Characterization Summary for a Radiation Hardened 16KX1 SRAM

Abstract

A radiation-hard 16kx1 SRAM with a typical access time of less than 100 ns and total dose hardness to 1E6 rads(SiO2) has been developed. Extensive radiation characterization has been performed with the aid of a test system developed to support testing in various radiation environments including total dose, dose rate upset, dose rate survival, dose rate photocurrent, and single event upset. Total dose testing of the 16kx1 included characterization of critical ac timing parameters as a function of dose as well as observation of standby current behavior as a function of array pattern. Dose rate tests were designed to explore the SRAM's sensitivities to Vdd, temperature, memory cell resistor value, dose rate pulse width, operational mode, and array pattern. Single event upset testing was also performed under a matrix of test conditions, including variations in supply voltage, temperature, memory cell resistor value, and particle angle of incidence. This paper describes 16kx1 SRAM radiation test procedures and characterization test results.