Solid-state imaging device with photoelectric conversion section, method of manufacturing the same, and electronic device with photoelectric conversion section

Abstract

A solid-state imaging device including a semiconductor layer including a photoelectric conversion section receiving incident light and generating a signal charge; and a light absorbing section for absorbing transmitted light transmitted by the photoelectric conversion section and having a longer wavelength than light absorbed by the photoelectric conversion section, the transmitted light being included in the incident light, the light absorbing section being disposed on a side of another surface of the semiconductor layer on an opposite side from one surface of the semiconductor layer, the incident light being made incident on the one surface of the semiconductor layer.

What is claimed is: 
     
         1 . A solid-state imaging device comprising:
 a semiconductor layer including a photoelectric conversion section configured to receive incident light and generate a signal charge; and   a light absorbing section configured to absorb transmitted light transmitted by said photoelectric conversion section and having a longer wavelength than light absorbed by said photoelectric conversion section, the transmitted light being included in said incident light, the light absorbing section being disposed on a side of another surface of the semiconductor layer on an opposite side from one surface of the semiconductor layer, said incident light being made incident on the one surface of the semiconductor layer.   
     
     
         2 . The solid-state imaging device according to  claim 1 , further comprising:
 a pixel transistor configured to output the signal charge generated in said photoelectric conversion section as an electric signal, the pixel transistor being disposed on said other surface of said semiconductor layer; and   a wiring layer covering said pixel transistor on said other surface of said semiconductor layer and including wiring electrically connected to said pixel transistor,   wherein said light absorbing section is disposed so as to be interposed between a part including said photoelectric conversion section in said semiconductor layer and said wiring layer.   
     
     
         3 . The solid-state imaging device according to  claim 2 , wherein:
 said photoelectric conversion section is formed so as to receive light of a visible light component in said incident light, and generate said signal charge, and   said light absorbing section is formed so as to absorb infrared light of the transmitted light transmitted by said photoelectric conversion section.   
     
     
         4 . The solid-state imaging device according to  claim 3 , wherein said light absorbing section includes a Schottky junction that absorbs said infrared light by the Schottky junction. 
     
     
         5 . The solid-state imaging device according to  claim 4 , wherein said Schottky junction of said light absorbing section is formed by joining one of a metallic layer and a metallic silicide layer with said semiconductor layer. 
     
     
         6 . The solid-state imaging device according to  claim 5 , wherein:
 said photoelectric conversion section includes (a) a first impurity region of a first conductivity type, (b) a second impurity region of a second conductivity type different from said first conductivity type, and (c) a third impurity region of the first conductivity type;   said first impurity region, said second impurity region, and said third impurity region are sequentially formed from a side of said one surface to the side of said other surface in said semiconductor layer; and   said Schottky junction of said light absorbing section is formed by joining one of said metallic layer and said metallic silicide layer with said third impurity region.   
     
     
         7 . The solid-state imaging device according to  claim 4 , further comprising an insulating film disposed on said other surface of said semiconductor layer so as to be interposed between said semiconductor layer and said light absorbing section, wherein:
 said light absorbing section includes a semiconductor film disposed such that said insulating film is interposed between said other surface of said semiconductor layer and the semiconductor film, and   said Schottky junction of said light absorbing section is formed by joining one of a metallic layer and a metallic silicide layer with said semiconductor film.   
     
     
         8 . The solid-state imaging device according to  claim 3 , wherein said light absorbing section includes a PN junction, and absorbs said infrared light by the PN junction. 
     
     
         9 . The solid-state imaging device according to  claim 8 , further comprising an insulating film disposed on said other surface of said semiconductor layer so as to be interposed between said semiconductor layer and said light absorbing section, wherein:
 said light absorbing section includes (a) a first semiconductor section of a first conductivity type, the first semiconductor section being disposed such that said insulating film is interposed between said other surface of said semiconductor layer and the first semiconductor section, and (b) a second semiconductor section of a second conductivity type opposite to the conductivity type of said first semiconductor section, the second semiconductor section being disposed such that said insulating film and said first semiconductor section are interposed between said other surface of said semiconductor layer and the second semiconductor section; and   said PN junction of said light absorbing section is formed by joining said first semiconductor section and said second semiconductor section with each other.   
     
     
         10 . The solid-state imaging device according to  claim 9 , wherein:
 said light absorbing section receives said infrared light and generates a signal charge, and   said pixel transistor is disposed so as to further output the signal charge generated in said light absorbing section as an electric signal.   
     
     
         11 . The solid-state imaging device according to  claim 9 , wherein:
 said pixel transistor includes a transfer transistor for transferring the signal charge generated in said photoelectric conversion section to a floating diffusion, and   said light absorbing section includes a part extending so as to cover a gate electrode of said transfer transistor from the part including said photoelectric conversion section at said other surface of said semiconductor layer.   
     
     
         12 . A solid-state imaging device manufacturing method comprising:
 forming a semiconductor layer including a photoelectric conversion section receiving incident light and generating a signal charge; and   forming a light absorbing section for absorbing transmitted light transmitted by said photoelectric conversion section and having a longer wavelength than light absorbed by said photoelectric conversion section, the transmitted light being included in said incident light, the light absorbing section being disposed on a side of another surface of the semiconductor layer on an opposite side from one surface of the semiconductor layer, said incident light being made incident on the one surface of the semiconductor layer.   
     
     
         13 . An electronic device comprising:
 a semiconductor layer including a photoelectric conversion section configured to receive incident light and generate a signal charge; and   a light absorbing section configured to absorb transmitted light transmitted by said photoelectric conversion section and having a longer wavelength than light absorbed by said photoelectric conversion section, the transmitted light being included in said incident light, the light absorbing section being disposed on a side of another surface of the semiconductor layer on an opposite side from one surface of the semiconductor layer, said incident light being made incident on the one surface of the semiconductor layer.