Hi
The easiest will be to oxidize the Si and then polish the surface. If you
don't have access to polish, you can use resist in the channels and etch but
this is a bit tricky
shay


-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of H.J. van der Linden
Sent: Monday, July 09, 2007 5:29 PM
To: General MEMS discussion
Subject: [mems-talk] anodic bonding and passivation layer thickness

Hi All,

I am making a microfluidic device for electrokinetic studies. The device
will consist of a channel deep-etched into silicon and a top layer
consisting of glass. I want to use anodic bonding to bond the device.
Because I will use the device for electrokinetic studies I need to be able
to apply high voltages over the liquid in the channel. A problem here is of
course that the native oxide on the silicon wafer will breakdown causing a
short circuit through the silicon wafer. Therefore I want to apply an
insulation layer on the silicon before the bonding. This layer will most
likely be an oxide.
The insulating layer is likely to interfere with the anodic bonding process.
Has anyone tried a similar process ? The parameters that I am most
interested in are the thickness of the insulating layer and the voltage and
temperature for the anodic bonding process.... Voltages that I expect to use
are around 50 - 250V.