China Wafers Etching Manufacturers, Suppliers, Factory

Silicon is a semiconductor material. In the absence of impurities, its own electrical conductivity is very weak. Impurities and crystal defects within the crystal are the main factors affecting its electrical properties.

Thick, high-purity silicon carbide (SiC) layers, typically exceeding 1mm, are critical components in various high-value applications, including semiconductor fabrication and aerospace technologies. This article delves into the Chemical Vapor Deposition (CVD) process for producing such layers, highlighting key process parameters, material characteristics, and emerging applications.

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.

The history of silicon carbide (SiC) dates back to 1891, when Edward Goodrich Acheson accidentally discovered it while attempting to synthesize artificial diamonds. Acheson heated a mixture of clay (aluminosilicate) and powdered coke (carbon) in an electric furnace. Instead of the expected diamonds, he obtained a bright green crystal adhering to the carbon. This crystal had a hardness second only to diamond, and was thus named carborundum. In 1904, French-Jewish chemist Henri Moissan discovered rare natural silicon carbide minerals while studying meteorite samples from the Diablo Canyon in Arizona, USA. He named these minerals moissanite, and his discovery earned him the 1906 Nobel Prize in Chemistry.

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.

Wide bandgap (WBG) semiconductors such as Silicon Carbide (SiC) and Gallium Nitride (GaN) are expected to play an increasingly important role in power electronic devices. They offer several advantages over traditional Silicon (Si) devices, including higher efficiency, power density, and switching frequency. Ion implantation is the primary method for achieving selective doping in Si devices. However, there are some challenges when applying it to wide bandgap devices. In this article, we will focus on some of these challenges and summarize their potential applications in GaN power devices.