DIAMOND TRANSISTOR AND METHOD OF MANUFACTURE THEREOF

摘要

A method of manufacturing a transistor, typically a MESFET, includes providing a substrate comprising single crystal diamond material having a growth surface on which further layers of diamond material can be deposited. The substrate is preferably formed by a CVD process and has high purity. The growth surface has a root-mean- square roughness of 3nm or less, or is free of steps or protrusions larger than 3nm. Further diamond layers are deposited on the growth surface to define the active regions of the transistor. An optional n+shielding layer can be formed in or on the substrate, following which an additional layer of high purity diamond is deposited. In one embodiment of the method, a layer of intrinsic diamond is formed directly on the upper surface of the high purity layer, followed by a boron doped ("delta doped") layer. A trench is formed in the delta doped layer to define a gate region.