Edge Contact Lateral Phase Change RAM with Super-Lattice-Like Phase Change Medium

Phase change RAM (PCRAM) is one of the best candidates for the next-generation nonvolatile memory. Recently lateral PCRAM using a thin phase change bridge was proposed as a promising approach to achieve high density due to simpler fabrication process and lower RESET current. This paper proposes a new lateral PCRAM structure - edge contact lateral structure, together with a Sb₇Te₃-GeTe super-lattice-like (SLL) phase change medium to reduce the contact area, improve thermal confinement and hence reduce current. Its RESET current of 1.23 mA is less than that of normal lateral PCRAM with SLL (1.5 mA). It also shows good stability and resistance ratio after 105 overwriting cycles. Testing results are consistent with the simulation results.