The present disclosure provides various embodiments of a via structure and method of manufacturing same. In an example, a method for forming a via structure includes forming a via in a semiconductor substrate, wherein via sidewalls of the via are defined by the semiconductor substrate; forming a dielectric layer on the via sidewalls; removing the dielectric layer from a portion of the via sidewalls; and forming a conductive layer to fill the via, wherein the conductive layer is disposed over the dielectric layer and the portion of the via sidewalls. In an example, the dielectric layer is an oxide layer.