China High Purity SiC Coated Graphite Manufacturers, Suppliers, Factory

The liquid phase method is closer to the thermodynamic equilibrium conditions and is able to grow SiC crystals with better quality.

We know that further epitaxial layers need to be built on top of some wafer substrates for device fabrication, typically LED light-emitting devices, which require GaAs epitaxial layers on top of silicon substrates; SiC epitaxial layers are grown on top of conductive SiC substrates for building devices such as SBDs, MOSFETs, etc. for high voltage, high current and other power applications; GaN epitaxial layers are built on top of semi-insulating SiC substrates for building HEMTs and other RF applications.

Etching Process: Silicon vs. Silicon Carbide

Currently, many semiconductor devices employ mesa device structures, which are predominantly created through two types of etching: wet etching and dry etching. While the simple and rapid wet etching plays a significant role in semiconductor device fabrication, it has inherent drawbacks such as isotropic etching and poor uniformity, which result in limited control when transferring small-sized patterns. Dry etching, however, with its high anisotropy, good uniformity, and repeatability, has become prominent in semiconductor device fabrication processes. The term “dry etching” broadly refers to any non-wet etching technology used for removing surface materials and transferring micro and nano patterns, including laser etching, plasma etching, and chemical vapor etching. The dry etching discussed in this text specifically pertains to the narrow application of processes using plasma discharge—either physical or chemical—to modify material surfaces.

Carbon-based materials such as graphite, carbon fibers, and carbon/carbon (C/C) composites are known for their high specific strength, high specific modulus, and excellent thermal properties, making them suitable for a wide range of high-temperature applications. These materials are widely utilized in aerospace, chemical engineering, and energy storage. However, their susceptibility to oxidation and corrosion in high-temperature environments, along with poor scratch resistance, restricts their further application.

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.