[mems-talk] Ni lift-off problem

[Tupelly Chandra Shekar Reddy]

Hi Zeng,
   
  I think you need adhesive layer between Ni and Si, Ti would work well.. few hundred angstroms would do for that. Other thing you need to consider is how thick you are depositing your Ni,  Ni has very high internal stresses. 
   
  Let us know if it works for you
   
  Regards 
  -Chandra

Yiyi Zeng <zengyy at interchange.ubc.ca> wrote:
  Dear all,

I'm working on deep dry etch of p-Si (>10um) and I was trying to evaporate Ni as etch mask. I was trying to use lift-off technique and my photoresist was AZP4110. The problem is when I was washing away the photoresist using Acetone, almost all of the Ni, no matter on the photoresist or on the Si, fell off the wafer. I tried three times and the results were same, but when I previously evaporate Al and Cr, I didn't see this kind of problem. I'm wondering if anyone has the similar experience? Did I do anything wrong? Any suggestion to improve the process?