China semiconductor material Manufacturers, Suppliers, Factory

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.

Defect-free epitaxial growth occurs when one crystal lattice has nearly identical lattice constants to another. Growth happens when lattice sites of the two lattices at the interface region are approximately matched, which is possible with a small lattice mismatch (less than 0.1%). This approximate matching is achieved even with elastic strain at the interface, where each atom is slightly displaced from its original position in the boundary layer. While a small amount of strain is tolerable for thin layers and even desirable for quantum well lasers, the strain energy stored in the crystal is generally lowered by the formation of misfit dislocations, which involve a missing row of atoms in one lattice.

Silicon carbide (SiC) has important applications in areas such as power electronics, high-frequency RF devices, and sensors for high-temperature-resistant environments due to its excellent physicochemical properties. However, the slicing operation during SiC wafer processing introduces damages on the surface, which, if left untreated, can expand during the subsequent epitaxial growth process and form epitaxial defects, thus affecting the yield of the device.

In the process of silicon wafer manufacturing, after the crystal rod is cut into silicon wafers, it will need to be polished and cleaned to obtain a single crystal silicon wafer like a mirror.

Homoepitaxy and heteroepitaxy play pivotal roles in material science. Homoepitaxy involves the growth of a crystalline layer on a substrate of the same material, ensuring minimal defects due to perfect lattice matching. In contrast, heteroepitaxy grows a crystalline layer on a different material substrate, which can lead to challenges like lattice mismatch. These processes are crucial in advancing semiconductor devices and thin films. For instance, heteroepitaxy significantly impacts microelectronics and quantum optics, contributing to innovations like Light Emitting Diodes.