串口型铁电存储器总剂量辐射损伤效应和退火特性

Serial ferroelectric memory ionizing radiation effects and annealing characteristics

对一款商用串口I2C型铁电存储器进行了60Coγ辐射和退火实验,研究了铁电存储器的总剂量效应和退火特性.使用了超大规模集成电路测试系统测试了铁电存储器的DC,AC,功能参数,分析了辐射敏感参数在辐射和退火过程中的变化规律.实验结果表明:总剂量辐射在器件内产生大量氧化物陷阱电荷,造成了铁电存储器外围控制电路MOS管阈值向负向漂移,氧化物陷阱电荷引入附加电场使铁电薄膜受肖特基发射或空间电荷限制电流的作用,产生辐射感生漏电流.由于浅能级亚稳态的氧化物陷阱电荷数量上多于深能级氧化物陷阱电荷,使得器件功能和辐射敏感参数在常温退火过程中快速恢复.

Ferroelectric random memory was irradiated and annealed by ^60 Coγ-rays, total ionizing dose （TID） failure mechanism and annealing characteristics of the device were analyzed. DC, AC and function parameters of the memory were tested in radiation and annealing by very large scale integrated cicuit （VLSI） test system, the radiation-sensitive parameters were obtained through analyzing the test data. Ionizing radiation produced a large number of oxide trapped charges, leading MOS transistor threshold to the negative drift in memory peripheral control circuit. Additional electric field was introduced in the ferroelectric film, and leakage current was produced since the Schottky emission or space-charge-limited current occurred. The number of shallower levels and metastable state oxide trapped charges are more than the deep level oxide trapped charge, so that the device functions and the radiation-sensitive parameters were restored in the annealing.