Sapphire ingots are aluminum oxide crystals used to produce sapphire substrates.
The application of the sapphire ingots is the application of sapphire. As long as we know the performance of sapphire, we can know the application of sapphire ingots. Sapphire has a hexagonal lattice structure, and many properties are determined by its crystal orientation. Through the epitaxial film growth, different crystal orientations will show different lattice matching with the target material. Sapphire has a certain birefringence, and a special crystal axis is used in some optical fields.
For example, polarized substrate:
C-section sapphire substrate is used to grow III-V and II-VI group deposited films, such as Gallium Nitride, which can produce blue LED products, laser diodes, and infrared detector applications.
A-typle substrates produce uniform permittivity/dielectric, and high insulation is used in Hybrid Microelectronics. High-temperature superconductors can be produced by long crystals on A-type substrates.
Different deposited silicon externally elongated crystals grown on R-type substrates has been used in microelectronic integrated circuits. Because of its high capacitance, sapphire is the best choice for hybrid substrates, such as in microwave integrated circuits. In addition, high-speed integrated circuits and pressure sensors can also be formed in the process of epitaxial silicon film making. The R-type substrate growth can also be used in the fabrication of mounds, other superconducting components, high resistance resistors, and gallium arsenide.
M. Both type A and type R can grow non-polar or semi-polar Gan. Sapphire as a commercial product still needs a lot of research to improve the material quality of Gan epitaxial.
Purity:
Sapphire is an insulating material, and its semiconductor properties are changed by dopants and impurities. Therefore, most of the purity control is not due to the strict control of the substrate materials (silicon, gallium arsenide, indium phosphide...). However, some trace dopants change their optical properties (color, photoconductive range), which is very important for applications in some fields (Optics, military).
Because the purity of sapphire has a strong influence on the electrical properties and cross-contamination of the metal surface when applied to CMOS (complementary metal-oxide-semiconductor), it is also very important in the application of SOS (silicon on sapphire technology). There is no evidence that sapphire purity has an impact on LED applications, and SOS manufacturers attribute their characteristics to sapphire substrates.
