Total Ionization Dose Effects on Charge-Trapping Memory With Al2O3/HfO2/Al2O3 Trilayer Structure

This paper investigates total ionization dose (TID) effects on the electrical characteristics of Al
₂
O
₃
/HfO
₂
/Al
₂
O
₃
-based charge trapping memory (CTM) devices by 10-keV X-ray. The Al
₂
O
₃
layers serve as tunnel and blocking oxides, respectively, while HfO
₂
layer acts as charge-trapping layer. The C-V curves in pristine state shifted toward negative direction, but dc memory window almost kept the same after irradiation. Storage electrons decreased significantly with accumulated dose and reached approximately the same final value regardless of initial values. The impact of TID irradiation on program and erase conditions is also investigated. The program ability still worked well, but the erase ability disappeared gradually after irradiation. The physical mechanisms triggered by TID irradiation on Al
₂
O
₃
/HfO
₂
/Al
₂
O
₃
-based CTM structure are discussed in detail with energy band diagrams.