Total Ionization Dose Effects on Charge Storage Capability of Al2O3/HfO2/Al2O3-Based Charge Trapping Memory Cell**Supported by the National Natural Science Foundation of China under Grant No 616340084, the Youth Innovation Promotion Association of Chinese Academy of Sciences under Grant No 2014101, the International Cooperation Project of Chinese Academy of Sciences, and the Austrian-Chinese Cooperative R&D Projects under Grant No 172511KYSB20150006.

Abstract

Because of the discrete charge storage mechanism, charge trapping memory (CTM) technique is a good candidate for aerospace and military missions. The total ionization dose (TID) effects on CTM cells with Al2O3/HfO2/Al2O3 (AHA) high-k gate stack structure under in-situ 10 keV x-rays are studied. The C–V characteristics at different radiation doses demonstrate that charge stored in the device continues to be leaked away during the irradiation, thereby inducing the shift of flatband voltage (Vfb). The dc memory window shows insignificant changes, suggesting the existence of good P/E ability. Furthermore, the physical mechanisms of TID induced radiation damages in AHA-based CTM are analyzed.