Influence of band non-parabolicity on the quantized gate capacitance in δ-doped MODFED of III–V and related materials

Abstract

We have investigated analytically the influence of band non-parabolicity on the quantized gate capacitance in n-channel inversion layers of AlxGa1−xAs∣GaAs, In1−xAsxSb∣InSb, and In1−xAlxAs∣In1−xGaxAsyP1−x δ-doped modulation field effect devices, whose channel electrons obey the three, two, and the parabolic energy band models of Kane. The quantized gate capacitance has been investigated by including the effects of electric subbands under quantum mechanical treatment on GaAs, InSb, and In1−xGaxAsyP1−y lattices matched to InP as channel materials. The oscillatory dependence of the quantized gate capacitance as a function of surface electric field and gate bias signatures directly the two-dimensional quantum confinement of the carriers. The influence of the band non-parabolicity of the confined carriers significantly influences the value of the gate capacitance. The result of the gate capacitances for the parabolic energy band model forms a special case of our generalized theoretical formalism.