Dear MEMS researchers,
A problem as old as micromachining: How can I feed electrical current
through an anodic bond? I am sorry to pose this old question but I have to
solve it and do not want to reinvent the wheel. The only solutions I know
are doped silicon resistors (not applicable since not sufficiently
insulating) and an old patent by K.E. Petersen, "Method and apparatus for
forming hermetically sealed electrical feed-through conductors," WO
85/03381,1985. His method seems not to work with interconnection lines
thicker than a few 100 nm and mechanically weakens the bond considerably.
We have tried recessing the metal line into the pyrex substrate or in the
silicon top wafer and have even used meander structures but have not achieve
tight sealing.
Before searching for alternative methods, I would ask you to tell me about
practicable ways you know of. A report on the answers will be posted here.
Yours sincerely, Kai Hiltmann
Kai Hiltmann, HSG-IMIT, Wilhelm-Schickard-Str. 10, D-78052
Villingen-Schwenningen, Germany
Ext. ++49-7721-943-132, Fax ++49-7721-943-140