China Silicon Epitaxial Wafer 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.

The four main molding methods for graphite molding are: extrusion molding, molding, vibratory molding and isostatic molding. Most of the common carbon/graphite materials on the market are molded by hot extrusion and molding (cold or hot), and isostatic molding is a method with leading molding performance. Vibration molding is generally used to manufacture medium and coarse structural graphite, particle size between 0.5-2mm particle size, generally dominated by di-roasted graphitized products, density between 1.55-1.75kg/m³, coarser particles, rougher surface, can not be used for precision machining. It is mainly used in chemical industry and metal smelting.

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.

Etching Process: Silicon vs. Silicon Carbide