A contact resistance model for scanning probe phase-change memory

A novel mechanical model was proposed to calculate the contact resistance at tip and capping layer interface for scanning probe phase-change memory applications. The resulting I–V curve calculated from this model that combines Hertzian contact theory with the Schottky diode effect has exhibited a good agreement with the experimental measurements under the same system architecture. The role of contact resistance on the write efficacy of scanning probe phase-change memory was also evaluated by introducing the calculated contact resistance into the previous electrothermal simulations for cases of writing crystalline bits in amorphous starting phase and writing amorphous bits in crystalline starting phase. The consequent written marks and I–V curve show a closer match with the experimental observation compared to the case without including contact resistance.