Image sensor

An image sensor, comprising:

• a substrate including a first surface and a second surface, which are opposite to each other;
• an isolation pattern provided in the substrate to define a pixel region, the pixel region comprising an active region adjacent to the second surface, the active region comprising a source region and a drain region;
• a color filter on the first surface of the substrate;
• a micro lens on the color filter;
• a device isolation pattern provided on the second surface of the substrate to define the active region;
• a source follower gate pattern on the active region;
• and
• an interconnection line provided on the source follower gate pattern and electrically connected to the source follower gate pattern,
• wherein the source follower gate pattern comprises a body portion and a buried portion, which buried portion extends from the body portion into the substrate, and
• wherein the buried portion is disposed to be closer to the drain region than to the source region.

An image sensor, comprising:

• a circuit chip;
• and
• a sensor chip stacked on the circuit chip and electrically connected to the circuit chip,
• wherein the sensor chip comprises:
• a first substrate including a first surface and a second surface, which are opposite to each other;
• an isolation pattern defining a pixel region in the first substrate, the pixel region comprising an active region adjacent to the second surface;
• a color filter on the first surface of the first substrate;
• a micro lens on the color filter;
• a source follower gate pattern on the active region;
• and
• a first interconnection layer on the second surface,
• wherein:
• the first interconnection layer comprises an interconnection line electrically connected to the source follower gate pattern,
• the source follower gate pattern comprises a body portion, which is provided on the second surface, and a buried portion, which extends from the body portion into the first substrate,
• the active region comprises a drain region, which is adjacent to a first side surface of the source follower gate pattern, and a source region, which is adjacent to a second side surface of the source follower gate pattern, and
• the buried portion is disposed to be closer to the first side surface than to the second side surface.