A method for forming a semiconductor device includes incorporating first dopant atoms of a first conductivity type into a semiconductor substrate to form a first doping region of the first conductivity type. Further, the method includes forming an epitaxial semiconductor layer on the semiconductor substrate and incorporating second dopant atoms of a second conductivity type before or after forming the epitaxial semiconductor layer to form a second doping region including the second conductivity type adjacent to the first doping region so that a pn-junction is located between the first doping region and the second doping region. The pn-junction is located in a vertical distance of less than 5 μm to an interface between the semiconductor substrate and the epitaxial semiconductor layer. Additionally, the method includes thinning the semiconductor substrate based on a self-aligned thinning process. The self-aligned thinning process is self-controlled based on the location of the pn-junction.