Abstract: A PIN photodiode having a low leakage current comprises a substrate (10) of indium phosphide (InP) which is n.sup.30 doped and on whose first surface is formed a layer (11) of indium phosphide (InP) which is n.sup.- doped and on which is disposed a MESA structure formed by a layer (b 12) of gallium indium arsenide (InGaAs) which is n.sup.- doped and is moreover constituted by a layer (13, 113, 213) of the p.sup.+ type formed at the surface, at the edges and along the circumference of the MESA structure. The structure further comprises a metallic contact (22) formed on the second surface of the substrate and an ohmic contact (21) formed on a part of the p.sup.+ layer. The invention is characterized in that the n.sup.- doping of the layer of indium phosphide (InP) (11) is chosen to be lower than the n.sup.- doping of the layer of gallium indium arsenide (InGaAs) (12), and in that the ohmic contact (21) is formed on a part (213) of the p.sup.

Abstract: A PIN photodiode having a low leakage current comprises a substrate (10) of indium phosphide (InP) which is n.sup.+ doped and on whose first surface is formed a layer (11) of indium phosphide (InP) which is n.sup.- doped and on which is disposed a MESA structure formed by a layer (12) of gallium indium arsenide (InGaAs) which is n.sup.- doped and is moreover constituted by a layer (13, 113, 213) of the p.sup.+ type formed at the surface, at the edges and along the circumference of the MESA structure. The structure further comprises a metallic contact (22) formed on the second surface of the substrate and an ohmic contact (21) formed on a part of the p.sup.+ layer. The invention is characterized in that the n.sup.- doping of the layer of indium phosphide (InP) (11) is chosen to be lower than the n.sup.- doping of the layer of gallium indium arsenide (InGaAs) (12), and in that the ohmic contact (21) is formed on a part (213) of the p.sup.