China Semiconductor Focus Ring Coating 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.

In November 2023, Semicorex released 850V GaN-on-Si epitaxial products for high-voltage, high-current HEMT power device applications. Compared to other substrates for HMET power devices, GaN-on-Si enables larger wafer sizes and more diversified applications, and it can also be quickly introduced into the mainstream silicon chip process in fabs, which is a unique advantage for improving the yield of power devices.

The Silicon Carbide (SiC) production process encompasses the preparation of substrate and epitaxy from the materials side, followed by chip design and manufacturing, device packaging, and finally, distribution to downstream application markets. Among these stages, substrate material processing is the most challenging aspect of the SiC industry. SiC substrates are both hard and brittle, making cutting, grinding, and polishing extremely difficult. This increases the likelihood of defects during processing and reduces the yield rate. Currently, major international SiC manufacturers are planning to transition from 6-inch to 8-inch SiC wafers. Overcoming the challenges associated with 8-inch substrates has become a critical benchmark for the SiC industry. This article will introduce the key parameters of SiC substrates.

The most basic stage of all processes is the oxidation process. The oxidation process is to place the silicon wafer in an atmosphere of oxidants such as oxygen or water vapor for high-temperature heat treatment (800~1200℃), and a chemical reaction occurs on the surface of the silicon wafer to form an oxide film (SiO2 film).

The degree of graphitization is an essential measure used to assess how close carbon atoms are to forming a tightly-packed hexagonal graphite crystal structure.

Etching Process: Silicon vs. Silicon Carbide