Nickel films up to 20/~m thick have been selectively
deposited on exposed silicon surfaces in an electroless plating
process. Roughening of the silicon surface is found to be
critical for good adhesion of the plated nickel to the silicon
substrate. The most suitable pretreated surface for electroles~
plating had many small (e.g., less than 1 p~n) etch pits and
provided smooth nickel surfaces after plating. Optimum plating
conditions for smooth surfaces and practical deposition
rates are determined to be solution temperatures of 70-85°C
at pH 5. Our results clearly show that electroless plating is
suitable for the fabrication of micromechanical stn.~ctures on
silicon.