Abstract: The method of making a silicon device including a pn-junction includes the steps of providing a p-doped monocrystalline silicon substrate (1) with a doping concentration C.sub.S ; making a pn-junction by forming a first n-doped layer portion (21) directly on one side of the p-doped monocrystalline silicon substrate (1) with a doping concentration C.sub.D greater than the doping concentration C.sub.S of the silicon substrate; depositing epitaxially at least one other n-doped layer portion (22) having a doping concentration C.sub.E on the first n-doped layer portion (21) to form a silicon layer including the first n-doped layer portion and the at least one other n-doped layer portion; and etching a portion of the p-doped monocrystalline silicon substrate (1) so as to form a blind hole extending to the pn-junction from another side of the silicon substrate opposite to the side on which the first n-doped layer portion (21) is formed, the etching being such that the hole ends at the pn-junction.