China SIC Epitaxy Silicon-Based Manufacturers, Suppliers, Factory

In semiconductor fabrication, etching is one of the major steps, along with photolithography and thin-film deposition. It involves removing unwanted materials from the surface of a wafer using chemical or physical methods. This step is carried out after coating, photolithography, and developing. It is used to remove the exposed thin film material, leaving only the desired portion of the wafer, and then removing the excess photoresist. These steps are repeated numerous times to create complex integrated circuits.

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.

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.

An Electrostatic Chuck (ESC) is a device used to hold semiconductor wafers in place during processes such as etching, deposition, or polishing.

One of the unique properties of semiconductor materials is that their conductivity, as well as their conductivity type (N-type or P-type), can be created and controlled through a process called doping. This involves introducing specialized impurities, known as dopants, into the material to form junctions on the surface of the wafer. The industry employs two main doping techniques: thermal diffusion and ion implantation.