Highly-conductive Transparent Films Sputter-deposited under Water Vapor Atmosphere

铟锡氧化物薄膜广泛用于液晶显示器件等的透明电极。本课题的目的是建立一种新型的在水蒸气气氛下溅射沉积工艺，在不加热衬底的情况下获得高导电性的透明薄膜。在第二年(1990年的S)，人们计划通过沉积参数对薄膜生长机制的影响来理解薄膜的性质。结果表明：1)在不加水蒸气的情况下沉积厚膜时，薄膜中载流子浓度降低，而在水蒸气气氛下沉积时，薄膜中的载流子浓度保持较高的浓度；2)水蒸气促进了晶体的生长，这是载流子迁移率增加的原因；3)上述1)和2)的实验数据相差很大；4)薄膜的表面状况对薄膜的性能有显著的影响。在实验之前，表面状况的影响从来都是不可预测的。

Indium-Tin-Oxide (ITO) files are widely used for transparent electrodes of liquid crystal display device etc. The object of the present project is to establish a deposition process by a novel sputtering method under the atmosphere of water vapor to obtain highly-conductive transparent films without heating the substrates.In the first year (1989's), the optimization of the deposition parameters was successfully completed. In the second year (1990's), it was scheduled that the film properties be understood by the growth mechanism which was affected by the deposition parameters. The following results were obtained at the present :1) The carrier concentration in the film decreased when the thick films were deposited without water vapor introduction, while high carrier concentration was maintained when deposited under the atmosphere of water vapor.2) The water vapor enhanced the crystal growth which explains the increase of carrier mobility.3) The experimental data for the above mentioned 1) and 2) were extremely deviated.4) The film properties were influenced remarkably by the surface condition of the substrate. The influence of the surface condition had never been unpredicted before the experiments.