September 11, 2006 – Samsung Electronics Co. Ltd. says it has completed a working prototype of phase-change random access memory (PRAM), seen as a replacement for high-density NOR flash memory within the next few years. The 512Mbit PRAM device was developed by using vertical diodes with the 3D transistor structure Samsung currently uses to produce DRAMs.
PRAM offers fast processing speed of RAM (30x faster than conventional flash memory, since it can rewrite data without having to erase previously accumulated data), with nonvolatile features of flash memory for storage, and at least 10x longer lifespan than flash, according to the company. This particular PRAM’s cell size (0.0467 sq. microns) is the smallest cell size of any working memory, half that of NOR flash, and requires 20% fewer process steps to manufacture.
Samsung said versions of PRAM competitive with NOR flash are expected to be available beginning in 2008, starting with 512Mbit high-density devices targeting multifunction handsets and other mobile applications.