The Impact of Mechanical Strain on Reliability Issue for PD SOI MOSFETs

摘要

This work studies the impact of mechanical strain on reliability issue for partial depleted silicon-on-insulator metal-oxide-semiconductor field effect transistors (PD SOI p-MOSFETs), including negative bias temperature instability (NBTI) and hot carrier stress (HCS) for p-MOSFETs and n-MOSFETs, respectively. Based on AEI model, the mechanical compressive strain was introduced into the SOI p-MOSFET under NBT stress. It shows the strained FB device exhibits a much less NBTI degradation, since significant accumulation of electron induced by strain-induced band gap narrowing, reducing the Eox during NBT stress. Additionally, the degradation of HCS on SOI n-MOSFETs is also studied. It can be seen that the FB device shows worse degradation than GB device due to FBEs. However, the impact of mechanical strain results more serious degradation on HCS for GB device. Therefore, based on the lucky electron mode, we found that strain-induced band gap narrowing dominates the increase in impact ionization rate, aggravating HCS.