Generalized Model for Microcircuit Transient Radiation Response Prediction.
Abstract
Predictions of electrical switching and the response to pulsed ionizing radiation over dose rates ranging from 10 to the 7th power rads/sec to 10 to the 12th power rads/sec were successfully carried out for two dielectrically-isolated and two junction-isolated microcircuits. The success of the predictions compared to previous attempts was attributed to the advancement in the state-of-the-art of techniques for characterizing parameters, which had occurred since the previous microcircuit modeling attempts, and to the inclusion of conductivity modulation. Although the competition for free carriers in the collector region was negligible in the two junction-isolated circuits, the competition phenomenon was modeled as current-dependent photo-currents in the base-collector and collector-substrate junctions, and verified using one of the microcircuit transistors. A special set of junction-isolated transistors with varied parameters was constructed and showed a correlation between the substrate transistor gain and the degree of competition when the collector geometry was held fixed. A computer program was developed to study competition through a two-dimensional solution of the continuity equations. Detailed study of the transistor variations indicated they exhibited presaturation, which was modeled with qualitative success using a topological approach to this distributive phenomenon. A study of component spacing on the chip revealed no interactions between adjacent junction-isolated components other than through the normal resistive paths. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1968
- Accession Number
- AD0845450
Entities
People
- Allan H. Johnston
- Wendland Beezhold
- William C. Bowman
Organizations
- Boeing