Image capturing element, manufacturing method, and electronic device
The present disclosure relates to an image capturing element, a manufacturing method, and an electronic device that make it possible to improve effects of reducing crosstalk. A trench part provided from a light-receiving surface side of a semiconductor substrate in which photoelectric conversion parts that photoelectrically convert emitted light are formed and between the plurality of photoelectric conversion parts; and a protrusion part provided with at least an inclined surface that is inclined with respect to a side surface of the trench part to widen a space of the trench part in one part of the trench part are provided. The present technology can be applied, for example, to backlit solid-state image capturing elements.
1. An image capturing element comprising:
a semiconductor substrate in which photoelectric conversion parts that photoelectrically convert emitted light are formed;
a trench part provided from a light-receiving surface side of the semiconductor substrate and between a plurality of the photoelectric conversion parts; and
a protrusion part provided with at least an inclined surface that is inclined with respect to a side surface of the trench part to widen a space of the trench part in one part of the trench part, wherein
a material that inhibits transmission of light is embedded in the trench part and the protrusion part,
a first material embedded in a projection part of the protrusion part projecting laterally from a side surface of the trench part, and a second material embedded inside the trench part other than the projection part have different characteristics,
the first material has a higher absorption coefficient to light than the second material, and
the second material has a higher reflectance to light than the first material.
2. The image capturing element according to claim 1 , wherein
the protrusion part includes the inclined surface along a predetermined plane orientation of a crystal constituting the semiconductor substrate.
3. The image capturing element according to claim 1 , wherein
the protrusion part is provided at a tip of the trench part.
4. The image capturing element according to claim 1 , wherein
the protrusion part is provided in a middle stage from the light receiving surface of the semiconductor substrate to a tip of the trench part.
5. The image capturing element according to claim 1 , wherein
the protrusion part is provided at a plurality of places from the light receiving surface of the semiconductor substrate to a tip of the trench part.
6. The image capturing element according to claim 1 , wherein
the semiconductor substrate is an Si {111} substrate with a thickness direction defined as a first direction and having a first crystal plane represented with a plane index {111} extending along a horizontal plane orthogonal to the first direction, and
the inclined surface of the protrusion part includes a surface along a crystal plane of the Si {111} substrate that is inclined with respect to the first direction and is represented with the plane index {111}.
7. An image capturing element comprising:
an Si substrate having a thickness direction defined as a first direction and extending along a horizontal plane orthogonal to the first direction;
photoelectric conversion parts provided in the Si substrate and generating a charge according to an amount of received light by photoelectric conversion; and
a protrusion part including at least an inclined surface that is inclined with respect to a side surface of a trench part to widen a space of the trench part in one part of the trench part provided between a plurality of the photoelectric conversion parts,
wherein the protrusion part includes a plane along a second crystal plane that is inclined with respect to the first direction and has three Si back bonds.
8. A manufacturing method comprising, by a manufacturing device that manufactures an image capturing element:
digging a trench part provided from a light-receiving surface side of a semiconductor substrate in which photoelectric conversion parts that photoelectrically convert emitted light are formed and between a plurality of the photoelectric conversion parts; and
forming a protrusion part including at least an inclined surface inclined with respect to a side surface of the trench part to widen a space of the trench part in one part of the trench part, and
embedding, in the trench part and the protrusion part, a material that inhibits transmission of light, wherein
a first material is embedded in a projection part of the protrusion part projecting laterally from a side surface of the trench part, and a second material is embedded inside the trench part other than the projection part have different characteristics,
the first material has a higher absorption coefficient to light than the second material, and
the second material has a higher reflectance to light than the first material.
9. An electronic device comprising an image capturing element including:
a semiconductor substrate in which photoelectric conversion parts that photoelectrically convert emitted light are formed;
a trench part provided from a light-receiving surface side of the semiconductor substrate and between a plurality of the photoelectric conversion parts; and
a protrusion part including at least an inclined surface that is inclined with respect to a side surface of the trench part to widen a space of the trench part in one part of the trench part, wherein
a material that inhibits transmission of light is embedded in the trench part and the protrusion part,
a first material embedded in a projection part of the protrusion part projecting laterally from a side surface of the trench part, and a second material embedded inside the trench part other than the projection part have different characteristics,
the first material has a higher absorption coefficient to light than the second material, and
the second material has a higher reflectance to light than the first material.