Improvement of alpha-particle-induced soft-error immunity in a GaAs SRAM by a buried p-layer

Alpha-particle-induced soft-error immunity in a 1-kB GaAs SRAM was improved by a buried p-layer, which was formed in isolation regions as well as in FET regions and was designed to be completely depleted. The mean time between failures exceeded 10/sup 4/ at an alpha-particle fluence of about 2.0*10/sup 4/ cm/sup -2/-s/sup -1/ with a 1.0- mu Ci/sup 241/Am source. The alpha-particle energy had a peak at 4.0 MeV and was distributed from nearly 0 to 4.6 MeV. This value is five orders of magnitude better than that for a conventional SRAM without a buried p-layer. This improvement in the soft-error immunity can be achieved without increasing the access time or the power consumption by depleting the p-layer completely. Also discussed is the possibility of using a conductive p-layer scheme for higher integration of GaAs SRAMs.<
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