The authors report on the temperature dependence of electronic transport property of Ag/ La 2 CuO 4+x ͑LCO͒ heterostructures with different oxygen contents. Bipolar resistance switching was observed in the sample with larger oxygen content and disappears below 200 K, consistent with the characteristic temperature of oxygen migration in LCO. The resistance relaxation of the low resistance state shows similar behavior as that of oxygen diffusion in LCO and vanishes below 200 K. Analysis of the results strongly indicates that the resistance switching results from the modulation of Schottky barrier by oxygen electromigration at the interface.

In this study low temperature copper-gold bonding in ambient is demonstrated successfully with the help of organic monolayers. Further investigation is made to evaluate the influence of chain length of these monolayers to alleviate bonding temperature. We found that a single coat of organic monolayer on copper showed superior bond strength as compared to a double-coating on both copper and gold surfaces respectively. Despite effective surface passivation against oxide formation (Cu) and organic contaminant from ambient (Au) by long chain organic monolayers, when both surfaces are coated with the longest monolayer, weaker bond strength was observed. The results suggest that the ease of removal of organic monolayers from Cu and Au surface respectively prior to bonding plays a dominant role in enabling low temperature Cu-Au bonding.