DRESDEN, Germany — There's really nothing special about 200mm wafer fabs any longer. Worldwide, many fabs moved to 300mm wafers more than a decade ago, and Europeans are now talking about the 450mm transition as "opportunities for Europe."
The topic of 200mm wafers no longer generates much excitement, except for occasional news about a chip company mothballing an old fab, typically prompting other vendors to buy the depreciated fab, tools, and equipment.
A recent visit to Infineon's 200mm fabs in Dresden is surprising on two levels: Infineon's commitment to its older fabs and the level of "factory automation" it has pulled off there.
Of course, when placed within an industrywide perspective, 200mm fabs are everywhere.
However, when I dared to suggest that such fabs as a dying breed, I got set straight quickly by Len Jelinek, senior director and chief analyst at IHS Electronics and Media. "Virtually everybody except Intel operates 200mm fabs," he told me. "Even Samsung, Hynix, and Micron run 200mm fabs. The list would also include TSMC, Globalfoundries, Samsung, Intel (up until this year), Texas Instruments… They all operate 200mm fabs."
Even though "Infineon has optimized their internal manufacturing on 200mm wafers, so have about 150 other companies."
That may be so. But Infineon's Dresden fab, viewed from the factory automation perspective, appears to stand head and shoulders above other companies' 200mm fabs. Infineon claims its fabs in Dresden offer "the highest level of automation among the 200mm fabs worldwide."
300mm vs. 200mm wafer fabs
Here's a little background. Completely automated semiconductor production lines are not uncommon -- when you're talking 300 mm.
Before rolling out 300mm wafer fabs in the 2000s, the semiconductor industry had already standardized automation tools and other related equipment. Chip vendors could share and implement standard technology for new 300mm fabs. We've all seen a container of wafers automatically running on rails hanging from the ceiling, moving from one production process to another.
But the typical 200mm fab was built in the 1990s, when semiconductor manufacturers hadn't yet developed the automated tools to handle the several hundred steps required in chip production -- especially as necessary processes differed from device to device.
In short, in automating older 200mm fabs, chip vendors have been winging it, individually inventing proprietary automation tools.
In doing so, they faced constraints, including issues of space and clean rooms. Because 200mm fabs generally weren't designed with full automation in mind, they offered little room to add, for example, an automated transport system.
Then there's the clean room issue.
When Infineon built its 200mm fabs in Dresden, the decision was to maintain the "class one" -- the highest clean-room status -- throughout the fab and the fab floors.
Hence, everything that followed -- the addition of automated tools and their system designs -- had to be implemented in the class-one environment. "We understand it's much costlier to pull this off in the class-one environment," said Helmut Warnecke, managing director of Infineon Dresden. "But you can't change older fabs -- already built as class-one fabs -- into something different. We had to work with the existing infrastructure."
Since 2009, Infineon has spent about €300 million ($379 million) on its Dresden fabs to increase its capacity with modern copper technology tools. It also developed its own automation solutions.
A tour inside Infineon's 200mm fabs in Dresden offers ideas on what to expect from the so-called smart fab of the future.
For instance, wafer transport (fully automated), carrier handling (fully automated), and line control are all connected and controlled by IT systems. Wafer edge tests are part of the process.
More significantly, movable parts such as transport boxes with wafers are equipped with RFID chips, enabling a single wafer to be automatically tracked and located at all times.