Oxide bonding patent litigation has begun
On December 6th, Ziptronix Inc. filed a patent infringement complaint against Omnivision Technologies, TSMC, and TSMC North America in US District court, alleging willfull and deliberate use of several patents pertaining to low-temperature oxide bonding. Omnivision acknowledged the complaint in its recent 10Q filing, and pledged to "vigorously defend ourselves" against the allegations.
Ziptronix was spun out from North Carolina's RTI International in Oct. 2000 for the purpose of commercializing wafer and die bonding technology. In the intervening years, such technologies have found an important role in the evolving areas of chip-on-chip bonding, 3D IC integration, and backside illumination of CMOS image sensors.
Ziptronix's patent portfolio is centered around its ZiBond (Ziptronix bonding) and DBI (direct bond interconnect) technologies. ZiBond is based on their discovery that one can achieve significantly higher bond energy between wafers (with thermal or other oxide) after treatment with various surface "activating and terminating" processes. The direct oxide bonding, which is initiated at low temperature, is characterized by a very high bond energy between the surfaces.
In 2008, Donabedian acknowledged the availability of some commercial tools that claimed to support low-temperature oxide bonding processes, but asserted the company had neither granted nor intended to grant any IP licenses to equipment manufacturers (it later licensed the DBI technology to Raytheon Vision Systems). "Anyone running a low-temperature oxide bonding process as part of their manufacturing scheme is likely to be infringing on our IP,"1 he said then. We will soon see whether this was bravado or simply a statement of fact. — Dr. Phil Garrou, contributing editor
1. "Ziptronix pioneering 3D integrated circuit process technology", i-Micronews, Aug. 2008