SOLID-STATE IMAGE PICKUP DEVICE, METHOD OF MANUFACTURING SOLID-STATE IMAGE PICKUP DEVICE, AND ELECTRONIC APPARATUS
There is provided a solid-state image pickup device including: a semiconductor substrate; a photodiode formed in the semiconductor substrate; a transistor having a gate electrode part or all of which is embedded in the semiconductor substrate, the transistor being configured to read a signal electric charge from the photodiode via the gate electrode; and an electric charge transfer layer provided between the gate electrode and the photodiode.
1 . A light detecting device, comprising:
a first photodiode formed in a semiconductor substrate;
a floating diffusion disposed in the semiconductor substrate; and
a gate electrode configured to transfer a signal electric charge from the first photodiode to the floating diffusion, at least a portion of the gate electrode being embedded in the semiconductor substrate, wherein all the first photodiode is disposed below a bottom of the portion of the gate electrode.
2 . The light detecting device according to claim 1 , wherein the semiconductor substrate comprises a light incident surface, and wherein all of the first photodiode is disposed between the bottom of the portion of the gate electrode and the light incident surface.
3 . The light detecting device according to claim 1 , wherein the portion of the gate electrode overlaps the first photodiode in a plan view.
4 . The light detecting device according to claim 1 , further comprising an electric charge transfer layer disposed in the semiconductor substrate, wherein a portion of the electric charge transfer layer is disposed between the first photodiode and the bottom of the portion of the gate electrode.
5 . The light detecting device according to claim 4 , wherein the electric charge transfer layer is in contact with the first photodiode.
6 . The light detecting device according to claim 1 , further comprising:
a second photodiode, wherein the first photodiode is formed at a first depth in the semiconductor substrate and the second photodiode is formed at a second depth in the semiconductor substrate and overlaps with the first photodiode, wherein the first photodiode at the first depth is closer to a light receiving surface of the semiconductor substrate than the second photodiode at the second depth.
7 . The light detecting device according to claim 1 , wherein the portion of the gate electrode fills a concave section in the semiconductor substrate.
8 . The light detecting device according to claim 7 , further comprising an electric charge transfer layer disposed in the semiconductor substrate, wherein the electric charge transfer layer is adjacent to and self-aligned with a bottom face of the concave section so that the electric charge transfer layer covers the bottom face but not side faces of the concave section.
9 . The light detecting device according to claim 8 , wherein the electric charge transfer layer is formed by ion implantation through the bottom face of the concave section.
10 . The light detecting device according to claim 1 , further comprising:
an electric charge transfer layer between the first photodiode and the portion of the gate electrode; and
a dark current suppression layer of a different conductivity type than the electric charge transfer layer and between the portion of the gate electrode and the electric charge transfer layer.
11 . An electronic apparatus, comprising:
a lens;
a signal process circuit; and
a light detecting device, comprising:
a first photodiode formed in a semiconductor substrate;
a floating diffusion disposed in the semiconductor substrate; and
a gate electrode configured to transfer a signal electric charge from the first photodiode to the floating diffusion, at least a portion of the gate electrode being embedded in the semiconductor substrate, wherein all of the first photodiode is disposed below a bottom of the portion of the gate electrode.
12 . The electronic apparatus according to claim 11 , wherein the semiconductor substrate comprises a light incident surface, and wherein all of the first photodiode is disposed between the bottom of the portion of the gate electrode and the light incident surface.
13 . The electronic apparatus according to claim 11 , wherein the portion of the gate electrode overlaps the first photodiode in a plan view.
14 . The electronic apparatus according to claim 11 , further comprising an electric charge transfer layer disposed in the semiconductor substrate, wherein a portion of the electric charge transfer layer is disposed between the first photodiode and the bottom of the portion of the gate electrode.
15 . The electronic apparatus according to claim 14 , wherein the electric charge transfer layer is in contact with the first photodiode.
16 . The electronic apparatus according to claim 11 , further comprising:
a second photodiode, wherein the first photodiode is formed at a first depth in the semiconductor substrate and the second photodiode is formed at a second depth in the semiconductor substrate and overlaps with the first photodiode, wherein the first photodiode at the first depth is closer to a light receiving surface of the semiconductor substrate than the second photodiode at the second depth.
17 . The electronic apparatus according to claim 11 , wherein the portion of the gate electrode fills a concave section in the semiconductor substrate.
18 . The electronic apparatus according to claim 17 , further comprising an electric charge transfer layer disposed in the semiconductor substrate, wherein the electric charge transfer layer is adjacent to and self-aligned with a bottom face of the concave section so that the electric charge transfer layer covers the bottom face but not side faces of the concave section.
19 . The electronic apparatus according to claim 18 , wherein the electric charge transfer layer is formed by ion implantation through the bottom face of the concave section.
20 . The electronic apparatus according to claim 11 , further comprising:
an electric charge transfer layer disposed in the semiconductor substrate between the first photodiode and the portion of the gate electrode; and
a dark current suppression layer of a different conductivity type than the electric charge transfer layer and disposed in the semiconductor substrate between the portion of the gate electrode and the electric charge transfer layer.