Image sensing device including protection device

An image sensing device comprising:

• a plurality of photosensors structured to convert light into electrical signals;
• a plurality of transistors structured to perform operations associated with the plurality of photosensors;
• and
• a plurality of protection devices structured to carry electric charges accumulated in the transistors by connecting to gates of the transistors,
• wherein the protection device includes:
• a contact portion doped with P-type impurities;
• a first well doped with the P-type impurities, and formed below the contact portion;
• a second well doped with N-type impurities, and formed to contact the first well by surrounding the first well;
• and
• a first deep well doped with the N-type impurities, and formed below the second well,
• wherein:
• the first deep well is formed between the semiconductor substrate and the first well;
• and
• each of the first well and the second well is doped with a lower density than the contact portion.

An image sensing device comprising:

• a plurality of photosensors structured to convert light into electric charges;
• a plurality of first devices structured to accumulate the electric charges generated by plurality of photosensors;
• and
• a plurality of second devices structured to carry the electric charges accumulated in the plurality of first devices,
• wherein each of the plurality of second devices includes:
• a first region doped with a first type of conductive impurities;
• a second region doped with a second type of conductive impurities and surrounding the first region;
• and
• a third region doped with the first type of conductive impurities and surrounding the second region,
• wherein the first region includes a contact portion and a first well located below the contact portion, and
• wherein the contact portion has a higher doping density than the first well, and is coupled to any one of the plurality of first devices.