Muhammad,

The BOE solution will definately attack metals and eat them away.

Try protecting the front side with a resist (1827 or 1813). I have succesfully
striped oxide using BOE, without damaging the metals on the front side on
numerous occassions.

- Harsh Sundani

Graduate Research Assistant
University of Toledo, OH

> From: qazi@email.sc.edu
> To: mems-talk@memsnet.org
> Date: Mon, 24 May 2010 17:14:18 +0000
> Subject: [mems-talk] Does BOE solution disolve Ti/Al/Ti/Au?
>
> Dear all,
>
> Sample: AlGaN/GaN (2um) on Silicon substrate (500um)
> Size: 1.4cmx1.4cm pieces
>
> At some point of my process line I have Ti/Al/Ti/Au contact on the top side.
After that, I had to deposit PECVD 12um oxide on the back side to have pockets
for Si etch (SiO2 acts as masking layer for anisotrpic Si etch- Bosch process).
After I dip it in BOE soltion, the top contacts wash away :( .
>
> Any solution or suggestion?
>
> Muhammad Qazi
> Dept of EE
> University of South Carolina