Resistive Switching Characteristics of Tm$_{2}$O $_{3}$, Yb$_{2}$O $_{3}$, and Lu$_{2}$ O$_{3}$-Based Metal–Insulator–Metal Memory Devices

In this paper, we investigated the electroforming-free resistive switching (RS) behavior in the Ru/RE
₂
O
₃
/TaN (rare-earth, RE, RE = Tm, Yb, and Lu) memory device fabricated with full room temperature process. The conduction mechanism of RE
₂
O
₃
-based memory devices in the low-resistance state is ohmic emission, whereas Tm
₂
O
₃
, Yb
₂
O
₃
, and Lu
₂
O
₃
memory devices in the high-resistance state are space charge limited conduction (SCLC), ohmic behavior, and SCLC, respectively. The Ru/Lu
₂
O
₃
/TaN device showed a high-resistance ratio of ~ 10
⁴
, a high device yield of ~70%, a good data retention as long as 10
⁵
s measured at 85°C, and a reliable endurance for up to 100 cycles, suggesting the optimal chemical defects (metallic Lu and nonlattice oxygen ion) in Lu
₂
O
₃
film. All of these results suggest that Ru/Lu
₂
O
₃
/TaN structure memory is a good candidate for future nonvolatile RS memory applications.