Effect of indium concentration on InGaAs channel metal-oxide-semiconductor field-effect transistors with atomic layer deposited gate dielectric

Abstract

In0.53Ga0.47As and In0.7Ga0.3As surface channel metal-oxide-semiconductor field-effect transistors (MOSFETs) with atomic layer deposition of Al2O3 and ZrO2 have been fabricated and investigated. The device performance of InGaAs channel MOSFETs with various indium compositions (53% and 70%) has been studied, including drain current, transconductance, subthreshold swing, and interface trap density (Dit)⁠. It has been found that In0.53Ga0.47As MOSFETs exhibit higher transconductance and lower subthreshold swing than In0.7Ga0.3As MOSFETs for both Al2O3 and ZrO2 gate dielectric (e.g., 125 mV/decade versus 160 mV/decade for Al2O3⁠). The interface trap density measured using conductance method (⁠1.1×1012 eV−1 cm−2 versus 3.2×1012 eV−1 cm−2 for Al2O3⁠) suggests a better interface at high-k dielectric/In0.53Ga0.47As channel. Capacitance-voltage measurement at 77 K also correlates with the above results, showing smaller frequency dispersion for In0.53Ga0.47As devices.