Solid-state imaging apparatus for converting incident light entered from one surface into electrical signals on another surface

A solid-state imaging apparatus comprising:

• a photoelectric conversion element to generate a signal charge by photoelectric conversion of incident light;
• and
• a transfer transistor to transfer the signal charge generated by the photoelectric conversion element to an outside of the photoelectric conversion element, the solid-state imaging apparatus converting, and outputting, the signal charge generated by the photoelectric conversion element into an image signal by signal processing, the solid-state imaging apparatus comprising:
• a semiconductor region on a first main surface side of a first conductivity type semiconductor substrate and separated by an element separation region,
• wherein a plurality of the photoelectric conversion elements and the transfer transistors are in the semiconductor region, wherein
• the photoelectric conversion element includes:
• a second conductive type photoelectric conversion region to photoelectrically convert incident light on a second main surface of the first conductivity type semiconductor substrate on an opposite side of the first main surface;
• a second conductivity type electric charge accumulating region to accumulate a signal charge generated by photoelectric conversion in the second conductivity type photoelectric conversion region, on to the first main surface side of the first conductivity type semiconductor substrate;
• and
• a first conductivity type front surface semiconductor region on the first main surface side of the second conductivity type electric charge accumulating region to entirely cover the second conductivity type electric charge accumulating region,
• the semiconductor region separated by the element separation region includes:
• a second conductivity type signal charge accumulating section to accumulate the signal charge transferred from the photoelectric conversion element;
• and
• a first conductivity type electric charge transferring region to transfer the signal charge from the second conductivity type electric charge accumulating region to the second conductivity type signal charge accumulating section,
• the second conductivity type electric charge accumulating region and the first conductivity type electric charge transferring region are on the second conductivity type photoelectric conversion region,
• the second conductivity type electric charge accumulating region and the first conductivity type front surface semiconductor region have a same width in a sectional view and a same area in a plan view,
• an impurity concentration of the first conductivity type front surface semiconductor region is 1×1016cm−3to 5×1017 cm−3,
• a lateral end of the second conductivity type electric charge accumulating region and a lateral end of the first conductivity type front surface semiconductor region directly contact the first conductivity type electric charge transferring region,
• the impurity concentration of the first conductivity type front surface semiconductor region exceeds an impurity concentration of the first conductivity type electric charge transferring region, and
• a gate electrode of the transfer transistor entirely covers a surface of the first main surface side of the first conductivity type front surface semiconductor region, a surface of the first main surface side of a region between adjacent photoelectric conversion elements, and a region between the photoelectric conversion element and the element separation region, in the semiconductor region.