Commercialization of germanium based nanocrystal memory

Abstract

This thesis explores the commercialization of germanium-based nanocrystal memories. Demand for smaller and faster electronics and embedded systems supports the development of high-density, low-power non-volatile electronic memory devices. Flash memory cells designed for ten years of data retention require the use of a thick tunneling oxide. This compromises writing and reading speed as well as endurance. A smaller device size can be achieved and speed and can be improved by decreasing the oxide thickness. However, significant charge leakage will occur if the oxide is too thin, which will reduce the data retention time dramatically. This imposes a limit to the amount by which the oxide thickness can be decreased in conventional devices. Research has shown that by incorporating nanocrystals in the tunnel oxide, charge traps are created which reduce charge leakage and improve endurance through charge-storage redundancy. By replacing the conventional floating gate memory with one using Si or Ge nanocrystals, the nonvolatile memory exhibits high programming speed with low programming voltage and superior retention time, and yet is compatible with conventional silicon technology. This thesis provides an analysis of competing technologies, an intellectual property analysis, costs modeling as well as ways to improve nanocrystal memories in order to compete with other forms of emerging technologies to replace conventional Flash memories.