China pv cell Manufacturers, Suppliers, Factory

In the high voltage field, particularly for high-voltage devices above 20,000V, the SiC epitaxial technology still faces several challenges. One of the main difficulties is achieving high uniformity, thickness, and doping concentration in the epitaxial layer. For the fabrication of such high-voltage devices, a 200um thick silicon carbide epitaxial wafer with excellent uniformity and concentration is required.

Compression molding, isostatic pressing, and rod extrusion are the three most common methods for producing graphite rods, similar to those used for creating graphite tubes.

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.

The current third-generation semiconductors are primarily based on Silicon Carbide, with substrates accounting for 47% of device costs, and epitaxy accounting for 23%, totaling approximately 70% and forming the most crucial part of the SiC device manufacturing industry.

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.