极薄栅极绝缘层锗基MOS器件的平带电压漂移机理及其抑制方法的研究

项目名称： 极薄栅极绝缘层锗基MOS器件的平带电压漂移机理及其抑制方法的研究

项目编号： No.61306097

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 张睿

作者单位： 浙江大学

项目金额： 29万元

中文摘要： 传统的硅器件微细化方法已接近物理极限，因此进一步提高硅沟道场效应晶体管的性能已比较困难。锗由于具有非常高的电子、空穴迁移率，以及和当前硅器件工艺的良好兼容性，有希望作为新一代场效应晶体管的沟道材料。高质量的极薄栅绝缘层是实现高性能锗沟道场效应晶体管的关键问题，受到了广泛关注。尽管近年来锗基栅绝缘层的研究已取得较大进展，但是目前仍然无法解决其平带电压漂移的问题。本项目将从极薄Al2O3/GeOx/Ge栅绝缘层的平带电压漂移机理入手，对造成这一问题的关键原因进行分析并澄清其物理起因。通过对锗MOS界面的成分和结构的控制，实现对锗基MOS器件平带电压的调控。在此基础上，还将通过对Al2O3/GeOx/Ge栅绝缘层在表面极薄范围内进行原位氮化的方法，在保持高质量GeOx/Ge界面的情况下制备AlON/GeOx/Ge栅绝缘层，减少栅绝缘层中固定电荷、偶极子等缺陷，实现对锗基MOS器件平带电压的调控。

中文关键词： 锗；场效应晶体管；栅极工程；载流子迁移率；输运机理

英文摘要： Further enhancement of the Si metal-oxide-semiconductor field-effect transistor (MOSFET) performance is becoming increasing difficult due to the limitation of conventional device scaling. Germanium has been attracting a lot of interest as the most promising candidate as channel material of MOSFET to replace Si, because of not only its high bulk hole and electron mobility but also the compatibility with Si technology. In order to realize high performance Ge MOSFET, advanced Ge gate stacks with high quality and thin thickness simultaneously are mondatory. Recently, many researches have been carried out to improve the properties of Ge gate stacks. However, the flat band voltage shift, which is one of the major problems in Ge gate stacks, is still not solved yet. Additionally, the physical mechanism resulting in the flat band voltage shift of Ge gate stacks is also not clear, in spite of importance. In this research, the ultrathin Al2O3/GeOx/Ge gate stacks, which has been demonstrated to be one of the most promising gate stack structures for Ge MOSFETs, will be invesgated intensively. The defects dominating the flat band voltage shift will be characterized, and the physical mechanism of their generation will be studied. The impact of MOS (metal-oxide-semiconductor) interface structure on the flat band voltage shift

英文关键词： Germanium；MOSFET；Gate Stack；Carrier mobility；Transport mechanism