Elpida Memory has for the first time overtaken Samsung in the race to miniaturize microchip technology, developing the world's first DRAM made with a 25-nanometer manufacturing process. Elpida plans to start mass production in July, a spokesman said Monday.

The Japanese firm overtook its Korean rivals 19 years after Samsung developed a 64 MB DRAM chip in 1992.

One nanometer is equivalent to 1/100,000th the thickness of a human hair. Semiconductor makers are trying to reduce the width of microscopic circuits to a nano level to store as much information as possible in a tiny space.

Samsung currently produces chips using a 30-nanometer process, but a spokesman claimed it too will start mass production using a 25-nanometer process "this year."