[labnetwork] Gold Deposition over Chrome

[Andrei Alamariu]

Hello,
I think of “Reverse side exposure Lift-Off”, as:

1. Coat thick Negative photoresist on FrontSide of the mask.
2. Expose it from the BackSide of the mask and develop it.
3. Deposit the thin Gold on the FrontSide.
4. Lift-Off.

It might work depending on the layout: Cr features/spaces as the
UV light diffraction from the BackSide of the mask might affect it.
Success!
Bernard

Sent from my iPad

> On May 30, 2019, at 4:23 PM, Jim Carroll <jim at photomaskportal.com> wrote:
> 
> Dear LabNetwork colleagues,
> 
> We are trying to add a thin film of gold over patterned chrome on a standard photomask using e-beam evaporation.  We want the gold to preferentially adhere to the chrome while lifting off the glass.
> 
> After a few tests, it appears that the gold sticks equally well to both the glass and chrome.  Ultrasonic agitation and swabbing do not selectively remove the gold from the glass while leaving it on the chrome.  Eventually, after enough pressure is applied with a swab, the gold releases from both the glass and chrome.  
> 
> Does anyone have a suggested approach?
>  
> Thanks,
> Jim Carroll
> PhotomaskPORTAL
> We help you make masks
> (415) 448-6275
> 
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