Next-generation semiconductor competition: superconductor contacts are expected to achieve 1nm chips

It has always been the dream of scientists to make chips thinner and thinner.

But we all know that the existing silicon crystals are getting closer and closer to the physical limit.

To make a breakthrough from "nano-level" to "atomic level", we can only rely on ultra-thin semiconductor materials such as molybdenum disulfide to help.

Recently, researchers from the University of Basel in Switzerland announced that they have successfully added a superconductor contact to the molybdenum disulfide material, thereby exhibiting similar properties to silicon crystals.

The success of this experiment verifies the feasibility of manufacturing semiconductor components with ultra-thin semiconductor materials.

Experiments show the new characteristics of ultra-thin semiconductor materials

This experiment is led by Dr. Andreas Baumgartner, whose research team plans to layer some natural materials with semiconductor properties to form three-dimensional crystals, and then combine them with superconductors to explore the properties of new materials.

At the beginning of the experiment, the researchers first separated the molybdenum disulfide into individual layers, the thickness of these monolayers is no more than one molecule.

Next, the researchers added two thin layers of boron nitride on both sides of the single layer of molybdenum disulfide like a "sandwich". Under the protection of protective nitrogen in the glove box, the researchers stacked the boron nitride layer on the molybdenum disulfide layer and combined the bottom with another layer of boron nitride and a layer of graphene.

Swiss researchers add superconductor contacts to ultra-thin semiconductor materials, and the next generation of semiconductors has a new idea!

Then, the researchers placed this complex van der Waals heterostructure (a special three-dimensional structure) on top of the silicon/silicon dioxide wafer.

In this way, a new synthetic material similar to a semiconductor element is stacked.

After the stacking was completed, the researchers began to realize observations at a low temperature above absolute zero (-273.15 degrees Celsius).

Finally, they found that under ultra-low temperature conditions, superconductivity measurements clearly showed the effects caused by superconductivity; for example, single electrons were no longer allowed to pass. In addition, the researchers also found signs of strong coupling between the semiconductor layer and the superconductor. These characteristics are very similar to the physical characteristics of current semiconductor chips.

Research project manager Baumgartner explained: “In superconductors, electrons arrange themselves in pairs, just like dancing partners, producing strange and wonderful results, such as the flow of electric current without resistance. On the other hand, in semiconductors In molybdenum disulfide, electronics perform a completely different dance, a strange solo dance, which also contains their magnetic moments. Now, if we combine these materials, we want to see this strange dance in person."

To put it simply, this experiment verifies the feasibility of ultra-thin semiconductor materials to replace silicon crystals and provides new ideas for the next generation of semiconductor manufacturing devices.

Two-dimensional materials renew the life of "Moore's Law"

Today's chip manufacturing process has completed a 5nm breakthrough, and scientists have made efforts to sprint to the limit of 1nm. On May 6 this year, IBM took the lead in announcing the creation of a 2nm chip, which immediately rejoiced the entire semiconductor circle.

However, due to the existence of Moore's Law, even if the number of transistors per unit area is gradually advanced, the performance cannot be significantly improved. Under the background that the physical characteristics of silicon wafers are about to reach their limits, the 1nm process is like a mountain-blocking silicon technology.

In addition, in the current advanced manufacturing process, the existence of insulators is required. The meaning of their existence is to help electrons smoothly pass through the channels in the transistors. When the process continues to go down, the channels are bound to become smaller and smaller, and the crosstalk between the transistors will be very large, and the performance of the chip will be greatly reduced.

For example, in a chip made of 5nm process material, too many transistors have been plugged. Once the electrons stick to the oxide insulator inside the chip, it will make the current difficult to pass, and eventually cause problems such as increased power consumption and chip heating.

This is why we will complain about TSMC and Samsung's 5nm process one after another because this is really too much consideration for later polishing.

Since the three-dimensional material allows the charge to attach to it, the use of two-dimensional materials as a substitute can perfectly avoid the problem of current passing.

At present, the industry generally uses molybdenum disulfide as a two-dimensional ultra-thin single-layer material, which is also considered to be the most powerful substitute for breaking the limitations of silicon wafer miniaturization.

TSMC bets on bismuth (Bi) material

In fact, in addition to the study of the University of Basel in Switzerland, the academic community has already made breakthroughs in the connection of two-dimensional materials.

Earlier, the international joint research team led by Professor Kong Jing of the Massachusetts Institute of Technology (MIT) announced that it has completed cooperation with National Taiwan University and TSMC to use atomic-grade thin material bismuth (Bi) instead of silicon to effectively connect these 2D materials to other materials. Chip components.

When the bismuth (Bi) material is used as the contact electrode of the two-dimensional material, the resistance can be greatly reduced and the current can be increased.

As mentioned earlier, the interface between metal and semiconductor material will produce a phenomenon called metal-induced gap (MIGS) state, which inhibits the flow of charge carriers. The semi-metal bismuth (Bi) material has electronic properties between metals and semiconductors, which can effectively eliminate the problem of charge flow.

At present, TSMC's technology research department has begun the research of "bismuth (Bi) deposition process" technology, and this research has become a breakthrough in the future 1nm process.

Through this technology, researchers can design miniaturized transistors with extraordinary performance, which can effectively meet the requirements of future transistor and chip technology roadmaps.

1nm is slowly becoming a reality

The successful verification of ultra-thin semiconductor materials has shown us the unlimited potential of the next generation of semiconductors, and future computers may show a new attitude as ultra-thin semiconductor materials mature.

At the same time, we must also see that TSMC and IBM are actively seizing 1nm advanced process technology.

The competition for next-generation semiconductors has quietly begun.