China high purity quartz boat for semiconductor Manufacturers, Suppliers, Factory

SiC substrate can have microscopic defects, such as Threading Screw Dislocation (TSD), Threading Edge Dislocation (TED), Base Plane Dislocation (BPD), and others. These defects are caused by deviations in the arrangement of atoms at the atomic level. SiC crystals may also have macroscopic dislocations, like Si or C inclusions, micropipe, hexagonal voids, polymorphs, etc. These dislocations are typically large in size.

The process of isostatic graphite manufacturing is Selecting raw materials, Blending, Molding, Isostatic pressing, Carbonization, Graphitization. 

Currently, most SiC substrate manufacturers use a new crucible thermal field process design with porous graphite cylinders: placing high-purity SiC particle raw materials between the graphite crucible wall and the porous graphite cylinder, while deepening the entire crucible and increasing the crucible diameter.

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.

The ultra-high synthesis temperature and the difficulty of achieving dense sintering of SiC ceramics have limited their development. The sintering process is crucial for SiC ceramics.

Based on the reaction chamber configuration, heat treatment equipment (furnace tube equipment) is mainly divided into three categories: vertical furnace tubes, horizontal furnace tubes, and rapid thermal processing (RTP) furnaces.