Mr Casale,
Thanks for your suggestion of using 2 coating runs.  Am I right to presume that
to eliminate pinholes in Chromium, apart from coating twice, the thickness
should be 100nm to be sufficiently thick to eliminate pinholes?

Mr. Jeffrey Mun Pun YUE
余文彬
Division of Bioengineering
E3A-07-02, Nanobioanalytics Lab
7 Engineering Drive 1
National University of Singapore
Singapore 117574
Tel: (65) 65166482, Fax: (65) 68723069
E-mail:  [email protected]

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of David Casale
Sent: Tuesday, March 20, 2007 2:35 AM
To: General MEMS discussion
Subject: RE: [mems-talk] Pin holes in evaporated Chromium, Titanium and Gold

Pin holes are pretty common in evaporated chrome. We evap chrome on glass pretty
often, and we often do two coating runs if we want to eliminated pinholes.
Pinholes are much more likely to happen if the chamber and or the substrate is
dirty. For instance, you are much more likely to have pinholes if you evap a
single 1000 angstrom film of chrome than if you do two 500 angstrom coatings.
Cleanliness is next to godliness ;)