Hot-electron degradation in NMOSFET's: Results from temperature anneal

Abstract

0.6 μm N-channel MOSFET's are hot-electron stressed at Vg = Vd = 8 V, t = 103 s to produce large changes in device saturation drain current Id, linear channel conductance gd, maximum transconductance gm, subthreshold slope S, and threshold voltage shift Vt. Isochronal post-stress anneal up to 300 °C depopulates the trapped electrons, resulting in substantial recovery of the hot-electron degradation to within 10% of the pre-stress value. Gate-to-drain capacitance reveals that interface traps, which are also generated in significant numbers, are only partially annealed. These results provide direct confirmation that trapped electrons rather than interface traps are mainly responsible for degradation in the following NMOSFET device parameters: Id,gd,gm,S,Vt.