Patent ID: 7012273

Claim:
A phase change memory device comprising: a substrate; insulation material formed over the substrate and including a hole formed therein; spacer material disposed in the hole and having a surface that defines an opening having a width that narrows along a depth of the opening; a first block of conductive material disposed in the hole and having an upper surface; a layer of phase change memory material disposed in the opening and extending along the spacer material surface and at least a portion of the first block of conductive material upper surface; and a second block of conductive material disposed in the opening and on the phase change memory material layer; wherein the second block of conductive material and the layer of phase change memory material form an electrical current path that narrows in width as the current path approaches the first block of conductive material upper surface, so that electrical current passing through the current path generates heat for heating the phase change memory material disposed between the first and second blocks; wherein the substrate is semiconductor material having a first conductivity type, and the memory device further comprises: first and second spaced-apart regions formed in the substrate and having a second conductivity type, with a channel region defined in the substrate therebetween; and a third block of conductive material disposed over and insulated from the substrate including the channel region; wherein the first block is disposed over and electrically connected to the first region.