Methods for fabricating conductive vias of circuit structures

Abstract

Methods and structures for fabricating conductive vias in circuit structures are provided. Methods may include, for example, providing a substrate that includes a dopant and at least one trench formed in the substrate; providing an undoped semiconductor layer over a surface of the substrate within the trench; and providing a conductive material on top of dielectric layer in the trench, the conductive material forming the conductive via. The undoped semiconductor layer, having no dopant, reduces a parasitic capacitance between the conductive via and the substrate. The undoped semiconductor layer may also prevent migration of dopant from the substrate into the undoped semiconductor layer, further reducing capacitance in the circuit structure.

Dependencies are inferred from the claim text.