Memory maker enters sensor business

ProMOS Technologies Inc.'s move into CMOS image sensors will let the memory maker use its older production capacity and capitalize on growing demand from the cellphone business. It has invested $10 million in an unidentified Silicon Valley startup that will initially target low-density sensors for handsets.

ProMOS' image sensors are expected to roll out in 2008 and be in the 1.3Mpixel range.

Like several of its rivals, ProMOS is looking to leverage its older DRAM fabrication facilities to make the sensors: "How to optimize the remaining value of those 200mm wafer fabs as their cost-effectiveness diminishes poses a challenge," ProMOS said in its 2005 annual report.

"It's been well-established by Micron and then Samsung that, compared with a normal foundry, a DRAM fab is better for a CMOS sensor because both products require very low leakage current," said Ben Tseng, VP of sales and marketing at ProMOS. Micron Technology Inc. began making CMOS image sensors in 2003, followed by Samsung Electronics Co. Ltd.

Sales of CMOS image sensors for cellphones will hit $5.9 billion by 2010, increasing at a CAGR of 27.4 percent, iSuppli Corp. predicts.

ProMOS owns Taiwan's oldest 300mm wafer fab, built in Hsinchu Science Park in 2002. Tseng said the fab is a good candidate for producing the sensors since it is almost fully depreciated. Another possibility is its 200mm wafer fab, also in Hsinchu, that will be shut down in 2008 and its work transferred to mainland China to lower costs. The sensor business would also be able to source at other foundries if capacity is tight at ProMOS, Tseng said.

Although it aims to increase its product lines in sensors and DRAM chips for CE devices, such as DTVs and DVD recorders, ProMOS intends to remain true to its commodity DRAM roots, Tseng said. "Still, beyond DRAM, we need to look at what we can do to find some value out of these older fabs," he said.

Another possibility is NAND flash. Tseng said ProMOS is developing NAND and will probably move into production in the next year or so.

- Mike Clendenin
EE Times