Influence of polarity inversion on the electrical properties of Ga-doped ZnO thin films

被引：7
作者：
Nulhakim, Lukman [1 ]
Makino, Hisao [1 ,2 ]
机构：
[1] Kochi Univ Technol, Grad Sch Engn, Kami, Kochi 7828502, Japan
[2] Kochi Univ Technol, Res Inst, Kami, Kochi 7828502, Japan
来源：
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS | 2016年 / 10卷 / 07期
关键词：
ZnO; Ga; doping; polarity; thickness; thin films; electrical properties; valence band spectra; ZINC-OXIDE FILMS; SAPPHIRE; GLASS; THICKNESS;
D O I：
10.1002/pssr.201600113
中图分类号：
T [工业技术];
学科分类号：
08 ;
摘要：
This study investigates how polarity inversion influences the relationship between the electrical properties of heavily Ga-doped ZnO (GZO) films deposited by RF magnetron sputtering and their thickness. The electrical properties observed in very thin films are correlated with a change of polarity from O-polar to Zn-polar face upon increasing the film thickness based on results of valence band spectra measured by X-ray photoelectron spectroscopy. It is found that the electrical properties of very thin GZO films deposited on Zn-polar ZnO templates are significantly improved compared to those deposited on O-polar face. A low resistivity of 2.62 x 10(-4) Omega cm, high Hall mobility of 26.9 cm(2)/V s, and high carrier concentration of 8.87 x 10(20) cm(-3) being achieved with 30 nm-thick GZO films using Zn-polar ZnO templates on a glass substrate. In contrast, the resistivity of 30 nm-thick GZO films on bare glass that shows more likely O-polar is very poor about 1.44 x 10(-3) Omega cm with mobility and carrier concentration are only 11.9 cm(2)/V s and 3.64 x 10(20) cm(-3), respectively. It is therefore proposed that polarity inversion plays an important role in determining the electrical properties of extremely thin GZO films. (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
引用
收藏
页码：535 / 539
页数：5
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