China epitaxial layer growth Manufacturers, Suppliers, Factory

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 wafer boats, loaded with a batch of wafers to be processed, are positioned on long cantilevered paddles.

Tantalum carbide coating is an important high-strength, corrosion-resistant and chemically stable high-temperature structural material with a melting point of up to 4273 °C, one of the several compounds with the highest temperature resistance. It has excellent high-temperature mechanical properties, resistance to high-speed airflow scouring, ablation resistance, and good chemical and mechanical compatibility with graphite and carbon/carbon composites. Therefore, in the epitaxial process of GaN LEDs and SiC power devices such as MOCVD, TaC coating has excellent acid and alkali resistance to H2, HCl, NH3, which can completely protect the graphite substrate material and purify the growth environment.

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.

The first generation of semiconductor materials is mainly represented by silicon (Si) and germanium (Ge), which began to rise in the 1950s. Germanium was dominant in the early days and was mainly used in low-voltage, low-frequency, medium-power transistors and photodetectors, but due to its poor high temperature resistance and radiation resistance, it was gradually replaced by silicon devices in the late 1960s. Silicon is still the main semiconductor material in the field of microelectronics due to its high technological maturity and cost advantages.

The wafer notch is a V-shaped or U-shaped groove on the edge of a semiconductor wafer. Far from being a defect incurred during the manufacturing process, it is the critical structural marker that was intentionally designed, whose core function lies in enabling precise positioning and orientation identification of the wafer. Wafer flat was used as the orientation marking in the early stages of wafer technology development. However, as wafer sizes gradually increased, the flat-edge design occupied more effective area, thus being gradually replaced by the more compact notch.