US 12,191,329 B2
Uniform-bridge-gradient time-of-flight photodiode for image sensor pixel
Robert Daniel McGrath, San Diego, CA (US)
Assigned to Shenzhen Goodix Technology Co., Ltd., Shenzhen (CN)
Filed by Shenzhen Goodix Technology Co., Ltd., Shenzhen (CN)
Filed on Nov. 16, 2021, as Appl. No. 17/527,170.
Prior Publication US 2023/0154947 A1, May 18, 2023
Int. Cl. H01L 27/146 (2006.01); H01L 25/16 (2023.01); H01L 31/0224 (2006.01); H04N 25/705 (2023.01); H04N 25/75 (2023.01); H04N 25/778 (2023.01)
CPC H01L 27/1461 (2013.01) [H01L 25/167 (2013.01); H01L 27/14643 (2013.01); H01L 31/0224 (2013.01); H04N 25/705 (2023.01); H04N 25/75 (2023.01); H04N 25/778 (2023.01)] 20 Claims
OG exemplary drawing
 
1. A uniform-bridge-gradient (UBG) time-of-flight (ToF) photodiode block comprising:
a plurality of taps disposed onto a semiconductor substrate of a first doping type, the plurality of taps comprising at least a first readout tap and a second readout tap, each of the plurality of taps having one of a plurality of transfer gates configured for selective activation by an activation network;
a photodiode region implanted into the semiconductor substrate and comprising:
a photodiode-defining implant of a second doping type complementary to the first doping type implanted to a first implant depth over the photodiode region;
a first bridging implant of the second doping type implanted to a second implant depth over a first portion of the photodiode region that forms a first lateral bridge region across the plurality of taps along an edge of the photodiode region nearest to the plurality of taps; and
a second bridging implant of the second doping type implanted to a third implant depth over a second portion of the photodiode region that forms a second lateral bridge region across the plurality of taps and at least partially overlaps with both the photodiode-defining implant and the first bridging implant, the third implant depth being deeper than both the first implant depth and the second implant depth.