Hi Suzanne,

I use AZ 300MIF, which etches the ProLIFT at about 300
nm/s, but I'm fairly sure you can use any photoresist developer.
Regarding the critical point dryer, if you are at a university with
scanning electron microscope facilities and a biology department, they
may have one: critical point drying is used to prepare biological
samples without collapsing any delicate structures. Or, you may be
able to send your samples off to another lab to get dried if you are
only anticipating a small number of samples. A critical point dryer
isn't something that you want to try and build yourself- I'm told that
they used to be referred to as 'lab bombs', with good reason.

Good luck!

Jason Milne
PhD Candidate
Microelectronics Research Group
School of Electrical, Electronic and Computer Engineering
The University of Western Australia


Quoting "Paradis, Suzanne" :

> Good afternoon Jason,
>
> Thank you for your response.  The suspended membrane is Si3N4.  I
> will search for the properties of ProLIFT and see if it can work for
>  a gap of 4 microns. What photoresist developer do you use? Also, I
> will get more info about what you call a  critical point dryer, it
> is the first time I hear about that (well, I am new in
> microfabrication, maybe that explains why...).
>
> Thank you very much :-)
>
> Suzanne Paradis, eng. M.Sc.