Epitaxial Growth

Epitaxy is a process that grows a uniform layer of silicon carbide on the polished surface of a silicon carbide wafer.  Polished wafers are transferred to Caracal’s epitaxial reactor, which has the capacity to process multiple wafers.  A recipe reflecting customer specifications is programmed for each run.  The epitaxial layer is designed to have different compositional and electrical properties from the underlying substrate, tailored to the specific demands of the device.

The epitaxial growth technique employed by Caracal is called chemical vapor deposition (CVD).  In this process, source gases such as silane and propane are introduced into a heated reaction chamber that also includes the silicon carbide substrate upon which the source gases react to form the epitaxial layer.  In order to help control the rate of growth reaction, the gases are typically introduced with a carrier gas, with the carrier gas forming the largest volume of the gas flow.

We have filed a patent for our enhancements to this process which improve growth rates, produce smoother surfaces, and allow for higher reactor capacity.  In order to capitalize on these improvements, we have designed and built in-house CVD reactors which are technologically superior to any available in today’s market.  As is the case with our bulk growth reactors, the design effort focused on reducing production cost while improving quality through a recipe-driven, fully automated control system.