Modeling of SILC based on electron and hole tunneling. II. Steady-state

For pt. I see ibid., vol. 47, no. 6 (June 2000). A numerical model for the stationary stress-induced leakage current (SILC) is presented, accounting for both electron and hole tunneling. Detailed comparisons against experimental results on both n- and p-channel devices highlight that the steady-state SILC is due to positively charged centers, with an energy level located in correspondence of the silicon bandgap. Electron-hole recombination at these sites dominates normal trap-assisted tunneling at low oxide fields, and successfully accounts for recently observed hole steady-state leakage. The contribution from neutral traps seems instead marginal. Based on this new picture, the impact of the recombination process on the leakage properties of ultrathin gate is also discussed.