China isostatic graphite block Manufacturers, Suppliers, Factory

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.

In the semiconductor industry, epitaxial layers play a crucial role by forming specific single-crystal thin films atop a wafer substrate, collectively known as epitaxial wafers. Particularly, silicon carbide (SiC) epitaxial layers grown on conductive SiC substrates produce homogenous SiC epitaxial wafers, which are instrumental in the fabrication of power devices such as Schottky diodes, MOSFETs, and IGBTs, with 4H-SiC substrates being the most widely utilized.

The process of monocrystalline silicon growth predominantly occurs within a thermal field, where the quality of the thermal environment significantly impacts crystal quality and growth efficiency. The design of the thermal field plays a pivotal role in shaping temperature gradients and gas flow dynamics within the furnace chamber. Furthermore, the materials used in constructing the thermal field directly influence its lifespan and performance.

Wide bandgap (WBG) semiconductors such as Silicon Carbide (SiC) and Gallium Nitride (GaN) are expected to play an increasingly important role in power electronic devices. They offer several advantages over traditional Silicon (Si) devices, including higher efficiency, power density, and switching frequency. Ion implantation is the primary method for achieving selective doping in Si devices. However, there are some challenges when applying it to wide bandgap devices. In this article, we will focus on some of these challenges and summarize their potential applications in GaN power devices.

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 thermal conductivity of bulk 3C-SiC, recently measured, is the second-highest among inch-scale large crystals, ranking just below diamond. Silicon carbide (SiC) is a wide bandgap semiconductor extensively used in electronic applications, and it exists in various crystalline forms known as polytypes. Managing high localized heat flux is a significant challenge in power electronics, as it can lead to device overheating and long-term performance and reliability issues.