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.