Provided is a voltage regulator including an overcurrent protection circuit in which an output voltage-output current characteristic exhibits an optimal fold-back characteristic even when an overcurrent state is detected. The method may comprise producing a substrate from a first material in which the substrate has a bearing portion, and causing particles of a second material to be formed onto at least the bearing portion of the substrate. The semiconductor device structure includes an isolation structure positioned in the semiconductor substrate and adjacent to a first active region of the semiconductor substrate. When the feedthrough is compressively secured to the structure, the bushing expands radially between the first diameter and the second diameter to maintain at least one contact point between the fastener and the structure.