Photoelectric conversion device, method for producing photoelectric conversion device, and image pickup system

A photoelectric conversion device comprising:

• a pixel region that includes a plurality of pixels, each pixel including a photoelectric conversion element, an amplifying MOS transistor configured to amplify a signal in response to electric charges of said photoelectric conversion element, and a reset MOS transistor electrically connected to a gate of said amplifying MOS transistor;
• and
• a peripheral circuit region arranged outside of said pixel region, said peripheral circuit region including a plurality of MOS transistors configured to at least one of:
• drive said reset MOS transistors and amplify the signals read from said pixel region, said pixel region and said peripheral circuit region being located on a same semiconductor substrate,
• wherein a drain region of each of said reset MOS transistors includes a first region that is in direct contact with a conductor and a second region that is located between said first region and a channel of said reset MOS transistor, at least one of said MOS transistors arranged in said peripheral circuit region includes a drain having a third region that is in direct contact with a conductor and a fourth region that is located between said third region and a channel of said at least one MOS transistor arranged in said peripheral circuit region, and said fourth region includes a first subregion adjacent to said channel of said at least one MOS transistor arranged in said peripheral circuit region, and a second subregion located between said first subregion and said third region,
• wherein an impurity concentration in said second region is lower than an impurity concentration in said second subregion, and
• wherein a side spacer is disposed on a side wall of a gate electrode of each of said MOS transistors arranged in said peripheral circuit region, and no side spacer is disposed on a side wall of a source region side and a drain region side of a gate electrode of each of said reset MOS transistors.

A photoelectric conversion device comprising:

• a pixel region that includes a plurality of pixels, each pixel including a photoelectric conversion element, an amplifying MOS transistor configured to amplify a signal in response to electric charges of said photoelectric conversion element, and a reset MOS transistor electrically connected to a gate of said amplifying MOS transistor;
• and
• a peripheral circuit region arranged outside of said pixel region, said peripheral circuit region including a plurality of MOS transistors configured to at least one of:
• drive said reset MOS transistors and amplify the signals read from said pixel region, said pixel region and said peripheral circuit region being located on a same semiconductor substrate,
• wherein a drain region of each of said reset MOS transistors includes a first region that is in direct contact with a conductor and a second region that is located between said first region and a channel of said reset MOS transistor, at least one of said MOS transistors arranged in said peripheral circuit region includes a drain having a third region that is in direct contact with a conductor and a fourth region that is located between said third region and a channel of said at least one MOS transistor arranged in said peripheral circuit region, and said fourth region includes a first subregion adjacent to said channel of said at least one MOS transistor arranged in said peripheral circuit region, and a second subregion located between said first subregion and said third region,
• wherein an impurity concentration in said second region is lower than an impurity concentration in said second subregion,
• wherein a side spacer is disposed on a side wall of a gate electrode of each of said MOS transistors arranged in said peripheral circuit region, and no side spacer is disposed on a side wall of a source region side and a drain region side of a gate electrode of each of said reset MOS transistors, and
• wherein each of said photoelectric conversion elements and said reset MOS transistors are covered with an insulating film comprising a silicon oxide film and a silicon nitride film, and said side spacer of each of said MOS transistors arranged in said peripheral circuit region has a silicon oxide film and a silicon nitride film.

A photoelectric conversion device comprising:

• a pixel region that includes a plurality of pixels, each pixel including a photoelectric conversion element, an amplifying MOS transistor configured to amplify a signal in response to electric charges of said photoelectric conversion element, and a reset MOS transistor electrically connected to a gate of said amplifying MOS transistor;
• and
• a peripheral circuit region arranged outside of said pixel region, said peripheral circuit region including a plurality of MOS transistors configured to at least one of:
• drive said reset MOS transistors and amplify the signals read from said pixel region, said pixel region and said peripheral circuit region being located on a same semiconductor substrate,
• wherein each MOS transistor arranged in said peripheral circuit region includes a drain that has an LDD structure including a first semiconductor region and a second semiconductor region that is closer to a channel of said MOS transistor arranged in said peripheral circuit region than said first semiconductor region, and that has a lower impurity concentration than said first semiconductor region, and a drain region of each of said reset MOS transistors includes a third semiconductor region formed during a same step as that forming said first semiconductor region and a fourth semiconductor region that is in direct contact with a conductor with which a contact hole through an interlayer insulating film disposed on said drain region of said reset MOS transistor is filled, and
• wherein said fourth semiconductor region is formed by introducing an impurity into said contact hole in a self-aligned manner.