3D memory chips get closer to market

Matrix Semiconductor is shipping samples of a new, cheaper memory chip that has been delayed by technological problems for nearly...

Matrix Semiconductor is shipping samples of a new, cheaper memory chip that has been delayed by technological problems for nearly two years, the company said.

Matrix's memory chips are based on a 3D design technology that increases the density of memory cells on a chip by stacking them in layers.

In a typical chip, a single layer of circuitry rests on top of a silicon substrate, with additional layers of metal interconnects and insulators. However, the 3D design stacks layers of circuitry one on top of another, separated by layers of polysilicon.

Stacking the cells, or bits, of a memory chip vertically reduces the size of a chip and allows more chips to be manufactured on a single silicon wafer, thereby reducing manufacturing costs.

In December 2001, Matrix announced plans to offer a line of memory chips based on its 3D technology. At that time Matrix said the chips would be available in 2002.

The chips were to be so inexpensive to manufacture that users would be able to purchase single-use 64Mbyte memory cards for $10 (£5.50) or less, the company said.

That did not happen and Matrix officials declined to explain why the chips had not been shipped on schedule.

However, progress has been made, said Phil Gomes, a Matrix public relations representative. The 3D memory chips are being shipped in sample quantities and Matrix plans to announce information on pricing and availability later this year, he said.

The chips are being produced by Taiwan Semiconductor Manufacturing.

The delayed introduction of Matrix's 3D chips is largely the result of technical problems related to production of the novel chip design that had to be overcome, Gomes said. "Matrix learned a lot through that process," he said.

For example, Matrix adapted technology used to apply layers of polysilicon to thin-film transistors liquid crystal displays to create the layers of polysilicon needed to separate the layers of circuitry on the chip, according the company.

Now, Matrix is gearing up once again to launch the 3D memory chips sometime in the next four months.

Marking another step toward that event, the company announced that the MultiMediaCard (MMC) Association has certified the memory chips as compatible with the MMC standard, clearing the way for the chips to be used in MMC cards.

Single-use memory cards based on the chips can be distributed with content or as blank media, Gomes said, adding the chips can be used in other card formats besides MMC. "It depends on what the customer specifies," he said.

No information on which companies have agreed to incorporate the 3D memory chips is yet available. However, that information will be made public before the end of this year, Gomes said.
Sumner Lemon writes for IDG News Service

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