Experimental determination of quantum and centroid capacitance in arsenide–antimonide quantum-well MOSFETs incorporating nonparabolicity effect

Abstract—Experimental gate capacitance (Cg) versus gate voltage data for InAs0.8Sb0.2 quantum-well MOSFET (QW-MOSFET) is analyzed using a physics-based analytical model to obtain the quantum capacitance (CQ) and centroid capac-itance (Ccent). The nonparabolic electronic band structure of the InAs0.8Sb0.2 QW is incorporated in the model. The effec-tive mass extracted from Shubnikov–de Haas magnetotransport measurements is in excellent agreement with that extracted from capacitance measurements. Our analysis confirms that in the op-erational range of InAs0.8Sb0.2 QW-MOSFETs, quantization and nonparabolicity in the QW enhance CQ and Ccent. Our quanti-tative model also provides an accurate estimate of the various con-tributing factors toward Cg scaling in future arsenide–antimonide MOSFETs. Index Terms—Effective mass, high-κ dielectric, InAsSb, interface states, nonparabolicity, quantum capacitance, split capacitance–voltage. I