US 12,439,732 B1
Time-of-flight pixel sensor with high modulation contrast
Jiaju Ma, Monrovia, CA (US); and Michael Guidash, Fairport, NY (US)
Assigned to Gigajot Technology, Inc., Pasadena, CA (US)
Filed by Gigajot Technology Inc., Pasadena, CA (US)
Filed on Sep. 25, 2020, as Appl. No. 17/033,248.
Claims priority of provisional application 62/942,532, filed on Dec. 2, 2019.
Claims priority of provisional application 62/905,883, filed on Sep. 25, 2019.
Int. Cl. H01L 31/02 (2006.01); G01S 7/4863 (2020.01); H01L 31/0232 (2014.01); H01L 31/103 (2006.01); H10F 30/221 (2025.01); H10F 77/00 (2025.01); H10F 77/40 (2025.01)
CPC H10F 77/953 (2025.01) [G01S 7/4863 (2013.01); H10F 30/221 (2025.01); H10F 77/413 (2025.01)] 21 Claims
OG exemplary drawing
 
1. A pixel implemented within a time-of-flight sensor, the pixel comprising:
a silicon photoconversion structure to generate photocharge in response to incident light during an exposure interval, wherein the silicon photoconversion structure is surrounded by one or more trench structures;
first and second storage diodes;
first and second modulation gates disposed adjacent the silicon photoconversion structure to generate, throughout the exposure interval, alternating first and second electrostatic fields that compel the photocharge generated within the silicon photoconversion structure to the first and second storage diodes, respectively, wherein the first and second modulation gates are located at least partly above a modulation chamber of the silicon photoconversion structure and extend vertically into the one or more trench structures toward the modulation chamber;
a first readout circuit having a first floating diffusion node and a first transfer gate to enable, upon conclusion of the exposure interval, transfer of accumulated photocharge from the first storage diode to the first floating diffusion node; and
a second readout circuit having a second floating diffusion node and a second transfer gate to enable, upon conclusion of the exposure interval, transfer of accumulated photocharge from the second storage diode to the second floating diffusion node.