Synthesis of transparent conductive films with very low resistivity

利用溅射工艺，引入臭氧或氢气，研究了具有代表性的薄膜透明导电氧化物如ITO或GZO的合成，其具有非常低的电阻率。使用合金靶来存款透明导电氧化物（TCO）的反应磁控溅射被预期具有高沉积速率的低成本沉积的高潜力。然而，在较低的衬底温度下，与使用氧化物陶瓷靶的溅射相比，具有高结晶度的完全氧化膜是相当困难的存款。在这项研究中，氧气-臭氧混合气体被用作反应气体，用于在反应磁控溅射工艺中的薄膜生长过程中的氧化增强。采用直流反应溅射法，在In-Sn（Sn：10wt%）合金靶上，通入O2-O3混合气体（O3：0 ~ 10 vol. %），制备了掺锡氧化铟（ITO）薄膜在沉积期间未加热并确认低于60℃的钠钙玻璃基板上。在沉积过程中，通过引入臭氧，观察到氧化增强的目标表面和膜表面。通过在“金属模式”区域引入臭氧成功地沉积了多晶透明ITO膜，其中靶表面未被完全氧化，因此沉积速率比“氧化物模式”下的沉积速率高约一个数量级。在使用ITO氧化物靶的溅射沉积的情况下，证实氢引入对于降低膜的电阻率是有效的。

Synthesis of representative thin film transparent conductive oxides such as ITO or GZO with very low resistivity have been studied using sputtering processes with ozone or hydrogen introduction. Reactive magnetron sputtering using alloy targets to deposit transparent conductive oxide (TCO) is expected to have a high potential for low cost deposition with high deposition rates. However, at low substrate temperature fully oxidized films with high crystallinity are rather difficult to deposit compared with the sputtering using oxide ceramic targets. In this study oxygen-ozone mixture gas was used as a reactive gas for the enhancement of the oxidation during film growth in the reactive magnetron sputtering processes. Tin-doped Indium Oxide (ITO) films were deposited by dc reactive sputtering using an In-Sn (Sn:10wt%) alloy target with the introduction of oxygen-ozone mixture gases (ozone: 0〜10 vol.%) on soda-lime glass substrates which were not heated and confirmed to be lower than 60℃ during the deposition. The oxidation enhancement by the ozone introduction was observed for both target surface and film surface during the deposition. Polycrystalline transparent ITO films were successfully deposited by the ozone introduction at the "metal mode" region where the target surface was not fully oxidized and hence deposition rate was higher by about one order of magnitude than the one at "oxide mode". In the case of sputter deposition using an ITO oxide target, hydrogen introduction was confirmed to be effective for decreasing resistivity of the films.