Semi-insulating 4H-SiC layers formed by the implantation of high-energy (53 MeV) argon ions into n-type epitaxial films

Abstract

It is shown that 9-μm-thick semi-insulating surface layers can be formed in moderately doped n-type silicon carbide (donor concentration 2 × 10¹⁶ cm^–3) via the comparatively low-dose (7 × 10¹¹ cm^–2) implantation of high-energy (53 MeV) argon ions. The free-carrier removal rate is estimated at ~10⁴ cm^–1. The resistivity of the semi-insulator is no less than 7 × 10¹² Ω cm. Analysis of the monopolar current of electron injection into the semi-insulator shows that the impurity-conductivity compensation is due to radiationinduced defects pinning the equilibrium Fermi level at a depth of 1.16 eV below the conduction-band bottom. The density of defect states at the Fermi level is 2.7 × 10¹⁶ cm² eV^–1.