Semiconductor light sensor

A light sensitive semiconductor structure comprising:

• a substrate;
• a doped upper region of said substrate having a first type of doping;
• a first implant region located below and being in direct contact with said doped upper region, said first implant region having a second type of doping so that a pn junction is located between said doped upper region and said first implant region;
• a first and a second contact structure configured to apply a voltage across said pn-junction, wherein the first contact structure is directly connected to said upper doped region, and said second contact structure is directly connected to a low resistance region of said substrate, wherein said low resistance region is in direct contact with said first implant region and comprises at least three vertically arranged doped regions comprising:
• a heavily doped region directly connected to said second contact structure,
• a doped well region in said substrate, and
• a second implant region laterally separated from said first implant region.

A light sensitive semiconductor structure comprising:

• a substrate;
• a first doped upper region of said substrate having a first type of doping;
• a second doped upper region laterally separated from said first doped upper region and having a second type of doping;
• an isolation structure between said first and second upper doped regions;
• a low resistance path for current flow between said first and second doped upper regions arranged underneath said isolation structure and around an enclosed region of said substrate having a higher resistance;
• a first implant region located below and being in direct contact with said first doped upper region, said first implant region having said second type of doping so that a pn-junction is located between said doped upper region and said first implant region, wherein said enclosed region is enclosed at least partially on one side by said first implant region and wherein said low resistance path goes through said first implant region;
• and
• a second implant region having said second type of doping and being arranged below and in direct contact with said first implant region, wherein said enclosed region is enclosed on one side by said second implant region and wherein said low resistance path goes through said second implant region.

A light sensitive semiconductor structure comprising:

• a substrate;
• a doped upper region of said substrate having a first type of doping;
• a first implant region located below and being in direct contact with said doped upper region, said first implant region having a second type of doping;
• a pn-junction located between said doped upper region and said first implant region for collecting light generated charge carriers;
• a second implant region located below said first implant region and having said second type of doping, and wherein a peak in a doping profile of said second type of doping is located in said second implant region, wherein said peak doping concentration is located at a depth in the range of 2 μm to 5 μm;
• a collection volume enclosing said pn-junction and defined by a peak doping concentration in the substrate, such that an intrinsic electric field generated by a doping profile prevents charge carriers outside the collection volume from reaching said pn-junction.