Pseudo-Wrap-Gate InAs Nanowire Field Effect Transistor with Pre-Deposited Gate Insulator

Abstract

We fabricated the lateral pseudo-wrap-gated n-type InAs nanowire (NW) field effect transistor (FET) with markedly reduced fabrication steps. The whole surfaces of n-InAs NWs were uniformly covered with gate insulator (Al2O3) at grown (vertical) state on Si substrate by using atomic layer deposition (ALD). This all-around Al2O3 gate insulator is found to be the main contributor of stable device operation and channel passivation [1]. The device fabrication was completed simply with single metal (source, drain, gate contact pads) deposition and photoresist coating after transferring n-InAs NW onto SiO2/Si substrate. The cross-sectional high-resolution transmission electron microscopy (HRTEM) image taken after device fabrication confirms that the n-InAs NW has hexagonal cross-section and its surface is uniformly coated with ~10 nm thick Al2O3 layer. The completed n-InAs NW FET showed the good current saturation and low voltage operation with the peak transconductance of ~13.4 mS/mm, the field effect mobility of ~1,039 cm2/Vs, and the current on/off ratio of ~750.