Leakage current conduction mechanisms and electrical properties of atomic-layer-deposited HfO2/Ga2O3 MOS capacitors

In this paper, current conduction mechanisms in HfO2/β-Ga2O3 metal-oxide-semiconductor (MOS) capacitors under positive and negative biases are investigated using the current-voltage (I-V) measurements conducted at temperatures from 298 K to 378 K. The Schottky emission is dominant under positively b...

Full description

Saved in:
Bibliographic Details
Published in:Journal of physics. D, Applied physics Applied physics, 2018-01, Vol.51 (7)
Main Authors: Zhang, Hongpeng, Jia, Renxu, Lei, Yuan, Tang, Xiaoyan, Zhang, Yimen, Zhang, Yuming
Format: Article
Language:English
Subjects:
ALD hafnium oxide
current conduction mechanism
Ga
gallium oxide
high
MOSCAP
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In this paper, current conduction mechanisms in HfO2/β-Ga2O3 metal-oxide-semiconductor (MOS) capacitors under positive and negative biases are investigated using the current-voltage (I-V) measurements conducted at temperatures from 298 K to 378 K. The Schottky emission is dominant under positively biased electric fields of 0.37-2.19 MV cm−1, and the extracted Schottky barrier height ranged from 0.88 eV to 0.91 eV at various temperatures. The Poole-Frenkel emission dominates under negatively biased fields of 1.92-4.83 MV cm−1, and the trap energy levels are from 0.71 eV to 0.77 eV at various temperatures. The conduction band offset (ΔEc) of HfO2/β-Ga2O3 is extracted to be 1.31  ±  0.05 eV via x-ray photoelectron spectroscopy, while a large negative sheet charge density of 1.04  ×  1013 cm−2 is induced at the oxide layer and/or HfO2/β-Ga2O3 interface. A low C-V hysteresis of 0.76 V, low interface state density (Dit) close to 1  ×  1012 eV−1 cm−2, and low leakage current density of 2.38  ×  10−5 A cm−2 at a gate voltage of 7 V has been obtained, suggesting the great electrical properties of HfO2/β-Ga2O3 MOSCAP. According to the above analysis, ALD-HfO2 is an attractive candidate for high voltage β-Ga2O3 power devices.
ISSN:0022-3727
1361-6463
DOI:10.1088/1361-6463/aaa60d