Advantages of CVD diamond in semiconductor field

The appearance and composition of CVD diamond are almost the same as natural diamond, and the physical and chemical characteristics are not much different, and no difference can be seen between the two under the naked eye. However, the reason why CVD diamond is valued, the most important reason is "pure", it is more clean than natural diamond, almost no impurities.

The rising star of semiconductor materials: CVD diamond

The extremely high purity makes CVD diamonds more likely to be used than natural diamonds - for example, thanks to their excellent electrical properties, diamond materials are now leading the way in the semiconductor field. Diamond and c-BN (6.4eV), Ga2O3 (4.8eV), AIN (4.eV) and other materials with bandgap width of about 5eV, both belong to the current hot ultra-wide bandgap semiconductor materials. Among them, the band gap of diamond is 5.47eV, which is the widest material in the current simple semiconductor materials, and its electrical properties are extremely excellent:

① Extremely high breakdown electric field: up to 109Vem-1, which is 17 times that of gallium baside material, 2 times that of gallium nitride material, and 2.5 times that of silicon carbide material.

2 saturated carrier speed: in terms of saturated carrier speed, diamond is 2.7 times that of silicon and gallium arsenide, and the carrier speed is larger than the peak value of gallium foundation, that is, it can also maintain its high rate when the field strength increases.

③ Carrier mobility: diamond electron mobility and hole mobility are better than other semiconductor materials, electron mobility at room temperature is 4500cm2/V·S, silicon is only 1500cm2/V·S, gallium arsenide is 8500cm²/ v-s, gallium nitride is less than 1000cm2/V·S; The hole mobility of diamond is 3800cm2/V·S, while silicon is only 600cm2/VS, gallium arsenide is 400cm2/V·S, and gallium nitride is <50cm2/V·S. Therefore, diamond can make high-frequency electronic devices.

4 Low dielectric constant: the dielectric constant of diamond is 5.7, about half of gallium arsenide and less than half of InP, that is, at a given frequency, diamond semiconductors have superior capacitive loads, which provides great convenience for the design of millimeter wave devices.