Measurement and control of high-aspect-ratio structures such as dynamic random-access memory trenches is an important step in the manufacture of modern memory devices. We present a novel technique based on infrared interferometry that has been implemented in manufacturing and is capable of measuring sub- 0.25-μm -wide and 10-μm -deep trenches nondestructively and with an accuracy of better than 0.1μm .
© 1999 Optical Society of America
(120.0120) Instrumentation, measurement, and metrology : Instrumentation, measurement, and metrology
(120.3940) Instrumentation, measurement, and metrology : Metrology
(120.4290) Instrumentation, measurement, and metrology : Nondestructive testing
T. van Kessel and H. K. Wickramasinghe, "Measurement of trench depth by infrared interferometry," Opt. Lett. 24, 1702-1704 (1999)