2005 R&D 100 Winner
The single biggest variable influencing the profit margin of a wafer fabrication line is yield. Yield depends on maintaining precise, uniform temperature control across the entire wafer during the various processing steps. Therefore, it is crucial to have a temperature-mapping tool that reliably collects thermal data across the area of a standard wafer without itself perturbing the thermal test environment. Researchers at Oak Ridge National Laboratory, Tenn., in a joint effort with SensArray Corp., Fremont, Calif., have offered up a solution with the SensArray INtegrated Wafer, a fully integrated wireless metrology system that responds like a production wafer.

The low profile, wireless design of the INtegrated Wafer allows the user to conduct thermal surveys without modifying equipment or disrupting production. With components embedded in the silicon wafer, INtegrated Wafer produces a thermal mass and dynamic response equivalent to that of a product wafer. It delivers precise, artifact-free temperature data and highly repeatable run-to-run data in processes from 15 to 145°C with ±0.1°C accuracy. It captures both static and dynamic data for improved control of critical dimensions. Advanced battery technology provides >100 hours of battery life. Currently, the INtegrated Wafer is used in a variety of applications, including lithography tracks, lithography steppers/scanners, low temp deposition, and wafer probing.

Fully integrated wireless metrology system

Oak Ridge National Laboratory
SensArray Corp.