A power converter embodied in a semiconductor substrate member

A power converter, such as a DC-DC converter or a power amplifier, embodied on a semiconductor substrate member (101), comprising: a first region (102) with a passive electrical component (104) with a first electrically conductive layer pattern (105) of an electrically conductive material and a second electrically conductive layer pattern (106) of an electrically conductive material deposited on respective sides (107, 108) of the semiconductor substrate member; wherein a trench (109) or through-hole (110) is formed (by etching) in the substrate within the first region, and wherein the electrically conductive material is deposited at least on a bottom portion of the trench or on a sidewall of the through-hole and electrically connected to one or both of the first conductive layer pattern (105)and the second conductive layer pattern (106); and a second region (103) with an active semiconductor component (111) integrated with the semiconductor substrate (101) by being fabricated by a semiconductor fabrication process. There is also provided a power supply, such as a DC-DC converter, embedded the semiconductor substrate member.