Making multilayer 3D capacitors using arrays of upstanding rods or ridges
In one embodiment, a method for making a 3D Metal-Insulator-Metal (MIM) capacitor includes providing a substrate having a surface, forming an array of upstanding rods or ridges on the surface, depositing a first layer of an electroconductor on the surface and the array of rods or ridges, coating the first electroconductive layer with a layer of a dielectric, and depositing a second layer of an electroconductor on the dielectric layer. In some embodiments, the array of rods or ridges can be made of a photoresist material, and in others, can comprise bonded wires.
1. A method for making a capacitor, the method comprising:
providing a substrate having a surface;
depositing a first electroconductive layer on the surface;
bonding an end of at least one upstanding wire to the first electroconductive layer by a first bond comprising at least one of a molten ball bond and an ultrasonic bond;
coating the first electroconductive layer and the at least one wire with a dielectric layer, which comprises at least part of capacitor dielectric for the capacitor; and
depositing a second electroconductive layer on the dielectric layer, the second electroconductive layer comprising at least part of a first capacitor electrode for the capacitor.
2. The method of claim 1 , wherein the bonding comprises bonding respective ends of an array of upstanding wires to the first electroconductive layer.
3. The method of claim 1 , wherein the at least one wire comprises gold (Au), copper (Cu) or aluminum (Al).
4. The method of claim 1 , wherein the first bond comprises a stitch bond.
5. The method of claim 1 , wherein the first bond comprises a molten ball bond.
6. The method of claim 1 wherein the at least one wire comprises at least part of a second capacitor electrode for the capacitor.
7. The method of claim 1 wherein said bonding comprises, for the at least one wire:
providing a supply of wire in a bonding tool, the supply of wire comprising the at least one wire exposed at an opening of a capillary of the bonding tool;
bonding the at least one wire to the first electroconductive layer; and
severing the at least one wire from the supply of wire.
8. A method for making a capacitor, the method comprising:
providing a substrate having a surface;
depositing a first electroconductive layer on the surface;
bonding an end of at least one upstanding wire to the first electroconductive layer;
coating the first electroconductive layer and the at least one wire with a dielectric layer; and
depositing a second electroconductive layer on the dielectric layer;
wherein the at least one wire comprises gold (Au), copper (Cu) or aluminum (Al); and
wherein the at least one wire is plated with palladium (Pd).
9. A structure comprising:
a surface;
one or more first structures located on the surface, each first structure extending away from the surface, each first structure comprising:
a wire bonded to the surface by a first bond comprising at least one of a molten ball bond and a stitch bond;
one or more dielectric features covering the wire, each dielectric feature comprising at least part of a capacitor dielectric for a capacitor; and
one or more electroconductive layers each of which overlies at least one said dielectric layer and comprises at least part of a first capacitor electrode for the capacitor.
10. The structure of claim 9 , wherein in at least one said first structure, the wire is bonded to the surface by the respective first bond comprising the stitch bond.
11. The structure of claim 9 , wherein in at least one said first structure, the wire is bonded to the surface by the respective first bond comprising the molten ball bond.
12. The structure of claim 9 wherein in at least one said first structure, the wire comprises at least part of a second capacitor electrode for the capacitor.
13. The structure of claim 9 wherein the one or more first structures are a plurality of first structures.
14. A method for making a capacitor, the method comprising:
providing a first electroconductive layer;
providing a supply of wire comprising a portion exposed at an opening of a capillary of a bonding tool;
bonding the portion of the supply of wire to the first electroconductive layer to form a bond between the supply of wire and the first electroconductive layer;
severing a length of wire from the supply of wire, the length of wire being a wire bonded to the first electroconductive layer by the bond and comprising a longitudinal segment extending away from the bond and away from the first electroconductive layer;
coating the longitudinal segment with a dielectric which comprises at least part of a capacitor dielectric for the capacitor; and
coating the dielectric with a second electroconductive layer, the second electroconductive layer comprising at least part of a first capacitor electrode for the capacitor.
15. The method of claim 14 wherein the wire comprises at least part of a second capacitor electrode for the capacitor.