Method and apparatus for providing structural support for interconnect pad while allowing signal conductance
View Patent ↗A method provides an interconnect structure having enhanced structural support when underlying functional metal layers are insulated with a low modulus dielectric. A first metal layer having a plurality of openings overlies the substrate. A first electrically insulating layer overlies the first metal layer. A second metal layer overlies the first electrically insulating layer, the second metal layer having a plurality of openings. An interconnect pad that defines an interconnect pad area overlies the second metal layer. At least a certain amount of the openings in the two metal layers are aligned to improve structural strength of the interconnect structure. The amount of alignment may differ depending upon the application and materials used. A bond wire connection or conductive bump may be used with the interconnect structure.
1. An interconnect pad structure formed within an interconnect pad region comprising:
a substrate having semiconductor devices formed therein; and
a plurality of conductive layers positioned in differing horizontal planes and electrically insulated between at least a portion of adjacent ones of the differing horizontal planes to have no continuous connection underlying the interconnect pad region between all horizontal planes of the plurality of conductive layers, each overlying the substrate within the interconnect pad region and in contact with one or more dielectric material(s), the plurality of conductive layers being formed with vertically aligned slots over a predetermined portion of the interconnect pad region sufficient to provide mechanical support for the interconnect pad structure.
2. The interconnect pad structure of claim 1 further comprising:
a dielectric layer overlying an uppermost of the plurality of conductive layers, the dielectric layer comprising no metal; and
a conductive interconnect pad layer overlying the dielectric layer.
3. An interconnect pad structure formed within an interconnect pad region comprising:
a substrate and active circuitry functionally using the substrate;
a plurality of metal interconnect layers overlying the substrate, the plurality of metal interconnect layers being in contact with one or more dielectric materials and formed with vertically aligned slots within a predetermined portion of the interconnect pad region, the plurality of metal interconnect layers positioned in differing horizontal planes, some of the metal interconnect layers in differing horizontal planes having all portions thereof electrically insulated from any portion of an adjacent metal interconnect layer;
an uppermost metal interconnect layer overlying the plurality of metal interconnect layers;
an insulating layer overlying the uppermost metal interconnect layer and having one or more openings to expose a first electrical conductor of the uppermost metal interconnect layer; and
a conductive pad formed overlying the insulating layer and connected to the first electrical conductor by filling the one or more openings, wherein a second electrical conductor of the uppermost metal interconnect layer is electrically insulated from the conductive pad only by the insulating layer and the second electrical conductor is not directly connected to the conductive pad.
4. The interconnect pad structure of claim 3 wherein a slot of the vertically aligned slots in one of the plurality of metal interconnect layers is not fully aligned with a remainder of the vertically aligned slots of the plurality of metal interconnect layers.
5. An interconnect pad structure within an interconnect pad region comprising:
a substrate having active circuitry;
a plurality of metal interconnect layers overlying the substrate and positioned in differing horizontal planes and electrically insulated between at least a portion of adjacent ones of the differing horizontal planes, each of the plurality of metal interconnect layers being in contact with one or more dielectric materials and formed with vertically aligned slots within a predetermined portion of the interconnect pad region;
an insulating layer overlying the plurality of metal interconnect layers; and
a metal pad formed overlying the insulating layer and connected to a first electrical conductor of an uppermost one of the plurality of metal interconnect layers by filling one or more openings in the insulating layer, wherein a second electrical conductor of the uppermost one of the plurality of metal interconnect layers is electrically insulated from the metal pad only by the insulating layer and the second electrical conductor is not directly connected to the metal pad.
6. The interconnect pad structure of claim 1 wherein the interconnect pad structure has an ORed metal density within a predetermined area having a value of 0.85.
7. The interconnect pad structure of claim 1 wherein the interconnect pad structure has an ORed metal density within a predetermined area having a value within a range from 0.80 to 0.85, inclusive.
8. The interconnect pad structure of claim 1 wherein the interconnect pad structure has an ORed metal density within a predetermined area having a value within a range from 0.70 to 0.95, inclusive.
9. The interconnect pad structure of claim 1 further comprising:
at least one device in the substrate below the interconnect pad structure.
10. The interconnect pad structure of claim 9 wherein the at least one device further comprises:
a transistor having a drain and a source formed in the substrate and a gate overlying the substrate, wherein a first of the plurality of conductive layers comprises first, second and third electrical conductors which respectively make contact to the drain, gate and source of the transistor.
11. The interconnect pad structure of claim 3 wherein the interconnect pad structure has an ORed metal density within a predetermined area having a value of 0.85.
12. The interconnect pad structure of claim 3 wherein the interconnect pad structure has an ORed metal density within a predetermined area having a value within a range from 0.80 to 0.85, inclusive.
13. The interconnect pad structure of claim 3 wherein the interconnect pad structure has an ORed metal density within a predetermined area having a value within a range from 0.70 to 0.95, inclusive.
14. The interconnect pad structure of claim 3 further comprising:
at least one device in the substrate below the interconnect pad structure.
15. The interconnect pad structure of claim 14 wherein the at least one device further comprises:
a transistor having a drain and a source formed in the substrate and a gate overlying the substrate, wherein a first of the plurality of conductive layers comprises first, second and third electrical conductors which respectively make contact to the drain, gate and source of the transistor.
16. The interconnect pad structure of claim 5 wherein the interconnect pad structure has an ORed metal density that is within a range from 0.70 to 0.95, inclusive.
17. The interconnect pad structure of claim 5 further comprising:
at least one device in the substrate below the interconnect pad structure.
18. The interconnect pad structure of claim 17 wherein the at least one device further comprises:
a transistor having a drain and a source formed in the substrate and a gate overlying the substrate, wherein a first of the plurality of conductive layers comprises first, second and third electrical conductors which respectively make contact to the drain, gate and source of the transistor.
19. The interconnect pad structure of claim 5 wherein a slot of the vertically aligned slots in one of the plurality of metal interconnect layers is not fully aligned with a remainder of the vertically aligned slots of the plurality of metal interconnect layers.