Method for forming an oxide-filled trench in silicon carbide

A method for forming an oxide-filled trench in silicon carbide includes the steps of amorphizing a portion of a monocrystalline silicon carbide substrate to thereby define an amorphous silicon carbide region in the substrate and then oxidizing the amorphous region to thereby form an oxide-filled trench in the substrate. Because of the enhanced rate of oxidation in the amorphous region as compared to the rate of oxidation of the surrounding monocrystalline silicon carbide regions at relatively low temperatures, the oxide-filled trench is generally defined by the lateral and vertical dimensions of the amorphous silicon carbide region. The amorphizing step includes the steps of masking an area on the face on the monocrystalline silicon carbide substrate to thereby expose a portion of the substrate wherein the amorphous region is to be formed and then directing ions to the face, such that the ions implant into the exposed portion of the substrate and create an amorphous silicon carbide region therein. The implanted ions are preferably selected from the group consisting of silicon, hydrogen, neon, helium, carbon and argon.