Hardy molecule makes memory

Scientists are continually trying to shrink the space a bit of information takes up in order to fit more bits per square inch in storage media. One idea is to use layers of molecules as bits in hybrid organic/silicon devices. The challenge is finding molecules that can stand up to the harsh conditions needed to manufacture silicon and write and rewrite data.

Researchers from the University of California at Riverside and North Carolina State University have shown that a type of porphyrin molecule holds up under temperatures as high as 400 degrees Celsius and after being written to and read from trillions of times.

The researchers had previously shown that it is possible to use the molecule to store charge. Charged and uncharged molecules can represent the 1s and 0s of computer information. The researchers chemically tethered porphyrin molecules to a silicon platform and used voltage to write charges to and erase charges from the molecules.

The researchers have also shown that it is possible to store two or three bits of information per memory element rather than the usual one. This is significant because it could allow existing 0.13-micron memory chips to store as much as chips made using future 0.09- or 0.07-micron manufacturing processes, according to the researchers. The sizes refer to the smallest elements a chip can contain.

Hybrid semiconductor/organic memory could become practical in two to five years, according to the researchers. The work appeared in the November 27, 2003 issue of Science.