Solid-state image sensor and camera

A solid-state image sensor including a semiconductor substrate having a first face and a second face opposite to the first face, the solid-state image sensor comprising:

• a plurality of pixel groups each including a plurality of photoelectric converters located in the semiconductor substrate;
• a wiring layer located at a side of the first face of the semiconductor substrate;
• and
• a plurality of microlenses located at a side of the second face of the semiconductor substrate, wherein each of the plurality of microlenses is provided for the plurality of photoelectric converters of a corresponding one of the plurality of pixel groups,
• wherein each of the plurality of photoelectric converters of each of the plurality of pixel groups includes a semiconductor region of a first conductivity type that is configured to accumulate charges generated by photoelectric conversion,
• wherein, in each of the plurality of pixel groups, an impurity concentration of a second conductivity type in a region of the semiconductor substrate that is located between the first face and an end portion of a corresponding microlens of the plurality of microlenses is greater than an impurity concentration of the second conductivity type in a region of the semiconductor substrate that is located between the first face and a center of the corresponding microlens, and
• wherein each of the plurality of pixel groups includes a floating diffusion arranged to overlap with one of the plurality of microlenses in a plan view, a first transfer gate configured to transfer charges from a first photoelectric converter of the plurality of photoelectric converters to the floating diffusion, and a second transfer gate configured to transfer charges from a second photoelectric converter of the plurality of photoelectric converters to the floating diffusion, the floating diffusion being arranged between the first transfer gate and the second transfer gate in the plan view.

A solid-state image sensor including a semiconductor substrate having a first face and a second face opposite to the first face, the solid-state image sensor comprising:

• a plurality of pixel groups each including a plurality of photoelectric converters located in the semiconductor substrate;
• a wiring layer located at a side of the first face of the semiconductor substrate;
• and
• a plurality of microlenses located at a side of the second face of the semiconductor substrate, wherein each of the plurality of microlenses is provided for the plurality of photoelectric converters of a corresponding one of the plurality of pixel groups,
• wherein the plurality of pixel groups includes first, second, and third pixel groups, which are arranged adjacent to each other, and the plurality of microlenses includes first, second, and third microlenses respectively corresponding to the first, second, and third pixel groups,
• wherein the second microlens borders the first microlens, and the third microlens is spaced apart from the first microlens,
• wherein each of the plurality of photoelectric converters of each of the plurality of pixel groups includes a semiconductor region of a first conductivity type that is configured to accumulate charges generated by photoelectric conversion,
• wherein an impurity concentration of a second conductivity type in a region of the semiconductor substrate that is located between the first face and a border between the first microlens and the second microlens is greater than an impurity concentration of the second conductivity type in a region of the semiconductor substrate that is located between the first face and a center of the first microlens, and
• wherein each of the plurality of pixel groups includes a floating diffusion arranged to overlap with one of the plurality of microlenses in a plan view, a first transfer gate configured to transfer charges from a first photoelectric converter of the plurality of photoelectric converters to the floating diffusion, and a second transfer gate configured to transfer charges from a second photoelectric converter of the plurality of photoelectric converters to the floating diffusion, the floating diffusion being arranged between the first transfer gate and the second transfer gate in the plan view.

A solid-state image sensor including a semiconductor substrate having a first face and a second face opposite to the first face, the solid-state image sensor comprising:

• a plurality of pixel groups each including a plurality of photoelectric converters located in the semiconductor substrate and arranged along the second face of the semiconductor substrate, the plurality of photoelectric converters of each of the plurality of pixel groups being arranged so as not to overlap with each other in a plan view;
• a wiring layer located at a side of the first face of the semiconductor substrate;
• and
• a plurality of microlenses located at a side of the second face of the semiconductor substrate, wherein each of the plurality of microlenses is provided for the plurality of photoelectric converters of a corresponding one of the plurality of pixel groups,
• wherein each of the plurality of pixel groups includes a floating diffusion arranged to overlap with one of the plurality of microlenses in the plan view, a first transfer gate configured to transfer charges from a first photoelectric converter of the plurality of photoelectric converters to the floating diffusion, and a second transfer gate configured to transfer charges from a second photoelectric converter of the plurality of photoelectric converters to the floating diffusion, the floating diffusion being arranged between the first transfer gate and the second transfer gate in the plan view.

A solid-state image sensor including a semiconductor substrate having a first face and a second face opposite to the first face, the solid-state image sensor comprising:

• a plurality of pixel groups each including a plurality of photoelectric converters located in the semiconductor substrate and arranged along the second face of the semiconductor substrate, each of the plurality of photoelectric converters of each of the plurality of the pixel groups including a first semiconductor region having a first conductivity type, and a second semiconductor region arranged between the first semiconductor region and the second face and having the first conductivity type, impurity concentration of the first conductivity type of the second semiconductor region being lower than that of the first semiconductor region, the second semiconductor regions of the plurality of photoelectric converters of each of the plurality of the pixel groups being arranged in the same depth from the first face;
• a wiring layer located at a side of the first face of the semiconductor substrate;
• and
• a plurality of microlenses located at a side of the second face of the semiconductor substrate, wherein each of the plurality of microlenses is provided for the plurality of photoelectric converters of a corresponding one of the plurality of pixel groups,
• wherein the plurality of pixel groups includes first, second, and third pixel groups, which are arranged adjacent to each other, and the plurality of microlenses includes first, second, and third microlenses respectively corresponding to the first, second, and third pixel groups, and
• wherein the second microlens borders the first microlens, and the third microlens is spaced apart from the first microlens.