Solid-state image sensor, imaging device, and electronic device

Abstract

The present technology relates to a solid-state image sensor, an imaging device, and an electronic device capable of switching FD conversion efficiency in all pixels of a solid-state image sensor. A photodiode performs photoelectric conversion on incident light. A floating diffusion (FD) stores charge obtained by the photodiode. FD2, which is a second FD to which the capacity of an additional capacitor MIM is added, adds the capacity to the FD. The additional capacitor MIM is constituted by a first electrode formed by a wiring layer and a second electrode formed by a metallic light blocking film provided on a surface of a substrate on which the photodiode is formed. Switching between the FD and FD+FD2 allows switching of the FD conversion efficiency. The present technology is applicable to a CMOS image sensor.

What is claimed is: 
     
         1 - 14 . (canceled) 
     
     
         15 . A light detecting device comprising:
 a photoelectric converter configured to generate a charge corresponding to incident light;   a transfer transistor;   a floating diffusion configured to receive the charge via the transfer transistor;   a charge accumulation region;   a switching transistor disposed between the floating diffusion and the charge accumulation region in a first direction, wherein the switching transistor is configured to electrically connect the floating diffusion and the charge accumulation region;   an amplification transistor;   a selection transistor, and   wherein the floating diffusion is connected to a vertical signal line via the amplification transistor and the selection transistor,   wherein the amplification transistor is disposed between the switching transistor and the selection transistor in the first direction,   wherein a gate of the transfer transistor has an elongated shape in a plan view, a long side of the elongated shape extending in the first direction, and   wherein the long side of the elongated shape is longer in the first direction than a length of a region including the floating diffusion, the charge accumulation region and the switching transistor.   
     
     
         16 . The light detecting device of  claim 15 , further comprising a reset transistor connected to the floating diffusion and resetting the floating diffusion to a power supply voltage. 
     
     
         17 . The light detecting device of  claim 15 , wherein the charge accumulation region comprises a first electrode and a second electrode opposed to the first electrode,
 wherein the first electrode is provided in a wiring layer above a surface of a substrate on which the photoelectric converter is formed, wherein the surface is on a light incident side of the substrate, and wherein the second electrode is provided on the surface of the substrate.   
     
     
         18 . The light detecting device of  claim 17 , wherein the second electrode is a light blocking film, wherein a polysilicon gate layer is provided on the surface of the substrate, and wherein the light blocking film covers the polysilicon on the substrate. 
     
     
         19 . The light detecting device of  claim 15 , wherein the floating diffusion, the amplification transistor and the selection transistor are arranged in this order in the first direction. 
     
     
         20 . The light detecting device of  claim 15 , wherein the photoelectric converter and the transfer transistor are arranged in a second direction perpendicular to the first direction. 
     
     
         21 . The light detecting device of  claim 16 , wherein the reset transistor is disposed along the first direction where the floating diffusion, the charge accumulation region and the switching transistor are arranged. 
     
     
         22 . The light detecting device of  claim 21 , wherein the transfer transistor is disposed between the photoelectric converter and a region of the floating diffusion, the charge accumulation region, the switching transistor and the reset transistor in a second direction perpendicular to the first direction. 
     
     
         23 . The light detecting device of  claim 22 , wherein the long side of the elongated shape is longer in the first direction than a length of the region of the floating diffusion, the charge accumulation region, the switching transistor and the reset transistor. 
     
     
         24 . The light detecting device of  claim 15 , wherein the floating diffusion is a charge-to-voltage converter that converts the charge received via the transfer transistor into an electrical signal. 
     
     
         25 . The light detecting device of  claim 15 , further comprising another photoelectric converter adjacent to the photoelectric converter, wherein the photoelectric converters are arranged in the first direction. 
     
     
         26 . The light detecting device of  claim 15 , further comprising another transfer transistor adjacent to the transfer transistor, wherein the transfer transistors are arranged in the first direction. 
     
     
         27 . A light detecting device comprising:
 a photoelectric converter configured to generate a charge corresponding to an incident light;   a floating diffusion;   a transfer transistor disposed between the photoelectric converter and the floating diffusion and transferring the charge from the photoelectric converter to the floating diffusion, wherein a gate of the transfer transistor has two short sides and two long sides;   a charge accumulation region;   a switching transistor disposed between the floating diffusion and the charge accumulation region, wherein the switching transistor is configured to electrically connect the floating diffusion and the charge accumulation region; and   a reset transistor connected to the floating diffusion and resetting the floating diffusion to a power supply voltage,   wherein the charge accumulation region, the switching transistor and the floating diffusion are arranged in this order and along a line that is parallel to one of the long sides of the gate of transfer transistor, and   wherein the length of the long side is longer than a length of a region including the floating diffusion, the charge accumulation region, the reset transistor and the switching transistor.   
     
     
         28 . The light detecting device of  claim 27 , wherein the charge accumulation region comprises a first electrode and a second electrode opposed to the first electrode, wherein the first electrode is provided in a wiring layer above a surface of a substrate on which the photoelectric converter is formed, wherein the surface is on a light incident side of the substrate, and wherein the second electrode is provided on the surface of the substrate. 
     
     
         29 . The light detecting device of  claim 28 , wherein the second electrode is a light blocking film, wherein a polysilicon gate layer is provided on the surface of the substrate, and wherein the light blocking film covers the polysilicon on the substrate. 
     
     
         30 . The light detecting device of  claim 27 , wherein the transfer transistor is disposed between the photoelectric converter and a region of the floating diffusion, the charge accumulation region, the switching transistor and the reset transistor along a line that is parallel to the short sides of the gate of the transfer transistor. 
     
     
         31 . The light detecting device of  claim 27 , wherein the floating diffusion is a charge-to-voltage converter that converts the charge received via the transfer transistor into an electrical signal. 
     
     
         32 . The light detecting device of  claim 29 , wherein the light blocking film is provided for each pixel having the photoelectric converter, and shields any of an upper portion, a lower portion, a left portion and a right portion of the photoelectric converter only in a pixel for imaging plane phase difference detection. 
     
     
         33 . The light detecting device of  claim 27 , further comprising another photoelectric converter adjacent to the photoelectric converter, wherein the photoelectric converters are arranged in the first direction. 
     
     
         34 . The light detecting device of claim  13 , further comprising another transfer transistor adjacent to the transfer transistor, wherein the transfer transistors are arranged in the first direction.