Conversion of an ultra-wide bandgap amorphous oxide insulator to a semiconductor
Conversion of an ultra-wide bandgap amorphous oxide insulator to a semiconductor
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DOI：
10.1038/am.2017.20
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发表时间：
2017-03-01
影响因子：
9.7
通讯作者：
Kamiya, Toshio
中科院分区：
文献类型：
--
作者：
Kim, Junghwan;Sekiya, Takumi;Kamiya, Toshio
半导体材料的种类已经在各个方向上扩展，例如扩展到诸如氧化物半导体的非常宽带隙的材料以及非晶半导体。已知晶体β-Ga 2 O3是具有类似于4.9eV的超宽带隙的透明导电氧化物，但是非晶（α-）Ga 2 Ox仅仅是电绝缘体，因为超宽带隙和非晶结构的组合在获得电子导电方面具有严重的困难。本文报道了室温下在玻璃上沉积的半导体α-（GaOx）-O-2薄膜及其在薄膜晶体管和肖特基二极管中的应用。薄膜密度是最重要的参数，通过将薄膜生长速率提高一个数量级来提高薄膜密度。另外，与常规氧化物半导体的情况相反，对于a-Ga 2 Ox必须选择适当高的氧分压以减少电子陷阱。这些考虑产生半导体a-Ga 2 Ox薄膜，其具有类似于8 cm（2）V（-1）s（-1）的电子霍尔迁移率、类似于2 × 10（14）cm-3的载流子密度Ne和类似于4.12 eV的超宽带隙。a-Ga 2 Ox薄膜晶体管表现出诸如类似于1.5cm（2）V-1 s-1的饱和迁移率和开/关比4107的合理性能。
The variety of semiconductor materials has been extended in various directions, for example, to very wide bandgap materials such as oxide semiconductors as well as to amorphous semiconductors. Crystalline beta- Ga2O3 is known as a transparent conducting oxide with an ultra- wide bandgap of similar to 4.9 eV, but amorphous (a-) Ga2Ox is just an electrical insulator because the combination of an ultra-wide bandgap and an amorphous structure has serious difficulties in attaining electronic conduction. This paper reports semiconducting a-(GaOx)-O-2 thin films deposited on glass at room temperature and their applications to thin-film transistors and Schottky diodes, accomplished by suppressing the formation of charge compensation defects. The film density is the most important parameter, and the film density is increased by enhancing the film growth rate by an order of magnitude. Additionally, as opposed to the cases of conventional oxide semiconductors, an appropriately high oxygen partial pressure must be chosen for a-Ga2Ox to reduce electron traps. These considerations produce semiconducting a-Ga2Ox thin films with an electron Hall mobility of similar to 8 cm(2)V(-1) s (-1), a carrier density Ne of similar to 2x10(14) cm-3 and an ultra-wide bandgap of similar to 4.12 eV. An a-Ga2Ox thin-film transistor exhibited reasonable performance such as a saturation mobility of similar to 1.5 cm(2) V-1 s -1 and an on/ off ratio 4107.