BACK-SIDE DEEP TRENCH ISOLATION STRUCTURE FOR IMAGE SENSOR

• Main Authors: Wu, Cheng-Ta, Tu, Yeur-Luen, Tzeng, Kuo-Hwa
• Format: Patent
• Language: English
• Published: 30.11.2023
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

The present disclosure relates to an image sensor having a photodiode surrounded by a back-side deep trench isolation (BDTI) structure, and an associated method of formation. In some embodiments, a plurality of pixel regions is disposed within an image sensing die and respectively comprises a photodiode configured to convert radiation into an electrical signal. The photodiode comprises a photodiode doping column with a first doping type surrounded by a photodiode doping layer with a second doping type that is different than the first doping type. A BDTI structure is disposed between adjacent pixel regions and extending from the back-side of the image sensor die to a position within the photodiode doping layer. The BDTI structure comprises a doped liner with the second doping type and a dielectric fill layer. The doped liner lines a sidewall surface of the dielectric fill layer.