SEMICONDUCTOR DEVICE

The invention relates to a method of manufacturing a semiconductor device (10) with a substrate (11) and a semiconductor body (12) comprising silicon which is provided with at least one semiconductor element (T), wherein an epitaxial semiconductor layer (1) comprising silicon is grown on top of a first semiconductor substrate (14), wherein a splitting region (2) is formed in the epitaxial layer (1), wherein a second substrate (11) is attached by wafer bonding to the first substrate (12) at the side of the epitaxial layer (1) provided with the splitting region (2) while an electrically insulating region (3) is interposed between the epitaxial layer (1) and the second substrate (11), the structure thus formed is split at the location of the splitting region (2) as a result of which the second substrate (11) forms the substrate (11) with on top of the insulating region (3) a part (IA) of the epitaxial layer forming the semiconductor body (12) in which the semiconductor element (T) is formed. According to the invention for the thickness of the epitaxial layer (1) a thickness is chosen that is larger than about 3 mum. Preferably, the thickness is chosen between 5 and 15 mum. Best results are obtained with a thickness in the range of 7 to 13 mum. Devices 10, in particular high-voltage FETs, are obtained easily and with high yield and uniform properties like leakage current. The invention also comprises a method of manufacturing an SOI structure 12 and an SOI structure 12 thus obtained.