China Semiconductor Wafer Processing Boat Manufacturers, Suppliers, Factory

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.

In the high voltage field, particularly for high-voltage devices above 20,000V, the SiC epitaxial technology still faces several challenges. One of the main difficulties is achieving high uniformity, thickness, and doping concentration in the epitaxial layer. For the fabrication of such high-voltage devices, a 200um thick silicon carbide epitaxial wafer with excellent uniformity and concentration is required.

Silicon carbide (SiC) is an inorganic substance. The amount of naturally occurring silicon carbide is very small. It is a rare mineral and is called moissanite. Silicon carbide used in industrial production is mostly artificially synthesized.

The application areas of SiC-based and Si-based GaN are not strictly separated. In GaN-On-SiC devices, the cost of SiC substrate is relatively high, and with the growing maturity of SiC long crystal technology, the cost of the device is expected to fall further, and it is used in power devices in the field of power electronics.

Specialty graphite is graphite with carbon mass fraction greater than 99.99%, also known as "three high graphite" (high strength, high density, high purity). It is characterized by high strength, high density, high purity, high chemical stability, high thermal and electrical conductivity, high temperature resistance, radiation resistance, strong lubrication and easy processing. Isostatic graphite belongs to specialty graphite.

Both epitaxial and diffused wafers are essential materials in semiconductor manufacturing, but they differ significantly in their fabrication processes and target applications. This article delves into the key distinctions between these wafer types.