Giovanni Naso

A 3bit/cell 32Gb NAND flash memory at 34nm with 6MB/s program throughput and with dynamic 2b/cell blocks configuration mode for a program throughput increase up to 13MB/s

In recent years applications such as mp3 players, SSD, digital cameras and video camcorders have driven the development of increasingly higher density NAND memories. In the presented 3b/cell memory the read and programming throughputs are been enhanced with the adoption of a quad-plane architecture and an industry standard even-odd bitline (BL) decoding scheme. The architecture, while featuring same page size of 16KB as recently disclosed ABL architectures [3,4], avoids the shortcomings such an ABL scheme exhibits in programming mode due to floating-gate-to-floating-gate coupling. The chip features both the newly developed synchronous DDR interface and the standard, asynchronous NAND flash interface. A 66-cell string is adopted to optimize the die size at 126mm2.

A 128Gb 3b/cell NAND flash design using 20nm planar-cell technology

The authors develop a 128Gb 3b/cell NAND Flash memory based on 20nm fully planar cell process technology. The planar cell allows the memory cell to be scaled in both the wordline (WL) and bitline (BL) directions, resulting in a small 3b/cell memory device. The sensing scheme is based on a ramping technique that allows the detection of hard and soft states in a single operation.