Frontside-to-backside connection with cut for stacked transistor
Embodiments disclosed herein include a semiconductor structure. The semiconductor structure may include a device layer having a first top source/drain (S/D), a second top S/D, a first bottom S/D, and a second bottom S/D. The semiconductor structure may further include a first direct back side contact connected to the first bottom S/D, a second direct back side contact connected to the second bottom S/D, and a double via. The double via may include a first half connecting a front side of the device layer to the first direct back side contact, and a second half connecting the front side to the second direct back side contact. The double via may also include a dividing cut splitting the first half of the double via from the second half of the double via.
1 . A semiconductor structure, comprising:
a device layer comprising a first top source/drain (S/D), a second top S/D, a first bottom S/D, and a second bottom S/D;
a first direct back side contact connected to the first bottom S/D;
a second direct back side contact connected to the second bottom S/D;
a double via comprising:
a first half connecting a front side of the device layer to the first direct back side contact; and
a second half connecting the front side to the second direct back side contact; and
a dividing cut splitting the first half of the double via from the second half of the double via.
2 . The semiconductor structure of claim 1 , wherein the dividing cut comprises a taper from the front side to a back side.
3 . The semiconductor structure of claim 1 , wherein the dividing cut comprises a taper from a back side to the front side.
4 . The semiconductor structure of claim 1 , wherein the dividing cut splits the first direct back side contact from the second direct back side contact.
5 . The semiconductor structure of claim 1 , wherein the first half directly contacts the first S/D.
6 . The semiconductor structure of claim 1 , wherein the dividing cut comprises a first section tapered from the front side and a second section tapered from a back side.
7 . The semiconductor structure of claim 1 , wherein the dividing cut comprises a self-aligned dividing cut.
8 . A method of fabricating a semiconductor structure, comprising:
forming a first top source/drain (S/D), a second top S/D, a first bottom S/D, and a second bottom S/D in a stacked transistor architecture;
forming a double via between the first top S/D and the second top S/D, and between the first bottom S/D and the second bottom S/D;
forming a dividing cut to split the double via into i) a first half electrically connected between the first bottom S/D and a front side of the semiconductor structure and ii) a second half electrically connected between the second bottom S/D and the front side.
9 . The method of claim 8 , wherein the dividing cut is formed from the front side.
10 . The method of claim 8 , wherein the dividing cut is formed from a back side.
11 . The method of claim 8 , further comprising:
forming a direct back side contact; and
splitting the first direct back side contact from the second direct back side contact with the dividing cut.
12 . The method of claim 8 , wherein forming the double via comprises etching an interlayer dielectric from the first bottom S/D and depositing the double via directly onto the first bottom S/D.
13 . The method of claim 8 , wherein forming the dividing cut comprises forming a first section tapered from the front side and forming a second section tapered from a back side.
14 . A semiconductor structure, comprising:
a double via comprising:
a first half electrically connected between a front side of a device layer and a first bottom source/drain (S/D) in a stacked transistor architecture; and
a second half electrically connected between the front side and a second bottom S/D in the stacked transistor architecture, wherein the first half of the double via is split from the second half of the double via by a dividing cut.
15 . The semiconductor structure of claim 14 , wherein the cut comprises a taper from the front side to a back side.
16 . The semiconductor structure of claim 14 , wherein the dividing cut comprises a taper from a back side to the front side.
17 . The semiconductor structure of claim 16 , wherein the dividing cut also splits i) a first direct back side contact between the first bottom S/D and the first half from ii) a second direct back side contact between the second bottom S/D and the second half.
18 . The semiconductor structure of claim 14 , wherein the first half directly contacts the first S/D.
19 . The semiconductor structure of claim 18 , wherein the dividing cut comprises a first section tapered from the front side and a second section tapered from a back side.
20 . The semiconductor structure of claim 14 , wherein the dividing cut comprises a self-aligned dividing cut.