Commissariat a L'energie Atomique Et Aux Energies Alternatives

Cédric Giroud-Garampon

Norbert Moussy

Olivier Saxod

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 method of forming an insulation structure inside and on top of a first semiconductor substrate, including the steps of: a) forming a trench vertically extending in the first substrate from a first surface of the first substrate; b) filling the trench, from the first surface of the first substrate, with a polysilicon region; c) thinning the first substrate on the side of a second surface of the first substrate, opposite to the first surface, to expose the polysilicon region at the bottom of the trench; d) removing the polysilicon region from the second surface of the first substrate; and e) filling the trench, from the second surface of the first substrate, with a metal.

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Grenoble, France

Cédric Giroud-Garampon