In this work, two aspects of phase change memory: information storage cell and access device are studied to give some design guidelines of PCM. To better understand characteristics of the storage cell of PCM, fabrication has been conducted in Nano Fabrication Facility of HKUST and Dalian University of Technology. Both the PN diode and FETs access devices are studied. An analytic model of PN diode access device is developed to further optimize its performance. The model includes non-uniform current flow in the buried contact layer, injection current to the substrate, and disturb current to neighboring cells. Model is verified by extensive 3-D numerical simulations. Based on the model, the impact of various geometrical parameters on the memory array performance can be predicted before act...[ Read more ]

In this work, two aspects of phase change memory: information storage cell and access device are studied to give some design guidelines of PCM. To better understand characteristics of the storage cell of PCM, fabrication has been conducted in Nano Fabrication Facility of HKUST and Dalian University of Technology. Both the PN diode and FETs access devices are studied. An analytic model of PN diode access device is developed to further optimize its performance. The model includes non-uniform current flow in the buried contact layer, injection current to the substrate, and disturb current to neighboring cells. Model is verified by extensive 3-D numerical simulations. Based on the model, the impact of various geometrical parameters on the memory array performance can be predicted before actual fabrications. Performance of FETs are then studied in the sub-90nm technology node, which will bring in a lot of extra effects like quantum mechanics modification, poly depletion and so on. At last, circular surrounding gate MOSFET performance is compared with PN diode to find an optimal access device for PCM application.