Abstract: An array of “mushroom” style phase change memory cells is manufactured by forming a separation layer over an array of contacts, forming an isolation layer on the separation layer and forming an array of memory element openings in the isolation layer using a lithographic process. Etch masks are formed within the memory element openings by a process that compensates for variation in the size of the memory element openings that results from the lithographic process. The etch masks are used to etch through the separation layer to define an array of electrode openings. Electrode material is deposited within the electrode openings; and memory elements are formed within the memory element openings. The memory elements and bottom electrodes are self-aligned.

Abstract: A multi-chip package with die having shared input and unique access IDs. A unique first ID is assigned and stored on die in a die lot. A set of die is mounted in a multi-chip package. Free access IDs are assigned by applying a sequence of scan IDs on the shared input. On each die, the scan ID on the shared input is compared with the unique first ID stored on the die. Upon detecting a match, circuitry on the die is enabled for a period of time to write an access ID in nonvolatile memory, whereby one of the die in the multi-chip package is enabled at a time. Also, the shared input is used to write a free access ID in nonvolatile memory on the one enabled die in the set. The unique first IDs can be stored during a wafer level sort process.