Dear Rahul,

I have used PEPR 2400 to pattern 400um deep structures (not in silicon). A
paper describing our work will be published shortly, but in the meantime
here are a few comments that you might find useful:

1 You may need to make some compensation in your mask design to allow for
the diffraction around the edges of features when imaging fine features in
deep trenches.
2 In order to achieve a consistant coating thickness it is important to
maintain the thickness controller 'TC' concentration, however TC has a low
vapour pressure and volatilises from the PEPR. Hence minimise the time you
have the PEPR out of a sealed bottle.
3 Make sure that the silicon surface is fully wetted before PEPR deposition,
else you'll get pin holes (or worse) in your coatings. In my experience this
is best achieved by liquid sparging (i.e. squirt PEPR at the substrate).
4 If you need a thinner coating, then reduce bias voltage and/or increase TC
concentration. Don't increase temperature, since this exacerbates TC
volatilisation.
5 Useful references:
  Christensen et al, IEEE Trans. CPMT A19(4), 1996, 516-521.
  Heschel et al, Sensors and Actuators A70 (1998) 75-80.
  Schnupp et al, Sensors and Actuators A85 (2000) 310-315.
  Moosburger et al, IEEE Photonics Technology Letters, 11 (1999) 848-850.

Best regards,

Gavin Williams
Electronic and Electrical Engineering Department
University of Sheffield, UK



----- Original Message -----
From: Rahul Agarwal 
To: 
Sent: 03 February 2003 17:18
Subject: [mems-talk] electrodepositable photoresist


> Hi,
> is any one familiar with the electrodepositable photoresist. Shipley makes
> electroplatable photoresist named PEPR 2400. Does any one has any kind of
> experience with it. I want to Plate this photoresist in the deep trenches
in
> silicon wafer.
> Any sort of feedback is appreciated.
> Thanks
> Rahul agarwal
> University of South Florida
> Electrical Engineering Dept.
> Micro Electro Mechanical systems Lab.
>
>
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