I am trying to form boron and arsenic doped sidewalls in trenches in a silicon
wafer.  I thought of doing reactive ion or electrochemical etching of the trench
bottom after isotropic doping, but I'm worried that the reaction will be hard to
time correctly because the silicon underneath would etch much faster than the
doped layer.  Any thoughts you have on the most efficient process to form doped
sidewalls would be greatly appreciated.

Thanks,

Daniel