Fabrication process for photodiodes responsive to blue light

摘要

A method is provided for the fabrication of a photodiode sensitive to blue light. This photodiode has a very flat pn junction (2) in order to achieve a high blue sensitivity. The pn-junction (2) is formed in an n-conducting (100)-oriented silicon monocrystal (1) through implantation of B+ ions. Subsequently, an upper layer (3) generated during the implantation with relatively low p-doping is eroded through anisotropic etching to extend into a region of a deeper lying layer (4) having a relatively high p+-doping. This high p+-doping layer is then located to provide high sensitivity of the silicon photodiodes light corresponding to blue in the visual spectrum.