December 10, 2002 2:12 PM PST
Wanted: Successor to flash memory
So-called flash memory will remain viable for several more years, but researchers anticipate that later this decade manufacturing limitations will force the industry to adopt a new technology. A replacement is one of the topics being discussed at the International Electron Devices meeting in San Francisco this week.
Flash memory can store data even when batteries are removed from a device, cutting off the power supply. That makes flash an essential feature in millions of cellular phones, handheld computers, digital cameras and music players. Flash is also increasingly finding a home in cars, TV set-top boxes and network equipment.
Current flash technology will likely survive until 2006, when it will be replaced by flash technology manufactured using a 65-nanometer process. The nanometer figure refers to the distance between transistors on a chip. Chipmakers are currently selling so-called 130 nanometer chips and will soon make the move to 90 nanometers. A nanometer is one billionth of a meter.
Barring breakthroughs, the technology will need to be replaced by the time it gets to 45 nanometers, near the end of the decade, said Craig Sander, vice president of process technology development for Advanced Micro Devices. Because of physical limitations imposed by flash's current structure, no one is certain that conventional flash cells will be able to scale below 65 nanometers, he said.
One replacement AMD is exploring is Quantum Well technology, which uses tiny wires, of approximately 5 nanometers, to store data. AMD will discuss this approach in a paper presented at the San Francisco conference, Sander said.
"The nice thing about this is that it uses some very conventional techniques to produce the (memory) cell itself and the nanowires," Sander said.
Because Quantum Well would be able to take advantage of AMD's current chip manufacturing technology, the company could produce it for about the same cost as today's flash chips. Quantum Well, however, would offer substantially better performance while consuming less power.
AMD is the second largest manufacturer of flash memory, after Intel, which has said it is working with several potential replacements, including "plastic" memory, or polymer ferroelectric RAM (PFRAM); Ovonics Unified Memory, which uses the same materials as rewritable CDs; and magnetic RAM.
AMD is also investigating polymer memory technologies.
Meanwhile, Texas Instruments and Motorola will present papers on potential successors to flash memory. Motorola's will focus on SONOS technology, which it says could become an incremental upgrade to current flash technology. Motorola is also working on its own version of magnetic RAM, a representative said.
TI will present a paper on its work with ferroelectric RAM, or FRAM.