Image sensor

An image sensor comprising:

• a substrate having a first surface on which light is incident and a second surface opposite to the first surface;
• a pixel isolation structure in a deep trench, which defines a pixel region in the substrate, the pixel isolation structure having a first surface and a second surface opposite to the first surface;
• a photoelectric conversion region in the pixel region;
• and
• a device isolation layer provided in first and second shallow trenches and defining a pattern in the pixel region,
• wherein the first surface of the pixel isolation structure is coplanar with the first surface of the substrate and the second surface of the pixel isolation structure is coplanar with the second surface of the substrate,
• wherein the first shallow trench is recessed into the substrate from the second surface of the substrate to a first depth in a vertical direction perpendicular to the first surface of the substrate, and connected to the deep trench,
• wherein the second shallow trench is recessed into the substrate from the second surface of the substrate to a second depth in the vertical direction, and connected to the first shallow trench, and
• wherein the first depth is greater than the second depth.

An image sensor comprising:

• a substrate having a first surface and a second surface opposite to each other;
• a micro lens on the first surface of the substrate;
• a pixel isolation structure in a deep trench, which defines a pixel region in the substrate, the pixel isolation structure having a first surface and a second surface opposite to the first surface;
• a photoelectric conversion region in the pixel region;
• a first doped region contacting the pixel isolation structure in the pixel region;
• a device isolation layer provided in first and second shallow trenches and defining a pattern in the pixel region;
• and
• a second doped region in the pattern,
• wherein the first surface of the pixel isolation structure is coplanar with the first surface of the substrate and the second surface of the pixel isolation structure is coplanar with the second surface of the substrate,
• wherein impurities in the first doped region have a different conductivity type from that of impurities in the second doped region,
• wherein the first shallow trench is recessed into the substrate from the second surface of the substrate to a first depth in a vertical direction perpendicular to the first surface of the substrate, and connected to the deep trench,
• wherein the second shallow trench is recessed into the substrate from the second surface of the substrate to a second depth in the vertical direction, and connected to the first shallow trench,
• wherein the first shallow trench is above the first doped region, and
• wherein the first depth is greater than the second depth.