US 12,439,709 B2
Image sensor with diffusion barrier structure
Yu-Hung Cheng, Tainan (TW); Ching I Li, Tainan (TW); Chen-Hao Chiang, Jhongli (TW); Eugene I-Chun Chen, Taipei (TW); and Chin-Chia Kuo, Tainan (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed on Feb. 25, 2022, as Appl. No. 17/680,987.
Claims priority of provisional application 63/227,363, filed on Jul. 30, 2021.
Prior Publication US 2023/0033270 A1, Feb. 2, 2023
Int. Cl. H10F 39/12 (2025.01); H10F 39/00 (2025.01)
CPC H10F 39/199 (2025.01) [H10F 39/026 (2025.01); H10F 39/802 (2025.01)] 20 Claims
OG exemplary drawing
 
1. A method for forming an integrated chip, the method comprising:
depositing a base semiconductor layer over a substrate;
depositing a backside semiconductor layer over the base semiconductor layer, wherein the backside semiconductor layer has a first doping type;
forming a diffusion barrier structure over the backside semiconductor layer;
depositing a sensor semiconductor layer over the diffusion barrier structure, wherein the sensor semiconductor layer has the first doping type;
forming a photodetector in the sensor semiconductor layer; and
removing the base semiconductor layer and the substrate from along the backside semiconductor layer,
wherein the sensor semiconductor layer is doped with a first dopant and the backside semiconductor layer is doped with a second dopant, and wherein forming the diffusion barrier structure comprises depositing a plurality of diffusion barrier layers with a plurality of spacer layers arranged therebetween in an alternating fashion, the plurality of diffusion barrier layers comprising a semiconductor doped with a third dopant different from the first dopant and the second dopant.