Hardness Assurance Considerations for Long-Term Ionizing Radiation Effects on Bipolar Structures

The purpose of this work was to assess the theoretical understanding of long-term ionization effects in semiconductor bipolar devices in support of developing hardness assurance techniques. The principal effort was directed at studying transistor gain degradation mechanisms by use of models relating semiconductor physical and electrical parameters to surface properties. Ionizing radiation effects on surface properties were used to identify critical physical parameters for use in hardness assurance procedures. Model implications and predictions were then compared with existing data to evaluate their accuracy and usefulness as a hardness assurance tool.