Scientists at Philips have developed a new technology for non-volatile memory chips that, unlike flash memory, perform better the smaller the memory cells are made.

The Amsterdam-based company said its new memory, based on a phase-change material, will match the speed, density, low voltage and low power consumption requirements of future silicon chips.

Phase-change materials, which change their physical state when heated, are used widely in DVD rewritable discs. With rewritable DVDs, a laser is used to heat the material in order to switch it between phases and then to detect the change in its reflectivity.

In Philips' memory chip, a small voltage is sufficient to change the phase of the material between its two states; the changed state then remains even after the power is turned off, allowing the chip to retain the data.

The new phase-change memory could be an attractive alternative to DRAM (dynamic random access memory) for certain applications, the company said. DRAM, found in most PCs, doesn't store data when power is switched off.