Semiconductor materials are transitioning and replacing

From smartphones in your pockets to huge data centers that "power" the Internet, from electric scooters to supersonic aircraft, from pacemakers to weather forecast supercomputers. Inside each of these devices, whether they are widely known or lesser-known, they all rely on a tiny technology, that is, semiconductors. As an important material for semiconductors, silicon plays an irreplaceable role in it.

In the coming era of the Internet of Everything, chips have become the core of all smart devices. Semiconductor devices are the basic components of modern computing. Semiconductor devices called transistors are tiny electronic switches that run calculations inside computers.

American scientists built the first silicon transistor in 1947. Before that, computer science was done by vacuum tubes, which were large in size and slow in speed. Until later, silicon changed everything.

Silicon has opened a new door for semiconductor materials, and a large number of semiconductor components have become smaller and smaller. This change occurs year by year. Semiconductor components are becoming smaller and smaller, while also becoming more and more intelligent. The miniaturization of transistors enables people to install large-scale computing devices on microchips.

The speed of innovation is unprecedented, and the chip is miniaturized at a steady speed following the prediction of Moore's Law. Early transistors were visible to the naked eye, but nowadays, a small chip can hold billions of transistors. It can be said that the steady development of electronic computing has proved the outstanding value of silicon, and its development has been more than 70 years.

But the disadvantages of silicon are becoming prominent. For a long time, the computing power of microchips has been advancing at a rate of doubling every two years. This is the so-called Moore's Law, but this law that has been running for decades has been slowing down, and it may be very slow. It will end soon.

For now, using current methods, it is almost impossible to etch elements into silicon (such as transistors) with a minimum size of less than about 3 nanometers. (From one point of view, the thickness of a 3nm film can be as low as 15 atoms.) Therefore, the technology industry is looking for other materials comparable to silicon or at least combined with it to greatly increase the thickness and capacity of its silicon. material.

Researchers at the forefront of physics, chemistry, or engineering are experimenting with alternative materials for microchips, including graphene, black phosphorus, transition metal dihalides, and boron nitride nanosheets. These materials are also called 2-D materials because they are flat plates of only one atom or two thicknesses.

Since two-dimensional materials have only one atom or two thicknesses, they can be grown on silicon microchips or grown separately and placed carefully. Deep Jariwala, a professor of engineering at the University of Pennsylvania who specializes in nanotechnology, believes that this has two advantages over the solution that only stacks silicon layers. One is that many chips can be stacked without increasing the height of the chips. The second is that some two-dimensional materials (especially graphene) have a very good heat dissipation effect. Engineers can use them to make high-rise slabs, which run faster than traditional microchips without burning themselves.

In addition, the two-dimensional material has a unique sensitivity to light, and the treatment of it will make the current equipment upgrade more meaningful. Light will be a faster and more effective way of communication between microchips and other components in computers, internally and between them, thus accelerating the speed at which electrons are replaced by photons within microchips and communication networks.

It is particularly worth mentioning that the grandfather of all two-dimensional materials is graphene. Graphene has the properties of heat conduction, which allows it to be successfully applied to smartphones and their batteries to keep cool and extend the life of sports equipment. Because its characteristics are more similar to other conductors such as gold or copper, it is unlikely to replace silicon. But graphene has other unique characteristics that make it very useful when combined with traditional silicon microchips.

Semiconductors are the core of electronic products. Semiconductors, passive components, and module devices are connected through integrated circuit boards to form the core components of electronic products such as smartphones and PCs. They are responsible for the carrier and transmission of information and become the cornerstone of the information society. To a large extent, the breakthrough of semiconductors determines the progress of the current society, which also makes the search and development of two-dimensional materials have a more important mission.