Patent ID: 8026502
Filing Date: 2011-09-27
Classification: H01L

Abstract:
1. A phase-change nonvolatile memory comprising: a semiconductor substrate; a lower electrode formed on the semiconductor substrate; a first interlayer insulating film which is formed to cover the lower electrode and the semiconductor substrate, wherein a first hole is formed in the first insulating film so as to expose the lower electrode; an impurity diffusion layer embedded in the first hole, wherein the impurity diffusion layer is constituted of a first semiconductor layer and a second semiconductor layer which have different conductivity types; a second interlayer insulating film which is formed to cover the first interlayer insulating film and the impurity diffusion layer, wherein a second hole is formed in the second interlayer insulating film so as to expose the impurity diffusion layer; a phase-change recording layer which is formed to cover the second interlayer insulating film and to embed the second hole; and an upper electrode formed on the phase-change recording layer, wherein the first semiconductor layer is constituted of a base portion which is formed inside the first hole so as to cover the lower electrode and a projecting portion which projects from the base portion so that a heating spot thereof comes in contact with the phase-change recording layer in the second hole, while the second semiconductor layer is formed to at least partially surround the projecting portion, wherein a depletion layer is formed in proximity to a junction surface formed between the first semiconductor layer and the second semiconductor layer so as to reduce a diameter of the heating spot, and wherein the heating spot heats the phase-change recording layer in response to a current flowing between the impurity diffusion layer and the phase-change recording layer.