Kamlesh,

The type of test is related to the use of the film.  For example, if you are
making capacitors and want to test the quality of the film as a dielectric
layer, you might build the capacitors and stress test them.  If you are
interested in the film as a passivation layer and the quantity of pinholes
is important, one simple way is to immerse the substrate in a selective
etchant that will etch the underlying substrate but not the SiO2.  It may
take some time to etch, but pinholes will be fairly obvious when viewing in
an optical microscope.  This isn't a direct measure of porosity but may give
you some qualitative insight into the film.

Brad Cantos


On 9/20/08 1:14 AM, "kamlesh_engg@iitb.ac.in" 
wrote:

> hi
>
> i have deposited SiO2 by PECVD. Now i want to test the quality of the film
> more specifically i want to check the porosity of the deposited film
> please tell me how i can test porosity.