Firms Fight Over CMP Patents

Just as one lawsuit over chemical mechanical planarization (CMP) has been decided, a new one is getting under way. CMP is the use of abrasive slurries to polish, or planarize, the surface of silicon wafers used in the manufacture of electronic components. In the first case, the U.S. Court of Appeals for the Federal Circuit affirmed a lower court’s August 2010 judgment that neither the DuPont Air Products NanoMaterials joint venture nor Cabot Microelectronics violated the other’s patents on alumina- and silica-based CMP slurries. In a separate case, Hitachi Chemical just filed a lawsuit in U.S. District Court against K. C. Tech of South Korea for violating Hitachi’s U.S. patents on cerium oxide-based CMP slurries. Before taking legal action, Hitachi says, it first talked with K. C. Tech about a license deal to end the Korean firm’s unauthorized use of Hitachi patents. The court battles are about dominant CMP slurry producers Cabot Micro and Hitachi vying to preserve their market shares, explains Mike Corbett, managing partner of Linx Consulting, a specialist in electronic chemicals and materials.