Integrated circuit with back side inductor
A method for providing an inductively loaded integrated circuit includes providing a wafer with an integrated circuit formed thereon, the integrated circuit comprising at least one substrate via, including one or more substrate vias that are to be inductively loaded, and fabricating an inductive element on the backside of the wafer that electrically connects to the substrate vias that are to be inductively loaded. A corresponding apparatus includes a wafer with an integrated circuit formed on a top side of the wafer and an inductive element formed on a back side of the wafer, and at least one substrate via that extends through the wafer and electrically connects the inductive element to the integrated circuit. In certain embodiments, the inductive element comprises a plurality of conductive layers. In some embodiments, the inductive element comprises multiple turns on each conductive layer.
1. A method for providing an inductively loaded integrated circuit, the method comprising:
providing a wafer with an integrated circuit formed on a top side of the wafer, the integrated circuit comprising at least one substrate via etched from the top side of the wafer including one or more substrate vias that are to be inductively loaded;
bonding a stiffening member to the wafer;
thinning the entire wafer to a selected thickness from the backside of the wafer to expose the at least one substrate via from the back side of the wafer;
fabricating an inductor comprising multiple turns on a single layer on the backside of the wafer, without any intervening substrates, that electrically connects to the substrate vias that are to be inductively loaded;
removing the stiffening member from the wafer; and
dicing the wafer to provide diced integrated circuits.
2. The method of claim 1 , wherein fabricating the inductor comprises conducting a lithography process using a middle ultra-violet or longer light source.
3. The method of claim 1 , wherein fabricating the inductor comprises forming one or more insulating layers.
4. The method of claim 1 , further comprising packaging the diced integrated circuits.
5. The method of claim 1 , wherein the stiffening member and the wafer comprise substantially identical materials.
6. The method of claim 1 , wherein the inductor is part of a voltage conversion circuit for the integrated circuit.