24.3: 32‐inch LCD TV Using Conventional PECVD Microcrystalline‐Silicon TFTs

Abstract

AbstractA 32‐inch microcrystalline silicon thin film transistor liquid crystal display was manufactured on 1500×1850 mm2 (G6) glass substrate. We have successfully deposited non‐porous and highly crystalline microcrystalline silicon film with interfacial treatment as the active channel layer for TFTs in such large size display. Microcrystalline silicon was deposited by a conventional (13.56 MHz) plasma‐enhanced chemical vapor deposition (PECVD) system, and the crystalline fraction is 60%. Crystalline fraction was successfully improved with optimized gas treatment on SiNx layer before μc‐Si:H film deposition. Microcrystalline silicon TFTs with interfacial modification have about 2.8 times and 4 times more on‐current than μc‐Si:H TFT without interfacial modification measured at room temperature and at −10°C, respectively. The μc‐Si:H film with good crystallinity used as the active channel layer will significantly improve the reliability of the microcrystalline silicon TFTs. Furthermore, during the bias‐temperature‐stress test (BTS), VTH shift for μc‐Si:H TFT with treatment after 3hr BTS test is only 1.3V while μc‐Si:H TFT without treatment has a VTH shift of 13V.