Method for producing a low-impedance contact between a metallizing layer and a semiconductor material

In a method for producing a contact between a metallizing layer and a semiconductor material of a first conductivity type having a semiconductor surface, an insulation layer on the semiconductor surface and a semiconductor layer on the insulation layer, the improvement which comprises:

• applying a first insulating layer with a content of dopants on the semiconductor layer, and structuring the first insulating layer by anisotropic etching, forming an opening;
• anisotropically etching the semiconductor layer by using the first insulating layer as a mask;
• implanting and driving a first dopant of a second conductivity type through the opening into the semiconductor material with a first phototechnique, forming a first zone in the semiconductor material;
• implanting a second dopant of the first conductivity type through the opening into the semiconductor material with a second phototechnique, forming a second zone of the first conductivity type in an upper region of the first zone;
• applying a second doped insulating layer over the entire surface;
• back-etching the second doped insulating layer anisotropically down to the semiconductor surface of the semiconductor material at least in a region of the opening, with an insulating sidewall spacer remaining in the opening;
• anisotropically etching the semiconductor material down to the first zone for forming a top surface, by using the second doped insulating layer and the insulating side wall spacer as a mask;
• implanting a third dopant of the second conductivity type into the first zone by using the second doped insulating layer and the insulating side wall spacer as a mask;
• and
• applying a metallizing layer on the top surface.