China wafer pedestal Manufacturers, Suppliers, Factory

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.

Specialty graphite is graphite with carbon mass fraction greater than 99.99%, also known as "three high graphite" (high strength, high density, high purity). It is characterized by high strength, high density, high purity, high chemical stability, high thermal and electrical conductivity, high temperature resistance, radiation resistance, strong lubrication and easy processing. Isostatic graphite belongs to specialty graphite.

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.

In the process of wafer preparation, there are two core links: one is the preparation of the substrate, and the other is the implementation of the epitaxial process. The substrate, a wafer carefully made of semiconductor single crystal material, can be directly put into the wafer manufacturing process as a basis to produce semiconductor devices, or further enhance the performance through the epitaxial process.

High-purity quartz possesses remarkable physical and chemical properties. Its inherent crystal structure, shape, and lattice variations contribute to exceptional characteristics such as high-temperature resistance, corrosion resistance, abrasion resistance, low thermal expansion coefficient, high insulation, piezoelectric effects, resonant effects, and unique optical properties. These attributes make it an irreplaceable foundational material for the development of strategic and pillar industries.

When producing large-sized GaN single crystal substrates, HVPE is currently the best choice for commercialization. However, the back carrier concentration of the grown GaN cannot be precisely controlled.