ABSTRACT
Ion-implantation is an indispensable technique for planar selective-area doping of SiC devices. Thermal diffusion of the desired dopants is not possible because of their extremely low diffusivities in SiC at temperatures <1800°C [1]. At these high temperatures, it is difficult to find a suitable mask for the dopant diffusion, and at the same time the SiC surface itself also incurs severe damage from Si sublimation. An alternative method for selective-area doping of SiC devices is in situ doping of SiC layers during epitaxial growth, followed by reactive ion etching to define doped regions of the devices. Problems with in situ doping include a loss of planarity, which results in a low yield of integrated circuit manufacturing, and the complexity of obtaining different doping profiles for different devices on the same wafer.
