High-mobility GeSn n-channel MOSFETs by low-temperature chemical vapor deposition and microwave annealing
Journal
IEEE Electron Device Letters
Journal Volume
39
Journal Issue
4
Pages
184-190
Date Issued
2018
Author(s)
Tzu-Hung Liu
Yen Chuang
Po-Yuan Chiu
Chia-You Liu
Cheng-Hong Shen
Guang-Li Lou
Jiun-Yun Li
李峻霣
Abstract
A Ge 0.955 Sn 0.045 nMOSFET with a record high mobility of 440 cm 2 /V · s is demonstrated in this letter by a gate-first process. By low-temperature chemical vapor deposition, high-quality GeSn films were epitaxially grown. The ambipolar leakage is effectively suppressed by the low-thermal-budget microwave annealing (MWA) step. Furthermore, the peak mobility in the device after the MWA step is enhanced by a factor of two compared with those after rapid thermal annealing. This can be attributed to the weaker Coulomb scattering at the oxide interface after the MWA step, suggesting that MWA is effective for dopant activation and a better oxide interface quality at the same time.
Type
journal article