There is no such way by which you can protect Al not to be effected during
sacrificial layer removal. you can use a tradeoff by increasing the Al
thickness and try to remove the undeneath sacrificial layer in a diluted HF
solution, it will slow down your etch rate for removing undeneath oxide but
will improve the situation a lot for Al

Good luck,

Manish Hooda
----- Original Message -----
From: "Brent Garber" 
To: "General MEMS discussion" 
Sent: Thursday, February 02, 2006 10:12 PM
Subject: Re: [mems-talk] Protecting coating of Al in HF


> Bin,
>
> Photoresist will not hold up to HF.  Your Al will undercut very fast.
>
> Brent
>