标题: | 利用超真空化学气相沉积成长复晶矽薄膜电晶体特性之研究 A Study of Polycrystalline Silicon Thin-Film Transistors Fabricated by Ultra-High Vacuum/ Chemical Vapor Deposition |
作者: | 胡志昌 Jyh-Chang Hwu 张俊彦 Dr.Chun-Yen Chang 电子研究所 |
关键字: | 超真空化学气相沉积;薄膜电晶体;化学机械研磨.;Ultra-High Vacuum/Chemical Vapor Deposition; Chemically and Mechanically polished. |
公开日期: | 1994 |
摘要: | 在本论文中,我们成功地利用超真空化学气相沉积系统制造出高性能的上 闸极及下闸极复晶矽薄膜电体.并和传统低压化学气相沉积所制成的元件 比较, 前者制成的电晶体在电性上比后者好很多, 它拥有高的场效载子迁 移率和开/ 关电流比, 及低的临界电压和闸极波动率( 氢化后可小于250 mV/dec), 它的活化能随闸极电压的增加而下降很快, 这些是因为用超真 空化学气相沉积的复晶矽薄膜界面中拥有很小的缺陷密度所致. 在此实验 中我们使用化学机械研磨(CMP) 来改善上闸极电晶体的闸极氧化层和复晶 矽薄膜界面的平坦度, 同时氢化及复晶矽薄膜厚度对电晶体电性的影响也 加以探讨. In this research,high performance bottom-gate and top- gate poly-Si TFTs with active layer grown by ultra-high vacuum /chemical vapor deposition (UHV/CVD) system have been success- fully fabricated, and firstly compared its electrical character- istics with those of devives with films grown by conventional low pressure/chemical vapor deposition (LPCVD) system. Of these two devices the former exhibits consistently a superior performance. It owns high field-effect mobility, high ON/OFF current ratio, low threshold voltage and low subthreshold swing (< 250mV/dec after hydrogenation), and its activation energy decreases very fast with the gate voltage. The improve- ment was attributed to very less trap-state density in the UHV /CVD-processed poly-Si films grain boundary. In order to get more smooth the oxide-semiconductor interface of the top-gate TFTs,the surface of the poly-Si films were chemically and mechanically polished (CMP) before oxidation, In the same time ,the effects of hydrogenation passivation and poly-Si film thickness on the performance were studied also. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#NT830430067 http://hdl.handle.net/11536/59256 |
显示于类别: | Thesis |