# US 12,192,659 B2 · Solid-state imaging element, imaging device, and method for controlling solid-state imaging element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,192,659 B2 - Document ID: US12192659B2 - Status: Granted - Kind: B2 - Application number: 17/904,316 - Filed: 2020-11-25 - Published: 2023-02-23 - Granted: 2025-01-07 - Earliest claimed: 2020-02-26 - Assignees: Sony Semiconductor Solutions Corporation - Applicants: Sony Semiconductor Solutions Corporation - Inventors: Luonghung Asakura - Web page: https://patentgrep.com/patent/US12192659B2 ## CPC - H04N 25/771: comprising storage means other than floating diffusion - H04N 25/42: by switching between different modes of operation using different resolutions or aspect ratios, e.g. switching between interlaced and non-interlaced mode - H04N 25/77: Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components - H04N 25/778: comprising amplifiers shared between a plurality of pixels, i.e. at least one part of the amplifier must be on the sensor array itself - H10F 39/12: Image sensors - H10F 39/8057: {Optical shielding} - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION ## Abstract PLS resistance is improved in a solid-state imaging element in which all pixels are simultaneously exposed. A front-stage transfer transistor transfers a charge from a photoelectric conversion element to a front-stage charge holding region and a rear-stage charge holding region which have different capacities. A rear-stage transfer transistor transfers the charge from the rear-stage charge holding region to a floating diffusion region. An intermediate transfer transistor transfers a charge, which remains in the front-stage charge holding region after the charge has been transferred from the rear-stage charge holding region to the floating diffusion region, to the floating diffusion region via the front-stage charge holding region. ## Claims ### Claim 1 A solid-state imaging element, comprising: a photoelectric conversion element; a front-stage charge holding region; a rear-stage charge holding region, wherein a capacity of the rear-stage charge holding region is different from a capacity of the front-stage charge holding region; a front-stage transfer transistor configured to transfer a first charge from the photoelectric conversion element to the front-stage charge holding region and the rear-stage charge holding region; a rear-stage transfer transistor configured to transfer the first charge from the rear-stage charge holding region to a floating diffusion region; an intermediate transfer transistor configured to transfer a second charge, which remains in the front-stage charge holding region after the first charge has been transferred from the rear-stage charge holding region to the floating diffusion region, to the floating diffusion region via the front-stage charge holding region; a light-shielding wall configured to prevent the first charge to leak from the photoelectric conversion element to the rear-stage charge holding region; and a signal processing circuit configured to: compare, between a first pixel signal corresponding to an amount of charge transferred from the rear-stage charge holding region and a second pixel signal corresponding to an amount of charge transferred from the front-stage charge holding region and the rear-stage charge holding region, the first pixel signal with a specific threshold; and select one of the first pixel signal or the second pixel signal based on a comparison result. ### Claim 2 (depends on 1) The solid-state imaging element according to claim 1, wherein the front-stage charge holding region and the rear-stage charge holding region are impurity diffusion regions, a polarity of the front-stage charge holding region is same as a polarity of the rear-stage charge holding region, a specific impurity diffusion region is between the front-stage charge holding region and the rear-stage charge holding region, and a polarity of the specific impurity diffusion region is different from the polarity of the front-stage charge holding region and the rear-stage charge holding region. ### Claim 3 (depends on 1) The solid-state imaging element according to claim 1, wherein the front-stage charge holding region and the rear-stage charge holding region are in a same impurity diffusion region. ### Claim 4 (depends on 3) The solid-state imaging element according to claim 3, wherein an impurity concentration in a specific region between the front-stage charge holding region and the rear-stage charge holding region in the same impurity diffusion region is different from an impurity concentration in a vicinity of the specific region. ### Claim 5 (depends on 3) The solid-state imaging element according to claim 3, further comprising an adjustment transistor configured to adjust a height of a potential barrier between the front-stage charge holding region and the rear-stage charge holding region. ### Claim 6 (depends on 1) The solid-state imaging element according to claim 1, further comprising a vertical scanning circuit configured to: control each of the front-stage transfer transistor, the rear-stage transfer transistor, and the intermediate transfer transistor to be turned on or off; turn the front-stage transfer transistor and the intermediate transfer transistor on while the rear-stage transfer transistor is off to transfer the first charge to the front-stage charge holding region and the rear-stage charge holding region; turn the rear-stage transfer transistor on while the front-stage transfer transistor and the intermediate transfer transistor are off to transfer the charge from the rear-stage charge holding region to the floating diffusion region; and turn the intermediate transfer transistor and the rear-stage transfer transistor on to transfer the first charge from the front-stage charge holding region to the floating diffusion region. ### Claim 7 (depends on 1) The solid-state imaging element according to claim 1, further comprising a specific semiconductor substrate, wherein the photoelectric conversion element is on a wired front surface of both surfaces of the specific semiconductor substrate. ### Claim 8 (depends on 1) The solid-state imaging element according to claim 1, further comprising a specific semiconductor substrate, wherein the photoelectric conversion element is on a back surface of a wired front surface of both surfaces of the specific semiconductor substrate. ### Claim 9 (depends on 1) The solid-state imaging element according to claim 1, wherein the photoelectric conversion element includes a first photoelectric conversion element and a second photoelectric conversion element, the front-stage charge holding region includes a first front-stage charge holding region and a second front-stage charge holding region, the rear-stage charge holding region includes a first rear-stage charge holding region and a second rear-stage charge holding region, the front-stage transfer transistor includes a first front-stage transfer transistor and a second front-stage transfer transistor, the intermediate transfer transistor includes a first intermediate transfer transistor and a second intermediate transfer transistor, and the rear-stage transfer transistor includes a first rear-stage transfer transistor and a second rear-stage transfer transistor. ### Claim 10 (depends on 1) The solid-state imaging element according to claim 1, further comprising: a charge discharge transistor configured to discharge the first charge from the photoelectric conversion element; a reset transistor configured to initialize the floating diffusion region; an amplification transistor configured to amplify a signal corresponding to an amount of charge transferred to the floating diffusion region; and a selection transistor configured to output the amplified signal as a pixel signal based on a specific selection signal. ### Claim 11 An imaging device, comprising: a photoelectric conversion element; a front-stage charge holding region; a rear-stage charge holding region, wherein a capacity of the rear-stage charge holding region is different from a capacity of the front-stage charge holding region; a front-stage transfer transistor configured to transfer a first charge from the photoelectric conversion element to the front-stage charge holding region and the rear-stage charge holding region; a rear-stage transfer transistor configured to transfer the first charge from the rear-stage charge holding region to a floating diffusion region; an intermediate transfer transistor configured to transfer a second charge, which remains in the front-stage charge holding region after the first charge has been transferred from the rear-stage charge holding region to the floating diffusion region, to the floating diffusion region via the front-stage charge holding region; a light-shielding wall configured to prevent the first charge to leak from the photoelectric conversion element to the rear-stage charge holding region; and a signal processing circuit configured to: compare, between a first pixel signal corresponding to an amount of charge transferred from the rear-stage charge holding region and a second pixel signal corresponding to an amount of charge transferred from the front-stage charge holding region and the rear-stage charge holding region, the first pixel signal with a specific threshold; select one of the first pixel signal or the second pixel signal based on a comparison result; and process the selected one of the first pixel signal or the second pixel signal. ### Claim 12 A method, comprising: in a solid-state imaging element comprising: transferring a first charge from a photoelectric conversion element to a front-stage charge holding region and a rear-stage charge holding region which have different capacities; transferring the first charge from the rear-stage charge holding region in which leakage of the first charge to the photoelectric conversion element is prevented by a light-shielding wall to a floating diffusion region; transferring a second charge, which remains in the front-stage charge holding region after the first charge has been transferred from the rear-stage charge holding region to the floating diffusion region, to the floating diffusion region via the front-stage charge holding region; comparing, between a first pixel signal corresponding to an amount of charge transferred from the rear-stage charge holding region and a second pixel signal corresponding to an amount of charge transferred from the front-stage charge holding region and the rear-stage charge holding region, the first pixel signal with a specific threshold; and selecting one of the first pixel signal or the second pixel signal based on a comparison result.