The ideal method would be to use "covered-chuck" technology provided on the QSSE
Spin coaters OPTICOAT SB/ST 20

Or the DOMINUS coating  ( a spray coating method ) also provided by QSSE Sister
Semiconductor Equipment.

The covered chuck technology is almost eliminating turbulence caused by the
corners of the substrate and also allows a almost constant viscosity of the
resist during spreading and thinning of the resist.
The atmosphere between the chuck and the rotating cover is closed and will move
in the same speed as the substrate.
You will also sue less resist for the coating.

The DOMINUS Coating is a spray coating method where the substrate is static
during coating and the nozzle scans the surface of the substrate in cross
sections.
With this technology the Edge bead is also reduced to a minimum.
The unique micro nozzle allows all type of standard resist to be applied.

You can also try to use a static plate placed in a small distance ( apprx 2 mm)
over the substrate during spreading and thinning for this smaler size of
substrate this "airbarriere" plate effect might also work.

You can contact me directly for more details.

Best Regards

Markus Reuter

SSE Sister Semiconductor Equipment GmbH
Josef-Schüttler-Str. 2
D-78224 Singen
GERMANY
Phone: +49 (0) 7731 189 - 230
Mobile: +49 (0) 151 1205 5053
Fax: +49 (0) 7731 189 - 100
[email protected]
WWW.QSSE.COM



-----Ursprüngliche Nachricht-----
Von: Zheng Xia [mailto:[email protected]]
Gesendet: Freitag, 27. Februar 2004 17:30
An: [email protected]
Betreff: [mems-talk] resist on rectangular shape slides


Hi,

Does anyone have suggestion on how to apply uniform resist on rectangular shape
glass slides (1 x 3 inch)? I tried to spin them with full coverage of resist on
slides, but the result is not good. Resist sometimes cannot reach corners, and
it shows certain interference pattern under light, indicating the unevenness of
resist thickness. Thank you.

Best,

-------------------------
XIA, ZHENG
Microfluidics and BioMEMS Lab
Interdisciplinary Microsystems Group
Department of Mechanical and Aerospace Engineering
University of Florida
-------------------------