Title :
Abrupt breakdown in dielectric/metal gate stacks: a potential reliability limitation?
Author :
Kauerauf, T. ; Degraeve, R. ; Zahid, M.B. ; Cho, M. ; Kaczer, B. ; Roussel, Ph ; Groeseneken, G. ; Maes, H. ; De Gendt, S.
Author_Institution :
Interuniversity Micro-Electron. Center, Leuven, Belgium
Abstract :
In downscaled poly-Si gate MOSFET devices reliability margin is gained by progressive wearout. When the poly-Si gate is replaced with a metal gate, the slow wearout phase observed in ultrathin SiON and HfSiON dielectrics with poly-Si gate disappears, and with it, the reliability margin. We demonstrate for several combinations of dielectric and gate materials that the large abrupt current increase (ΔI) as compared to poly-Si is not likely due to process issues, but is an intrinsic property of the dielectric/metal gate stack. The occurrence of large ΔI is a potential limitation for the reliability of metal gate devices.
Keywords :
MOSFET; dielectric materials; elemental semiconductors; hafnium compounds; semiconductor device breakdown; semiconductor device reliability; silicon; silicon compounds; HfSiON; HfSiON dielectrics; MOSFET device reliability; Si; SiON; dielectric breakdown; metal gate stacks; poly-Si gate; ultrathin SiON; Area measurement; Current measurement; Degradation; Dielectric breakdown; Dielectric measurements; Electric breakdown; Hafnium oxide; Leakage current; MOSFETs; Tin; Dielectric breakdown (BD); metal gate; reliability;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2005.856015
