Process for producing an array of mesa-structured photodiodes , including at least the following steps: a) producing a layer, referred to as the useful layer , including an upper face and an opposite lower face , resting on a carrier layer via the lower face , including a stack of a first zone located at the upper face and having a first doping type, and of a second zone located between the first zone and the carrier layer having a second doping type, opposite the first type; b) producing an etch mask positioned on said upper face , formed of a plurality of pads, referred to as etch pads , which are distinct from one another; c) wet-etching part of the useful layer located between the etch pads , thus forming a plurality of mesa-structured photodiodes , each having an upper surface on which one of said etch pads rests, said wet etch being adapted so that the upper surface of each photodiode has a mean lateral dimension that is smaller than that of the corresponding etch pad , thus forming a recess between the etch pad and the corresponding photodiode ; d) conformally depositing, on the etch pads and the photodiodes , a passivation layer made of at least one dielectric or semiconductor material, with deposition conditions chosen so that the passivation layer has a local thickness that is less than or equal to 200 nm below the recess , and a columnar polycrystalline structure, the columns of which extend longitudinally along the thickness of the passivation layer with a constant transverse dimension, and are separated laterally from one another by grain boundaries; e) removing the etch pads by chemical dissolution, thus leaving the upper surface exposed, a surface, referred to as the lateral surface , of the photodiodes, which surrounds the upper surface , being covered by the passivation layer ; f) producing electrically conductive pads on and in contact with the upper surface . a) producing a layer, referred to as the useful layer , including an upper face and an opposite lower face , resting on a carrier layer via the lower face , including a stack of a first zone located at the upper face and having a first doping type, and of a second zone located between the first zone and the carrier layer having a second doping type, opposite the first type; b) producing an etch mask positioned on said upper face , formed of a plurality of pads, referred to as etch pads , which are distinct from one another; c) wet-etching part of the useful layer located between the etch pads , thus forming a plurality of mesa-structured photodiodes , each having an upper surface on which one of said etch pads rests, said wet etch being adapted so that the upper surface of each photodiode has a mean lateral dimension that is smaller than that of the corresponding etch pad , thus forming a recess between the etch pad and the corresponding photodiode ; d) conformally depositing, on the etch pads and the photodiodes , a passivation layer made of at least one dielectric or semiconductor material, with deposition conditions chosen so that the passivation layer has a local thickness that is less than or equal to 200 nm below the recess , and a columnar polycrystalline structure, the columns of which extend longitudinally along the thickness of the passivation layer with a constant transverse dimension, and are separated laterally from one another by grain boundaries; e) removing the etch pads by chemical dissolution, thus leaving the upper surface exposed, a surface, referred to as the lateral surface , of the photodiodes, which surrounds the upper surface , being covered by the passivation layer ; f) producing electrically conductive pads on and in contact with the upper surface . <EOS>