Replacement buried power rail
AssigneeInternational Business Machines Corporation
InventorsRuilong Xie, Stuart Sieg, Somnath Ghosh, Kisik Choi, Kevin Shawn Petrarca
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Abstract
Embodiments disclosed herein describe a semiconductor structure. The semiconductor structure may include a device region with a first source/drain (S/D) and a second S/D. The semiconductor structure may also include a buried power rail (BPR) under the device region. A critical dimension of the BPR may be larger than a distance between the first S/D and the second S/D. The semiconductor structure may also include a via-contact-to-buried power rail (VBPR) between the BPR and the S/D.
Claims20
A semiconductor structure, comprising:
- a device region comprising a first source/drain (S/D) and a second S/D;
- a buried power rail (BPR) under the device region, wherein a critical dimension of the BPR is larger than a distance between the first S/D and the second S/D;
- a via-contact-to-buried power rail (VBPR) between the BPR and the S/D.
A method, comprising:
- forming a dummy buried power rail (BPR) in an insulator layer between a first fin field-effect transistor (FET) and a second fin FET;
- forming a first source/drain (S/D) electrically connected to the first fin FET, and a second S/D electrically connected to the second fin FET;
- forming a via-contact-to-buried power rail (VBPR) that contacts a top surface of the dummy BPR and the first S/D;
- selectively etching the dummy BPR from a bottom surface opposite the top surface to form a BPR trench;
- widening the BPR trench;
- and
- metalizing the BPR trench to form a BPR.
A semiconductor structure, comprising:
- a back side power delivery network (BSPDN);
- a buried power rail (BPR) coupled to the BSPDN;
- a via-contact-to-buried power rail (VBPR) coupled to the BPR, wherein the BPR wraps around a bottom of the VBPR;
- a first source/drain (S/D) coupled to a middle of the VBPR;
- and
- a back-end-of-line layer coupled to a top of the VBPR.
Dependencies are inferred from the claim text.