Dear Kim, You can use Aluminium metallization by thermal evaporation and if your cell is having the O-ring sealing then the HF soln. will not come to the back. Sujatha ---------- Original Message ----------- From: "Jeehwan Kim"To: Sent: Wed, 6 Sep 2006 11:39:42 -0700 Subject: [mems-talk] HF resistance materials that have conductivity > Dear all, > > I am fabricating micro-porous Si through anodization from the back > side of wafer using HF-ethanol solution. The front surface becomes > very rough after anodization. I need to protect this surface by > depositing or spin coating something. The condition for protection > layer is conductive and resistant to HF solution. Please let me know > if you have any idea about these protection materials.