Paper
23 March 2009 A study on effect of point-of-use filters on defect reduction for advanced 193nm processes
Nelson Vitorino, Elizabeth Wolfer, Yi Cao, DongKwan Lee, Aiwen Wu
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Abstract
Bottom Anti-Reflective Coatings (BARCs) have been widely used in the lithography process for decades. BARCs play important roles in controlling reflections and therefore improving swing ratios, CD variations, reflective notching, and standing waves. The implementation of BARC processes in 193nm dry and immersion lithography has been accompanied by defect reduction challenges on fine patterns. Point-of-Use filters are well known among the most critical components on a track tool ensuring low wafer defects by providing particle-free coatings on wafers. The filters must have very good particle retention to remove defect-causing particulate and gels while not altering the delicate chemical formulation of photochemical materials. This paper describes a comparative study of the efficiency and performance of various Point-of-Use filters in reducing defects observed in BARC materials. Multiple filter types with a variety of pore sizes, membrane materials, and filter designs were installed on an Entegris Intelligent(R) Mini dispense pump which is integrated in the coating module of a clean track. An AZ(R) 193nm organic BARC material was spin-coated on wafers through various filter media. Lithographic performance of filtered BARCs was examined and wafer defect analysis was performed. By this study, the effect of filter properties on BARC process related defects can be learned and optimum filter media and design can be selected for BARC material to yield the lowest defects on a coated wafer.
© (2009) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Nelson Vitorino, Elizabeth Wolfer, Yi Cao, DongKwan Lee, and Aiwen Wu "A study on effect of point-of-use filters on defect reduction for advanced 193nm processes", Proc. SPIE 7272, Metrology, Inspection, and Process Control for Microlithography XXIII, 72723M (23 March 2009); https://doi.org/10.1117/12.814152
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KEYWORDS
Semiconducting wafers

Particles

193nm lithography

Lithography

Manufacturing

Scanning electron microscopy

Composites

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