IBM, Infineon Develop Better Magnetic Memory

What if you could turn computers on and off as quickly as a light switch without having to wait for software to “boot up”? Sound like science fiction?

Researchers at IBM and German-based Infineon Technologies AG don’t think so. The two companies Monday highlighted their advances on Magnetic (or Magnetoresistive) Random Access Memory (MRAM). The nonvolatile memory technology uses magnetic, rather than electronic, charges to store bits of data. The companies say they’ve advanced the technology so much it could replace current computer memory as early as 2005.

“MRAM has the potential to become the universal memory technology of the future,” IBM Research vice president Dr. T. C. Chen said at the VLSI Symposia in Kyoto, Japan. “This breakthrough demonstrates that MRAM technology is rapidly maturing and could fundamentally alter the entire memory marketplace within the next few years.”

Development of MRAM basically followed two scientific schools of thought. There is the spin electronics theory, which is the science behind giant magnetoresistive heads used in disk drives and then there is tunneling magnetic resistance, or TMR, which is the basis of IBM and Infineon’s current version of the memory and future MRAM.

The latest IBM/Infineon advance has a 128Kbit core and is fabricated with a 0.18 micron logic-based process technology, the smallest size reported to date for MRAM. The base memory-cell size alone measures 1.4 square microns or about 20 million times smaller than the average pencil eraser top. The goal now is to have a product demonstrator jointly developed and available in early 2004 through Altis Semiconductor, a joint venture between Armonk, N.Y.-based IBM and Munich-based Infineon.

“Nonvolatile memory technologies like MRAM will play a major role in technology lifestyle solutions and we want to be the number one semiconductor company in this area,” Infineon CTO of the Memory Product Division Dr. Wilhelm Beinvogl said.

IBM Research pioneered the development of tiny, thin-film magnetic structures as early as 1974, which paved the way for the first super-sensitive GMR read/write heads for hard-disk drives, stimulating dramatic increases in data density.

In the late 1980s, IBM scientists made a string of key discoveries about the “giant magnetoresistive” effect in thin-film structures. These developments enabled IBM to create the Altering many of the GMR materials enabled IBM scientists to make the “magnetic tunnel junctions” that are at the heart of MRAM.

The technology has become so attractive; in 1995 the U.S. Defense Advanced Research Projects Agency (DARPA) began funding three private groups with the goal of making MRAM a general-purpose memory with high density, high speed, and low power usage. IBM, Motorola , and Honeywell led the research. Hewlett-Packard , Matsushita , NEC , Fujitsu, Toshiba, Hitachi , and Siemens also have invested in MRAM study.

IBM and Infineon have been working together for more than 10 years on new chip technologies, including traditional Dynamic RAM (DRAM), logic and embedded-DRAM technologies. In November 2000, they established a joint MRAM development program.

MRAM Good for Mobile Devices

The non-volatility attribute of MRAM carries significant implications, especially for mobile computing devices. Memory technologies like DRAM and SRAM require constant electrical power to retain stored data. When power is cut off, all data in memory is lost. A laptop computer, for example, works from a copy of its software stored in memory. When turned on, a working version of the software is copied from the hard-disk drive into memory, so the user can access it quickly. Every time the power is turned off and then back on, the process must start over. By using MRAM, the companies say a laptop could work more like other electronic devices such as a television or radio: turn the power on and the machine jumps almost instantly to life with settings just as you had left them.

Non-volatility can save power as well. Since MRAM will not need constant power to keep the data intact, it could consume much less than current random access memory technologies, extending the battery life of cell phones, handheld devices, laptops and other battery-powered products.

The high-speed attribute of MRAM means that electronic products can more quickly access data, and MRAM’s high-density means greater storage capacity.

IBM and Infineon are reportedly working on a 256-megabit MRAM chip they say could also be on the market in 2004.