This week Intel privately shared parts of
its roadmap for memory technologies through 2008. Intel’s
progress on phase-change memory, PCM or PRAM, will soon be
sampled to customers with mass production possible before the end of the year.
Phase-change memory is positioned as a replacement for
flash memory, as it has non-volatile characteristics, but is faster and can be
scaled to smaller dimensions. Flash memory cells can degrade and become
unreliable after as few as 10,000 writes, but PCM is much more resilient at more
than 100 million write cycles. For these reasons, Intel believes that
phase-change memory could one day replace DRAM.
“The phase-change memory gets pretty close to Nirvana,” said
Ed Doller, CTO of Intel’s flash memory group. “It will start to displace some
of the RAM in the system.”
For its implementation of phase-change memory, Intel has since 2000 licensed technology from Ovonyx Inc.. The Ovonyx technology uses the properties of chalcogenide
glass, the same material found in CD-RW and DVD-RW, which can be switched
between crystalline and amorphous states for binary functions.
Every potential PCRAM memory maker thus far licenses Ovonyx technology. According
to Ovonyx’s Web site, the first licensee of the technology was Lockheed Martin
in 1999, with Intel and STMicroelectronics in the following year. Four years
after that, Nanochip signed an agreement. Elpida and Samsung were the next two in 2005,
and Qimonda marks the latest with a signing this year.
IBM, Macronix and Qimonda detailed last December its recent developments on
phase-change memory. Researchers at IBM’s labs demonstrated a prototype
phase-change memory device that switched more than 500 times faster than flash
while using less than one-half the power to write data into a cell. The IBM device’s cross-section is a minuscule 3 by 20 nanometers in size, far
smaller than flash can be built today and equivalent to the industry’s
chip-making capabilities targeted for 2015.
Intel’s initial phase-change technology, however, is already
a reality, as the chipmaker revealed that it has produced a 90
nanometer phase-change memory wafer. At the 90 nanometer process size, the
power requirements to write are approximate to that required for flash. Intel
said that its early test work shows data retention abilities of greater than 10
years even at temperatures of 85 degree Celsius.
Intel touts PCM as a “new category of memory,” as its
attributes are distinctly different, and typically superior to many of the
memory technologies today as it combines the best attributes of RAM, NOR and
NAND. Intel wouldn’t give a firm date on the availability of its phase-change
memory as several details still need to be finalized after the sampling
process.
“We're going to be using this to allow customers to get
familiar with the technology and help us architect the next generation device.”
Doller said. “We're hoping we can see [mass] production by the end of the year,
but that depends on the customers.”
