Simulations of carrier confinement in boron delta-doped diamond devices
Résumé
Diamond delta-doped field effect transistors are expected to combine high speed and high power commutation. Critical parameters for the design of a diamond 2D hole gas were determined. The investigated diamond structures were made of an infinite or semi-infinite diamond crystal with a low boron concentration and of a thin highly boron-doped 2D diamond layer called the delta-layer. The carrier density, wave-function extension, energy spectrum, and band-edges along the device depth were calculated depending on the delta-layer thickness, boron concentration, and device geometry. The simulations showed that the thickness of the delta-layer and the boron doping concentration were the most important parameters, the fraction of holes delocalized out of the delta-layer decreasing from 90% for an ideal single atomic plane boron doped at 10(21) cm(-3) down to 30% for a 3 nm thick layer.