Imaging device and electronic device
An imaging device includes a semiconductor substrate including a plurality of photoelectric conversion elements, a plurality of color filters on the semiconductor substrate and faces each of the plurality of photoelectric conversion elements, and a partition wall on the semiconductor substrate and separates one color filter from an adjacent color filter adjacent among the plurality of color filters. The partition wall includes a first metal layer, a first translucent partition wall layer that covers side surfaces and a top surface of the first metal layer, and a second translucent partition wall layer located between the first metal layer and the first translucent partition wall layer and covers the side surfaces and the top surface of the first metal layer. A refractive index of the second translucent partition wall layer is larger than a refractive index of the first translucent partition wall layer.
1. An imaging device, comprising:
a semiconductor substrate that includes a plurality of photoelectric conversion elements;
a plurality of color filters on the semiconductor substrate, wherein the plurality of color filters face a corresponding photoelectric conversion element of the plurality of photoelectric conversion elements;
a partition wall on the semiconductor substrate, wherein the partition wall separates one color filter from an adjacent color filter among the plurality of color filters; and
a lens on a side opposite to the semiconductor substrate, wherein the plurality of color filters are between the lens and the semiconductor substrate,
wherein the partition wall includes
a first metal layer having a first side surface, a second side surface, and an upper end surface located on a side of the lens,
a first translucent partition wall layer that covers the first side surface, the second side surface, and the upper end surface of the first metal layer,
a second translucent partition wall layer located between the first metal layer and the first translucent partition wall layer, wherein the second translucent partition wall layer covers the first side surface, the second side surface, and the upper end surface of the first metal layer, and
a refractive index of the second translucent partition wall layer is larger than a refractive index of the first translucent partition wall layer.
2. The imaging device according to claim 1 , wherein refractive indexes of the plurality of color filters are larger than the refractive index of the first translucent partition wall layer.
3. The imaging device according to claim 1 , wherein the second translucent partition wall layer, the first translucent partition wall layer, and the plurality of color filters are laminated in order on the plurality of photoelectric conversion elements.
4. The imaging device according to claim 1 , further comprising a light-shielding film between the partition wall and the semiconductor substrate.
5. The imaging device according to claim 4 , wherein the light-shielding film is made of a metal.
6. The imaging device according to claim 1 , wherein
a thickness of a portion of the second translucent partition wall layer that covers the first side surface of the first metal layer is different from a thickness of a portion of the second translucent partition wall layer that covers the second side surface of the first metal layer.
7. The imaging device according to claim 1 , wherein each of the plurality of color filters has a different width.
8. The imaging device according to claim 1 , wherein
the semiconductor substrate further includes an element separation layer that separates a first photoelectric conversion element of the plurality of photoelectric conversion elements from a second photoelectric conversion element of the plurality of photoelectric conversion elements,
the first photoelectric conversion element is adjacent to the second photoelectric conversion element,
the partition wall is located on the element separation layer, and
an amount of shift of the partition wall, towards a central region of an imaging region including the plurality of photoelectric conversion elements with respect to the element separation layer, increases toward a side further separated from the central region.
9. The imaging device according to claim 1 , wherein
the semiconductor substrate further includes an element separation layer that separates a first photoelectric conversion element of the plurality of photoelectric conversion elements from a second photoelectric conversion element of the plurality of photoelectric conversion elements,
the first photoelectric conversion element is adjacent to the second photoelectric conversion element,
the partition wall is located on the element separation layer, and
the element separation layer includes
a second metal layer, and
an insulating layer that covers a side surface of the second metal layer.
10. The imaging device according to claim 9 , wherein the first metal layer is integrated with the second metal layer.
11. The imaging device according to claim 9 , further comprising a metal light-shielding film between the first metal layer and the second metal layer,
wherein the second metal layer is integrated with the metal light-shielding film.
12. The imaging device according to claim 1 ,
wherein the second translucent partition wall layer is configured of a silicon carbide film having an amorphous crystal structure, and
the first translucent partition wall layer is configured of a silicon oxide film.
13. An electronic device, comprising:
an optical component;
an imaging device on which light transmitted through the optical component is incident; and
a signal processing circuit configured to process a signal output from the imaging device,
wherein the imaging device includes:
a semiconductor substrate that includes a plurality of photoelectric conversion elements;
a plurality of color filters on the semiconductor substrate and face each of the plurality of photoelectric conversion elements; and
a partition wall on the semiconductor substrate, wherein the partition wall separates one color filter from an adjacent color filter among the plurality of color filters; and
a lens on a side opposite to the semiconductor substrate, wherein the plurality of color filters are between the lens and the semiconductor substrate,
the partition wall includes
a first metal layer having a first side surface, a second side surface, and an upper end surface located on a side of the lens,
a first translucent partition wall layer that covers the first side surface, the second side surface, and the upper end surface of the first metal layer,
a second translucent partition wall layer located between the first metal layer and the first translucent partition wall layer, wherein the second translucent partition wall layer covers the first side surface, the second side surface, and the upper end surface of the first metal layer, and
a refractive index of the second translucent partition wall layer is larger than a refractive index of the first translucent partition wall layer.