The present invention relates to a semiconductor device that has a semiconductor-on-insulator (SeOI) structure, which includes a substrate, an insulating layer such as an oxide layer on the substrate and a semiconductor layer on the insulating layer with a field-effect-transistor (FET) formed in the SeOI structure from the substrate and deposited layers, wherein the FET has a channel region in the substrate, a gate dielectric layer that is made from at least a part of the oxide layer of the SeOI structure; and a gate electrode that is formed at least partially from a part of the semiconductor layer of the SeOI structure. The invention further relates to a method of forming one or more field-effect-transistors or metal-oxide-semiconductor transistors from a semiconductor-on-insulator structure that involves patterning and etching the SeOI structure, forming shallow trench isolations, depositing insulating, metal or semiconductor layers, and removing mask and/or pattern layers.