A Low-Leakage Epitaxial High-κ Gate Oxide for Germanium Metal–Oxide–Semiconductor Devices
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- 作者：Chengqing Hu ; Martin D. McDaniel ; Aiting Jiang ; Agham Posadas ; Alexander A. Demkov ; John G. Ekerdt ; Edward T. Yu
- 刊名：ACS Applied Materials & Interfaces
- 出版年：2016
- 出版时间：March 2, 2016
- 年：2016
- 卷：8
- 期：8
- 页码：5416-5423
- 全文大小：424K
- ISSN：1944-8252
文摘
Germanium (Ge)-based metal–oxide–semiconductor field-effect transistors are a promising candidate for high performance, low power electronics at the 7 nm technology node and beyond. However, the availability of high quality gate oxide/Ge interfaces that provide low leakage current density and equivalent oxide thickness (EOT), robust scalability, and acceptable interface state density (D<sub>itsub>) has emerged as one of the most challenging hurdles in the development of such devices. Here we demonstrate and present detailed electrical characterization of a high-κ epitaxial oxide gate stack based on crystalline SrHfO<sub>3sub> grown on Ge (001) by atomic layer deposition. Metal–oxide–Ge capacitor structures show extremely low gate leakage, small and scalable EOT, and good and reducible D<sub>itsub>. Detailed growth strategies and postgrowth annealing schemes are demonstrated to reduce D<sub>itsub>. The physical mechanisms behind these phenomena are studied and suggest approaches for further reduction of D<sub>itsub>.