Stacked inductors in multi-die stacking
Microelectronic devices having stacked electromagnetic coils are disclosed. In one example, a microelectronic device can include a first semiconductor element and a second semiconductor element disposed on the first semiconductor element. The microelectronic device can also include an electromagnetic coil. A first portion of the electromagnetic coil and a second portion of the electromagnetic coil may be spaced apart by the first semiconductor element. A first conductive via extending through the first semiconductor element may connect the first and second portions of the electromagnetic coil. Methods for forming such microelectronic devices are also disclosed.
1 . A microelectronic device comprising:
a first semiconductor element having a first substrate;
a second semiconductor element having a second substrate, the second semiconductor element directly bonded to the first semiconductor element without an intervening adhesive; and
an electromagnetic coil, wherein a first coil portion of the electromagnetic coil and a second coil portion of the electromagnetic coil are spaced apart by at least the first substrate of the first semiconductor element, and wherein a first conductive via extending through the first semiconductor element connects the first and second coil portions of the electromagnetic coil.
2 . The microelectronic device of claim 1 , wherein the electromagnetic coil is configured to operate as an inductor.
3 . The microelectronic device of claim 1 , wherein the electromagnetic coil is configured to operate as an autotransformer.
4 . The microelectronic device of claim 1 , wherein the electromagnetic coil is configured to operate as part of a transformer.
5 . The microelectronic device of claim 1 , wherein the direct bonds between the first and second semiconductor elements comprises conductor-to-conductor and dielectric-to-dielectric hybrid bonds.
6 . The microelectronic device of claim 1 , wherein the first coil portion of the electromagnetic coil is disposed in a back end of line (BEOL) layer associated with the first semiconductor element.
7 . The microelectronic device of claim 1 , wherein the first coil portion of the electromagnetic coil is disposed in an outermost metallization layer of a back end of line (BEOL) layer associated with the first semiconductor element.
8 . The microelectronic device of claim 1 , wherein the second coil portion of the electromagnetic coil is disposed in a back end of line (BEOL) layer associated with the second semiconductor element.
9 . The microelectronic device of claim 1 , wherein the second coil portion of the electromagnetic coil is disposed in an outermost metallization layer of a back end of line (BEOL) layer associated with the second semiconductor element.
10 . The microelectronic device of claim 1 , wherein the second semiconductor element is disposed on a surface of the first semiconductor element, and wherein the second coil portion of the electromagnetic coil is disposed in a metallization layer on the surface of the first semiconductor element.
11 . The microelectronic device of claim 1 , wherein the second coil portion of the electromagnetic coil is disposed in a second bonding layer which directly bonds an associated BEOL layer of the second semiconductor element to the first semiconductor element.
12 . The microelectronic device of claim 1 , further comprising a third semiconductor element disposed on the second semiconductor element, wherein a third coil portion of the electromagnetic coil is spaced apart from the second coil portion of the electromagnetic coil by at least the second substrate of the second semiconductor element, and wherein a second conductive via extending through the second semiconductor element connects the second and third coil portions of the electromagnetic coil.
13 . A microelectronic device comprising:
a first semiconductor element having a first substrate;
a second semiconductor element having a second substrate, the second semiconductor element directly bonded to the first semiconductor element without an intervening adhesive;
a first electromagnetic coil adjacent to the first substrate of the first semiconductor element, and
a second electromagnetic coil adjacent to the second substrate of the second semiconductor element,
wherein the first electromagnetic coil and the second electromagnetic coil are spaced apart by at least the first substrate of the first semiconductor element, and
wherein at least one of the first electromagnetic coil and the second electromagnetic coil is disposed in a layer configured for direct bonding.
14 . The microelectronic device of claim 13 , wherein the second electromagnetic coil is disposed in a bonding layer which directly bonds an associated BEOL layer of the second semiconductor element to the first semiconductor element.
15 . The microelectronic device of claim 13 , wherein the first electromagnetic coil is disposed in an outermost metallization layer of a back end of line (BEOL) layer associated with the first semiconductor element.
16 . A method of forming a microelectronic device, the method comprising:
providing a first semiconductor element and a first coiled structure adjacent to the first semiconductor element, a first conductive via extending through the first semiconductor element;
providing a second semiconductor element and a second coiled structure adjacent to the second semiconductor element; and
directly bonding the second semiconductor element to the first semiconductor element without an intervening adhesive, such that the first coiled structure and the second coiled structure are connected by the first conductive via forming an electromagnetic coil, the first coiled structure and the second coiled structure spaced apart by the first semiconductor element.
17 . The microelectronic device of claim 13 , wherein direct bonds between the first and second semiconductor elements comprise conductor-to-conductor and dielectric-to-dielectric hybrid bonds.
18 . The method of claim 16 , wherein directly bonding the second semiconductor element to the first semiconductor element without an intervening adhesive comprises forming conductor-to-conductor and dielectric-to-dielectric hybrid bonds.
19 . The method of claim 16 , wherein the electromagnetic coil is configured to operate as an inductor.
20 . The method of claim 16 , wherein the electromagnetic coil is configured to operate as a transformer.