The measurement of critical dimension for materials intended for use in manufacturing devices with features of 150nm or less is a significant challenge. Currently available metrology is inadequate at providing robust measurements with the precision and accuracy needed to quantify differences. The added challenge needing to understand the impact on process and material changes on profiles further complicates the analysis of the these data. The further challenge of measuring contact holes or vias smaller than 200nm for size and shape as well as profile is an essential but elusive need for all CD metrology. CD Scatterometry shows great promise in meeting the precision and accuracy needs of current and future metrology needs. First generation library-based solutions showed great capability, but were limited in their sensitivity and flexibility. We report here the results of using next generation optical metrology equipment coupled with robust real-time analysis software to measure the critical dimensions on several difficult organic films on production and research levels. Demonstrations of capability and flexibility of measurements of various linewidths and pitches across 248nm and 193nm technologies, as well as contact hole metrology, will be featured. Special focus on sensitivity to material and process variability and intentional changes will be included. Specific examples of production level decision guidance based on real-time critical dimension measurements will also be presented.
The measurement of optical constants for materials intended for use at wavelengths less than 200 nm is critical for production monitoring and process control when manufacturing devices with features of 0.15 micrometers or smaller. The challenges of organic ARC film measurement at 193 nm are due to the more complicated optical spectral signatures of the organic films and the necessary signal to noise improvements in the ultraviolet. Sharp features in the spectra of the organic ARC films are used to control the extinction value of the films, and they complicate the analysis of the optical constants. Research grade instruments available have shown the ability to accurately measure these films at 193 nm. We report here the results of using next generation optical metrology equipment to measure the optical constants on these difficult organic ARC films on a production level. Specific examples of production level monitoring of the optical constants of these films will be presented.
Currently, the state-of-the-art for particle detection in photoresist is liquid laser scattering technology, which has a particle size capability of approximately 0.25 micrometer for photoresist. Surface tool particle size capabilities are similar, at 0.2 micrometer in a typical application. In our search for techniques which would allow detection of sub-quarter micron particles in photoresists, we sought to explore whether surface particle detection techniques could be of use in determining resist cleanliness. If so, could any correlation be made between counts at various particle sizes measured using liquid laser techniques and those measured with a surface detection tool? To begin to answer these questions, a screening study was undertaken. Two resist chemistries were selected for comparison: diazonaphthoquinone/novolak-based Shipley MegapositR SPRR 510A i-line photoresist and chemically-amplified Shipley APEX-E DUV photoresist. Each resist was prepared at three different cleanliness levels, as determined by liquid laser particle counting. These samples were evaluated on six different surface detection tools, including both laser scattering and digital image processing technologies. For the particle sizes examined, none of the surface detection tools evaluated were consistently able to distinguish between cleanliness levels.
Conference Committee Involvement (6)
Metrology, Inspection, and Process Control for Microlithography XXII
25 February 2008 | San Jose, California, United States
Metrology, Inspection, and Process Control for Microlithography XXI
26 February 2007 | San Jose, California, United States
Metrology, Inspection, and Process Control for Microlithography XX
20 February 2006 | San Jose, California, United States
Metrology, Inspection, and Process Control for Microlithography XIX
28 February 2005 | San Jose, California, United States
Metrology, Inspection, and Process Control for Microlithography XVIII
23 February 2004 | Santa Clara, California, United States
Metrology, Inspection, and Process Control for Microlithography XVII
24 February 2003 | Santa Clara, California, United States
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