Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
209 words
A method of manufacturing a semiconductor device for generating an electron beam by avalanche multiplication across a reverse biased p-n junction, said method comprising the steps of: providing a semiconductor body having a surface, said body having a surface-adjoining n-type conductivity layer and a p-type conductivity layer adjoining the n-type layer, the n-type layer being disposed between the surface of the semiconductor body and the p-type layer, said p-type and n-type layers forming a p-n junction therebetween; covering the surface of the semiconductor body with a layer of an electrically insulating material; covering the layer of electrically insulating material with a layer of electrically conductive material; covering the layer of electrically conductive material with a layer of masking material; providing an aperture in the mask layer; etching apertures into the conductive, insulating, and n-type layers through the aperture in the mask layer, the aperture in the conductive layer being larger than the aperture in the n-type layer; doping the p-type layer through the apertures with acceptor atoms to form a heavily doped p-type region of higher doping concentration than the p-type layer; removing the mask layer; and doping the p-type region through the apertures with donor atoms to form a surface-adjoining n-type region in the heavily doped p-type region.
Claim 2
Independent Claim
209 words
A method of manufacturing a semiconductor device for generating an electron beam by avalanche multiplication across a reverse biased p-n junction, said method comprising the steps of: providing a semiconductor body having a surface, said body having a surface-adjoining n-type conductivity layer and a p-type conductivity layer adjoining the n-type layer, the n-type layer being disposed between the surface of the semiconductor body and the p-type layer, said p-type and n-type layers forming a p-n junction therebetween; covering the surface of the semiconductor body with a layer of an electrically insulating material; covering the layer of electrically insulating material with a layer of electrically conductive material; covering the layer of electrically conductive material with a layer of masking material; providing an aperture in the mask layer; etching apertures into the conductive, insulating, and n-type layers through the aperture in the mask layer, the aperture in the conductive layer being larger than the aperture in the n-type layer; doping the p-type layer through the apertures with acceptor atoms to form a heavily doped p-type region of higher doping concentration than the p-type layer; removing the mask layer; and doping the p-type region through the apertures with donor atoms to form a surface-adjoining n-type region in the heavily doped p-type region.
Claim 3
Dependent Claim
16 words
A method as claimed in claim 1, wherein the doping steps comprise ion implanting the dopants.
Claim 4
Dependent Claim
23 words
A method as claimed in claim 2, wherein before implanting the donor ions, any exposed semiconductor surfaces are provided with an oxide layer.
Claim 5
Dependent Claim
31 words
A method as claimed in claim 3, wherein the energy of the donor ions is selected such that the maximum donor concentration is substantially at the surface of the semiconductor body.
Claim 6
Dependent Claim
48 words
A method as claimed in claim 4, wherein after the formation of the heavily doped p-type region and prior to doping the heavily doped p-type region with donor ions, the aperture in the insulating layer is enlarged until it is larger than the aperture in the conductive layer.