We introduce a new optical interferometry system for fast areal surface measurement of microscale and nanoscale surfaces that are immune to environmental noise. Wavelength scanning interferometry together with an acousto-optic tunable filtering technique is used to measure surfaces with large step heights. An active servo control system serves as a phase-compensating mechanism to eliminate the effects of environmental noise. The system can be used for online or in-process measurement on a shop floor. Measurement results from two step height standard samples and a structured surface of a semiconductor daughterboard are presented. In comparison with standard step height specimens, the system achieved nanometer measurement accuracy. The measurement results of the semiconductor daughterboard, under mechanical disturbance, showed that the system can withstand environmental noise.
© 2010 Optical Society of America
Instrumentation, Measurement, and Metrology
Original Manuscript: November 12, 2009
Revised Manuscript: March 26, 2010
Manuscript Accepted: April 17, 2010
Published: May 17, 2010
Xiangqian Jiang, Kaiwei Wang, Feng Gao, and Hussam Muhamedsalih, "Fast surface measurement using wavelength scanning interferometry with compensation of environmental noise," Appl. Opt. 49, 2903-2909 (2010)