Patent ID: 6746892
Filing Date: 2004-06-08
Classification: H01L

Abstract:
A method of fabricating a low heat loss and small contact area electrode structure for a phase change media memory device, comprising:depositing a mask layer on a dielectric layer; patterning and then etching the mask layer to define a mandrel mask; dry etching the dielectric layer and the mandrel mask with an etch gas comprising a first etch gas for etching the dielectric layer and a second etch gas for etching the mandrel mask; continuing the dry etching until the mandrel mask is entirely dissolved and until the dielectric layer comprises a dielectric mandrel having a tapered shape that terminates at a vertex; conformally depositing an electrically conductive material on the dielectric mandrel to form a composite electrode including a shape that complements the dielectric mandrel and terminates at a tip; depositing a first dielectric layer on the composite electrode until the first dielectric layer completely covers an entirety of the composite electrode including the tip; planarizing the first dielectric layer; dry etching the first dielectric layer until the first dielectric layer recedes below a predetermined distance from the tip of the composite electrode so that an exposed portion of the composite electrode adjacent to tip is not covered by the first dielectric layer; depositing a layer of phase change media on the first dielectric layer and the exposed portion; patterning and then etching the layer of phase change media to define an island; depositing a second dielectric layer on the first dielectric layer and the island; planarizing the second dielectric layer; patterning and then etching the second dielectric layer to form a via extending to the island; depositing an electrically conductive material on the second dielectric layer and in the via so that the electrically conductive material is in contact with the island; and patterning and then etching the electrically conductive material to define an electrode.