Solid-state image sensor and imaging system
AssigneeCanon Kabushiki Kaisha
InventorsToru Koizumi, Akira Okita, Tetsuya Itano, Sakae Hashimoto, Ryuichi Mishima
Life of this patent
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Abstract
At least one exemplary embodiment is directed to a solid state image sensor including at least one antireflective layer and/or non rectangular shaped wiring layer cross section to reduce dark currents and 1/f noise.
Claims22
A solid-state image sensor including a substrate, light-receiving sections placed on the substrate, a plurality of wiring layers, a plurality of interlayer insulating layers, and a first insulating layer, the wiring layers and the interlayer insulating layers being alternately arranged on the substrate, at least one of the wiring layers being placed on the first insulating layer, the solid-state image sensor comprising:
- a second insulating layer which is placed on the wiring layer on the first insulating layer, which has portions in contact with the first insulating layer, the portions being located at the positions corresponding to the light-receiving sections, and which has a refractive index different from that of the first insulating layer;
- and
- a third insulating layer which is placed above the light-receiving sections and which reduces reflected light from the interface between the substrate and the interlayer insulating layer placed on the substrate.
A solid-state image sensor including a substrate, light-receiving sections placed on the substrate, a plurality of wiring layers, a plurality of interlayer insulating layers, and a substantially flat first insulating layer, the wiring layers and the interlayer insulating layers being alternately arranged on the light-receiving sections, at least one of the wiring layers being placed on the first insulating layer, the solid-state image sensor comprising:
- a silicon oxide layer;
- a silicon nitride layer;
- and
- a silicon oxynitride layer,
- wherein the silicon oxide layer and the silicon nitride layer are placed above the light-receiving sections in that order, the silicon nitride layer is placed on the wiring layer on the first insulating layer and has portions in contact with the first insulating layer with the silicon oxynitride layer placed between therebetween, and the contact portions correspond to the light-receiving sections.
A method of formation of a solid state image sensor comprising:
- depositing at least one source-drain region of MOS transistors;
- depositing a first layer on the at least one source drain region;
- planarizing the first layer;
- depositing a plurality of mixed layers, wherein a mixed layer includes an insulating layer and a wiring layer, wherein the wiring layer further from the first layer is referred to as the outer wiring layer;
- planarizing each of the mixed layers in the plurality of alternating layers;
- depositing a plasma layer on the outer wiring layer;
- heating the plasma layer at a target temperature in a target environment for a target period of time;
- and
- depositing an optical element on the plasma layer.
Dependencies are inferred from the claim text.