Low Temperature Impurity Diffusion into Large-Band-Gap Semiconductors

Abstract

Low temperature diffusion of boron and phosphorus has been performed for the first time into the monocrystalline diamond and 6H-SiC wafers through the controlled surface injection of vacancies. By varying the parameters of the surface oxide and polycrystalline silicon overlayer during the boron/phosphorus diffusion process, it was possible to obtain the planar quantum-size pn and np junctions respectively in the 6H-SiC and diamond wafers as well as the 6H-SiC transistor structures. The first findings of the high temperature (77 K) quantized conductance and single-hole transistor operation are present, which identify the formation of self-assembled quantum wells inside ultra-shallow pand ndiffusion profiles. These large-band-gap nanostructures are shown to cause the high electroluminescence efficiency of the diamond and 6H-SiC p-n junctions.