Physical Analysis And Design Of Nanoscale Floating Body Dram Cells

Download or read book Physical Analysis and Design of Nanoscale Floating-body Dram Cells written by Zhichao Lu and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: This dissertation addresses physical analysis and design issues of nanoscale floatingbody cells (FBC), which are also known as capacitorless dynamic random-access memory (DRAM) cells. A novel two-transistor floating-body/gate cell (FBGC), and upgraded versions of it, are proposed and experimentally demonstrated. As the conventional one-transistor and one-capacitor (1T/1C) DRAM technology is aggressively scaled, novel device structures and materials have to be introduced to meet International Technology Roadmap for Semiconductors (ITRS) performance requirements. Novel device structures and materials bring a lot of processing and integration challenges to current complementary metal-oxide-semiconductor (CMOS) technology. To avoid these challenges, capacitorless DRAM, which is based on silicon-on-insulator (SOI) CMOS including partially depleted (PD) and fully depleted (FD) MOS transistors (MOSFETs), is attracting a lot of interest. This technology, which uses the floating body of the SOI MOSFET as the storage element, can potentially replace the conventional 1T/1C DRAM cell in the near future. The basic working principle of the FBC is to utilize the floating-body effect inherent in the PD/SOI MOSFET; the FD/SOI MOSFET also shows the floating-body effect when the substrate, or back gate is biased for accumulation. However, the physical explanation of the floating-body effect in the FD/SOI device is not clear. Based on 14 numerical simulations, physical insights are gained on the effect and on FBC performance, e.g., the sense margin.