Re: Ways of creating micron sized dots on surfaces

Consider using a suspension of uniformly sized spheres (typically
polystryrene, as I recall).  They are commercially available.  With the
right concentration, surface preparation, etc., you can get them to
self-assemble onto a substrate (e.g. microscope slide) as the solution
evaporates.  In some areas, you'll get a monolayer of hexagonal close packed
spheres.  Vacuum evaporate metal (e.g. silver) over the spheres and lift off
the spheres.  You'll be left with an array of dots, well, actually
triangles.  Annealing can turn the triangles into round dots.

For details, check out this site:

http://www.chem.northwestern.edu/~vanduyne/

See the "Nanosphere Lithography FAQ" link, left-hand column.

It's not very controlled approach, but without any fancy optical or e-beam
lithography equipment, you can obtain some areas of arrayed dots of uniform
size.  It also can be used for reactive ion (plasma) etching of the surface,
since the spheres tend to stay in place on the surface and serve as an etch
mask for shallow etching of the substrate.

Good luck!

Grant


"Rallyjo" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> Hi!
>
> I am looking for a technique by which i can apply micron/sub-micron
> sized dots on flat surfaces. Can i sputter fine dots of some metal say
> Aluminum on the surface of a substrate? Else, is it possible to etch
> fine dots over a Al coated substrate by spraying some etchant over
> it??
>
> If you are aware of any technique, please let me know.
> Thanks.
>
> ---|Rahul|---
>