Solid-state imaging device, method for driving the same, and electronic device for improved autofocusing accuracy
The present disclosure relates to a solid-state imaging device, a method for driving the solid-state imaging device, and an electronic device capable of improving auto-focusing accuracy by using a phase difference signal obtained by using a photoelectric conversion film. The solid-state imaging device includes a pixel including a photoelectric conversion portion having a structure where a photoelectric conversion film is interposed by an upper electrode on the photoelectric conversion film and a lower electrode under the photoelectric conversion film. The upper electrode is divided into a first upper electrode and a second upper electrode. The present disclosure can be applied to, for example, a solid-state imaging device or the like.
1. A solid-state imaging device, comprising:
a photoelectric conversion unit, comprising:
a photoelectric conversion film;
a first electrode;
a second electrode; and
a third electrode;
at least one photoelectric conversion region disposed in a semiconductor substrate; and
an on-chip lens,
wherein the photoelectric conversion film is disposed between the first electrode and the third electrode and disposed between the second electrode and the third electrode,
wherein the photoelectric conversion unit is disposed between the on-chip lens and the semiconductor substrate,
wherein the on-chip lens overlaps the first electrode, the second electrode, and one of the at least one photoelectric conversion region in a plan view,
wherein the photoelectric conversion unit photoelectrically converts predetermined color light,
wherein the photoelectric conversion unit is formed outside the semiconductor substrate, and
wherein another photoelectric conversion unit photoelectrically converts light of a color different from the predetermined color light which the photoelectric conversion unit photoelectrically converts is further included inside the semiconductor substrate.
2. The solid-state imaging device according to claim 1 , wherein the first electrode and the second electrode constitute an upper electrode.
3. The solid-state imaging device according to claim 1 , wherein different voltages are applied to the first electrode and the second electrode.
4. The solid-state imaging device according to claim 1 , wherein a first voltage applied to the first electrode allows charges to be generated in the photoelectric conversion film, and a second voltage applied to the second electrode allows charges not to be generated in the photoelectric conversion film.
5. The solid-state imaging device according to claim 4 , wherein, after the first voltage is applied to the first electrode and the second voltage is applied to the second electrode, the first voltage is applied to the second electrode and the second voltage is applied to the first electrode.
6. The solid-state imaging device according to claim 4 , wherein the second voltage is controlled so that a potential difference with respect to the third electrode is constant.
7. The solid-state imaging device according to claim 1 ,
wherein a voltage for allowing charges to be generated in the photoelectric conversion film is applied to the first electrode and the second electrode, and signals are output from the photoelectric conversion unit.
8. The solid-state imaging device according to claim 7 , wherein at least one of a first signal output from the photoelectric conversion unit and a second signal output from the photoelectric conversion unit is used as a phase difference signal.
9. The solid-state imaging device according to claim 1 , wherein the photoelectric conversion unit is one of multiple photoelectric conversion units, and the multiple photoelectric conversion units are two-dimensionally arranged in a matrix shape.
10. The solid-state imaging device according to claim 1 , wherein the third electrode faces the first electrode and the second electrode and is divided into a first lower electrode and a second lower electrode.
11. The solid-state imaging device according to claim 10 , wherein a first charge retaining portion is connected to the first lower electrode and a second charge retaining portion is connected to the second lower electrode.
12. The solid-state imaging device according to claim 11 , wherein a charge combining portion combines charges, and the charge combining portion combines charges retained in the first charge retaining portion and charges retained in the second charge retaining portion.
13. The solid-state imaging device according to claim 12 , further comprising:
switch elements between the first charge retaining portion and the charge combining portion and between the second charge retaining portion and the charge combining portion.
14. The solid-state imaging device according to claim 1 , wherein any one of the first electrode and an upper electrode is formed so as to extend over an adjacent photoelectric conversion unit.
15. The solid-state imaging device according to claim 1 , wherein the photoelectric conversion unit photoelectrically converts light which passes through a color filter.
16. The solid-state imaging device according to claim 1 , wherein the first electrode and the second electrode are formed so as to be symmetric with respect to an optical axis.
17. A method for driving a solid-state imaging device including a photoelectric conversion unit having a structure comprising a photoelectric conversion film disposed between a first electrode and a third electrode and disposed between a second electrode and the third electrode, the photoelectric conversion unit disposed between an on-chip lens and a semiconductor substrate, and the on-chip lens overlapping the first electrode, the second electrode, and one of multiple photoelectric conversion regions in a plan view, comprising:
applying different voltages to the first electrode and the second electrode;
photoelectrically converting predetermined color light by the photoelectric conversion unit,
wherein the photoelectric conversion unit is formed outside the semiconductor substrate;
including inside the semiconductor substrate, another photoelectric conversion unit photoelectrically; and
converting light of a color different from the predetermined color light which the photoelectric conversion unit photoelectrically converts by the another photoelectric conversion unit.
18. An electronic device, comprising:
a solid-state imaging device including:
a photoelectric conversion unit having a structure comprising:
a photoelectric conversion film disposed between a first electrode and a third electrode and disposed between a second electrode and the third electrode,
the photoelectric conversion unit disposed between an on-chip lens and a semiconductor substrate, and
the on-chip lens overlapping the first electrode, the second electrode, and one of multiple photoelectric conversion regions in a plan view,
wherein the photoelectric conversion unit photoelectrically converts predetermined color light,
wherein the photoelectric conversion unit is formed outside the semiconductor substrate, and
another photoelectric conversion unit photoelectrically converts light of a color different from the predetermined color light which the photoelectric conversion unit photoelectrically converts is further included inside the semiconductor substrate.
19. The method according to claim 17 , wherein the first electrode and the second electrode constitute an upper electrode.
20. The electronic device according to claim 18 , wherein the first electrode and the second electrode constitute an upper electrode.