Apparatuses and methods with conductive plugs for a memory device are described. An example method includes: forming a plurality of shallow trench isolations elongating from a first surface of a semiconductor substrate toward a second surface of the semiconductor substrate; thinning the semiconductor substrate until first surfaces of the plurality of shallow trench isolations are exposed; forming a plurality of via holes, each via hole of the plurality of via holes through a corresponding one of the plurality of shallow trench isolations; and filling the plurality of via holes with a conductive material to form a plurality of conductive plugs.