Radiation hardness of static random-access-memory tested using dose-to-failure and gamma-ray exposure

A dose-to-failure, which is extracted by measuring the number of error bytes as a function of dose, is proposed and then demonstrated to be an ideal parameter for radiation-hardness test of a static random-access-memory (SRAM). The radiation exposure is performed using the Co-60 gamma ray. The test conditions of dose rate, power-supply voltage, and temperature must be specified. The possible mechanisms for the changes of radiation hardness at various test conditions are explained. The radiation hardness tests of SRAM are useful for the practical assessment of integrated circuit (IC) reliability.