The aim of this paper is to present a new method of in-line determination of etching tool parameters deviation during the transistor fabrication. For that, we study the possibility to use an optical metrology technique, the scatterometry, and its capability to determine quickly and accurately the temporal evolution of geometric dimensions of a periodic pattern. In this case, this optical tool can be considered as an external monitoring probe. The experiments developed in this article are based on a DOE where 20 different experiments are made, followed both by scatterometric measurements and internal etching tool probes. Comparing the two outputs, we determine the correlations between the evolution of the geometrical parameters of the pattern and the fluctuation of the internal tool parameters. We conclude that the use of a scatterometer following the evolution of the geometrical parameters of a pattern during an etching process is also a good tool to in-line anticipate the drift of the etching parameters.

Date Published: 13 May 2013
PDF: 10 pages
Proc. SPIE 8789, Modeling Aspects in Optical Metrology IV, 878902 (13 May 2013); doi: 10.1117/12.2020486

Published in SPIE Proceedings Vol. 8789:
Modeling Aspects in Optical Metrology IV
Bernd Bodermann; Karsten Frenner; Richard M. Silver, Editor(s)