ITO 於後續CVD製程影響下的缺陷分析

Abstract

本論文研究的主題，是在ITO成膜後於後續沉積氮化矽薄膜的CVD製程影響下所產生的缺陷分析。在TFT-LCD面板需求精緻化的現在，提高開口率與廣視角往往成為面板廠商的重要課題。因此，在TFT製程中新增第二道ITO製程是最經濟與高成效的方法。我們的做法是在閘極金屬層與半導體層之間新增一道Bottom ITO製程。但是在完成Bottom ITO 製程進入CVD製程沉積氮化矽薄膜製程後發現，ITO與氮化矽薄膜之間有高的或然率會形成球型結晶粒。此球型結晶粒會使得穿透率下降以及電阻值降低，並會有嚴重的雲紋(mura)現象出現。本論文試著尋找新的ITO 和CVD 製程參數，以達到抑制球型結晶粒的發生率，並保持ITO膜的透光率和導電度。

This thesis reports the detection and analysis of defects of ITO films generated by follow-up deposition of silicon nitride film by CVD process. Recent market demand on high-resolution TFT LCDs requires high aperture ratio of TFT-array to achieve low-power consumptions. The most effective and economic way to achieve the goal is add a bottom ITO layer as part of storage capacitor into pixel circuit of the TFT-LCD. After the deposition and process of the bottom ITO layer, a follow-up PECVD process was necessary to deposit a dielectric layer such as silicon nitride film as an insulator to form a storage capacitor. However, the follow-up PECVD process usually had a high probability of generating spherical defects on the bottom ITO layer to degrade its optical transmittance and conductivity. This thesis reports the experimental attempts to reduce the spherical defects on the bottom ITO layer by finding new process parameters for the ITO layer as well as the follow-up PECVD process.