Solid-state imaging device
Provided is a solid-state imaging device capable of forming a pixel separation groove having a suitable action in a substrate. A solid-state imaging device of the present disclosure includes: a first photoelectric conversion unit and a second photoelectric conversion unit that are provided in a first semiconductor substrate and are adjacent to each other; a first pixel separation groove provided between the first photoelectric conversion unit and the second photoelectric conversion unit not to penetrate through the first semiconductor substrate; and a second pixel separation groove provided to penetrate through the first semiconductor substrate.
1 . A solid-state imaging device comprising:
first and second photoelectric conversion units that are provided in a first semiconductor substrate and are adjacent to each other;
a first pixel separation groove provided between the first photoelectric conversion unit and the second photoelectric conversion unit and configured not to penetrate through the first semiconductor substrate so as to permit charge transfer between the first and second photoelectric conversion units in at least one operating mode;
a second pixel separation groove provided to penetrate through the first semiconductor substrate and configured to electrically isolate the first and second photoelectric conversion units from other photoelectric conversion units in the first semiconductor substrate; and
first and second transfer transistors respectively associated with the first and second photoelectric conversion units, the first and second transfer transistors being operable to selectively enable or disable the charge transfer permitted by the first pixel separation groove.
2 . The solid-state imaging device according to claim 1 , wherein the first pixel separation groove is provided from a side of a light incident surface of the first semiconductor substrate toward a surface of the first semiconductor substrate on a side opposite to a light reflecting surface.
3 . The solid-state imaging device according to claim 1 , wherein the second pixel separation groove is provided to surround at least the first and second photoelectric conversion units in a plan view.
4 . The solid-state imaging device according to claim 1 , wherein the second pixel separation groove forms a pixel separation groove that surrounds the first and second photoelectric conversion units together with the first pixel separation groove.
5 . The solid-state imaging device according to claim 1 , wherein the second pixel separation groove is further provided between the first photoelectric conversion unit and the second photoelectric conversion unit together with the first pixel separation groove.
6 . The solid-state imaging device according to claim 1 , wherein
the second pixel separation groove surrounds N photoelectric conversion units (N is an integer of two or more) including the first and second photoelectric conversion units, and
the N photoelectric conversion units correspond to one on-chip lens provided on the first semiconductor substrate.
7 . The solid-state imaging device according to claim 6 , wherein the N photoelectric conversion units are provided in N pixels which are pixels of an identical color.
8 . The solid-state imaging device according to claim 1 , wherein
the second pixel separation groove surrounds N photoelectric conversion units (N is an integer of two or more) including the first and second photoelectric conversion units, and
the N photoelectric conversion units correspond to two lenses provided on the first semiconductor substrate.
9 . The solid-state imaging device according to claim 1 , wherein
the second pixel separation groove surrounds N photoelectric conversion units (N is an integer of two or more) including the first and second photoelectric conversion units, and
the N photoelectric conversion units correspond to N on-chip lenses provided on the first semiconductor substrate.
10 . The solid-state imaging device according to claim 9 , wherein the N is a square of K (K is an integer of three or more).
11 . The solid-state imaging device according to claim 1 , further comprising a floating diffusion unit provided at a position at least partially overlapping the first pixel separation groove in a plan view in the first semiconductor substrate.
12 . The solid-state imaging device according to claim 11 , wherein
the first pixel separation groove includes a first portion extending in a first direction and a second portion extending in a second direction, and
the floating diffusion unit is provided at a position at least partially overlapping an intersection portion between the first portion and the second portion in a plan view in the first semiconductor substrate.
13 . The solid-state imaging device according to claim 1 , wherein
the first pixel separation groove includes a first portion extending in a first direction and a second portion extending in a second direction, and
the first direction and the second direction are non-parallel and non-perpendicular to an end surface of a chip including the solid-state imaging device.
14 . The solid-state imaging device according to claim 1 , wherein the first and second transfer transistors are provided under the first and second photoelectric conversion units and have gate electrodes, respectively, that are at least partially provided in a first interlayer insulating film.
15 . The solid-state imaging device according to claim 14 , wherein the second pixel separation groove surrounds N photoelectric conversion units (N is an integer of two or more) including the first and second photoelectric conversion units,
the solid-state imaging device further comprises a reset, selection, or amplification transistor provided under any photoelectric conversion unit of the N photoelectric conversion units, and
the first transfer transistor, the second transfer transistor, and the reset, selection, or amplification transistor are provided on a surface of the first semiconductor substrate that is opposite to a light incident surface of the first semiconductor substrate.
16 . The solid-state imaging device according to claim 15 , further comprising a second semiconductor substrate that is provided to face the first interlayer insulating film provided on the surface of the first semiconductor substrate that is opposite to the light incident surface,
wherein the second semiconductor substrate includes at least a part of a pixel transistor other than the transfer transistors.
17 . A solid-state imaging device comprising:
first and second photoelectric conversion units that are provided in a first semiconductor substrate and are adjacent to each other;
a floating diffusion unit provided in the first semiconductor substrate;
first and second transfer transistors respectively provided under the first and second photoelectric conversion units; and
a first pixel separation groove provided between the first photoelectric conversion unit and the second photoelectric conversion unit and configured not to penetrate through the first semiconductor substrate, the floating diffusion unit being provided under the first pixel separation groove in the first semiconductor substrate,
wherein the first and second transfer transistors operate to provide
a first mode in which a path of a charge from the first photoelectric conversion unit to the floating diffusion unit is closed and a path of a charge from the first photoelectric conversion unit to the second photoelectric conversion unit is closed,
a second mode in which the path of the charge from the first photoelectric conversion unit to the floating diffusion unit is closed, and the path of the charge from the first photoelectric conversion unit to the second photoelectric conversion unit is opened, and
a third mode in which the path of the charge from the first photoelectric conversion unit to the floating diffusion unit is opened.
18 . The solid-state imaging device according to claim 17 , further comprising a second pixel separation groove provided to penetrate through the first semiconductor substrate,
wherein the second pixel separation groove is provided to surround at least the first and second photoelectric conversion units in a plan view.
19 . The solid-state imaging device according to claim 18 , further comprising a second semiconductor substrate that is provided to face a first interlayer insulating film provided on a surface of the first semiconductor substrate on a side opposite to a light incident surface,
wherein the second semiconductor substrate includes at least a part of a pixel transistor other than the transfer transistors.
20 . The solid-state imaging device according to claim 17 ,
wherein, in the second mode, the path of the charge from the first photoelectric conversion unit to the second photoelectric conversion unit is opened via a region under the first pixel separation groove.