Anomalous Field Transistor BTI Failure Mechanism in an 80V Technology

Abstract

During the transfer of an 80V 0.35µm based technology (I3T80U) developed at AMI Semiconductor from the mother fab to a second fab, field transistor biased-temperature instability (BTI) failures were encountered. The polarity of the degradation in the field transistor threshold voltage does not indicate a mobile ion problem. Also, the behavior does not follow a typical signature of traps at the silicon-oxide interface. The degradation model will be shown. The proposed mechanism is the presence of a residual film. Simulation results of the proposed mechanism, as well as a manufacturing solution for these failures is explained in this paper.