This is closely related to its own characteristics.

First of all, although the carbon nanotube chip is small in size, it has stronger energy-saving and efficiency-enhancing capabilities.

Carbon nanotubes are carbon materials rolled into a tubular shape by a single layer of carbon atoms. They have excellent electrical conductivity, and carbon is abundant on the earth.

The diameter of carbon nanotubes can be made from several nanometers to tens of nanometers according to different processes; the thickness of the tube wall is smaller. According to the number of carbon atoms in the wall layer, carbon nanotubes can be divided into single-walled carbon nanotubes and multi-walled carbon nanotubes. tube; in the case of the same level of integration, carbon nanotube chips are smaller than silicon components.

At the same time, carbon nanotubes have extremely high toughness, can withstand stress such as bending and stretching, and the delay in the transmission of electrical signals is very short. Therefore, from the perspective of material physical properties, carbon nanotubes have the potential to replace silicon chips.

Secondly, carbon materials have a variety of allotropes. In addition to carbon nanotubes, there are well-known diamonds, graphite, fullerenes, activated carbons, and the like.

Its conductive properties are strongly dependent on the structure, and can be transformed from insulators to semiconductors and from semiconductors to conductors.

Moreover, its conduction method and principle are different from traditional transistors, and it has stronger conduction ability.

In addition, existing transistors will inevitably generate leakage current during the conduction process, which will cause heat generation, but carbon nanotubes can avoid this problem, so the energy efficiency is relatively high.

Theoretically speaking, the energy utilization rate of carbon nanotube chips is expected to exceed the energy efficiency ratio of existing chips (60% to 70%).

The solution to the heating problem also reduces the pressure on the heat dissipation of the chip.

Silicon transistors consume a lot of power. In a small chip space, the heat is extremely serious. In order to prevent the chip from overheating and unable to work, part of the power consumption needs to be allocated for chip heat dissipation, which increases the power consumption of silicon transistors.

The carbon nanotube chip itself produces less heat, and the thermal conductivity of the carbon nanotube itself is very high, which effectively reduces the energy consumption for heat dissipation, so the energy efficiency of the carbon nanotube will be much higher than that of silicon. of transistors.

Worldwide, IBM was the first to realize the preparation of carbon nanotube devices. It successfully prepared a carbon nanotube 20nm gate length device in 2014. However, the performance of the device was much worse than expected.

In recent years, various foreign laboratories have also claimed to have prepared carbon nanotube devices with a gate length of 1nm, but more of them are just gimmicks, and the actual performance is very poor.

In China's research on carbon nanotube devices, after Pang Xuelin completed the mass production of ultra-high-purity electronic-grade carbon nanotubes, the team led by Xu Xingguo began to work on high-performance carbon nanotube (CMOS complementary metal oxide semiconductor) transistors. In-depth research on heterogeneous preparation and polarity control of transistors, and has accumulated a lot of technology.

Among them, the carbon nanotube top-gate CMOS field-effect transistor with a gate length of 10 nanometers (corresponding to the 5-nanometer technology node) prepared by the team has successfully overcome related problems such as device structure and fabrication process.

Not only that, the performance of the carbon nanotube devices prepared by it far exceeds the carbon nanotube devices that have been reported internationally.

For carbon tube transistors fabricated with conventional structures, when the gate length is less than 5 nanometers, it will be more obviously affected by the short channel effect and tunneling leakage current. In the past, it was difficult to effectively solve the leakage current by fusing high-k gate dielectric films. problem, so that the device cannot be effectively turned off.

Xu Xingguo's team used graphene instead of metal as the source-drain contact of carbon tube transistors, which effectively suppressed the short-channel effect and direct source-drain tunneling.

Moreover, since only about one electron participates in the switch conversion of the carbon tube device with a gate length of 5 nanometers, the gate delay (42 femtoseconds) is close to the physical limit of the binary electronic switching device (40 femtoseconds, measured by Heisenberg quasi-principle and the Shannon-von Neumann-Landauer law).

This is the first time that China has mastered the most advanced transistor technology in the world, and the overall technology is extremely mature. As the cost of carbon nanotubes decreases and the process yield increases, this technology is expected to become the most advanced chip manufacturing technology.

The mastery of this new technology is equivalent to the advantage of more than six generations of the most advanced silicon-based technology (leading 20 years), so that the advantages of international chip giants will no longer exist, and the domestic semiconductor manufacturing industry will be in the near future. Overtaking on curves will be realized in the future.

In fact, Pang Xuelin met engineers from Huawei and SMIC in Xu Xingguo's laboratory.

According to Xu Xingguo, the first generation of carbon-based chips will be mass-produced within the next year, and will be first applied to Huawei's 5G base station products.

As for carbon-based chips on the consumer side, it is estimated that it will take another two years before they can be widely used in mobile phones, PCs and other fields.

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