Solid-state imaging device including an on-chip lens with two inorganic films thereon
View Patent ↗A solid-state imaging device includes a plurality of pixels formed on a semiconductor substrate and include a photoelectric conversion unit; a color filter on the pixels; an on-chip microlens made of an organic film on the color filter, corresponding to each of the pixels; a first inorganic film formed on a surface of the on-chip microlens and having a higher refraction index than the on-chip microlens; and a second inorganic film formed on a surface of the first inorganic film and having a lower refraction index than the on-chip microlens and the first inorganic film, in which at least the second inorganic film includes a non-lens area at an interface of an adjacent second inorganic film.
1. A solid-state imaging device comprising:
a plurality of pixels formed on a semiconductor substrate and including a photoelectric conversion unit;
a color filter on the pixels;
an on-chip microlens made of an organic film on the color filter, corresponding to each of the pixels;
first inorganic films formed on a surface of the on-chip microlens and having a higher refraction index than the on-chip microlens; and
second inorganic films formed on a surface of the first inorganic film and having a lower refraction index than the on-chip microlens and the first inorganic film,
wherein,
adjacent first inorganic films are in contact with each other at an interface between adjacent first inorganic films,
adjacent second inorganic films have a V-shaped recess in-between adjacent on-chip lenses such that the ends of adjacent second inorganic films are in contact with each other,
at an interface between adjacent second inorganic films, and
the on-chip microlens area is continuous between adjacent first inorganic films.
2. The solid-state imaging device according to claim 1 , wherein the first inorganic film is formed of a silicon nitride film or a silicon oxynitride film and the second inorganic film is formed of a silicon oxide film or a silicon oxycarbide film.
3. The solid-state imaging device according to claim 1 , wherein a lower organic film that is in contact with the first inorganic film is thermoplastic resin and the film thickness of the first inorganic film is 450 nm or less.
4. The solid-state imaging device according to claim 1 , wherein a lower organic film that is in contact with the first inorganic film is thermoplastic resin and the first inorganic film is a silicon oxynitride film.
5. The solid-state imaging device according to claim 4 , wherein the lower layer made of thermoplastic resin in contact with the first inorganic film is a color filter cover film that is exposed between adjacent on-chip microlenses.
6. The solid-state imaging device according to claim 1 , wherein the color filter cover film on the color filter is not planarized.
7. The solid-state imaging device according to claim 1 , wherein the total film thickness of the first and second inorganic film is set such that the thickness of a concave portion corresponding to the interface of adjacent second inorganic films than that of the pex of the on-chip microlens, and the surface of the second inorganic film is formed in an aspheric surface.
8. The solid-state imaging device according to claim 1 , wherein the pixel includes the photoelectric conversion unit, and a plurality of pixel transistors and the solid-state imaging device is a CMOS solid-state imaging device.
9. The solid-state imaging device according to claim 1 , wherein the pixel includes the photoelectric conversion unit and a transfer unit corresponding to the photoelectric conversion unit of a vertical transfer resistor, and the solid-state imaging device is a CCD solid-state imaging device.
10. An electronic apparatus comprising:
a solid-state imaging device;
an optical system that introduces incident light to a photoelectric conversion unit of the solid-state imaging device; and
a signal processing circuit that processes an output signal of the solid-state imaging device,
wherein,
the solid-state imaging device comprises (a) a plurality of pixels formed on a semiconductor substrate and including a photoelectric conversion unit, (b) a color filter on the pixels, (c) an on-chip microlens made of an organic film on the color filter, corresponding to each of the pixels, (d) a first inorganic films formed on a surface of the on-chip microlens and having a higher refraction index than the on-chip microlens, and (e) second inorganic films formed on a surface of the first inorganic film and having a lower refraction index than the on-chip microlens and the first inorganic film, and
adjacent first inorganic films are in contact with each other at an interface between adjacent first inorganic films,
adjacent second inorganic films have a V-shaped recess in-between adjacent on-chip lenses such that the ends of adjacent second inorganic films are in contact with each other at an interface between adjacent second inorganic films, and
the on-chip microlens area is continuous between adjacent first inorganic films.