Characterization of n-type layers formed in (11-20)-4H-SiC by phosphorus ion implantation

Phosphorus ions have been implanted in p-type, (11-20)-oriented 4H-SiC to fabricate highly doped n-type layers, with a box-shaped electrical profile, in the substrate. It has been shown that an implantation-induced amorphous layer epitaxially re-crystallizes during annealing at 1000 °C. Electrical profile measurements have been successfully made on samples annealed at/above 1200 °C. An ∼100 nm-thick n-type layer, uniformly doped at carrier concentrations of ∼1 × 1020 cm−3, is formed after annealing at 1500 °C and an extremely low resistivity of 1.4 × 10−3 Ω cm is achieved in the P-implanted layer. It is also demonstrated that a considerable large number of P atoms are lost from the substrate during annealing above 1400 °C. The surface morphology of P-implanted 4H-SiC is deteriorated when annealed at 1600 °C.