δ-Doping in diamond Original Research Article

δ-Boron-doped homoepitaxial diamond films grown by microwave CVD were optimized for field effect transistor application to obtain steep profiles. The critical growth steps of the δ-doped device structures were analyzed and improved using mass spectrometry gas analysis, determining growth- and etch rates, hall-effect-measurements, elastic recoil detection and conductivity measurements. Optimized growth procedures were obtained and residual doping in the gate control layer was compensated using nitrogen. This results in a novel lossy dielectric Junction FET channel with high sheet charge activation and high drain current densities at moderate operation temperatures of 200°C.