March 2, 2001–Gaithersburg, Maryland–Larger wafers demand exceedingly accurate measurements of flatness and thickness, while advanced lithography systems require exact assessments of the curvature of the specialized lenses and mirrors used. To make things more difficult, the readings must consistently be within 0.25nm.

The U.S. National Institute of Standards and Technology (NIST) has developed an x-ray optics calibration interferometer device (XCALIBIR) that may help meet these needs. XCALIBIR’s operators hope to provide semiconductor manufacturers with atomic-level measurements of their “eyeglasses,” the optics by which circuit patterns are affixed to silicon wafers. Achieving such precise measurements requires XCALIBIR to be housed in an enclosure that controls the temperature to within 0.05 degree Celsius, and set upon a 15-metric-ton (16-ton) granite table that suppresses measurement-upsetting vibrations.

The instrument currently is undergoing performance testing.