[mems-talk] AlN peels off in Developer

[sebastian wicklein]

Colleagues,

I'm manufacturing micro-capacitors. In doing so I put down an AlN layer as a
dielectric between the plates via reactive sputtering.

During manufacturing I need to pattern the AlN-surface with Photoresist
AZ9260. 

The problem I'm having at this step, is, that my Developer AZ400K 1:4
(Developer : H2O) @ 27C takes off the AlN layer for some reason. It attacks
it and makes it peel off.

However, XRD shows a clear 0002-peak and EDX is fine. The layer is 2microns
thick. Underneath the AlN you can find Cu, or Al as a capacitor plate or
highly B-doped Si.

I need to mention here that I don't have the possibility to take off the
native oxide with a plasma prior to AlN deposition.


So, what is the problem with my AlN layer and how can I improve my layer?

Might the native oxide on the above mentioned materials cause that effect?


I appreciate your help

Best Regards,

Sebastian