| CPC H10F 39/806 (2025.01) [H10F 39/024 (2025.01); H10F 39/184 (2025.01); H10F 39/199 (2025.01); H10F 39/8067 (2025.01)] | 18 Claims |
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1. A backside illumination type integrated image sensor, comprising:
a substrate having a backside configured to be illuminated by an optical signal and containing a first semiconductor material having a first optical refractive index; and
a pixel array in the substrate;
wherein each pixel has a photosensitive active zone;
wherein each photosensitive active zone is an index contrast zone including a matrix formed of the first semiconductor material and a periodic structure embedded in said matrix, said periodic structure extending in said matrix from said backside;
wherein the periodic structure has a two-dimensional periodicity in a parallel plane with the backside;
wherein a value of the two-dimensional periodicity is linked with a wavelength of the optical signal and with the first optical refractive index; and
said periodic structure is formed by a plurality of elements made of a second optically transparent material having a second refractive index less than the first refractive index positioned at locations in the parallel plane defined by the two-dimensional periodicity; and
wherein the photosensitive active zone includes a region at one of said locations in said parallel plane defined by the two-dimensional periodicity which is devoid of a corresponding one of the elements;
wherein the one of said locations that is devoid of the corresponding one of the elements is surrounded in the photosensitive active zone by locations in said parallel plane defined by the two-dimensional periodicity which include elements.
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