SiOxNy / SiNz 閘極絕緣層特性用於薄膜液晶顯示器

Abstract

Amorphous silicon (a-Si:H) TFT technology is widely used in highly reliable, high resolution, high performance and large size active matrix liquid crystal displays (AMLCDs) that are necessary for multimedia applications. The gate insulator is important layer of TFT structure. For good electrical performance and throughput of PECVD, the bottom insulator should be changed from silicon oxygen nitride to silicon nitride. On early stages, the gate insulator was made of silicon oxy-nitride (SiON) for bottom insulator and silicon nitride (SiN) for top insulator, the longer PECVD deposition of SiON will affect the process throughput and cost even its properties of performance are better on some items, a more suitable bottom insulator was needed to improve throughput. This thesis use Takuchi analysis to find better and uniform silicon nitride film which gives rise to better TFT performance. In fact, SiNtop is main factor that property will influence TFT threshold voltage directly. In order to achieve high quality AMLCDs, it is very important to fabricate TFTs with high on-current and low off-current and the off current had better < 10-12A, efficient plasma ashing treatment on TFT can reduce leakage between drain and source.