Memory chips

Spansion, a joint venture between Advanced Micro Devices Inc. (AMD) and Fujitsu Ltd, plans to use a silicon foundry one node behind, like Taiwan Semiconductor Mfg Co. Ltd (TSMC), in order to dedicate its finances to the latest technology, such as 45nm and 32nm process technologies. The 65nm process technology for the company’s SP1 facility in Japan was developed at the Submicron Development Centre (SDC) in San Jose, California, which was acquired from AMD and copied exactly to the fab, and has been producing Spansion’s MirrorBit products on 300mm wafers since Q4 2007. All the 65nm products underwent built-in self-test (BIST), allowing the company to test one wafer at a time rather than die by die, reducing operational cost. SP1 marks Spansion’s move into true high volume manufacturing, supplying key components for next-generation equipment with a scalable, cost-effective technology based on 65nm, 45nm and even 32nm process.

On the other hand, Intel Corp. and STMicroelectronics, together with venture capital partner, Francisco Partners, have combined their flash operations to create Numonyx. This potentially market leading joint venture, had a combined revenue of $3.6 billion—34 percent of the total flash memory sales in 2007, compared to 32 percent cornered by the other major player, Spansion. Numonyx focuses on supplying non-volatile memory solutions for a variety of consumer and industrial devices including cellular phones, MP3 players, digital cameras, computers and other high-tech equipment.

NOR flash market shakes up

NAND flash memory technology, made by companies such as Samsung Semiconductor Inc. and the partnership of Toshiba Corp. and SanDisk Corp., is mainly used in MP3 players and for storage. But it is the faster NOR flash market that is now seeing the shakeup.

Spansion’s MirrorBit architecture uses charge storage like a DRAM memory rather than the traditional floating gate technology, which is slowly running out of steam. The architecture is fundamentally different and more advanced than conventional multi-level cell (MLC) and single-level cell (SLC) floating gate technology. The MirrorBit cell doubles the intrinsic density of a flash memory array by storing two physically distinct bits on opposite sides of a memory cell, enabling it to deliver higher read and write performance for wireless and embedded markets.

Spansion is also making moves into the NAND flash area with a nitride-based technology, targeted at data storage applications in the integrated flash memory markets. MirrorBit ORNAND2, which will use a SONOS-like memorycell connected in a NAND memory array at 45nm, will provide both fast write performance with high packing density. Expected to be available in early 2009, the products will be manufactured on 300mm wafers.

Additionally, by acquiring Saifun Semiconductors Ltd, Spansion has entered the technology licensing business, significantly expanding its market opportunity by offering NROM and MirrorBit to NAND and DRAM memory and system-on-a-chip (SoC) makers.

One such deal by Spansion is with US company Virident inc., who has integrated Spansion’s MirrorBit Eclipse flash memory into its chips designed for data centers. The energy-efficient memory incorporates specific optimizations for server applications that enables fast read performance and high capacity at only 10 percent of the power of DRAMs per-Gigabyte.