UMC Gear Up for 5 megapixel CMOS sensors
EETimes report that UMC in partnership with Photobit Corp said it has readied a special CMOS image sensor process that will enable pixel sizes as low as 3 microns and resolutions of more than 5 megapixels. UMC said it will start accepting image sensor designs in the first quarter and predicts products based on the technology could be on the shelves at the end of the year.
UMC process enables 5-Mpixel CMOS image sensors
Paul Kallender, EE Times
MANHASSET, N.Y. Gearing up for a twin assault on the digital still-camera and emerging cell phone camera markets, semiconductor foundry United Microelectronics Corp. said it has readied a special CMOS image sensor process that will enable pixel sizes as low as 3 microns and resolutions of more than 5 megapixels.
Working with partner Photobit Corp., a developer of CMOS image sensors, UMC has used a generic mixed-mode 0.18-micron CMOS sensor process to demonstrate a device that integrates an analog-to-digital converter, a digital image processor and a sensor on a single chip. With that kind of integration camera manufacturers could use the same optics they use for CCD-based products, said Jim Ballingall, vice president of worldwide marketing at UMC (Hsinchu, Taiwan).
"We have achieved an imager that is state of the art," said Ballingall, who said the sensor draws dark-current levels as low as 65 picoamperes/cm2. "The industry benchmark is 100 pA per square inch. We've eclipsed that by a fair amount," he said.
"UMC's CMOS sensor process has by far exceeded our expectations for quantum efficiency and sensitivity," said Sabrina Kemeny, chief executive officer at Photobit (Pasadena, Calif.). Founded in 1995, Photobit has designed more than 40 standard and custom CMOS sensors for applications such as PC video cameras, medical imaging and dental radiography.
UMC said it will start accepting image sensor designs in the first quarter and predicts products based on the technology could be on the shelves at the end of the year.
One step closer
Strategically, the move puts CMOS-based sensor technology a step closer to encroaching on the traditional market for camcorders based on charge-coupled devices (CCDs). That will happen next year, Ballingall said, and the technology will migrate into cameras for cell phones and personal digital assistants starting in 2002.
UMC has been making CMOS sensors with partners such as Photobit and Rockwell on 0.35- and 0.25-micron process technology, mainly for PC cameras.
"We're aiming for all the markets," Ballingall said. "We will compete on the high end, certainly for the digital still-camera market. [But] our expectation is that the largest volume market will be cell phones."
The move foreshadows a sea change in the sensor business as CMOS increasingly replaces sensors based on charge-coupled devices, said Brian O'Rourke, a senior analyst at Cahners In-Stat Group.
Based on the MOS process, CCD sensors have dominated the camcorder and high-end digital still-camera markets since the 1980s, but the technology is said to have little room for improvement. With their smaller footprints, lower power requirements and more scalable process technology, CMOS sensors hold more potential, O'Rourke said.
More than 28 companies have entered the market to develop CMOS-based alternatives. The entry of a high-volume foundry like UMC means the technology may compete with CCDs in cost and quality.
The image sensor market broke the $1 billion revenue barrier in 1999 and is set to grow more than 75 percent each year through 2004, O'Rourke said. CMOS-based cell phone cameras should account for a large portion of that growth, proving potentially very rich pickings for UMC, he said.
"We are projecting sales of one billion cell phones [globally] in 2003," O'Rourke said. "Even if you get only a small percentage of that, you are still talking about a tremendously large market. CMOS has a very bright future."
In addition, UMC's entry could mean a shakeout in business plans for companies such as Eastman Kodak, which has decades of image sensor experience but limited process technology. Kodak will have to decide whether to develop costly new fabs or go to a foundry, said O'Rourke.
"We've been doing this for a fair amount of time, but the markets have been fairly small and limited by the image quality," said UMC's Ballingall. "It's just been a question of when we could do it, and we've finally reached that point."
So far, only Rockwell and Photobit have publicly disclosed that they intend to use UMC's process. Rockwell said it is considering developing a high-end video camera.
"We committed to UMC's 0.25-micron CMOS image sensor process technology for developing our CMOS imaging system-on-a-chip for high-performance video cameras," said Derek Cheung, vice president of research and director of the Rockwell Science Center (Costa Mesa, Calif.). "We look forward to migrating to UMC's 0.18-micron process soon and achieving even greater performance."
Ballingall said that most of the household-name cell phone makers have expressed interest in UMC's CMOS sensor process, but he declined to give details.
"Most people we talk to are very eager to become partners," he said. "In terms of timing it's a great fit for UMC."