Influences of Inserted Layers and Extra Impurities for Nucleation Enhancement on Film Properties of Transparent Conductive Oxides

我们主要研究了以下三个主题：(1)在ZnO：Al薄膜中插入氧化锌层可以获得什么效果。(2)在ZRI共沉积条件下，在薄膜中掺入锰、钴、铬等杂质会产生什么样的影响？(3)在同时沉积ZnO和In_2O_3的情况下可以制备出什么样的薄膜。对于实验(1)，添加额外的锌可以有效地降低ZnO：Al的薄膜电阻率。这归因于促进了氧化锌生长的成核，从而提高了铝施主的掺杂效率，降低了微晶的晶界电位高度。随着薄膜电阻率的增加，Mn、Co、Cr等杂质对薄膜的影响逐渐显现。杂质的加入改善了微晶的晶粒度，但载流子浓度的降低抵消了晶粒度增大带来的载流子迁移率的增加。晶界的杂质氧化严重影响了薄膜的电阻率。在(3)中，我们制备了ZnO-In_2O_3系的三元化合物。在较宽的锌铟比范围内，出现了非晶相。非晶态薄膜的电阻率低于同质晶化相薄膜。Al的非晶相中存在掺杂效应。这一结果表明三元化合物的非晶相中存在非本征掺杂。

We investigated mainly the following 3 thema : (1) What effect can we obtain by the insertion of ZnO layers into ZnO : Al film. (2) What effect can we find in mixing impurities such as Mn, Co and Cr into ZnO : A1 film under the codeposition of Zri. (3) What kind of film can we prepare under the simultaneous deposition of ZnO and In_2O_3.For the subject (1), extra addition of Zn was effective in decreasing the film resistivity of ZnO:Al. This was ascribed to enhanced nucleation in ZnO growth and the resultant increase of doping efficiency of Al donors, and the decrease of potential height at the grain boundaries of ZnO:Al micro crystals. The influence of Mn, Co and Cr impurities appeared as the increase of film resistivity of ZnO:Al. The grain size of micro crystal was improved by impurity adding, but the decrease of carrier concentration cancelled the increase in carrier mobility due to the increased grain size. The impurity oxidization at the grain boundaries influenced severely on the ZnO:Al film resisitivity. In (3), we deposited ternary compounds of ZnO-In2O3 system. Amorphous phase appeared in wide range of Zn/In ratio. Amorphous films showed lower resistivity than homologous crystallized phase film. The doping effect was noticed in the amorphous phase for Al. This result suggests the extrinsic doping in amorphous phase of ternary compounds.