Solid-state imaging device and manufacturing method thereof

A manufacturing method of a solid-state imaging device comprising:

• forming a second conductivity type fifth impurity region in a first conductivity type semiconductor layer by forming a photoresist on the semiconductor layer and implanting a second conductivity type impurity ion in a first direction using the photoresist as a mask;
• forming a first conductivity type second impurity region in the semiconductor layer on a surface side of the semiconductor layer so as to be in contact with the fifth impurity region by implanting a first conductivity type impurity ion in a second direction using the photoresist as a mask;
• removing the photoresist;
• forming a second conductivity type third impurity region under the second impurity region in the fifth impurity region on a surface side of the fifth impurity region;
• forming a gate insulating film on the semiconductor layer;
• forming a gate electrode on the gate insulating film;
• forming a first conductivity type first impurity region in the semiconductor layer so as to be outside the gate electrode and start from the first end portion of the gate electrode in plan view by implanting a first conductivity type impurity ion using the gate electrode as a mask, the first end portion of the gate electrode serving as a first mask end portion;
• and
• forming a second conductivity type fourth impurity region in the semiconductor layer that is located in the semiconductor layer and includes a portion that is under a second end portion of the gate electrode by implanting a second conductivity type impurity ion using the gate electrode as a mask, the second end portion of the gate electrode serving as a second mask end portion,
• wherein the second impurity region is in contact with the first impurity region and is formed in the semiconductor layer so as to extend under the gate electrode from a first end portion side,
• the first impurity region, the second impurity region, the fifth impurity region, and the semiconductor layer are located in the stated order from the outside of the gate electrode on the first end portion side toward the second end portion of the gate electrode in plan view,
• the fifth impurity region is located so as to extend under the first impurity region and the third impurity region and surround the third impurity region in plan view,
• impurity concentration in the first impurity region, the second impurity region, and the semiconductor layer decreases in the stated order, and impurity concentration in the fifth impurity region is lower than that of the third impurity region,
• the first direction is a direction inclined relative to a vertical direction to a surface of the semiconductor layer, and
• the second direction is a direction closer to the vertical direction than the first direction is.

A manufacturing method of a solid-state imaging device comprising:

• forming a second conductivity type fifth impurity region in a first conductivity type semiconductor layer,
• forming a second conductivity type third impurity region in the semiconductor layer so as to have a smaller depth than the fifth impurity region,
• forming a gate insulating film on the semiconductor layer;
• forming a gate electrode on the gate insulating film;
• forming a first conductivity type second impurity region in the semiconductor layer by implanting a first conductivity type impurity ion in a first direction using the gate electrode as a mask, a first end portion of the gate electrode serving as a first mask end portion;
• forming a first conductivity type first impurity region that is located in the semiconductor layer so as to be outside the gate electrode and start from a first end portion of the gate electrode in plan view by implanting a first conductivity type impurity ion in a second direction using the gate electrode as a mask, the first end portion of the gate electrode serving as the first mask end portion;
• and
• forming a second conductivity type fourth impurity region in the semiconductor layer that is located in the semiconductor layer and includes a portion that is under a second end portion of the gate electrode by implanting a second conductivity type impurity ion using the gate electrode as a mask, a second end portion of the gate electrode serving as a second mask end portion,
• wherein the second impurity region is in contact with the first impurity region and is formed in the semiconductor layer so as to extend under the gate electrode from the first end portion side,
• the first impurity region, the second impurity region, the fifth impurity region, and the semiconductor layer are located in the stated order from the outside of the gate electrode on the first end portion side toward the second end portion of the gate electrode in plan view,
• the fifth impurity region is located so as to extend under the first impurity region and the third impurity region and surround the third impurity region in plan view,
• impurity concentration in the first impurity region, the second impurity region, and the semiconductor layer decreases in the stated order, and impurity concentration in the fifth impurity region is lower than that of the third impurity region,
• the first direction is a direction inclined relative to a vertical direction to a surface of the semiconductor layer, and
• the second direction is a direction closer to the vertical direction than the first direction is.