Title :
Polarity dependence of charge trapping in poly-silicon gate HfO2 MOSFETs
Author :
Bu, H.M. ; Wang, X.W. ; Guo, D.C. ; Song, L.Y. ; Ma, T.P. ; Tseng, H. ; Tobin, Phil
Author_Institution :
Yale Univ., New Haven, CT, USA
Abstract :
Polarity dependence of charge trapping in poly-Si gate HfO2 MOSFETs has been systematically studied. It is shown that both the stress-induced threshold voltage shift (ΔVth) and the transconductance degradation (ΔGm) are worse in nMOSFETs than in pMOSFETs. For substrate injection in nMOSFETs, electron trapping occurs at the n-poly/HfO2 interface and/or in bulk HfO2, whereas for gate injection in pMOSFETs hole trapping near the Si substrate is observed. These results strongly suggest the poly-Si/HfO2 interface should play an important role in hot carrier induced degradation in HfO2 gated nMOSFETs.
Keywords :
MOSFET; dielectric thin films; electron traps; hafnium compounds; hole traps; interface states; interface structure; semiconductor device breakdown; semiconductor device reliability; HfO2; charge trapping; electron trapping; hole trapping; nMOSFETs; pMOSFETs; polarity dependence; poly-silicon gate HfO2 MOSFETs; stress-induced threshold voltage shift; substrate injection; transconductance degradation; Degradation; Density measurement; Dielectric substrates; Electron traps; Hafnium oxide; MOSFETs; Silicon; Stress; Substrate hot electron injection; Voltage;
Conference_Titel :
Reliability Physics Symposium Proceedings, 2004. 42nd Annual. 2004 IEEE International
Print_ISBN :
0-7803-8315-X
DOI :
10.1109/RELPHY.2004.1315404
