A Modified Charge-Pumping Method for the Characterization of Interface-Trap Generation in MOSFETs

摘要

A novel recovery-free interface-trap measurement method is presented in detail. This method is the modification of the conventional charge pumping (CP) by extending the pulse low level to the stress-bias and minimizing the pulse high-level duty cycle to suppress the recovery effect. The method is applied to study the negative-bias temperature instability in p-MOSFETs. As compared with the conventional CP, a much larger interface-trap generation under stress is observed by the new method. A power law time dependence $(sim! t^{n})$ of interface-trap generation is observed. The index $n$ is less than that derived from conventional CP and increases with temperature, demonstrating a dispersive process involved in the trap generation dynamics.