MOS type solid-state imager and manufacturing method thereof
AssigneeKabushiki Kaisha Toshiba
InventorHiroaki Ishiwata
Life of this patent
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Abstract
A photodiode and a read gate are formed within an element region. A p+ type punch-through preventing region is not formed immediately under an n-type signal accumulating region of a photodiode. The n-type signal accumulating region is formed within a p-type semiconductor substrate. The p+ type punch-through preventing region is formed over the entire element region. The p+ type punch-through preventing region is also formed immediately under an insulative isolation layer in order to prevent punch-through between elements. A p+ type punch-through stopper is formed immediately under an n-type first semiconductor region.
Claims14
A MOS type solid-state imager comprising:
- a photoelectric conversion element formed in a semiconductor substrate of a first conductive type;
- a first MOS transistor of a second conductive type formed in a first element region of the semiconductor substrate for reading out a charge generated by the photoelectric conversion element;
- a second MOS transistor of the second conductive type formed in a second element region of the semiconductor substrate;
- an insulative isolation layer surrounding the first and second element regions;
- and
- a punch-through preventing region of the first conductive type for preventing punch-through, said punch-through preventing region being formed in a surface area of the second element region as well as being formed immediately under the insulative isolation layer,
- wherein a bottom surface of the punch-through preventing region of the second element region is deeper than a bottom surface of the punch-through preventing region formed immediately under the insulative isolation layer.
A MOS type solid-state imager comprising:
- a photoelectric conversion element formed in a semiconductor substrate of a first conductive type;
- a first MOS transistor of a second conductive type formed in a first element region of the semiconductor substrate for reading out a charge generated by the photoelectric conversion element;
- a second MOS transistor of the second conductive type formed in a second element region of the semiconductor substrate;
- and
- a punch-through preventing region of the first conductive type formed in a surface area of the second element region for preventing punch-through,
- wherein a depth of the punch-through preventing region of the second element region is set at between 0.2 μm or more and 0.4 μm or less.
Dependencies are inferred from the claim text.