Sublimation growth with a seed crystal—also known as Physical Vapor Transport—is a variation on the Lely Method. Today PVT is a standard method for growing monocrystalline Silicon Carbide. Thanks to their outstanding properties, crystals produced by means of PVT are used above all in the semiconductor industry and R&D sector.
In the PVT process polycrystalline Silicon Carbide (SiC) undergoes sublimation at the source at a high temperature (1,800–2,600 °C) and low pressure. In a carrier gas (e.g. Argon), the resulting Silicon and Carbon particles are transported through natural mechanisms to the cooler seed crystal, where crystallization through oversaturation takes place. In contrast to the CVD method, no chemical reaction with the carrier gas takes place. The seed crystal is usually located at the upper end of the crucible to prevent contamination from falling particles.
Our PVT-series systems are specially designed for producing Silicon-Carbide crystals for the semiconductor industry and R&D sector.