China test wafer Manufacturers, Suppliers, Factory

Semiconductor materials can be divided into three generations according to the time sequence. The first generation of germanium, silicon and other common monomaterials, which is characterised by convenient switching, generally used in integrated circuits. The second generation of gallium arsenide, indium phosphide and other compound semiconductors, mainly used for light-emitting and communication materials.

As a third-generation semiconductor material, Gallium Nitride is often compared with Silicon Carbide. Gallium Nitride still demonstrates its superiority with its large bandgap, high breakdown voltage, high thermal conductivity, high saturated electron drift velocity and strong radiation resistance. But it is undeniable that, like Silicon Carbide, Gallium Nitride also has various technical difficulties.

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.

Chemical Vapor Deposition (CVD) is a versatile thin-film deposition technique widely employed in the semiconductor industry for fabricating high-quality, conformal thin films on various substrates. This process involves chemical reactions of gaseous precursors onto a heated substrate surface, resulting in the formation of a solid thin film. This article delves into the intricacies of CVD, exploring its mechanisms, advantages, limitations, and key applications in semiconductor manufacturing.

The basic crystal unit cell of monocrystalline silicon is the zinc blende structure, in which each silicon atom bonds chemically with four neighboring silicon atoms. This structure is also found in monocrystalline carbon diamonds.

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.