Do you need the 'teeth' to be all metal, or is it ok to have, say,
silicon 'teeth' coated in metal?

If the second option is OK, then you can make a sawtooth pattern with
photoresist on silicon using greyscale lithography, then transfer that
pattern through onto the silicon substrate with a dry etch using CF4/O2
or SF6- do a search for 'silicon fresnel lenses'. Once you have the
silicon pattern, just sputter as normal. Come to think of it, if
sputtering doesn't affect the resist profile then you don't even need to
dry etch, just sputter directly onto the resist.

If you need all metal 'teeth' then I have never heard of a way, and look
forward to hearing other's suggestions!

Jason Milne
Microelectronics Research Group
The University of Western Australia


-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Aaron Datesman
Sent: Thursday, 13 March 2008 4:25 AM
To: General MEMS discussion
Subject: [mems-talk] Sawtooth Deposition Profile?

Dear List Members,

I would like to sputter deposit a metallic film to have a "sawtooth"
thickness profile, shown below:


   /|        /|        /|
  / |       / |       / |
 /  |___/  |___/  |___ etc.

The desired film height is ~100 nm and the width of each feature is ~500

nm.  Can anyone suggest a suitable method to accomplish this?