RESISTIVE SWITCHING EFFECT IN CO-DOPED ZNO THIN FILMS FOR NONVOLATILE MEMORY APPLICATIONS

Resistive switching phenomena have attracted considerable attention because of their potential application in the next
generation of nonvolatile memory. In this circumstance, resistive-change random access memory (RRAM) has got extensive
interests due to its high response speed, high scalability, multibit storage potential and simple structure. Co-doped ZnO is
diluted magnetic semiconductor and is would be of great interesting to realize the resistive switching property.
In this work, we have studied the cobalt doped ZnO thin films based RRAM structure which exhibit reproducible bipolar
resistive switching behavior. The cobalt doped ZnO films were deposited on the heavily doped n-type silicon (100) substrates
by ultrasonic spray pyrolysis method. The values of both a high resistance state ( HRS) and a low resistance state (LRS)
have little fluctuation during the cycling test, indicating the excellent switching stability. The resistance ratios of HRS to LRS
are in the range of 2-3 orders of magnitude within the 80cycles of test. To sum up, steady and reversible bistable resistive
switching behavior in Au/Co:ZnO/n+-Si device provides the possibilities for nonvolatile memory applications.