On the recovery of interface state in pMOSFETs subjected to NBTI and SHI stress

High temperature accelerated interface state (Nit) recovery is observed after the pMOSFETs experiencing negative bias temperature instability (NBTI) and substrate hole injection (SHI) stresses. It is found that there is hardly any Nit recovery at room temperature, but much recovery happened with a rise in temperature. The recovery is due to the H species released by the breaking of Si3Si–H, returning the Si/SiO2 interface and passivating the Si3Si–. Some of the H species are trapped by oxide as-grown traps when diffusing to the gate and these will be activated by high temperature. So, more H species return the interface at higher recovery temperature which results in a large-scale recovery. A similar activation energy of generation and recovery is obtained, which supports the proposed recovery mechanism.