Patent ID: 11955496
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 17:
18. An image sensor, comprising:
photodiodes for a plurality of pixel regions disposed from a front-side of an image sensing die, a photodiode comprising 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 doped isolation well disposed from the front-side of the image sensing die by implanting dopants into the photodiode doping layer through a plurality of implanting processes;
a gate structure and a metallization stack disposed on the front-side of the image sensing die, wherein the metallization stack comprises a plurality of metal interconnect layers arranged within one or more inter-level dielectric layers;
a logic die bonded to the image sensing die from the front-side of the image sensing die, wherein the logic die comprises logic devices; and
a back-side deep trench isolation (BDTI) structure comprising a deep trench from a back-side of the image sensing die between adjacent pixel regions, a doped liner with the second doping type lining a sidewall surface of the deep trench and a dielectric fill layer filling an inner space of the deep trench,
wherein the doped liner is formed under a protection layer followed by removing the protection layer prior to forming the dielectric fill layer, such that the doped liner is formed with a thickness smaller than 5 nm.