Reliability Of Hfsion Gate Dielectric Silicon Mos Devices Under [110] Mechanical Stress: Time Dependent Dielectric Breakdown

摘要

The time dependent dielectric breakdown (TDDB) of 7-8 nm thick nitrided hafnium silicate (HfSiON) dielectric silicon (Si) metal-oxide-semiconductor capacitors are measured under uniaxial mechanical stress using four point wafer bending along the [110] direction. Both applied tensile and compressive stresses are observed to degrade TDDB. The degradation for both stress polarity is consistent with a previously reported increase in mechanical stress-induced gate leakage via Poole-Frenkel emission. The independence of the charge to breakdown on HfSiON thickness suggests that the degradation under mechanical stress is primary mediated at the HfSiON/Si interface during constant negative gate voltage stressing.