浮栅器件和普通NMOS器件总剂量效应对比研究

Comparison of total ionizing dose effect between floating gate device and NMOS device

为深入了解应用NOR Flash工艺的多种器件的总剂量特性,特别是浮栅器件的特殊总剂量效应,开展了浮栅器件和多种NMOS器件总剂量效应的对比试验。基于器件级测试芯片,进行了多种剂量的总剂量试验和高温退火试验,分析了不同器件在总剂量辐照下的不同特性,所关注的特性包括器件的漏电流变化和阈值电压变化。通过试验发现浮栅器件受总剂量辐照后会产生弱编程效应且该效应无法通过退火恢复。这一研究成果为抗辐射Flash产品的抗总剂量加固设计提供了依据。

The effects of the total ionizing dose （TID） on the floating gate devices and the NMOS devices are compared based on the NOR Flash technology in order to further study the TID characteristic of the devices in the NOR Flash process, especially for the floating gate devices. Based on a device level test chip, the TID test with different dosages and annealing at a high temperature are conducted to acquire the radiation characteristics of different devices. The focus is on the leakage current change and the threshold voltage drift. The TID-induced soft program effect is determined, which cannot be recovered by annealing. This result provides a reference for the TID radiation hardening design for the Flash designers.