A method of forming a semiconductor structure in a semiconductor-on-insulator (SOI) substrate and semiconductor structure so formed are provided. The SOI substrate includes a semiconductor layer; a bulk semiconductor region underlying the semiconductor layer; and an insulation layer between the two. The structure includes first and second openings each having sidewalls, each of the first opening and the second opening formed substantially simultaneously and extending from a top surface of the semiconductor layer through the semiconductor layer and through the insulation layer to the conductive region; an insulating material adapted to provide electrical insulation to at least a portion of the side walls of the first opening; a semiconductor material at least partially filling the first opening, the semiconductor material defining an ohmic contact trench providing electrical contact with the semiconductor region; and an insulating material disposed in the second opening and defining a device isolation trench.