China Ceramic Tubes Suppliers Manufacturers, Suppliers, Factory

The development of high-powered blue and UV LEDs has enabled the creation of full-color LED TV displays, as well as white LED automotive and domestic lighting. These LEDs are based on Gallium Nitride, which is deposited on substrate wafers supported by CVD SiC-coated graphite susceptor using the MOCVD process.

Within the silicon carbide (SiC) industry chain, substrate suppliers hold significant leverage, primarily due to value distribution. SiC substrates account for 47% of the total value, followed by epitaxial layers at 23%, while device design and manufacturing constitute the remaining 30%. This inverted value chain stems from the high technological barriers inherent to substrate and epitaxial layer production. Three major challenges plague SiC substrate growth: stringent growth conditions, slow growth rates, and demanding crystallographic requirements. These complexities contribute to increased processing difficulty, ultimately resulting in low product yields and high costs. Furthermore, the epitaxial layer’s thickness and doping concentration are critical parameters directly impacting the final device performance.

The process of silicon carbide substrate is complex and difficult to manufacture. SiC substrate occupies the main value of the industry chain, accounting for 47%. It is expected that with the expansion of production capacity and the improvement of yield in the future, it is expected to drop to 30%.

The degree of graphitization is an essential measure used to assess how close carbon atoms are to forming a tightly-packed hexagonal graphite crystal structure.

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.

In the process of growing SiC and AlN single crystals by the physical vapor transport method (PVT), components such as the crucible, seed crystal holder and guide ring play a vital role. During the preparation process of SiC, the seed crystal is located in a relatively low temperature region, while the raw material is in a high temperature region exceeding 2400°C. The raw materials decompose at high temperatures to form SiXCy (including Si, SiC₂, Si₂C and other components).