**Table 2.**

*Comparison for of switching parameters for tunnel barrier type RS devices.*

react chemically with oxygen ions inducing formation of unwanted interfacial layer. The mechanism of tunnel ReRAM is radically different to interface based switching devices discussed above. In order to obtain good conductivity, both the conducing metal oxides e.g. (Pr, Ca)MnO3 and tunnel oxide layer are processed at high temperature to ensure optimum crystallinity of the deposited films (**Table 2**) [34].
