Method of manufacturing a semiconductor device whereby a laterally bounded semiconductor zone is formed in a semiconductor body in a self-aligning manner

摘要

A method of manufacturing a semiconductor device with a semiconductor element which includes a semiconductor zone (19) situated below an electrode (18) and adjoining a surface (5) of a semiconductor body (1), which semiconductor zone substantially does not project outside the electrode (18) in lateral direction. The electrode (18) is here formed on the surface (5) of the semiconductor body (1), after which semiconductor material adjoining the surface (5) and not covered by the electrode (18) is removed by an etching treatment, whereby the position of the semiconductor zone (19) below the electrode (18) is defined. Before the electrode (18) is formed, a surface zone (16) adjoining the surface (5) is formed in the semiconductor body (1) with a depth and a doping such as are desired for the semiconductor zone (19) to be formed below the electrode (18), after which the electrode (18) is formed on this surface zone and, during the etching treatment, the portion of the surface zone (16) not covered by the electrode (18) is etched away through its entire thickness. Conducting materials such as aluminium or aluminium alloys may be used for the electrode (18), i.e. materials which are not resistant to temperatures necessary for forming semiconductor zones through diffusion.