Paper
10 May 2005 Critical dimension uniformity control with combined ellipsometry and reflectometry
Author Affiliations +
Abstract
In the 90nm node and beyond, Critical Dimension Uniformity (CDU) control is essential for today's high performance IC devices. The desired control of CDU is just under 2nm (3 sigma) across a 300mm wafer with 577 die. In this study we used an Opti-Probe 7341 RT/CD system that combines broadband (190-840 nm) spectroscopic ellipsometry (SE), spectroscopic reflectometry (BB), single wavelength (673 nm) beam profile reflectometry (BPR) and single wavelength (633nm) absolute ellipsometry (AE). All of the above technologies were used to characterize the optical dispersions of the individual films in the stack of interest, resist/barc/sion/poly/oxide/silicon. We then used these dispersion results and the SE and BB technologies to characterize the CDU of the patterned wafer. With the SE technology we measured CDU's in the range of 1.9-2.0 nm compared with BB measured CDU's in the range of 4-5 nm, both SE and BB wavelength were in the range of 240 nm-780 nm. However, if the wavelength range of SE and BB were extended to 190nm-840 nm, the CDU with SE stayed at the same level while that of BB reduced a factor of 2 to about 2.0-2.5 nm.
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Jon Opsal, Jingmin Leng, and Xuelong Cao "Critical dimension uniformity control with combined ellipsometry and reflectometry", Proc. SPIE 5752, Metrology, Inspection, and Process Control for Microlithography XIX, (10 May 2005); https://doi.org/10.1117/12.600124
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KEYWORDS
Semiconducting wafers

Reflectometry

Thin films

Ellipsometry

Oxides

Line scan image sensors

Reflectance spectroscopy

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