Silicon Nanowire-Based Nonvolatile Memory Cells: Progress and Prospects
ECE Dept., George Mason University, Fairfax, VA 22030, USA
Semiconductor Electronics Division, NIST, Gaithersburg, MD 20899, U.S.A.
There is a widely recognized need for urgent progress in nonvolatile memory (NVM) technology,1 driven by the exponential market growth of the ubiquitous portable and mobile electronics, such as cell phones, music players, USB and memory cards, etc. Commensurate with this demand, intensive research is carried out around the world to improve present technologies and invent new ones: for example, no fewer than eight (out of a total of 31) dedicated technical sessions at the IEDM 2007 meeting2 and one3 out of three plenary talks at the IEDM 2008 meeting4 were dedicated on memory cell technology. To meet this demand and enable continued scaling (Moore’s Law), NOR flash memory is been replaced (where possible) with the much denser NAND technology, but the industry consensus is that fundamentally new innovations must be introduced beyond the 45-nm lithography node generation.3 One such innovation actively pursued by many research groups around the world is to design NVM cells based on silicon nanowires (SiNWs).5
There are several important reasons why SiNW NVM cells are expected to outperform a conventional (planar)6 silicon NVM cell. First, because of the cylindrical symmetry, for the same value ...