Experimental Determination of Quantum and Centroid Capacitance in Arsenide–Antimonide Quantum-Well MOSFETs Incorporating Nonparabolicity Effect

Experimental gate capacitance (Cg) versus gate voltage data for InAs_0.8Sb_0.2 quantum-well MOSFET (QW-MOSFET) is analyzed using a physics-based analytical model to obtain the quantum capacitance (CQ) and centroid capacitance (C_cent). The nonparabolic electronic band structure of the InAs_0.8Sb_0.2 QW is incorporated in the model. The effective mass extracted from Shubnikov-de Haas magnetotransport measurements is in excellent agreement with that extracted from capacitance measurements. Our analysis confirms that in the operational range of InAs_0.8Sb_0.2 QW-MOSFETs, quantization and nonparabolicity in the QW enhance CQ and C_cent. Our quantitative model also provides an accurate estimate of the various contributing factors toward Cg scaling in future arsenide-antimonide MOSFETs.