Transformation of Ramped Current Stress VBDto Constant Voltage Stress TDDB TBD

We have carried out an investigation for equivalence among three different stress methods: ramped voltage stress (RVS) method, ramped current stress (RCS) method, and constant voltage stress (CVS) method. Unlike the conventional RVS test with a constant ramp rate, we show the change of response voltage in RCS tests can be regarded as effectively a variable ramp rate. A data-analysis methodology along with a generalized Berman summation model [1] is presented to transform voltage-to-breakdown (V BD ) of RCS to Time-to-breakdown (T BD ) of CVS TDDB domain. We demonstrate the good agreement of directly T BD data and converted T BD data among three methods and thus establishes the fundamental equivalence of these different methods.