Yupin Fong

A 146-mm/sup 2/ 8-gb multi-level NAND flash memory with 70-nm CMOS technology

An 8-Gb multi-level NAND Flash memory with 4-level programmed cells has been developed successfully. The cost-effective small chip has been fabricated in 70-nm CMOS technology. To decrease the chip size, a one-sided pad arrangement with compacted core architecture and a block address expansion scheme without block redundancy replacement have been introduced. With these methods, the chip size has been reduced to 146 mm/sup 2/, which is 4.9% smaller than the conventional chip. In terms of performance, the program throughput reaches 6 MB/s at 4-KB page operation, which is significantly faster than previously reported and very competitive with binary Flash memories. This high performance has been achieved by the combination of the multi-level cell (MLC) programming with write caches and with the program voltage compensation technique for neighboring select transistors. The read throughput reaches 60 MB/s using 16I/O configuration.

128Gb 3b/cell NAND flash memory in 19nm technology with 18MB/s write rate and 400Mb/s toggle mode

This paper addresses challenges with improvements made over previous NAND generations to achieve high performance while maintaining a low fail-bit count (FBC) and cost savings from an improved architecture and tightly packed peripheral circuits. Air gap [2,3] technology further improves write throughput by reducing neighbor interference and WL RC. A toggle mode 400Mb/s I/O interface reduces system overhead and enhances overall performance.