[labnetwork] Mask of Al in HF

[Al Poly]

Hi Joe,

Adding Glycerin to an HF solution will reduce the Al etching or even 
inhibit it. I learned about this many years ago and do not have the 
references handy.  But by a quick search I found this:

https://gnusha.org/~nmz787/mems/unorganized/wet_etch.pdf

Good luck,

Alireza Mesgar

Equipment Engineer
Texas Instruments


On 10/26/21 15:48, Maduzia, Joseph Walter wrote:
>
> Hello,
>
> Does anyone have any suggestions for mask materials to protect Al in 
> HF 49% for SiO2 removal in SOI wafer? The device is SOI, ICP DRIE 
> etched to glass, HF etch to undercut and free devices, but have Al 
> contact pads and AL is dep’d first. Typically we use PR as pattern 
> mask, but the Al is etching behind the PR. In this case the Al is 
> deposited first, so although order of operations change might help, 
> it’s not a good option atm.
>
>
> Thank you for any suggestions you might have!
>
> *JOE MADUZIA*
> /MNMS Laboratory Specialist/
>
> The Grainger College of Engineering
> Mechanical Science and Engineering
>
> 2239 Sidney Lu Mechanical Engineering Bldg
> 1206 W. Green
> Urbana, IL 61801
> 217.244.6302 | jmaduzi2 at illinois.edu <mailto:jmaduzi2 at illinois.edu>
>
> https://cleanroom.mechse.illinois.edu/ 
> <https://cleanroom.mechse.illinois.edu/>
>
> <http://illinois.edu/>
>
> /Under the Illinois Freedom of Information Act any written 
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