Abstract: A method of manufacturing a semiconductor device, in particular a monolithic integrated circuit, in which highly doped zones are provided according to a given pattern on one side of a monocrystalline silicon substrate body by local diffusion of at least one impurity in a substantially flat surface of the substrate body and the substrate surface on said side is given a profile in a pattern which corresponds to the pattern of the highly doped zones, after which an epitaxial silicon layer is provided on said side and one or more semiconductor circuit elements are then formed while using at least one photoresist step, characterized in that the substantially flat substrate surface is given a crystal orientation lying between a {001} face and an adjacent {111} face, which orientation deviates at least 10.degree. from the said {001} face and at least 15.degree. from said {111} face and is present in a strip within 10.degree. from the crystallographic zone formed by the said two faces.