Transformation of charge-to-breakdown obtained from ramped current stresses into charge-to-breakdown and time-to-breakdown domains for constant current stress

Summary form only given. Charge-to-breakdown (Q/sub BD/) is one of the parameters that is used as a measure of gate oxide quality. It has been shown that, under the correct measurement conditions, there is good agreement between the Q/sub BD/ that is measured with an exponential current ramp (ECR) and the Q/sub BD/ that is measured with a constant current stress (CCS), and that Q/sub BD/ depends strongly on the ramp rate of the exponential current ramp and the current density of the constant current stress (Dumin, Int. Integrated Reliability Workshop Final Report, 1997). Previous work has shown that the breakdown distribution obtained from a linear voltage ramp can be transformed into the constant voltage stress TDDB domain for time-to-breakdown (Berman, Int. Reliability Physics Symp., pp. 204-209, 1981). Similar to this, a method is presented here for transformation of the Q/sub BD/ distribution obtained from exponential ramp experiments into the constant current stress TDDB domains of time-to-breakdown (t/sub BD/) and Q/sub BD/.