China asm epitaxy Manufacturers, Suppliers, Factory

There are two types of epitaxy: homogeneous and heterogeneous. In order to produce SiC devices with specific resistance and other parameters for different applications, the substrate must meet the conditions of epitaxy before production can begin. The quality of the epitaxy affects the device's performance.

Tantalum carbide coating is an important high-strength, corrosion-resistant and chemically stable high-temperature structural material with a melting point of up to 4273 °C, one of the several compounds with the highest temperature resistance. It has excellent high-temperature mechanical properties, resistance to high-speed airflow scouring, ablation resistance, and good chemical and mechanical compatibility with graphite and carbon/carbon composites. Therefore, in the epitaxial process of GaN LEDs and SiC power devices such as MOCVD, TaC coating has excellent acid and alkali resistance to H2, HCl, NH3, which can completely protect the graphite substrate material and purify the growth environment.

Graphitising is the process of transforming non-graphitic charcoal into graphitic charcoal with graphite three-dimensional regular ordered structure by high-temperature heat treatment, making full use of electrical resistance heat to heat the charcoal material to 2300~3000 ℃, and transforming the charcoal with amorphous chaotic layer structure into ordered graphite crystalline structure.

There are several materials currently under investigation, among which silicon carbide stands out as one of the most promising. Similar to GaN, it boasts higher operating voltages, higher breakdown voltages, and superior conductivity compared to silicon. Moreover, thanks to its high thermal conductivity, silicon carbide can be utilized in environments with extreme temperatures. Lastly, it is significantly smaller in size yet capable of handling greater power.

At present, the most important direction trend of substrate development is to expand the diameter. The 6-inch mass production line in the global SiC market is maturing, and leading companies have entered the 8-inch market.