Capacitance-voltage characteristics of MIS-structures on the basis of graded-band MBE Hg1−xCdxTe at passivation by epitaxially grown in situ CdTe

Abstract

The electrical properties of the interface between Hg1−xCdxTe (x = 0.22 and x = 0.32–0.36) and CdTe prepared in situ molecular beam epitaxy were estimated at 77 K. The methods of determination of main parameters of interface semiconductor/insulator and insulator from capacitance-voltage characteristics of MIS-structures based on graded-band Hg1−xCdxTe have been developed. The fixed charge states density, fast surface states density, and density of mobile charge are obtained from capacitance-voltage measurements. For improvement in stable and electrical strength of insulator coating for several samples over CdTe additional protective layers SiO2-Si3N4 are formed for x = 0.22 and ZnTe for x = 0.32–0.36.