静态随机存储器总剂量辐射损伤的在线与离线测试方法

以静态随机存储器为研究对象,对其在线和离线测试下的总剂量辐射损伤规律进行了研究,探寻了两种测试条件下总剂量损伤的差异并对造成差异的物理机制进行了分析和讨论,研究结果表明:由于静态随机存储器存在多种总剂量失效模式,相对于在线测试只能覆盖存储单元固定错误的一种失效模式,离线测试可覆盖多种功能失效模式;由于信号完整性对测试频率的限制,使得在线测试得到的动态功耗电流值要明显小于离线测试得到的动态功耗电流值;由于"印记效应"的存在,在线测试静态功耗电流小于离线测试中器件存储与辐照相反数据时的静态功耗电流值;在线无法测量的一些电参数,有可能先于在线可测参数而失效,这些研究结果对于静态随机存储器在星用辐射环境下的总剂量辐射损伤规律的研究和实验评估具有重要意义。

Online and offline test method of total dose radiation damage on static random access memory

In this paper, for the study of static random access memory (SRAM), the online-test and offline-test are carried out on the total dose radiation damages. The differences between the two kinds of test methods and physical mechanisms are investigated. The results show that SRAM present multiple failure mode, the online-test only includes one fixed failure mode and the offline-test includes multiple failure mode. Due to the restrictions on signal integrity at test frequency, the online dynamic current test value is significantly less than offline test value. Since the existence of imprinting effect, the online-test static current is significantly less than offline-test value when the device-stored data are opposite to irradiation data. The parameters that cannot be detected online, may lapse prior to the data that could be detected online. The results are significantly important for studying the total dose radiation effect and the experimental evaluation of SRAM under radiation environment.
Keywords： online-test offline-test static random access memory functional test