| 研究実績の概要 |
We propose and demonstrate a new channel strain control technology enabling to realize both high performance tensile strain Ge-on-insulator (GOI) n-MOSFETs and compressive strain GOI p-MOSFETs on a same substrate. It is found that additional oxidation at 850 oC after Ge condensation changes the strain condition in GOI from 1.8 % compressive strain to 0.5% tensile strain, resulting in the electron mobility enhancement of 2.1. Furthermore, thinning GOI channel thickness introduces significant mobility enhancement attributable to GOI band modulation, leading to electron mobility of 777 cm2/Vs in n-MOSFETs with GOI thickness of 2.5 nm. For performance enhancement of p-MOSFETs, (110)-oriented SGOI formation by Ge condensation is studied. It is found that SGOI with the Ge fraction of 54 % maximizes the hole mobility from the viewpoints of both strain and Ge fractions. Record high hole mobility of 837 cm2/Vs is demonstrated with compressive strain (110) 27-nm-thick Si0.46G0.54OI p-MOSFETs, compared with mobility in planar GOI/SGOI p-MOSFETs reported so far. In addition, high hole mobility of 295 cm2/Vs is still maintained for 5-nm-thick extremely-thin body (110) Si0.46G0.54OI p-MOSFETs.
As a result aforementioned contents of our research were reported at 2019 International Electron Devices Meeting (IEDM), which is one of most famous conferences in the research field.
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