Wafer-thin NEW INFRARED TOOL MEASURES SILICON WAFER THICKNESS

Aug. 1, 2005
To meet its quality control roadmap goals by 2010, researchers at the National Institute of Standards and Technology (NIST) developed the Improved Interferometer

To meet its quality control roadmap goals by 2010, researchers at the National Institute of Standards and Technology (NIST) developed the Improved Interferometer (IR3), which accurately measures differences in thickness across the new 300-mm wafer with repeatability to 5 N-m.

Optics and materials for printing nanoscale circuit lines require silicon wafers to be perfectly flat and of uniform thickness.

Using intersecting waves of light to create interference patterns as a ruler, the IR3 can illuminate the top and bottom on a 300-mm wafer and produce a detailed spatial map of differences in thickness in one pass. Traditionally, the wafer was spun and measured at multiple locations.

Precision measurements are made of the wafer's index of refraction — the amount of light that is bent as it passes through silicon — to interpret interference patterns. Increased precision of the refractive index is necessary before absolute measurements of thickness can be made.

Sponsored Recommendations

Pumps Push the Boundaries of Low Temperature Technology

June 14, 2024
As an integral part of cryotechnology, KNF pumps facilitate scientific advances in cryostats, allowing them to push temperature boundaries and approach absolute zero.

The entire spectrum of drive technology

June 5, 2024
Read exciting stories about all aspects of maxon drive technology in our magazine.

MONITORING RELAYS — TYPES AND APPLICATIONS

May 15, 2024
Production equipment is expensive and needs to be protected against input abnormalities such as voltage, current, frequency, and phase to stay online and in operation for the ...

Solenoid Valve Mechanics: Understanding Force Balance Equations

May 13, 2024
When evaluating a solenoid valve for a particular application, it is important to ensure that the valve can both remain in state and transition between its de-energized and fully...

Voice your opinion!

To join the conversation, and become an exclusive member of Machine Design, create an account today!