A 7MB/s 64Gb 3-bit/cell DDR NAND flash memory in 20nm-node technology

Abstract

Recently, the demand for 3b/cell NAND flash has been increasing due to a strong market shift from 2b/cell to 3b/cell in NAND flash applications, such as USB disk drives, memory cards, MP3 players and digital still cameras that require cost-effective flash memory. To further expand the 3b/cell market, high write and read performances are essential [1]. Moreover, the device reliability requirements for these applications is a challenge due to continuing NAND scaling to sub-30nm pitches that increases cell-to-cell interference and disturbance. We present a high reliability 64Gb 3b/cell NAND flash with 7MB/s write rate and 200Mb/s asynchronous DDR interface in a 20m-node technology that helps to meet the expanding market demand and application requirement.