Problem: As device manufacturers start 65nm production, their process tools require better process control and metrology. While wireless, wafer-based metrology has provided successful relief for some process applications, many aggressive process steps such as high powered dielectric etch or Chemical Mechanical Polishing (CMP) are still lacking cost effective, production compatible solutions. Previous wafer-based metrology systems had application-specific limitations due to their inherent design; the sensors and data analysis unit in the wafer were protected with encapsulant materials protruding over the wafer surface, causing uneven profile.

Solution: Constructed as a laminated wafer, the ultra thin, RF shielded electronics, sensors and battery cells are recessed into a silicon substrate and capped with a protective cover. This configurable, customer selectable top layer, or cover, constructed of semiconductor grade quality materials shields the embedded network from the processing environment and eliminates the possibility of contamination while enabling insitu process measurements.  The "zero height profile" architecture eliminates any prior equip fit issues and provides a flat measuring surface. With components embedded in the silicon wafer, Integrated Wafer produces a thermal mass and dynamic response equivalent to that of a product wafer. These advanced features, and the high sensor count, make the Integrated Wafer ideal for measuring critical hot plate heating zone elements in advanced lithography applications from 15° to 145°C with ± 0.1°C accuracy at a variety of process stages. The Integrated Wafer operates from a base station that provides for communications and battery charging. Integrated into standard fab equipment, the base station enables the Integrated Wafer to be deployed robotically, easily traveling through the fab with limited contamination risk, according to the company.

Applications: Integral Wafer is compatible with existing OEM plasma etch equipment and is currently available for plasma etch applications -- including high power dielectric etch. Additional applications under field testing include Chemical Mechanical Polishing, wet chemical etch/clean, spin rinse, implant, and immersion lithography.

Platform: Available in both 200mm and 300mm wafer sizes, Integral Wafer utilizes SensArray's existing Thermal Map software application for data display and analysis and the BaseStation and CarrierStation for production deployment and storage. A 300mm Integral Wafer includes 65 sensors to measure temperature in a rich spatial format and is capable of high accuracy measurements across a wide operating range of 20 degrees C to 130 degrees C.

Availability: July 2006 onwards.