On the gate capacitance of mos structures in N-Channel inversion layers on ternary chalcopyrite semiconductors

An attempt is made to investigate the gate capacitance of MOS structures in n-channel inversion layers on ternary chalcopyrite semiconductors at low temperatures, taking n-channel inversion layers on CdGeAs₂ as examples, under both the weak and strong electric field limits, respectively. We have formulated the gate capacitance on the basis of newly derived 2D electron energy spectra for both the limits by considering the various anisotropies of the band parameters within the framework ofk·p formalism. It has been observed that, the gate capacitance increases with increasing surface electric field in an oscillatory manner and the theoretical results are in good agreement with the experimental observations as reported elsewhere. In addition, the corresponding well-known results for n-channel inversion layers on isotropic parabolic semiconductors are also obtained from the generalized expressions derived under certain limiting conditions.