US 12,336,306 B2
SPAD structure
Ju Hwan Jung, Seoul (KR); Young Hwan Hyeon, Namyangju-si (KR); Jong Man Kim, Seongnam-si (KR); and Byoung Soo Choi, Suwon-si (KR)
Assigned to DB HiTek Co., Ltd., Bucheon-si (KR)
Filed by DB HITek Co., Ltd., Bucheon-si (KR)
Filed on Aug. 12, 2022, as Appl. No. 17/819,572.
Claims priority of application No. 10-2021-0115550 (KR), filed on Aug. 31, 2021.
Prior Publication US 2023/0066769 A1, Mar. 2, 2023
Int. Cl. H10F 30/225 (2025.01); H10F 39/00 (2025.01)
CPC H10F 30/225 (2025.01) [H10F 39/803 (2025.01); H10F 39/807 (2025.01)] 9 Claims
OG exemplary drawing
 
1. A single-photon avalanche diode (SPAD) structure, comprising a unit pixel comprising:
a substrate having a first conductivity type and a first surface and a second surface facing each other;
a first impurity region having a second conductivity type at the second surface of the substrate;
a second impurity region having a first conductivity type at the second surface of the substrate, the second impurity region surrounding the first impurity region;
a cathode connected to the first impurity region;
an anode connected to the second impurity region; and
an isolation film extending from the first surface and being spaced apart from the second surface of the substrate,
wherein the second impurity region is under the isolation film, and
a lowermost surface of the isolation film is in contact with an uppermost surface of the second impurity region.