May 15, 2009 Nobody likes staring at a screen while they wait for their computer to boot up. Sure, you can spend those few minutes making a cup of coffee or ferreting the dirt out from under your fingernails, but if you’re raring to go those few minutes can be a frustrating waste of time. This could soon be a thing of the past however, thanks to a clever materials science technique that may allow a new class of electronic devices that remember their last state, even after power is turned off.
The technique developed by a team of researchers from four universities, two federal laboratories and three corporate labs involves using a silicon crystal as a sort of nanoscale vise to squeeze another crystal into a more useful shape. By carefully layering a thin film of strontium titanate onto a pure silicon crystal, the team demonstrated it was possible to distort the titanium compound into something it normally wasn’t - a so-called “ferroelectric” compound with the ability to write, read, store and erase patterned bits of data in the strontium titanate film. In other words a fast, efficient medium for data storage.
In contrast to a traditional data storage material, which records data as a pattern of magnetic regions pointing in different directions, a ferroelectric storage material can do the same task with tiny regions of polarized electric charges. Ferroelectric memories are currently used in some “smart cards”, but these structures could be built directly onto silicon crystals, the most common materials base for consumer electronics, opening up their use to a much wider variety of applications. These include nonvolatile memory that retains data when power is turned off, and temperature or pressure sensors integrated into silicon-based microelectronics. But one of the potentially biggest prizes would be ferroelectric transistors that could retain their logic state (“on” or “off”) without power, which could enable computers that switch on instantly without needing a boot stage. Can I get a hallelujah?!