Si3N4 extrinsic defects and capacitor reliability

The capacitors implemented in RF/microwave MMICs seem to dominate the reliability in many cases, rather than the active devices (pHEMTs or HBTs) themselves. We have examined MIMCAP extrinsic defect density by extracting it from published data available in the open literature. The methodology for extracting defect densities from probability plots of times to breakdown or of ramped breakdown voltages is shown. We have noted that the extrinsic densities are quite varied across the dozen sets of data compiled. We also contributed data using Hg-dot-formed capacitors. Using this industry-wide data we provide some design charts for the sizing of capacitors in MMICs based upon their extrinsic reliability.