Patent ID: 8222071
Filing Date: 2012-07-17
Classification: H01L

Abstract:
1. A method for making a memory cell assembly, comprising: forming a memory cell access layer over a substrate to create an access device comprising first and second bottom electrodes, the first and second bottom electrodes separated along a line defining a second direction, the second direction being perpendicular to a first direction; forming a first memory assembly, comprising a first pillar-like memory element, and a second memory assembly, comprising a second pillar-like memory element, over the memory cell access layer, each memory element having an end with first and second dimensions measured in the first and second directions, the first and second memory elements being in electrical contact with the first and second bottom electrodes, the first memory assembly forming step carried out using a chosen mask forming process, the second dimension being smaller than the minimum feature size of the chosen mask forming process; forming a first fill layer over the memory cell access layer to at least partially surround the first and second memory assemblies; forming a top electrode over the first fill layer, the top electrode extending in the second direction and having a via connecting region and first and second top electrode regions on either side of the via connecting region, the first and second top electrode regions crossing over and being in electrical contact with the ends of the first and second memory elements; forming a second fill layer over the top electrode and the first fill layer; forming an electrically conductive via in the second fill material, the electrically conductive via having a via surface in electrical contact with the via connecting region of the top electrode; and sizing the surface areas of the via surface and the via connecting region so that (1) the surface area of the via connecting region is greater than the surface area of the via surface, and (2) the size of the via connecting region measured in each of the first and second direction is substantially greater than the size of either of the first and second top electrode regions measured in the second direction.