Total Dose Testing Methodology for Bipolar Circuits Operating in the Jovian Radiation Environment

Abstract

A total dose testing methodology for qualifying bipolar analog circuits for the Europa Clipper (EC) mission is presented. The method leverages the unique mission dose rate profile to bound device performance and reduces qualification test time from 1 year to 80 days. In addition, a new testing approach that simulates the mission dose profile revealed interesting information about the nature of radiation-induced defects in these “rad-hard” bipolar process lines. Results show that unlike bipolar parts from older generations (very sensitive to enhanced low dose rate sensitivity), these new processes seem to be dominated by oxide traps ( $\text{N}_{\mathrm {ot}}$ ) and not interface traps ( $\text{N}_{\mathrm {it}}$ ). This appears to be consistent with the mitigation used by vendors for reducing hydrogen (H2) contamination in their processing steps.