US 12,284,837 B2
Backside illuminated image sensor and manufacturing method thereof
Jun-Ming Su, Hsinchu (TW); Chih-Ping Chung, Hsinchu (TW); and Ming-Yu Ho, Taichung (TW)
Assigned to Powerchip Semiconductor Manufacturing Corporation, Hsinchu (TW)
Filed by Powerchip Semiconductor Manufacturing Corporation, Hsinchu (TW)
Filed on May 7, 2024, as Appl. No. 18/656,610.
Application 18/656,610 is a division of application No. 17/458,586, filed on Aug. 27, 2021, granted, now 12,040,343.
Claims priority of application No. 110128572 (TW), filed on Aug. 3, 2021.
Prior Publication US 2024/0290815 A1, Aug. 29, 2024
Int. Cl. H10F 39/00 (2025.01); H10F 39/12 (2025.01)
CPC H10F 39/199 (2025.01) [H10F 39/014 (2025.01); H10F 39/8033 (2025.01); H10F 39/80373 (2025.01); H10F 39/8053 (2025.01); H10F 39/8063 (2025.01)] 9 Claims
OG exemplary drawing
 
1. A backside illuminated image sensor, comprising:
a semiconductor layer, having a first surface and a second surface opposite to each other;
a first gate structure, disposed on the second surface;
a light sensing device, located in the semiconductor layer, wherein the light sensing device extends from the first surface to the second surface, the light sensing device has a third surface and a fourth surface, the third surface overlaps with the first surface, the fourth surface overlaps with the second surface, and
the light sensing device comprises:
a first doped region, located in the semiconductor layer; and
a second doped region, located in the semiconductor layer, wherein the second doped region is connected to the first doped region, the semiconductor layer is of a first conductivity type, the first doped region and the second doped region are of a second conductivity type, the first doped region is closer to the first surface than the second doped region, and the second doped region is closer to the second surface than the first doped region; and
a second gate structure, located on the second surface, wherein the first gate structure is located between the second gate structure and the fourth surface,
the first gate structure completely overlaps with the first doped region, and
the second gate structure completely overlaps with the first doped region.