Commissariat a L'energie Atomique Et Aux Energies Alternatives

Olivier Saxod

Norbert Moussy

François Ayel

Cédric Giroud-Garampon

Marie Guillon

An image sensor provided with a pixel including a photosensitive region formed in a semiconductor substrate and surrounded by a peripheral isolation trench; a sense node formed on a charge collecting region; a charge transfer gate around the sense node; a well; the pixel being provided with a so-called 'detection acceleration' transistor configured to, during a so-called “charge overflow detection” operation, be switched on so as to weaken a potential barrier generated by the transfer gate and thus to favour an overflow of photogenerated charges to the sense node of the photosensitive region and to accelerate detection of this overflow.

Device for detecting overflow of charges for backside illumination pixel

An image sensor including a plurality of avalanche photodiodes formed inside and on top of a semiconductor substrate of a first conductivity type having a front side and a back side, wherein: trenches vertically extend in the substrate from its front side to its back side, the trenches having, in top view, the shape of a continuous grid laterally delimiting a plurality of substrate islands, each island defining a pixel including a single individually-controllable avalanche photodiode, and including a doped area of collection of an avalanche signal of the pixel photodiode the lateral walls of the trenches are coated with a first semiconductor layer having a conductivity type opposite to that of the collection area, and a conductive region extends in the trenches, the conductive region being in contact with the surface of the first semiconductor layer opposite to the substrate.

Image sensor comprising a plurality of SPAD photodiodes

A SPAD-type photodiode comprising a depletion area in a first portion of a semiconductor substrate of a first conductivity type and further comprising a gate electrically-insulated from the substrate, extending into the substrate from an upper surface of the substrate, and separating the first portion of the substrate from a second portion. The photodiode further comprises a first region of the second conductivity type extending from the upper surface of the substrate into the second portion.

SPAD-type photodiode

The invention concerns a pixel of an image array comprising one or more charge storage structures (), each charge storage structure comprising: a first charge storage trench () doped to have a first conductivity type and having a first end () configured to receive charge accumulated by a photodiode; a second charge storage trench () doped to have the first conductivity type; and a first transfer gate () linking a second end () of the first charge storage trench () and the second charge storage trench () to a sense node (), wherein the first and second charge storage trenches are linked together by a linking channel () doped to have the first conductivity type and bordering a portion of an edge of the transfer gate ().

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Grenoble, France

Olivier Saxod