Solid-state imaging device
View Patent ↗A solid-state imaging device includes: a plurality of pixels arranged in a matrix form on a substrate, wherein the plurality of pixels each include a photoelectric conversion region disposed inside the substrate and configured to convert light entering the substrate into charge, a charge retaining region disposed more on a side from which the light enters, than the photoelectric conversion region inside the substrate and configured to retain the charge converted in the photoelectric conversion region, an indented region indented from a surface of the substrate on the side from which the light enters, toward the photoelectric conversion region to at least a depth corresponding to the charge retaining region, and a light blocking film formed covering the charge retaining region at the surface side of the substrate and extending along a side wall of the indented region.
1. A solid-state imaging device comprising:
a plurality of pixels arranged in a matrix form on a substrate,
wherein the plurality of pixels each includes
a photoelectric conversion region disposed inside the substrate and configured to convert light entering the substrate into charge,
a charge retaining region disposed more on a side from which the light enters, than the photoelectric conversion region inside the substrate and configured to retain the charge converted in the photoelectric conversion region,
an indented region indented from a surface of the substrate on the side from which the light enters, toward the photoelectric conversion region to at least a depth corresponding to the charge retaining region, and
a light blocking film formed covering the charge retaining region at the surface side of the substrate and extending along a side wall of the indented region.
2. The solid-state imaging device according to claim 1 , further comprising:
a charge transfer gate electrode configured to transfer the charge from the photoelectric conversion region to the charge retaining region,
wherein the charge is transferred to the charge retaining region through a charge transfer path reaching the charge retaining region from the photoelectric conversion region through the charge transfer gate electrode.
3. The solid-state imaging device according to claim 2 , wherein the charge transfer gate electrode is embedded in the substrate and covers a side surface of the charge retaining region.
4. The solid-state imaging device according to claim 1 ,
wherein the photoelectric conversion region is formed extending from a lower side of the indented region to a lower side of the charge retaining region.
5. The solid-state imaging device according to claim 1 ,
wherein the light blocking film is formed having a single or multiple film structure achieving a higher light reflectivity than a tungsten single layer.
6. The solid-state imaging device according to claim 1 , further comprising:
an interlayer insulating film formed on the light blocking film; and
an optical waveguide formed, on the interlayer insulating film, from a material having a refractive index different from a refractive index of the interlayer insulating film and configured to guide the light to the photoelectric conversion region.
7. The solid-state imaging device according to claim 1 , further comprising:
an interlayer insulating film formed on the light blocking film; and
an inner lens formed on the interlayer insulating film and configured to condense the light and to guide the light to the photoelectric conversion region,
wherein the inner lens is formed from a material that is the same as a material configuring the interlayer insulating film or at least one material having a refractive index that is different from a refractive index of the material configuring the interlayer insulating film.
8. The solid-state imaging device according to claim 6 , further comprising:
a passivation film formed between the interlayer insulating film and the optical waveguide,
wherein the passivation film has stress in a compressive direction of −5.0×10 −9 dyne/cm 2 or less.
9. The solid-state imaging device according to claim 7 , further comprising:
a passivation film formed between the interlayer insulating film and the inner lens,
wherein the passivation film has stress in a compressive direction of −5.0×10 −9 dyne/cm 2 or less.