Solid-state imaging device and manufacturing method thereof, and electronic apparatus
View Patent ↗A solid-state imaging device includes a photoelectric conversion unit that is formed on a semiconductor substrate, a reading unit that reads signal charges of the photoelectric conversion unit, a gate insulating film and an electrode disposed thereon that constitute the reading unit, a light shielding film that covers the electrode, and an antireflection film that is formed on the photoelectric conversion unit and is constituted by films of four or more layers. The film of the lower layer of the antireflection film is also used as a stopper film during patterning, and a gap between the end of the light shielding film and the semiconductor substrate which is defined by interposing a plurality of films of the lower layer of the antireflection film is set so as to be smaller than the thickness of the gate insulating film.
1. A solid-state imaging device comprising:
a photoelectric conversion unit that is formed on a semiconductor substrate;
a reading unit that reads signal charges of the photoelectric conversion unit;
a gate insulating film and an electrode disposed thereon that constitute the reading unit;
a light shielding film that covers the electrode; and
an antireflection film that is formed on the photoelectric conversion unit and is constituted by films of four or more layers,
wherein,
a film of a lower layer of the antireflection film is also used as a stopper film during patterning, and
a gap between the end of the light shielding film and the semiconductor substrate which is defined by interposing a plurality of films of the lower layer of the antireflection film is set so as to be smaller than the thickness of the gate insulating film.
2. The solid-state imaging device according to claim 1 , wherein:
the antireflection film is constituted by films of four layers, and
the gap between the end of the light shielding film and the semiconductor substrate is defined by films of two layers of the lower layer of the antireflection film.
3. The solid-state imaging device according to claim 1 , wherein:
the antireflection film is formed by alternatively laminating a silicon oxide film and a silicon nitride film, and
a film of a second layer of the antireflection film is a silicon nitride film which is also used as a stopper film.
4. The solid-state imaging device according to claim 1 , wherein:
the reading unit is a vertical transfer register, and
the electrode is a transfer electrode of the vertical transfer register.
5. The solid-state imaging device according to claim 1 , wherein:
the reading unit is a transfer transistor and a charge holding portion that constitute a pixel, and
the electrode is a transfer gate electrode of the transfer transistor and a gate electrode of the charge holding portion.
6. A manufacturing method of a solid-state imaging device comprising:
forming a photoelectric conversion unit and a reading unit that reads signal charges of the photoelectric conversion unit on a semiconductor substrate;
forming a gate insulating film and an electrode disposed thereon that selectively constitute the reading unit while excluding the photoelectric conversion unit;
forming films of four or more layers which cover the photoelectric conversion unit and the electrode and constitute an antireflection film;
providing a film of a lower layer of the films of four or more layers as a stopper film, and selectively removing upper films than the stopper film among the films of four or more layers which are disposed on the electrode including the periphery of the photoelectric conversion unit;
thereafter, forming a light shielding film covering the electrode via a plurality of films of the lower layer including the stopper film so that the end of a light shield unit is positioned on the periphery of the photoelectric conversion unit and the gap between the end of the light shielding film and the semiconductor substrate is defined so as to be set smaller than the thickness of the gate insulating film; and
forming the antireflection film constituted by the films of four or more layers on the photoelectric conversion unit.
7. The manufacturing method of a solid-state imaging device according to claim 6 , further comprising:
forming the antireflection film by films of four layers; and
defining the gap between the end of the light shielding film and the semiconductor substrate by films of two layers of the lower layer of the antireflection film.
8. The manufacturing method of a solid-state imaging device according to claim 6 , further comprising:
forming the antireflection film by alternatively laminating a silicon oxide film and a silicon nitride film; and
forming a film of a second layer of the antireflection film by a silicon nitride film so as to also act as a stopper film.
9. The manufacturing method of a solid-state imaging device according to claim 6 , wherein:
the reading unit is a vertical transfer register, and
the electrode is a transfer electrode of the vertical transfer register.
10. The manufacturing method of a solid-state imaging device according to claim 6 , wherein:
the reading unit is a transfer transistor and a charge holding portion that constitute a pixel, and
the electrode is a transfer gate electrode of the transfer transistor and a gate electrode of the charge holding portion.
11. An electronic apparatus comprising:
a solid-state imaging device;
an optical system that introduces incident light into 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 is constituted by the solid-state imaging device according to claim 1 .