SEU cross-sections of 6T SOI SRAM

Partially depleted (PD) SOI CMOS technology has provided great flexibility to extend the performance of high density SRAM and leading edge microprocessors in various CMOS microelectronics products. In today´s ASICs for defense electronics embedded 6T SOI SRAMs are used extensively and the SEU performance must be understood. The purpose of this paper is to present a rudimentary methodology for estimating the limiting SEU cross- sections induced by protons (sigma_PL) and by heavy ions (sigma_HL) for these SRAMs. The value of sigma_PL is usually found for proton energy (E) ges 200MeV and that of sigma_HL found for linear energy transfer (LET) ges 94MeV-cm²/mg. Two interesting observations are noted for the limiting SEU cross-sections: (1) ADE-hardened SOI SRAM is proportional to sigma_HL of 6T SOI SRAM; and (2) the single event rate (SER) is nearly proportional to sigma_HL in a figure-of-merit (FOM) calculation.