Solid state imaging device

Abstract

A solid-state imaging device having an arrangement in which well contact is achieved for each pixel is provided. In the solid-state imaging device, a well contact part is formed in an activation region of a photoelectric conversion portion. The well contact part fixes a well in which the photoelectric conversion portion and transistors of the pixel are provided at a predetermined potential.

What is claimed is: 
     
       1. A solid-state imaging device comprising:
 a pixel array area including pixels arranged in second conductivity type well regions in a two-dimensional array fashion, each of the pixels including: a photoelectric conversion portion including an activation region; and 
 a first impurity region of a first conductivity type and a second impurity region of a second conductivity type provided over the first impurity region;  
 well potential fixing parts for fixing the second conductivity type well regions at a predetermined potential; 
 wherein the photoelectric conversion portion includes a first impurity region of a first conductivity type and a second impurity region of a second conductivity type provided over the first impurity region, and
 wherein the well potential fixing parts have an activation region connected each connect to a metal wiring from an upper portion of the second conductivity type well region and a third impurity region of second conductivity type, wherein: 
 
 the photoelectric conversion portion includes a first impurity region of a first conductivity type and a second impurity region of a second conductivity type provided on the first impurity region and the well potential fixing parts are located in a part of a corresponding photoelectric conversion portion; and 
 each of the well potential fixing parts includes an impurity region of the second conductivity type whose density is higher than the second impurity region. 
 
     
     
       2. The solid-state imaging device according to claim 1, wherein each of the pixels further includes at least one or more transistors for transferring an image signal produced by the photoelectric conversion portion to an external device.  
     
     
       3. The solid-state imaging device according to claim 1, wherein each of the pixels further includes at least one or more transistors for amplifying an image signal produced by the photoelectric conversion portion.  
     
     
       4. The solid-state imaging device according to claim 1, wherein each of the well potential fixing parts is provided in a position among the pixels.  
     
     
       5. The solid-state imaging device according to claim 1, further comprising a signal processing area for generating information on the pixel in which the corresponding well potential fixing part is provided in accordance with information on peripheral pixels.  
     
     
       6. The solid-stale imaging device according to claim 5, wherein the peripheral pixels are pixels belonging to the same row as the pixel, pixels belonging to a same column as the pixel, or pixels belonging to the same row and the same column as the pixel.  
     
     
       7. The solid-state imaging device of claim 1, wherein the first impurity region for the photoelectric conversion portion extends continuously from the photoelectric conversion portion to the well potential fixing part for a given pixel.  
     
     
       8. The solid-state imaging device of claim 1, wherein the first impurity region for the photoelectric conversion portion is located between the well potential fixing part for a given pixel and a gate electrode of the reading portion.