MICROCIRCUIT RADIATION RESPONSE MECHANISMS.
Abstract
A total of 14 circuits and their associated components were tested at a linac using electrons, bremsstrahlung, and photoneutrons at dose rates ranging from 10 to the 7th power to 5 x 10 to the 11th power rad (Si)/sec and neutron fluences to 10 to the 15th power n/sq/cm. Eight of these circuits, representative of the 1966 microcircuit market and including monolithic, oxide isolation, and MOS constructions, were tested at room temperature only. These all failed in the dose rate range of 2 x 10 to the 7th power to 10 to the 9th power rads (Si)/sec. Six additional circuits that were tested previously were retested at various temperatures ranging from -50 C to 125 C. These temperature dependence studies indicated only small effects at the high ionization rates studied. Additional studies using a neodymium glass laser indicated temperature effects on component and circuit responses were similar to those expected from the subsequent variations in lifetime and mobility. Laser studies also revealed that the base-substrate competition for collector charge in junction-isolated transistors is strongly affected by electric fields set up in the collector region by current passing through the collector bulk resistivity from the respective junctions. These fields enhanced or retarded diffusion of carriers into the base and substrate junctions. Annealing times of the order of minutes were observed in the MOS circuits. The failure mechanism for all circuits irradiated with neutrons was the transistor gain degradation. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1967
- Accession Number
- AD0824214
Entities
People
- Allan H. Johnston
- Robert S. Caldwell
- William C. Bowman
Organizations
- Boeing