Abstract

The effects of aberrations on the accuracy and repeatability of critical dimension measurements made with an optical microscope are examined theoretically and practically. Aberrations in microscope objectives are studied to determine their effects on the image profiles of narrow (≈2-μm) line objects, such as the geometries on integrated circuits. A diffraction theory model is developed and used to investigate the effects of the primary aberrations. Microscope objectives from different manufacturers are examined, and agreement between the theoretical and practical image intensity profiles is demonstrated. It is concluded that the aberrations in many commercially available objective lenses introduce significant errors into semiconductor geometry measurements.

© 1987 Optical Society of America

Linewidth measurement with an optical microscope: the effect of operating conditions on the image profile

D. Nyyssonen
Appl. Opt. 16(8) 2223-2230 (1977)

Effect of spherical aberration on the imaging properties of scanning optical microscopes

C. J. R. Sheppard and T. Wilson
Appl. Opt. 18(7) 1058-1063 (1979)

Aberration measurement of photolithographic lenses by use of hybrid diffractive photomasks

Jinwon Sung, Mahesh Pitchumani, and Eric G. Johnson
Appl. Opt. 42(11) 1987-1995 (2003)

Effects of wavefront aberration on visual instrument performance, and a consequential test technique

Nigel D. Haig and G. J. Burton
Appl. Opt. 26(3) 492-500 (1987)

The Measurement of the Aberrations of a Microscope Objective

R. Kingslake
J. Opt. Soc. Am. 26(6) 251-256 (1936)