Semiconductor & Patent Expert Consulting

Litigation expert consultant and patent expert witness for process, device, and circuit of  Dynamic

 Ram (DRAM), Flash  (NAND, NOR, EEPROM), and Static Ram (SRAM) Memories,

 and Microprocessor, Logic, and Analog Devices

EE Times: Semi News
Who's the leader in NAND flash?

SAN JOSE, Calif. — Who is the technology leader in the NAND flash-memory race? It might be a moot point, as vendors face a difficult oversupply situation in the market for most of 2007, analysts warned.

In the meantime, two companies, Samsung Electronics Co. Ltd. and Toshiba Corp., claimed leadership by separately announcing samples — and mass production — of the world's first sub-60-nm NAND flash-memory parts in the marketplace.

South Korea's Samsung (Seoul), the world's largest supplier of NAND flash memories, has begun sampling a 50-nm, 16-Gbit part for use in solid-state disk drive applications. The memory is expected to go into volume production at some time during the first quarter of 2007, Samsung said.

Japan's Toshiba (Tokyo), the world's second largest supplier, is quietly sampling 56-nm NAND flash-memory devices, with initial production slated for January. Toshiba was originally supposed to roll out 52-nm NAND devices, but the company scaled back its technical targets, and instead, devised 56-nm parts, due to the complexities of the technology, it said.

Other suppliers, including Hynix, STMicroelectronics and the Intel/Micron duo, are scrambling to keep up with Samsung and Toshiba.

Nam Hyung Kim, an analyst with iSuppli Corp. (El Segundo, Calif.), believes that Toshiba is slightly ahead of Samsung despite the announcement in the sub-60-nm NAND race. ''An announcement doesn't mean you are sampling,'' Kim said. ''Toshiba is slightly ahead of Samsung [in the sub-60-nm race].''

A leadership position could be a moot point, as the NAND market is expected to be in the oversupply mode at least until the third quarter of 2007, Kim said. ''The market will be challenging in 2007,'' he said. ''We expect oversupply until Q3. In Q4, we expect shortages.''

In 2007, the NAND market is projected to hit $14.188 billion, up 17 percent over 2006, according to iSuppli. Bit growth is expected to jump 149 percent in 2007 over 2006, but average selling prices are projected to fall by 53 percent this year, according to the firm.

NAND prices fell by an average of 61 percent in 2006. And vendors faced an oversupply mode for the entire year, causing some companies to exit the business, namely Renesas Technology Corp. and Qimonda AG.

It has been a tough market in recent times. ''Everyone is unhappy with the price drop in NAND,'' said Frankie Roohparvar, vice president of NAND development at Micron Technology Inc. (Boise, Idaho). ''We look at it as a bump in the road.''

Long term, the NAND price drop drives down ASPs and opens up ''a whole new set of applications,'' such as solid-state drives, PC cache, cellular phones, among others, Roohparvar said. Traditionally, NAND has been used in MP3 players, USB drivers and flash cards.

Solid-state drives are a potentially new and huge market for NAND. ''We're not saying that NAND will replace hard drives,'' he said. ''The big issue is cost per bit. We're closing the gap.''

In the marketplace, Toshiba and Samsung separately claim to be the first vendors to sample sub-60-nm parts. Samsung did not state whether its 16-Gbit memory is monolithically integrated or made up from multiple chips in a single package, but it did say that the memory is the first NAND flash memory made using a 50-nm manufacturing process.

However, Samsung itself claimed to have made a 32-Gbit memory in a 40-nm process in September 2006 based on a novel high-k gate dielectric including tantalum. That claim came shortly after IM Flash Technologies LLC had claimed to have leapfrogged Samsung with a 4-Gbit NAND flash memory made using a 50-nm manufacturing process.

The latest Samsung samples have a multilevel cell (MLC) design with a 4-kbyte page size, the company said. The page function has been doubled in size compared with previous NAND flash memories and has enabled the memory to double the read speed, while increasing write performance by 150 percent, Samsung added.

The memory is set to be deployed in external memory cards for use with PCs and in mobile phone handsets. The introduction of a 16-Gbit (2-Gbyte) memory is also expected to accelerate the adoption of non-volatile memory applications such as flash-based solid state disks, which could be used with Microsoft's Vista operating system.

Two second-tier suppliers, Micron and Hynix Semiconductor Inc. (Seoul), are in hot pursuit of the market leaders. Micron has announced 70-nm devices, but the company skipped the 65-nm generation to focus on its 50-nm parts, Roohparvar said.

Micron is sampling 50-nm single-level cell (SLC) devices, with 50-nm MLC products due in mid-2007, he said. Micron and Intel Corp. (Santa Clara, Calif.) have a joint NAND manufacturing venture, dubbed IM Flash.

The company is in the catch-up mode after getting a late start in the NAND market. ''We are committed to become a market leader,'' he said. ''Some of our competitors took six years to accomplish what we have done in a span of a year-and-a-half.''

Not to be outdone, Hynix is expected to sample 60-nm NAND devices in the first quarter of 2007, with 50-nm parts due out in the second half of 2007, according to Kim.

Last year, STMicroelectronics Inc. and Hynix opened their joint memory manufacturing fab in Wuxi City, Jiangsu Province, China. The Chinese fab venture is ramping up leading-edge memories, including 110- and 90-nm DRAMs as well as 80-nm NAND flash parts. The plan is to devise single- and multi-level-cell NAND flash devices at least down to 55-nm.

The $2 billion joint-venture fab is financed with equity from STMicroelectronics and Hynix on a one-third and two-thirds basis, respectively.