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Proceedings Paper

Improved shallow trench isolation and gate process control using scatterometry based metrology
Author(s): P. Rudolph; S. M. Bradford
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Paper Abstract

The ability to control critical dimensions of structures on semiconductor devices is essential to improving die yield and device performance. As geometries shrink, accuracy of the metrology equipment has increasingly become a contributing factor to the inability to detect shifts which result in yield loss. Scatterometry provides optical measurement that better enables process control of critical dimensions. Superior precision, accuracy, and higher throughput can be achieved more cost effectively through the use of this technology in production facilities. This paper outlines the implementation of Scatterometry based metrology in a production facility. The accuracy advantage it has over conventional Scanning Electron Microscope (SEM) measurement is presented. The Scatterometry tool used has demonstrated repeatability on the order of 3σ < 1 nm at STI-Etch-FICD for CD and Trench Depth (TD), and Side Wall Angle (SWA) measurements to within 0.1 degrees. Poly CD also shows 3σ < 1 nm, and poly thickness measurement 3σ < 2.5 Å. Scatterometry has capabilities which include measurement of CD, structure height and trench depth, Sidewall angle (SWA), and film thickness. The greater accuracy and the addition of in-situ Trench depth and sidewall angle have provided new measurement capabilities. There are inherent difficulties in implementing scatterometry in production wafer fabs. Difficulties with photo resist measurements, film characterization and stack set-up will be discussed. In addition, there are challenges due to the quantity data generated, in how to organize and store this data effectively. A comparison of the advantages and shortcomings of the method are presented.

Paper Details

Date Published: 10 May 2005
PDF: 12 pages
Proc. SPIE 5752, Metrology, Inspection, and Process Control for Microlithography XIX, (10 May 2005); doi: 10.1117/12.600199
Show Author Affiliations
P. Rudolph, LSI Logic Inc. (United States)
S. M. Bradford, LSI Logic Inc. (United States)

Published in SPIE Proceedings Vol. 5752:
Metrology, Inspection, and Process Control for Microlithography XIX
Richard M. Silver, Editor(s)

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