Matrix Semiconductor has produced what it claims is the world's smallest 1GB chip.

It's all thanks to the company's write-once 3D technology and it could lead to cheaper one-use memory cards, the company said.

Matrix increases the density of memory cells on a chip by stacking them in layers, reducing the surface area occupied by the memory chip. This allows more chips to be made on a single wafer and cuts manufacturing costs, Matrix's chief operating officer Siva Sivaram said at a news conference in Tokyo today.

"We are building a skyscraper, because the cost of the surface area of silicon is very expensive," he said.

The company has developed a 1GB chip with an area of only 31 square millimeters - double the capacity of the company's prior generation of technology in the same area, and about a third the size of commercially available rewritable flash memory chips, he said.

Conventional Flash memory can be rewritten many times, but Matrix's chips can only be written once. That's no obstacle for companies that want to distribute content such as music, video or games on cards, though, said Dan Steere, Matrix's vice president of sales and marketing. Matrix's chips can store such content reliably for about 100 years, he said.

For example, Sharp has for some time been using the chips to store memory in dictionaries. Last year, Mattel started using the chips in cartridges for its Juice Box personal media player, Steere said.

As well as being smaller than flash chips of the same capacity, memory cards using Matrix memory will cost between 20 percent and 50 percent less, so Matrix believes its technology can replace flash for consumers who want to buy low-cost cards to archive video, still images, and other content.

Matrix chips are already available in MMC format memory cards, and will be available in most of the common card formats, including SD (Secure Digital) and Memory Stick, before the end of the year, according to Steere.

Several thousands commercial sample chips with capacities ranging from 128MB to 1GB are being produced by Taiwan Semiconductor. Volume production will start later this year. The write-once cards could appeal to music fans and photographers, one market analyst said.

"My feeling is this technology has some excellent potential. If they get their product priced right they could conceivably cut into the market for memory cards used in other consumer products like cameras and music players," said Mark DeVoss, a memory analyst with iSuppli.

"People may be willing to live with a consumable media and only choose to view or listen to the content they wish but with no editing capability," he said.