Optical scatterometry for process metrology

The intensity of radiation diffracted from periodic structures is extremely sensitive to slight variations in the geometry and composition of the diffracting structure. Rigorous diffraction theory provides a mechanism for accurate analysis of the scattered waves. Scatterometry is a metrology technique that combines the sensitivity of diffraction from periodic structures with a first principle solution of electromagnetic wave diffraction from these structures. The technique is self-calibrating, and sub-nm static and dynamic precision has been demonstrated for the measurement of sub-0.25 μm structures. We provide an overview of the development of this metrology technique, along with the theoretical foundation of rigorous diffraction analysis and its application to the analysis of the scattered data measured by the scatterometer.

[1]  J. McNeil,et al.  Ellipsometric Scatterometry for the Metrology of Sub-0.1- num-Linewidth Structures. , 1998, Applied optics.

[2]  H. P. Kleinknecht,et al.  Linewidth measurement on IC masks and wafers by grating test patterns. , 1980, Applied optics.

[3]  R. Guerrieri,et al.  Exploration of scattering from topography with massively parallel computers , 1989 .

[4]  S. Sohail H. Naqvi,et al.  Simple technique for linewidth measurement of gratings on photomasks , 1990, Advanced Lithography.

[5]  Diana Nyyssonen.  Design Of An Optical Linewidth Standard Reference Material For Wafers , 1982, Other Conferences.

[6]  Mark P. Davidson,et al.  Monte Carlo simulation for CD SEM calibration and algorithm development , 1995, Advanced Lithography.

[7]  Kenneth P. Bishop,et al.  Use of diffracted light from latent images to improve lithography control , 1992 .

[8]  Steve Farrer,et al.  Scatterometry measurements for process monitoring of polysilicon gate etch , 1997, Advanced Lithography.

[9]  T. Gaylord,et al.  Analysis and applications of optical diffraction by gratings , 1985, Proceedings of the IEEE.

[10]  Michael T. Postek,et al.  Submicrometer Microelectronics Dimensional Metrology: Scanning Electron Microscopy , 1987, Journal of Research of the National Bureau of Standards.

[11]  Raymond A. Cirelli,et al.  Ultraviolet-visible ellipsometry for process control during the etching of submicrometer features , 1995 .

[12]  S. Sohail H. Naqvi,et al.  Scatterometric process monitor for silylation , 1997, Advanced Lithography.

[13]  D. Nyyssonen.  Theory of optical edge detection and imaging of thick layers , 1982 .

[14]  Steven J. Holmes,et al.  Postexposure bake as a process-control parameter for chemically amplified photoresist , 1993, Advanced Lithography.

[15]  Egon Marx,et al.  Numerical reference models for optical metrology simulation , 1992, Advanced Lithography.

[16]  Mark P. Davidson,et al.  Linearity of coherence probe metrology: simulation and experiment , 1991, Other Conferences.

[17]  S.S.H. Naqvi.  Scattering from a strip grating placed on a multilayer dielectric sheet , 1990, International Symposium on Antennas and Propagation Society, Merging Technologies for the 90's.

[18]  J. McNeil,et al.  Multiparameter grating metrology using optical scatterometry , 1997 .

[19]  Ziad Hatab,et al.  Sixteen-megabit dynamic random access memory trench depth characterization using two-dimensional diffraction analysis , 1995 .

[20]  T. Gaylord,et al.  Diffraction analysis of dielectric surface-relief gratings , 1982 .

[21]  J M Zavada,et al.  Residual surface roughness of diamond-turned optics. , 1975, Applied optics.

[22]  Herschel M. Marchman,et al.  Dimensional metrology with scanning probe microscopes , 1995 .