Geometry based resistance model for phase change memory

A phase change memory resistance model accounting for the geometry of SET and RESET state is developed. The resistance of the memory cell with different dimensions and boundary conditions is solved using conformal mapping including the current crowding effect. When combining with a proper thermal heating model, the read resistance at different degree of crystallization can be predicted, which is important for multi-bit storage simulation. The model has been verified by numerical simulation with different cell geometry and programming current magnitude. The model calculation result is verified by the numerical simulation.