Growth and scaling of oxide conduction after breakdown

Abstract

Hard breakdown is shown to be a gradual process with the gate current increasing at a predictable rate, exponentially dependent on the instantaneous stress voltage. Adding the hard breakdown evolution time to the standard time to breakdown potentially reduces the projected fail rate of gate dielectrics by orders of magnitude. The scaling of the hard breakdown growth rate with respect to device area, substrate doping, oxide thickness, and channel length are explored. A two-voltage stress procedure is introduced that measures degradation rates on sub-micron devices several orders of magnitude more quickly than a conventional single voltage stress.