SELECTIVE ETCHING OF TOP ELECTRODE METAL TO PHASE-CHANGE MATERIAL BY TUNING WAFER TEMPERATURE

원문 (중국어)

Provide an initial structure including a bottom electrode layer, a phase change material layer outward of the bottom electrode, a top electrode layer outward of the phase change material layer, and a patterned hard mask outward of the phase change material layer. Etch the initial structure using a first halogen plasma etchant at high wafer temperature to partially remove portions of the top electrode layer not protected by the patterned hard mask to produce an intermediate structure. Etch the intermediate structure using a second halogen plasma etchant at low wafer temperature to remove a remaining portion of the top electrode layer down to the phase change material layer, leaving a web of top electrode layer material under the patterned hard mask. Etch portions of the phase change material layer not protected by the web of top electrode layer material down to the bottom electrode layer, and remove the patterned mask.