Lattice strains induced by N and Al ion implantation into 4H-SiC epilayers

Abstract Doping-induced strains in 4H-SiC epilayers may lead to generation of new defects which could degrade the performance and reliability of devices. In materials or devices of 4H-SiC doped by N or Al ion implantation, interfacial dislocations on the basal plane at the bottom of implanted layers after activation annealing have been reported in literature. However, the formation mechanism remains unclear. In this paper the resolved shear stress on the basal plane contributed by ion implantation and annealing processes is analyzed. The c-lattice and a-lattice strains induced by N and Al ion implantation into 4H-SiC epilayers before and after activation annealing are measured by high resolution X-ray diffraction. The conditions of interfacial dislocation formation after ion implantation and activation annealing are discussed.