Optical imaging is traditionally carried out using circular pupils, assuring the absence of orientation dependency. In the case of IC microlithography however, such dependency exists and is generally limited to orthogonal axes. We have previously reported the potential improvement to lithographic imaging through the use of a square character to an illumination pupil using fully open pupils, square rings, and slot shapes. In this paper we show lithographic results for this shaping at 193nm using a full field (ASML) imaging tool. Results show improvement in both DOF and exposure latitude over conventional circular shaping, leading to the consideration of this approach as a manufacturable method of resolution enhancement.

Date of creation, presentation, or exhibit



Copyright 2002 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.

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Document Type

Conference Paper

Department, Program, or Center

Microelectronic Engineering (KGCOE)


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