Bench-top versus in-line measurement

There are two different methods for obtaining metrology measurements on a CMP chemical supply system—bottle sample with subsequent bench-top analysis and inline measurement directiy on the system. The advantage of bench-top analysis generally is higher accuracy while the advantage of in-line measurement is real-time measurement for faster response to concentration changes in the system. 

Cost often becomes an important driver since in-line instrumentation can be quite costly to install and maintain multiplied across many systems. The financial impact of how much wafer production can be affected if an excursion occurs must be compared with the overall cost of ownership for in-line monitoring. Sometimes, increasing measurement frequency with using manual sampling and bench-top analysis can be an economical balance to reduce the potential for excursion impact but not burden the chemical system with additional metrology hardware and the associated maintenance. 

The authors would like to acknowledge their colleagues Joe Steigerwald and Danilo Castillo-mejia at Intel Corporation for their help in reviewing this chapter. 

Steigerwald, et al., Chemical Mechanical Planarization of Microelectronic Materials, WUey-Interscience, New York, 1997. 

JindaL S. Hegde, S.V. Babu, Evaluation of alumina/silica mixed abrasive slurries for chemical-mechanical pohshing of copper and tantalum, in Proceedings of the 18th Inti VLSI Multilevel Interconnection Conference, 2001, p. 297. 

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