Ellipsometric imaging of drying sol-gel films

Conference · Fri Jan 01 04:00:00 EST 1988

OSTI ID:7158879

Hurd, A J; Brinker, C J

Although controlled dip-coating is an established way to apply high quality uniform coatings, the details of the coating and drying process have not been deeply studied. Depending on the physical and chemical state of the sol and the parameters of dipping (dipping angle and speed), a variety of thicknesses and porosities can be achieved. For optical coatings, the refractive index and optical thickness can thereby be controlled. The authors have developed a method to view the drying front of a dip-coated film using broad beam ellipsometry, or ellipsometric imaging. In dip-coated films we take full advantage of the fact that a steady state is quickly reached where the drying line velocity matches the withdrawal velocity; however, the technique might also be used in unsteady situations such as spin coating. Imaging ellipsometry makes it possible to measure the refractive index and thickness profiles of both wet and dry films point-by-point in an entire image at once. These profiles provide important clues as to the relative importance of gravity, evaporation and other phenomena.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 7158879
• Report Number(s): SAND-88-1330C; CONF-880408-28; ON: DE88011785
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603 -- Materials-- Properties
42 ENGINEERING
420800* -- Engineering-- Electronic Circuits & Devices-- (-1989)
ELLIPSOMETRY
FILMS
MEASURING METHODS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
POROSITY
REFRACTIVITY
SOL-GEL PROCESS