Method for producing a solid state imaging device

A method for producing a solid state imaging device comprising the steps of:

• forming an oxide film on a first principal surface of a semiconductor substrate to define a plurality of cell regions, surrounded by a dielectric isolation layer and spaced from one another, on said first principal surface of said semiconductor substrate;
• forming electrode means, in a gap area among said cell regions, for transferring charges produced below said first principal surface of said semiconductor substrate to a location outside of said cell regions to read said charges;
• covering an area containing said cell regions and said electrode means with a first insulating film;
• removing portions of said oxide film and said first insulating film to uncover said first principal surface within each of said cell regions after covering said area with said first insulating film;
• depositing an electrically conductive material, different from said semiconductor substrate, on said first principal surface after said first principal surface is uncovered to form a plurality of photoelectric conversion layers, each of which is, respectively, located within one of said cell regions;
• covering each area containing said cell regions with a second insulating film having a uniform thickness on each of said photoelectric conversion layers;
• forming, on said second insulating film and without flattening the second insulating film, a plurality of metal reflecting films for reflecting light, passed through said plurality of photoelectric conversion layers from a side of said semiconductor substrate opposite to said first principal surface, back to said photoelectric conversion layers so that an entire reflective surface of each of said metal reflecting films is parallel to and faces one of said photoelectric conversion layers;
• covering said electrode means and said metal reflecting films with a third insulating film;
• flattening a surface of said third insulating film;
• and
• forming metal wiring for driving said electrode means on the surface of said third insulating film to face said metal reflecting films after flattening the surface of the third insulating film.

A method for producing a solid state imaging device comprising the steps of:

• forming an oxide film on a principal surface of a semiconductor substrate to define a plurality of cell regions, surrounded by a dielectric isolation layer and spaced from one another, on said principal surface of said semiconductor substrate;
• forming electrode means, in a gap area among said cell regions, for transferring charges produced below said principal surface of said semiconductor substrate to a location outside of said cell regions for the purpose of reading said charges;
• removing portions of said oxide film to uncover said principal surface within each of said cell regions after forming said electrode means;
• depositing an electrically conductive material, different from said semiconductor substrate, on said principal surface after uncovering the principal surface to form a plurality of photoelectric conversion layers, each of which is, respectively, located within one of said cell regions;
• covering each area containing said cell regions with a first insulating film having a uniform thickness on each of said photoelectric conversion layers;
• forming, on said first insulating film and without flattening the first insulating film, a plurality of metal reflecting films for reflecting light, passed through said plurality of photoelectric conversion layers from a side of said semiconductor substrate opposite to said principal surface, back to said photoelectric conversion layers so that an entire reflective surface of each of said metal reflecting films is parallel to and faces one of said photoelectric conversion layers;
• covering said electrode means and said metal reflecting films with a second insulating film;
• flattening a surface of said second insulting film;
• forming metal wiring for driving said electrode means on the surface of said second insulating film after flattening the surface of said second insulating film;
• and
• forming a metal thin film, for maintaining said metal reflecting films at a common potential so as to prevent nonuniformity and variation in photosensitive characteristics among said photoelectric conversion layers, on the surface of said second insulating film to face said metal reflecting films after flattening the surface of said second insulating film.

A method for producing a solid state imaging device comprising the steps of:

• forming an oxide film on a principal surface of a semiconductor substrate to define a plurality of cell regions, surrounded by a dielectric isolation layer and spaced from one another, on said first principal surface of said semiconductor substrate;
• forming electrode means, in a gap area among the cell regions, for transferring charges produced below said first principal surface of said semiconductor substrate to a location outside of said cell regions for the purpose of reading said charges;
• covering an area containing said cell regions and said electrode means with a first insulating film;
• removing portions of said oxide film and said first insulating film to uncover said first principal surface within each of said cell regions after covering the area with said first insulating film;
• depositing an electrically conductive material, different from said semiconductor substrate, on said first principal surface after it is uncovered to form a plurality of photoelectric conversion layers, each of which is, respectively, located within one of said cell regions;
• covering each area containing said cell regions with a second insulating film having a uniform thickness on each of said photoelectric conversion layers;
• forming, on said second insulating film and without flattening the second insulating film, a plurality of metal reflecting films for reflecting light, passed through said plurality of photoelectric conversion layers from a side of said semiconductor substrate opposite to said first principal surface, back to said photoelectric conversion layers so that an entire reflective surface of each of said metal reflecting films is parallel to and faces one of said photoelectric conversion layers;
• covering said electrode means and said metal reflecting films with a third insulating film;
• flattening a surface of said third insulating film;
• forming metal wiring for driving said electrode means on the surface of said third insulating film after flattening the surface of said third insulating film;
• and
• forming a metal thin film, for maintaining said metal reflecting films at a common potential so as to prevent nonuniformity and variation in photosensitive characteristics among said photoelectric conversion layers, on the surface of said third insulating film to face said metal reflecting films after flattening the surface of said third insulating film.