China epitaxy film Manufacturers, Suppliers, Factory

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.

Heat treatment is one of the essential and important processes in the semiconductor process. Thermal process is the process of applying thermal energy to a wafer by placing it in an environment filled with a specific gas, including oxidation/diffusion/annealing, etc.

The third generation of semiconductor materials AlN belongs to the direct bandgap semiconductor, its bandwidth of 6.2 eV, with high thermal conductivity, resistivity, breakdown field strength, as well as excellent chemical and thermal stability, is not only an important blue light, ultraviolet materials, or electronic devices and integrated circuits, important packaging, dielectric isolation and insulation materials, especially for high-temperature high-power devices. In addition, AlN and GaN have a good thermal match and chemical compatibility, AlN used as GaN epitaxial substrate, can significantly reduce the defect density in GaN devices, improve device performance.

In semiconductor manufacturing, the precision and stability of the etching process are paramount. One critical factor in achieving high-quality etching is ensuring that wafers are perfectly flat on the tray during the process. Any deviation can lead to uneven ion bombardment, causing undesirable angles and variations in etching rates. To address these challenges, engineers have developed Electrostatic Chucks (ESCs), which have significantly improved etching quality and stability. This article delves into the design and functionality of ESCs, focusing on one key aspect: the electrostatic principles behind wafer adhesion.

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.

The CVD process for SiC wafer epitaxy involves the deposition of SiC films onto a SiC substrate using a gas-phase reaction. The SiC precursor gases, typically methyltrichlorosilane (MTS) and ethylene (C2H4), are introduced into a reaction chamber where the SiC substrate is heated to a high temperature (usually between 1400 and 1600 degrees Celsius) under a controlled atmosphere of hydrogen (H2).