Enhancement of InSe Field-Effect-Transistor Performance against Degradation of InSe Film in Air Environment.

Yadong Zhang,Zhenhua Wu,Xiaoting Sun,Kunpeng Jia,Huaxiang Yin,Jiahan Yu,Kun Luo

doi:10.3390/nano11123311

Abstract

The degradation of InSe film and its impact on field effect transistors are investigated. After the exposure to atmospheric environment, 2D InSe flakes produce irreversible degradation that cannot be stopped by the passivation layer of h-BN, causing a rapid decrease for InSe FETs performance, which is attributed to the large number of traps formed by the oxidation of 2D InSe and adsorption to impurities. The residual photoresist in lithography can cause unwanted doping to the material and reduce the performance of the device. To avoid contamination, a high-performance InSe FET is achieved by a using hard shadow mask instead of the lithography process. The high-quality channel surface is manifested by the hysteresis of the transfer characteristic curve. The hysteresis of InSe FET is less than 0.1 V at Vd of 0.2, 0.5, and 1 V. And a high on/off ratio of 1.25 × 108 is achieved, as well relative high Ion of 1.98 × 10−4 A and low SS of 70.4 mV/dec at Vd = 1 V are obtained, demonstrating the potential for InSe high-performance logic device.

Highlights

InSe, which belongs to the family of metal chalcogenide layer semiconductors, is an attractive material in the field of electronics because of its direct and moderate band gap of 1.26 eV of monolayer, ultra-high mobility of 1000 cm2 ·V−1 ·s−1 at room temperature, which can be further optimized by strain engineering [12]
Compared with graphene, which is of high mobility but vanished band gap, InSe is more suitable as the channel material for field effect transistors (FETs) [13]
As the MoS2 flakes prepared on SiO2 /Si substrate [19], InSe films, prepared on HfO2 /Si substrate, have different kinds of colors reflecting under the optical microscope, which can be related to nanometric changes in the thickness of films

Summary

Introduction

Increasing attention has been attracted by two-dimensional (2D) materials, including transition metal dichalcogenides (TMDs), III-VI layered semiconductors (InSe, In2 Se3 ), black phosphorus and graphene, for their potential applications in photo electronic devices, field effect transistors (FETs), integrated circuits and three-dimensional integrated circuit (3D-IC) [1,2,3,4,5]. InSe, which belongs to the family of metal chalcogenide layer semiconductors, is an attractive material in the field of electronics because of its direct and moderate band gap of 1.26 eV of monolayer, ultra-high mobility of 1000 cm2 ·V−1 ·s−1 at room temperature, which can be further optimized by strain engineering [12]. Compared with graphene, which is of high mobility but vanished band gap, InSe is more suitable as the channel material for FETs [13].

Methods

Results

Conclusion