Abstract
This study proposed a confined structure of phase change random access memory (PRAM). We used growth-dominant phase change material (PCM) and copper bottom electrode for the device. By adopting this structure design, we were able to reduce the high power of amorphization pulse and shorten the crystallization programming time. The set and reset operations of PRAMs were studied using COMSOL finite-element simulation program. We used the 3ω thermal conductivity measurement to get thermal conductivity of our phase change material. After inputting the materials parameters and building the simulation device models, we can use set and reset operations to retrieve the temperature distributions in the cells. Through these temperature data, we acquire the data of smallest set and reset voltage, set/reset resistance ratio and temperatures at specific time to analyze the operation of PRAM. After comparing different device models, we obtained the optimized thickness of phase change layer, understanded the via size effect and confirmed the advantages of confined structure with copper electrode. Finally, accompanied with the static test result of PCM, we successfully demonstrated the potentials of 10 ns write/erase speed PRAM by simulations.