Resistive switching characteristics of a modified active electrode and Ti buffer layer in CuSe-based atomic switch

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Atomic switches are well-known promising candidates for future application in non-volatile logic memory devices. The resistive switching characteristics of these devices depend on the formation of a conductive filament (CF) by active metal electrodes. However, the formation of a stable CF is still a challenge owing to filament overgrowth in the solid electrolyte. To achieve controlled CF growth, we have used a modified active electrode with different Cu<SUB>x</SUB>Se<SUB>1−x</SUB> composition ratios (0.01 < x < 0.45) and a titanium (Ti) buffer layer. The optimum composition was determined to be Cu<SUB>0.11</SUB>Se<SUB>0.89</SUB>/Ti (2.5 nm) for which excellent resistive switching properties were observed, such as a high on/off ratio of 10<SUP>4</SUP>, low operating voltage, uniform resistance distribution, ten-year data retention at 85 °C, and <B>uniform endurance</B> (2000 cycles). The improvement is can be described from the high controllability of the oxidation-reduction reaction rate of the optimized CuSe modified active electrode by the means of Ti buffer layer and the TiO bond formation at the Ti/Al<SUB>2</SUB>O<SUB>3</SUB> interface. In addition, depth profiles of the conductive filament based on Cu<SUB>0.11</SUB>Se<SUB>0.89</SUB> with a Ti buffer layer were studied by performing current atomic force microscopy (I-AFM) to evaluate the enhancements in electrical performance and reliability resulting from the insertion of the Ti buffer layer.</P> <P><B>Highlights</B></P> <P> <UL> <LI> First report on CuSe based atomic switch. </LI> <LI> Improved reliability depends on interface reaction at Ti/Al<SUB>2</SUB>O<SUB>3</SUB>. </LI> <LI> CuSe/Ti/Al<SUB>2</SUB>O<SUB>3</SUB>/Pt device showed highly stable retention at 102 °C for ten years. </LI> <LI> 860 nm<SUP>2</SUP> area of cross section of conductive filament is observed from I-AFM. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Resistive switching characteristics of CuSe/Ti-based atomic switch with controlled filament.</P> <P>[DISPLAY OMISSION]</P>