Articles and semiconductor packages that incorporate glass-based substrates are disclosed, as well as methods of forming thereof. An article includes a glass-based substrate comprising first and second major surfaces spaced a distance from and parallel to each other, and a tapered via extending through the substrate. The tapered via includes a cross section that is symmetrical about a plane that is between and equidistant to the first and second major surfaces of the glass-based substrate and an interior wall with a first tapered region and a second tapered region positioned between the first major surface and the plane. The respective slopes of the first and second tapered regions are constant and the slope of the first tapered region is not equal to the slope of the second tapered region.