Enhancement of pH-sensitivity using In0.53Ga0.47As channel ion-sensitive-field-effect-transistors

Abstract

In this paper, for the first time, a pH-sensor using an In0.53Ga0.47As based ion-sensitive-field-effect-transistor (ISFET) is proposed to show its superior sensing performance as compared to its equivalent Si counterpart. Extensive numerical analyses of the proposed In0.53Ga0.47As-ISFET are performed in order to extract various sensitivity parameters, e.g., threshold voltage sensitivity (Vth-sensitivity), ON-current sensitivity (ION-sensitivity), and gate-voltage sensitivity (VGS-sensitivity), followed by the performance comparison with the equivalent Si-ISFET sensor, the experimental data of which are used for calibration of the simulation framework. The obtained results show that the long-channel In0.53Ga0.47As-ISFET sensor exhibits 10, 962%, and 9.75% improvement for Vth-sensitivity, ION-sensitivity, and VGS-sensitivity respectively, compared to the equivalent Si-ISFET-sensor at supply voltage of 0.5 V. Furthermore, our findings reveal that a down-scaled ISFET, for instance, a 40-nm-In0.53Ga0.47As-ISFET sensor shows 26, 213% and 10.5% improvement of Vth-sensitivity, ION-sensitivity, and VGS-sensitivity, respectively at the same supply voltage compared to its equivalent Si ISFET sensor.