Of Atoms and Electrons

According to Imago Scientific Instruments Corp., the decreasing feature sizes used in the microelectronics industry are challenging failure analysis engineers to analyze materials on an atomic scale. For example, manufacturers of read heads want to understand why some heads, which are composed of multiple layers as thin as 5 Å (0.5 nm), are working well while others are not.

Imago's LEAP microscope (www.imago.com/leap.htm) analyzes materials by removing and examining individual atoms, enabling metrology at the atomic scale. LEAP can tie compositional information to structure on the atomic scale, thereby allowing manufacturers to identify, analyze, and eliminate nanometer scale defects that result in yield loss.

Also working on the nano scale, spin-dependent tunneling is an emerging technology wherein the charge and spin of an electron are used to carry information (see the in-depth article from Sensors' March 2004 issue, www.sensorsmag.com/articles/0304/28/main.shtml). One of the earliest spin phenomena studied extensively, giant magnetoresistance (GMR) is leading the way toward commercialization of this technology, with GMR sensors holding a bulk of the market share in commercial hard disk drives.

Huge potential for spin-dependent tunneling (a.k.a. "spintronics") lies in embedded memories. Nonvolatile memory devices such as magnetoresistive random access memory (MRAM) will revolutionize the memory market, says Frost and Sullivan (F&S) in its new report, Spintronics—An Emerging Technology Analysis. The report posits that spin-dependent tunneling will contribute to the development of sophisticated and versatile computing and personal devices, and enable such conveniences as instantly bootable computers.

MRAM has already attracted considerable funding from organizations such as the U.S. Defense Advanced Research Projects Agency (DARPA) to enable private industry to conduct research into MRAM's massive potential.

A team of researchers at The Royal Institute of Technology in Sweden successfully developed a mixture of zinc oxide and manganese at room temperature that is not only a semiconductor but also exhibits exploitable magnetic properties at temperatures as high as 177°C.

"This breakthrough enables the technology to be applied commercially to a variety of applications and has opened the doors for its eventual mass production," says F&S's Sivakumar Muthuramalingam. "Circuits made with the new material have the potential to run hundreds of times faster or store thousands of times more information than current electronic designs."