High doped MBE Si pn and nn heterojunction diodes on 4H-SiC
The physical and electrical properties of heavily doped silicon (51019cm?3) deposited by molecular beam epitaxy (MBE) on 4H-SiC are investigated in this paper. Silicon layers on silicon carbide have a broad number of potential applications including device fabrication or passivation when oxidised. In particular, Si/SiC contacts present several atractive material advantages for the semiconductor industry and especially for SiC processing procedures for avoiding stages such as high temperature contact annealing or SiC etching. Si films of 100nm thickness have been grown using a MBE system after different cleaning procedures on n-type (0001) Si face 8 off 4H-SiC substrates. Isotype (nn) and an-isotype (pn) devices were fabricated at both 500 and 900C using antimonium (Sb) or boron (B), respectively. X-ray diffraction analysis (XRD) and scanning electronic mircorscope (SEM) have been used to investigate the crystal composition and morphology of the deposited layers. The electrical mesurements were performed to determine the rectifiying contact characteristics and band offsets.
silicon silicon carbide heterodiodes high doping si rectifying contact