RADIATION EFFECTS ON INSULATED GATE FIELD EFFECT (MOS) INTEGRATED CIRCUITS.
Quarterly technical rept. no. 1, 1 Jul-30 Sep 65,
MARTIN CO BALTIMORE MD
Pagination or Media Count:
The preliminary theoretical analysis of permanent radiation effects on MOS devices indicates that after 10 to the 14th power neutronssq cm the average carrier mobility in the channel decreases about 5, the reverse leakage current of the drain-substrate p-n junction I sub pno increases by a factor of 10 to 100, the terminal capacitances C sub gs, C sub gd, and C sub ds are not significantly changed except for the bias dependence of the channel capacitance which is influenced by shifts in threshold voltage V sub T, and the drain current transconductance, and channel conductance are significantly influenced by the variations in V sub T. The predicted changes in V sub T due to bulk damage in the substrate are too small to account for the V sub T changes observed experimentally by several workers in the field. The changes in V sub T are apparently caused by a redistribution of charge in the oxide, but the exact damage mechanism has not been established at this time. The analysis of transient effects revealed that the dominant response mechanisms are charge scattering from the device leads leakage resistance as dictated by ionization of the gas inside the encapsulated device transient gate current resulting from the generation of carriers in the transverse electric field of the channel and transient drain current resulting from the primary photocurrent of the drain p-n junction.
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