Some of My Spin-Coating Related Experience

Published work topic Major finding of work
Multilayer Interference Filter Depositions Tightly controlled sol-gel multilayers can be deposited to make optical interference filters
Tests of Chuck Mark Formation Mechanism Evaporative Cooling can Impose Local Thermal Differences that Influence Final Coating thickness.
Quantification of Evaporative Cooling Effects Evaporative Cooling is Verified using InfraRed video of solvent spinning on wafer surfaces.
Interferometry to Monitor Spin Coating (Pure Solutions) Technique is presented for analyzing interferograms to determine solvent evaporation rate and fluid flow rate
Interferometry to Monitor Spin Coating (Mixed Solutions) Above technique is extended to mixtures.
Evaporative Cooling and Thermocapillary Convection Evaporative Cooling effects not strong enough to drive thermocapillary convection.
Potential for Surface Skin Formation Evaporation Rate was too small to cause large concentration gradients until very late in process
Striation Spacing depends on Spin Speed Characteristic spacing is maintained over an entire wafer – suggesting local effect rather than out-flow effect.
Laser Diffraction to Measure Striation Spacing Laser diffraction at oblique angle can be used to characterize average striation spacing.
When do Striations Form During Spinning? Striation defects form only very near the end of spinning – during a time which might be mainly characterized by “drying”.
Color Video Observation of Fluid Thickness Profiles During Spinning Color Video is a good method for mapping the fluid thickness changes that occur near the end of spin coating.

Dunbar P. Birnie, III
Professor
Department of Materials Science and Engineering
Rutgers, The State University of New Jersey   
607 Taylor Rd.
Piscataway, New Jersey, 08854-8065



Major revisions installed in December 2004

Based on earlier version from July 2000
Updated in February 2005.
Page started 1 May 1998
(c) 1998,1999,2000,2004,2005  D. P. Birnie, III