February 04, 2010, 8:40 PM — When IM Flash Technologies (IMFT) announced this week that its manufacturing a 25-nanometer (nm) NAND flash chip, the company also admitted that shrinking the technology much further may not be possible because of problems with bit errors and cost.
If that turns out to be true, one of the basic building blocks used for storage in solid-state drives (SSDs) and memory cards may be nearing a dead end.
"I think in the next four years or five years, it's probably going to be the case" that NAND will no longer be the storage medium, said Gregory Wong, a flash memory analyst with market research firm Forward Insights. "Everybody's looking at alternatives." NAND flash memory has been the single biggest change to drive technology in recent several years, with the storage medium showing up in data centers, high-end laptops like Apple 's MacBook Air and in memory cards in mobile devices. Apple has largely driven the adoption rate with its use of NAND flash in its popular iPods and iPhones, sales of which helped drive flash memory costs down through mass production.
iSuppli Corp. forecasts that the global flash memory card market will grow from 530 million units this year to 9.5 billion units by 2013, a market that will then be worth $26.5 billion. The market for high-capacity memory chips has a lot of room to grow, according to iSuppli, largely because of the rise of smartphones. The more features they offer, whether it's touch screens, wireless Internet access or video capabilities, the more storage they need.
"As we move to high-definition video, that's going to require higher storage capacities," said Wong. "The issue, of course, is ... do you really need HD video on a tiny screen? No, but companies will use HD as a way to differentiate themselves."
For example, Samsung, the world's largest NAND flash memory maker, just released a new 64GB moviNAND embedded chip and 32GB microSD removable memory card for mobile devices. Both were created with its new 30nm lithography technology.
Steve Weinger, senior manager for NAND flash marketing at Samsung Semiconductor Inc., said mobile phone video capabilities and the desire to store a never-ending stream of applications, movies, television shows and video clips from sites like YouTube.com is driving chip development and a 34% annual growth in sales. In fact, NAND flash chip memory has doubled in capacity in a little more than a year, he said.
"You could eventually have in the palm of your hand, all your movies, your pictures and everything else," he said. "I recently watched a football game on my iPhone with the DirectTV application. It was really crystal clear."
The problem, Weinger said, is that it's becoming difficult to make NAND flash memory denser.
Currently, the 25nm lithography being used by IMFT, a joint venture of Intel and Micron, is the smallest NAND production technique in existence. And an intel spokesman was cautious about how much smaller NAND flash memory can reliably get. That's important because smaller chips means more capacity in the same amount of space.
"The challenge of stepping down in lithography is to continue to provide equivalent performance...as previous products," Troy Winslow, director of NAND marketing at Intel, said in an interview with Computerworld . "Those were challenges we were able to overcome with this generation. But looking into the next couple of generations, we do recognize materials and process technology will have to change as obstacles mount."
Intel is already approaching atomic size with its lithography technique. Lithography is the process of creating cells and transistors in silicon, which are used to store bits of data. The smaller they are, the more data that can fit on a single NAND flash chip. At 25nm, the cells in silicon are 3,000 times thinner than a human strand of hair. And at that level inter-cell electrical interference becomes a tougher obstacle to tackle.
According to Michael Yang, a senior analyst for memory & storage with iSuppli Corp., anything smaller than 20nm lithography is uncharted territory for NAND flash.
"Unless it can be proven that [10-19] nanometer or lower is possible with NAND, it will be a crossroads for a new memory technology," Yang wrote in an e-mail response to Computerworld .
In addition, the number of electrons that can be stored in the memory cell decreases with each generation of flash memory, making it more difficult for the cells to reliably retain data, according to Wong.
