标题: | 垂直型氧化物薄膜电晶体技术之研究 The study on vertical-channel oxide-based thin film transistors |
作者: | 赖宣颖 Lai, Hsuan-Ying 刘柏村 Liu, Potsun 显示科技研究所 |
关键字: | 垂直通道结构;非晶系铟锭锌氧;薄膜电晶体;vertical channel structure;amorphous IGZO;thin film transistor |
公开日期: | 2012 |
摘要: | 在本论文中,我们成功发展出垂直通道结构的非晶系铟镓锌氧薄膜电晶体,其通道长度只有五百奈米。经由对此垂直通道结构的元件做电特性分析,其电流开关比大于十的六次方倍。在垂直电晶体的元件结构中,源极和汲极之间是藉由一层绝缘层的厚度来决定通道长度。为了确认此元件垂直结构的正确性,我们使用扫描式电子显微镜对其做结构剖面的分析。我们藉由互换源极跟汲极电压的方式量测元件以探讨此不对称结构以及电极接触特性。此外,我们也发现在沉积闸极介电层的同时也会对主动层界面形成缺陷而造成其电特性不理想以及可靠度不佳等问题。最后,我们也对此元件做闸极偏压可靠度和光响应可靠度这两方面的分析。在正偏压可靠度部份,临界电压随着时间增加会往负的方向做些许的偏移;在负偏压可靠度部份,临界电压最终会往正的方向偏移4.1伏特当给的偏压时间达到120分钟。而此元件本身临界电压在光响应可靠度分析下几乎不变,所以其抗光性极佳。 We had successfully realized vertical-channel amorphous IGZO thin film transistors with submicron channel length (500nm). The device performance of the fabricated V-TFT was evaluated with the characteristics of Ion/Ioff current ratio greater than 106. The source and drain were separated by a insulator for V-TFTs, it meaned that the thickness of this insulator decided the channel length. The structure analysis of scanning electron microscopy was implemented to confirm the vertical structure of the TFT. We study the asymmetric structure and the electrode contact properties by switching the source and drain as we measuring the device performance. Besides, we find that the defects appeared in the a-IGZO channel region in deposition process of the PECVD SiO2 gate dielectric. This is the reason for non-optimum device performance and reliability. Finally, the reliability analysis for the V-TFTs was applied such as gate bias stress and light illumination sensitivity. The PGBS reliability analysis for our devices exhibits some negative threshold voltage shifts as the stress time increase, and the NGBS reliability analysis for that exhibits positive threshold voltage shifts to 4.1V as the stress time increase to 120 min. In terms of photo-reliability, the device is not sensitive to the environmental light, so it has nice resistance to light. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#GT079615510 http://hdl.handle.net/11536/42196 |
显示于类别: | Thesis |