Solid state imaging device in which a plurality of imaging pixels are arranged two-dimensionally, and a manufacturing method for the solid state imaging device
View Patent ↗A solid state imaging device includes a plurality of imaging pixels that are arranged two-dimensionally along a main face of a semiconductor substrate. Each imaging pixel in the solid state imaging device includes a photodiode that performs photoelectric conversion and a color filter that is disposed higher in the Z axis direction than the photodiode. Also, light blocking portions have been formed between pairs of adjacent imaging pixels, on the main face of the semiconductor substrate to a height in a thickness direction (Z axis direction) of the semiconductor substrate that is substantially equal to or higher than top edges of the optical filters. Each light blocking portion is constituted from a combination of a light blocking film and a light blocking wall.
1. A solid state imaging device in which a plurality of imaging pixels are arranged two-dimensionally along a main face of a semiconductor substrate with gaps between adjacent imaging pixels, the solid state imaging device comprising:
a plurality of light receiving portions that performs photoelectric conversion and have been formed in one-to-one correspondence with the plurality of imaging pixels;
a plurality of color filters that have been formed in one-to-one correspondence with the plurality of imaging pixels and are disposed above the plurality of light receiving portions;
a plurality of light blocking portions that blocks light, each being provided between a different pair of adjacent imaging pixels and having been formed on the main face of the semiconductor substrate to a height in a thickness direction of the semiconductor substrate that is greater than or substantially equal to top edges of the plurality of color filters; and
a plurality of top lenses, each having been formed above a different one of the color filters in the plurality of imaging pixels, wherein
each of the light blocking portions includes a part whose cross-sectional area gradually decreases in an upward direction with respect to the thickness direction of the semiconductor substrate.
2. The solid state imaging device of claim 1 , further comprising:
a plurality of transfer channels, each having been formed between a different pair of adjacent light receiving portions on the main face of the semiconductor substrate and in close proximity to one of the adjacent light receiving portions;
a plurality of transfer electrodes that have been formed on the main face of the semiconductor substrate in one-to-one correspondence with the plurality of transfer channels;
a light blocking film that has been formed above the main face of the semiconductor substrate so as to cover upper faces and lateral faces of the plurality of transfer electrodes; and
a plurality of light blocking walls that have been provided on or above the light blocking film and standing upright in the thickness direction of the semiconductor substrate, wherein
each light blocking portion includes the light blocking film and a different one of the light blocking walls.
3. The solid state imaging device of claim 2 , wherein
the plurality of light blocking walls are composed of an inorganic material.
4. The solid state imaging device of claim 2 , wherein
the plurality of light blocking walls are composed of one or more materials selected from the group consisting of W, TiN, Ti, and Al.
5. The solid state imaging device of claim 2 , wherein
the plurality of light blocking walls are composed of an inorganic material and an organic material.
6. The solid state imaging device of claim 2 , wherein
the plurality of light blocking walls are composed of a resin material and one or more materials selected from the group consisting of W, TiN, Ti, and Al.
7. The solid state imaging device of claim 2 , wherein
the light blocking film is electrically insulated from the plurality of light blocking walls.
8. The solid state imaging device of claim 1 , further comprising:
a plurality of intra-layer lenses, each having been formed between the light receiving portion and the color filter of a different one of the imaging pixels.
9. The solid state imaging device of claim 8 , wherein
each of the intra-layer lenses is convex in an upward direction or a downward direction with respect to the thickness direction of the semiconductor substrate, or convex in both the upward direction and the downward direction.
10. The solid state imaging device of claim 1 , wherein
top edges of the light blocking portions are positioned at or in a proximity of bottom edges of the plurality of top lenses.
11. The solid state imaging device of claim 1 , further comprising:
a planarizing film that has been formed between (i) a first area of each light blocking portion that is substantially equal in height to an area in which the plurality of color filters have been formed and (ii) a second area of each light blocking portion that is below the first area, wherein
a thickness of the planarizing film is smaller than a visible wavelength band of light.