Line Edge Roughness and Cross Sectional Characterization of Sub-50 nm Structures Using Critical Dimension Small Angle X-ray Scattering
- Polymers Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)
- Precision Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)
- Polymers Division, Intel assignee to NISI, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)
- Intel Corporation, Hillsboro, OR 97124 (United States)
- International SEMATECH Manufacturing Initiative (ISMI), Austin, TX 78741 (United States)
The need to characterize line edge and line width roughness in patterns with sub-50 nm critical dimensions challenges existing platforms based on electron microscopy and optical scatterometry. The development of x-ray based metrology platforms provides a potential route to characterize a variety of parameters related to line edge roughness by analyzing the diffracted intensity from a periodic array of test patterns. In this study, data from a series of photoresist line/space patterns featuring programmed line width roughness are measured by critical dimension small angle x-ray scattering (CD-SAXS). For samples with designed periodic roughness, CD-SAXS provides the wavelength and amplitude of the periodic roughness through satellite diffraction peaks. For real world applications, the rate of decay of intensity, termed an effective 'Debye-Waller' factor in CD-SAXS, provides an overall measure of the defects of the patterns. CD-SAXS data are compared to values obtained from critical dimension scanning electron microscopy (CD-SEM). Correlations between the techniques exist, however significant differences are observed for the current samples. A tapered cross sectional profile provides a likely explanation for the observed differences between CD-SEM and CD-SAXS measurements.
- OSTI ID:
- 21032726
- Journal Information:
- AIP Conference Proceedings, Vol. 931, Issue 1; Conference: 2007 international conference on frontiers of characterization and metrology, Gaithersburg, MD (United States), 27-29 Mar 2007; Other Information: DOI: 10.1063/1.2799407; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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