China nonlinear optics Manufacturers, Suppliers, Factory

The application areas of SiC-based and Si-based GaN are not strictly separated. In GaN-On-SiC devices, the cost of SiC substrate is relatively high, and with the growing maturity of SiC long crystal technology, the cost of the device is expected to fall further, and it is used in power devices in the field of power electronics.

Compared with the PVT method, the liquid phase method for growing SiC has the following advantages:

Chemical Vapor Deposition (CVD) refers to a process technology where multiple gaseous reactants at varied partial pressures undergo a chemical reaction under specific temperature and pressure conditions. The resulting solid substance deposits on the surface of the substrate material, thereby obtaining the desired thin film. In traditional integrated circuit manufacturing processes, the obtained thin film materials are generally compounds such as oxides, nitrides, carbides, or materials like polycrystalline silicon, amorphous silicon, etc.

Currently, most SiC substrate manufacturers use a new crucible thermal field process design with porous graphite cylinders: placing high-purity SiC particle raw materials between the graphite crucible wall and the porous graphite cylinder, while deepening the entire crucible and increasing the crucible diameter.

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.

A critical step in the fabrication of n-type GAAFETs involves the high-selectivity etching of SiGe:Si stacks prior to the deposition of inner spacers, generating silicon nanosheets and releasing channels.