The surface topology of a plug surface area-containing surface of a semiconductor device can be improved by removing material to create a first planarized surface with at least one plug surface area, typically a tungsten or copper plug area, comprising a recessed region. A material is deposited onto the first planarized surface, to create a material layer, and into the upper portion of the recessed region. The material layer is removed to create a second planarized surface with the material maintained in the upper portion of the recessed region. To form a semiconductor phase change memory device, a phase change element is formed between the at least one plug area, acting as a first electrode, at the second planarized surface and a second electrode.

A memory device including a memory cell comprising phase change material is described along with methods for programming the memory device. A method for programming disclosed herein includes applying an increasing first voltage across the memory cell and monitoring current in the memory cell to detect a beginning of a phase transition of the phase change material. Upon detection of the beginning of a phase transition of the phase change material, the method includes applying a second voltage across the memory cell that is a function of the level of the first voltage upon detection of the beginning of a phase transition of the phase change material.

Programmable resistive memory cells are accessed by semiconductor diode structures. Manufacturing methods and integrated circuits for programmable resistive elements with such diode structures are also disclosed.

A phase change memory device with improve thermal isolation. The device includes an electrode stack, including a first and second electrode elements, generally planar in form, separated by and in mutual contact with a dielectric spacer element, wherein the electrode stack includes a side surface; a phase change element having a bottom surface in contact with the electrode stack side surface, including electrical contact with the first and second electrode elements; and dielectric fill material surrounding and encasing the memory device, wherein the dielectric fill material is spaced from the phase change element, such that the phase change element and the dielectric fill material define a cavity adjacent the phase change element, and wherein the cavity contains a low pressure environment.