Hello,



I am looking for some information and advice on electrochemical etching
of silicon wafers.  I would like to etch an array of 400 x 400 um pores
in 300 um thick silicon wafers and then anodiclly bond the wafers to
glass.  I prefer them to be as high aspect ratio as possible.  I am
thinking that electrochemical etching would be the way to go but I am
not sure.



If it is possible to do this, any answers to the following questions or
a good reference will be greatly appreciated.



Would it be better using N type or P type wafers?

Is it better to use illumination or not?

What resistivity of wafers is best to use?

What current density and voltage works the best?

What area counter electrode will give optimum results?



Thank you very much,



Ed Castellana

Texas A&M University

Department of Chemistry



castellana@mail.chem.tamu.edu