ITO薄膜之電化學行為研究

Abstract

本研究主要探討一般視為n型半導體元件材料的ITO膜在採用0.3M鹽酸、氫氧化鈉（6wt%）、氯化鈉（6wt%）水溶液以及純水四種測試液中，進行循環伏安掃瞄後的結果，在使用此四種不同的測試液檢測時當往負電位掃瞄皆有還原電流產生並形成一完整的峰值（peak），試片測試完成後表面經場射SEM觀察以及EDX成分分析，其結果可發現許多含大量銦錫元素的相形成於ITO膜上，隨著測試溶液的不同此銦錫化合物的形狀也跟著改變；而原本為晶粒-次晶粒（grain-subgrain）形貌的ITO膜表面在經過此還原反應後，基底呈現出十分明顯的沿晶界甚而整個基底解離。本研究結果中可以證實當ITO膜處在濕性環境且偏置負電位時十分的不穩定容易產生銦錫元素組成之還原反應物，在最後本論文同時並推導出完整的還原反應機制。

The behavior of cyclic voltammetry stripping (CVs) of different-treated tin-doped indium oxide (ITO) thin film on SiO2- substrate in 0.3M HCl water solution was reported. From the result of CVs, an obvious reduction reaction occurs during the first negative potential striping. However, at the same time a spherical In-Sn phase was formed on ITO film, in which the grain boundary offers a prefer nucleation site for the phase. With HRSEM and TEM the spherical phase was studied and its chemical composition was analyzed together with EDX. Base on the microstructure and step-by-step growth examination of the compound a probable formation mechanism of the phase was proposed.