US 12,439,714 B2
3D CMOS image sensor structure and method of fabricating the same
Chih-Ping Chung, Hsinchu (TW); Ming-Yu Ho, Taichung (TW); and Saysamone Pittikoun, Hsinchu County (TW)
Assigned to Powerchip Semiconductor Manufacturing Corporation, Hsinchu (TW)
Filed by Powerchip Semiconductor Manufacturing Corporation, Hsinchu (TW)
Filed on Jan. 3, 2023, as Appl. No. 18/092,450.
Claims priority of application No. 111132684 (TW), filed on Aug. 30, 2022.
Prior Publication US 2024/0072083 A1, Feb. 29, 2024
Int. Cl. H10F 39/00 (2025.01); H10F 39/18 (2025.01)
CPC H10F 39/80377 (2025.01) [H10F 39/014 (2025.01); H10F 39/024 (2025.01); H10F 39/026 (2025.01); H10F 39/182 (2025.01); H10F 39/805 (2025.01); H10F 39/8053 (2025.01); H10F 39/8057 (2025.01); H10F 39/8063 (2025.01); H10F 39/807 (2025.01)] 10 Claims
OG exemplary drawing
 
1. A 3D CMOS image sensor structure, comprising:
a semiconductor substrate with a front surface and a back surface;
a photodiode formed in said semiconductor substrate;
a well formed in said semiconductor substrate, and said well partially overlaps said photodiode in a direction vertical to said front surface;
a shallow trench isolation layer formed on said front surface;
a fin protruding upwardly on said front surface from said semiconductor substrate through said shallow trench isolation layer, wherein said fin is composed of said photodiode and said well, and a photodiode portion of said fin horizontally and directly connects a well portion of said fin;
a first gate on said shallow trench isolation layer and spanning both said photodiode portion of said fin and said well portion of said fin abutting said photodiode to constitute a transfer transistor;
a second gate on said shallow trench isolation layer and spanning only said well portion of said fin to constitute a reset transistor; and
a floating diffusion region in said well portion of said fin between said first gate and said second gate, wherein said transfer transistor is electrically connected with said reset transistor through said floating diffusion region.