Latent B-Radiation Damage in Hermetically Sealed NMOS Devices

A failure mechanism in NMOS VLSI devices has been traced to radiation damage due to residual radioactive gas found in their hermetically sealed packages. The entrapped gas is a result of hermeticity testing. This report describes the characteristic failure mode of NMOS memories and the changes in transistor characteristics that result from radiation damage. Criteria for the implementation of radioactive tracer leak testing are proposed to prevent failures.