Title :
Ge n-MOSFETs on lightly doped substrates with high-/spl kappa/ dielectric and TaN gate
Author :
Bai, W.P. ; Lu, N. ; Ritenour, A. ; Lee, M.L. ; Antoniadis, D.A. ; Kwong, D.-L.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Texas, Austin, TX, USA
fDate :
3/1/2006 12:00:00 AM
Abstract :
We report successful fabrication of germanium n-MOSFETs on lightly doped Ge substrates with a thin HfO2 dielectric (equivalent oxide thickness /spl sim/10.8 /spl Aring/) and TaN gate electrode. The highest peak mobility (330 cm2/V/spl middot/s) and saturated drive current (130 μA/sq at V/sub g/--VT=1.5 V) have been demonstrated for n-channel bulk Ge MOSFETs with an ultrathin dielectric. As compared to Si control devices, 2.5× enhancement of peak mobility has been achieved. The poor performance of Ge n-MOSFET devices reported recently and its mechanism have been investigated. Impurity induced structural defects are believed to be responsible for the severe degradation.
Keywords :
MOSFET; electron mobility; elemental semiconductors; germanium; hafnium compounds; high-k dielectric thin films; semiconductor doping; substrates; tantalum compounds; Ge; HfO/sub 2/; TaN; germanium; high-k dielectric; impurity induced structural defects; lightly doped substrates; n-MOSFET; peak electron mobility; ultrathin dielectric; Annealing; CMOS technology; Degradation; Dielectric substrates; Electrodes; Fabrication; Germanium; Hafnium oxide; Impurities; MOSFET circuits; Ammonia treatment; MOSFET; germanium (Ge); hafnium oxide; high-;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2006.870242
