US Patent 11393819 Semiconductor device implemented with buried rails

Certain aspects of the present disclosure generally relate to a semiconductor device with buried rails (e.g., buried power and ground rails). One example semiconductor device generally includes a substrate; a first rail, wherein a portion of the first rail is disposed in the substrate, the portion of the first rail having a first width greater than a second width of another portion of the first rail; a second rail, wherein a portion of the second rail is disposed in the substrate, the portion of the second rail having a third width greater than a fourth width of another portion of the second rail; and one or more transistors disposed above the substrate and between the first rail and the second rail.