Abstract
Resistive random access memory (RRAM) has recently attracted great attention due to its potential for replacement of flash memory in next-generation nonvolatile memory applications. In this thesis, we have investigated the resistive switching property of doping Al in HfO2-based RRAM. The Al-doped HfO2 films were prepared as multistack-like structure on TiN/Ti/SiO2/Si substrate by atomic layer deposition (ALD), which can control the film thickness precisely with high coverage ability. Moreover, in order to make Al diffuse more evenly through whole HfO2 film, post-deposition annealing had been done before depositing Pt top electrode by DC sputtering. The effect of Hf/Al ratio would also be discussed, and the proportion of doped-Al was controlled by ALD cycle repeat. The HfO2-based RRAM shows a bipolar resistive switching behavior that the positive bias induces a low resistance state and the negative bias resets to the relative high resistance state. The improved uniformity of resistive switching characteristics in the Al-doped HfO2 thin film RRAM is demonstrated. More physical details is also obtained from thermal I-V curve analysis.