Interface engineering for a stable chemical structure of oxidized-black phosphorus via self-reduction in AlOx atomic layer deposition

被引：7

作者：

Kim, Dae-Kyoung ^{[1
]}

Chae, Jimin ^{[1
]}

Hong, Seok-Bo ^{[1
]}

Park, Hanbum ^{[1
]}

Jeong, Kwang-Sik ^{[1
]}

Park, Hyun-Woo ^{[2
]}

Kwon, Se-Ra ^{[2
]}

Chung, Kwun-Bum ^{[2
]}

Cho, Mann-Ho ^{[1
]}

机构：

[1] Yonsei Univ, Dept Phys, Seoul 03722, South Korea

[2] Dongguk Univ, Div Phys & Semicond Sci, Seoul 04620, South Korea

来源：

NANOSCALE | 2018年 / 10卷 / 48期

基金：

新加坡国家研究基金会;

关键词：

FIELD-EFFECT TRANSISTORS; EXFOLIATION; GRAPHENE; PASSIVATION; SURFACE;

D O I：

10.1039/c8nr06652c

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

We evaluated the change in the chemical structure between dielectrics (AlOx and HfOx) grown by atomic layer deposition (ALD) and oxidized black phosphorus (BP), as a function of air exposure time. Chemical and structural analyses of the oxidized phosphorus species (PxOy) were performed using atomic force microscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, first-principles density functional theory calculations, and the electrical characteristics of field-effect transistors (FETs). Based on the combined experiments and theoretical investigations, we clearly show that oxidized phosphorus species (PxOy, until exposed for 24 h) are significantly decreased (self-reduction) during the ALD of AlOx. In particular, the field effect characteristics of a FET device based on Al2O3/AlOx/oxidized BP improved significantly with enhanced electrical properties, a mobility of approximate to 253 cm(2) V-1 s(-1) and an on-off ratio of approximate to 10(5), compared to those of HfO2/HfOx/oxidized BP with a mobility of approximate to 97 cm(2) V-1 s(-1) and an on-off ratio of approximate to 10(3)-10(4). These distinct differences result from a significantly decreased interface trap density (D-it approximate to 10(11) cm(-2) eV(-1)) and subthreshold gate swing (SS approximate to 270 mV dec(-1)) in the BP device caused by the formation of stable energy states at the AlOx/oxidized BP interface, even with BP oxidized by air exposure.

引用

页码：22896 / 22907

页数：12