Solid-state image pickup device and method of driving the same

Abstract

Imaging sensors, imaging apparatuses, and methods of driving an image sensor are provided. An image sensor can include a semiconductor substrate with a photoelectric conversion element and a charge-conversion element. The sensor can further include a capacitance switch. A charge accumulation element is located adjacent the photoelectric conversion element. At least a portion of the charge accumulation element overlaps a charge accumulation region of the photoelectric conversion element. The charge accumulation element is selectively connected to the charge-voltage conversion element by the capacitance switch.

What is claimed is: 
     
         1 . A light detecting device, comprising:
 a semiconductor substrate including:   a plurality of photoelectric conversion elements formed in a semiconductor substrate, which includes a first photoelectric conversion element configured to receive light from a first surface of the semiconductor substrate;   a floating diffusion region configured to receive a first electric charge from the first photoelectric conversion element through a first transfer transistor; and   a wiring layer disposed over a second surface of the semiconductor substrate, the wiring layer including a first charge accumulation element selectively coupled to the floating diffusion region,   wherein the second surface is opposed to the first surface.   
     
     
         2 . The light detecting device of  claim 1 , wherein the first photoelectric conversion element is between an on-chip lens and the wiring layer. 
     
     
         3 . The light detecting device of  claim 1 , wherein at least a part of the first charge accumulation element overlaps the first photoelectric conversion element. 
     
     
         4 . The light detecting device of  claim 1 , further comprising a switch transistor coupled to the floating diffusion region and the first charge accumulation element. 
     
     
         5 . The light detecting device of  claim 4 , wherein
 the charge accumulation element includes:
 a first electrode coupled to the switch transistor; and 
 a second electrode coupled to a wiring. 
   
     
     
         6 . The light detecting device of  claim 5 , wherein the wiring configured to receive a ground potential. 
     
     
         7 . The light detecting device of  claim 5 , wherein the floating diffusion region is selectively coupled to the first electrode via the switch transistor. 
     
     
         8 . The light detecting device of  claim 4 , further comprising a reset transistor coupled to the switch transistor. 
     
     
         9 . The light detecting device of  claim 8 , wherein a source of the reset transistor and one of a drain or a source of the switch transistor are in a common region. 
     
     
         10 . The light detecting device of  claim 1 , further comprising
 an amplifier transistor coupled to the floating diffusion region.