The next generation of power devices will face major technical challenges in 2013

January 2013 is almost halfway through, and I would like to introduce a field that will attract attention in 2013. There are many such fields, but this time I would like to talk about the trends of next-generation power semiconductors such as SiC and GaN. The reason why this field is attracting attention is that in 2013, the scope of use of next-generation power semiconductors is expected to continue to expand after 2012.

　　In 2012, the adoption of SiC diodes in the railway and industrial equipment fields became active. With this trend, the development of SiC power components is also accelerating. The appearance of "full SiC" power module products equipped with SiC diodes and SiC MOSFETs became a hot news in 2012.

　　GaN power components also made great progress in 2012. The 600V withstand voltage GaN power transistor was unveiled in 2012, while the maximum withstand voltage of previous products was only 200V.

　　Therefore, in simple terms, SiC and GaN power devices are now more accessible than they were a few years ago. Compared to power devices using Si, these devices can switch at high speeds, which greatly reduces switching losses. They can also achieve "high-frequency operation" that switches at higher frequencies. This makes it easy to miniaturize peripheral components such as inductors. In addition, these new power devices can also "operate at high temperatures", which can make the size of the cooler smaller.

　　In fact, in order to take advantage of the advantages of high-speed switching, high-frequency operation, and high-temperature operation, many issues must be resolved. For example, high-speed switching requires the prevention of surges, transients, and electromagnetic noise; high-frequency operation has the problem of increased reactance loss; and high-temperature operation requires the use of low-cost peripheral components, and stable operation must be achieved at temperatures above 200°C. To solve these issues, new technologies must be accumulated.

　　Silicon carbide and gallium nitride have become the third-generation semiconductor materials.

　　Semiconductors are materials between conductors and insulators. Since their official invention on December 23, 1947, they have been widely used in home appliances, communications, networks, aviation, aerospace, national defense and other fields, bringing revolutionary impact to the electronics industry.

　　In 2010, the global semiconductor market reached US$298.3 billion, driving a trillion-dollar electronics market.

　　As the semiconductor market grows, semiconductor materials continue to make breakthroughs.

　　Germanium and silicon are generally referred to as first-generation semiconductor materials.

　　Gallium arsenide, indium phosphide, etc. are called second-generation semiconductor materials, while wide-bandgap silicon carbide, gallium nitride and diamond are called third-generation semiconductor materials.

　　Among the first generation of materials, 12-inch single crystal silicon has been mass-produced, and 18-inch single crystal silicon has been successfully developed in the laboratory. The global annual consumption of silicon in integrated circuits is approximately 20,000 tons.

　　As for polysilicon, due to the insufficient purity of domestic products, silicon wafers used in my country's integrated circuits are basically imported.

　　In 2011, my country's polysilicon production was 50,000 tons.

　　In terms of silicon-based microelectronics technology, 8 inches has been widely used in large-scale integrated circuits internationally, and my country currently has about 38 5- to 12-inch integrated circuit lines.

　　In terms of technology level, the international 12-inch 45-nanometer process has also been put into industrial production, and the 16-nanometer process is expected to be developed in 2016.

　　However, my country is still at the 0.18-micron, 90-nanometer, and 65-nanometer levels, and only a few companies have 45-nanometer technology.

　　By 2015, my country will have multiple 8-inch and 12-inch production lines with a capacity of 45 to 90 nanometers, and will be at the forefront of the world by 2022.

　　However, as the level of integration increases, silicon chips will encounter many difficulties. For example, the chip power consumption will increase sharply, which may cause the silicon wafer to melt.

　　It is internationally expected that the "limit" size of 10 nanometers will be reached in 2022.

　　Therefore, silicon-based microelectronics technology will eventually be unable to meet humanity's growing demand for information.

　　People are now beginning to place their hopes on developing new semiconductor materials and developing new technologies.

　　The second-generation semiconductor materials represented by gallium arsenide (GaAs) and indium phosphide (InP) continue to challenge silicon.

　　It can increase the speed of devices and circuits, and solve the problem of increased power consumption due to increased integration.

　　Materials such as GaAs and InP are widely used in satellite communications, mobile communications, optical communications, GPS navigation, etc. GaAs with diameters of 2, 4, and 6 inches have been commercialized, and 8-inch ones have also been successfully developed in the laboratory.

　　The third generation of semiconductor materials represented by gallium nitride, silicon carbide, zinc oxide, etc. are also developing rapidly. These materials are wide bandgap semiconductor materials. They have the characteristics of large bandgap width, high breakdown voltage, large thermal conductivity, fast electron saturation drift velocity, small dielectric constant, etc., and can be widely used in many fields. For example, in the field of semiconductor white light lighting, by 2015, my country will develop 150lm/W semiconductor lighting lamps, which only require 3 to 4 volts, and are very safe and energy-saving.

　　The development trend of semiconductor materials is from three-dimensional materials to low-dimensional materials. At present, low-dimensional materials based on GaAs and InP have been developed very maturely and are widely used in the fields of optical communication, mobile communication and microwave communication.

　　In fact, these low-dimensional semiconductor materials are also nanomaterials. The application of semiconductor nanoscience and technology will control and manufacture artificial microstructure materials with powerful functions and superior performance at the atomic, molecular and nanoscale levels, as well as devices, electrical appliances and circuits based on them, which is very likely to trigger a new technological revolution and enable humans to enter the unpredictable quantum world.