Patent ID: 8008114

Claim:
A method for making a phase change memory device comprising: forming a memory cell access layer on a substrate, the memory cell access layer comprising an access device and a top surface; forming a memory cell layer, operably coupled to the memory cell access layer, comprising a lithographically formed phase change memory cell, said memory cell comprising: first and second electrodes having first and second opposed, spaced apart contact elements, respectively; a phase change element positioned between the first and second contact elements and electrically coupling the first and second contact elements to one another; and the phase change element having a width, a length and a thickness, the length measured between the first and second contact elements and the width measured perpendicular to the length, both the width and the length measured parallel to the top surface; and the memory layer forming step being carried out so that: the volume of the phase change element is less than the cube of the minimum lithographic feature size used to form the phase change memory cell; at least one of the length and the width of the phase change element is less than said minimum lithographic feature size; and the area of contact between the phase change element and the first contact element, defined by the width and thickness of the phase change element, is less than the square of said minimum lithographic feature size.