Temperature and Field Dependences of Parameters of the Equivalent Circuit Elements of MIS Structures Based on MBE n-Hg0.775Cd0.225Te in the Strong Inversion Mode

Abstract

A technique is proposed for the determining the parameters of the equivalent circuit elements in strong inversion mode using the measurement results of the admittance of MIS structures based on n-Hg_0.775Cd_0.225Te grown by molecular beam epitaxy. It is shown that at 77 K and frequencies above 10 kHz, the capacitancevoltage characteristics of MIS structures based on n-Hg_0.775Cd_0.225Te with a near-surface graded gap layer have a high-frequency behavior with respect to the recharge time of surface states located near the Fermi level of intrinsic semiconductor. It is established that the electron concentration in the near-surface graded-gap layer exceeds an average concentration found by the Hall method by more than 2 times. The proposed technique was used for determining the temperature dependences of the insulator capacitance, capacitance and differential resistance of the space-charge region, and capacitance of the inversion layer in MIS structures based on n-Hg_0.775Cd_0.225Te without a graded-gap layer. The temperature and voltage dependences of the parameters of the equivalent circuit elements in strong inversion are calculated. The results of calculation are qualitatively consistent with the results obtained from the measurements of the admittance.