The invention is a method of fabricating electrically passive components or optical
elements on top or underneath of an integrated circuit by using a porous substrate
that is locally filled with electrically conducting, light emitting, insulating
or optically diffracting materials. The invention is directed to a method of fabricating
electrically passive components like inductors, capacitors, interconnects and resistors
or optical elements like light emitters, waveguides, optical switches of filters
on top or underneath of an integrated circuit by using porous material layer that
is locally filled with electrically conducting, light emitting, insulating or optically
diffracting materials. In the illustrated embodiment the fabrication of voluminous,
solenoid-type inductive elements in a porous insulating material by standard back-
and front-side-lithography and contacting these two layers by electroplating micro-vias
through the pores is described. By using a very dense interconnect spacing, an
inter-pore capacitor structure is obtained between the metalized pores and the
pore walls utilized as insulators.