# US 2023/0053574 A1 · 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 2023/0053574 A1 - Document ID: US20230053574A1 - Status: Published application - Kind: A1 - Application number: 17/904,316 - Filed: 2020-11-25 - Published: 2023-02-23 - Earliest claimed: 2020-02-26 - Assignees: Sony Semiconductor Solutions Corporation - Applicants: Sony Semiconductor Solutions Corporation - Inventors: LUONGHUNG ASAKURA - Web page: https://patentgrep.com/patent/US20230053574A1 ## 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 having a different capacity from the front-stage charge holding region; a front-stage transfer transistor that transfers a 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 that transfers the charge from the rear-stage charge holding region to a floating diffusion region; an intermediate transfer transistor that 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; and a light-shielding wall that prevents the charge from leaking from the photoelectric conversion element to the rear-stage charge holding region. ### 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 having the same polarity, and a predetermined impurity diffusion region having a different polarity from those of both the front-stage charge holding region and the rear-stage charge holding region is disposed between 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 formed in the same impurity diffusion region. ### Claim 4 (depends on 3) The solid-state imaging element according to claim 3, wherein an impurity concentration in a region between the front-stage charge holding region and the rear-stage charge holding region in the impurity diffusion region is different from that around the region. ### Claim 5 (depends on 3) The solid-state imaging element according to claim 3, further comprising an adjustment transistor that adjusts a height of the 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 that controls each of the front-stage transfer transistor, the rear-stage transfer transistor, and the intermediate transfer transistor to be turned either on or off, wherein the vertical scanning circuit turns the front-stage transfer transistor and the intermediate transfer transistor on while turning the rear-stage transfer transistor off to transfer the charge to the front-stage charge holding region and the rear-stage charge holding region, turns the rear-stage transfer transistor on while turning the front-stage transfer transistor and the intermediate transfer transistor off to transfer the charge from the rear-stage charge holding region to the floating diffusion region, and turns the intermediate transfer transistor and the rear-stage transfer transistor on to transfer the 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 signal processing circuit that compares, 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 predetermined threshold and performs processing of selecting one of the first and second pixel signals on the basis of a comparison result. ### Claim 8 (depends on 1) The solid-state imaging element according to claim 1, wherein the photoelectric conversion element is formed on a wired front surface of both surfaces of a predetermined semiconductor substrate. ### Claim 9 (depends on 1) The solid-state imaging element according to claim 1, wherein the photoelectric conversion element is formed on a back surface of a wired front surface of both surfaces of a predetermined semiconductor substrate. ### Claim 10 (depends on 1) The solid-state imaging element according to claim 1, wherein the photoelectric conversion element includes first and second photoelectric conversion elements, the front-stage charge holding region includes first and second front-stage charge holding regions, the rear-stage charge holding region includes first and second rear-stage charge holding regions, the front-stage transfer transistor includes first and second front-stage transfer transistors, the intermediate transfer transistor includes first and second intermediate transfer transistors, and the rear-stage transfer transistor includes first and second rear-stage transfer transistors. ### Claim 11 (depends on 1) The solid-state imaging element according to claim 1, further comprising: a charge discharge transistor that discharges the charge from the photoelectric conversion element, a reset transistor that initializes the floating diffusion region, an amplification transistor that amplifies the signal corresponding to the amount of charge transferred to the floating diffusion region, and a selection transistor that outputs the amplified signal as a pixel signal in accordance with a predetermined selection signal. ### Claim 12 An imaging device comprising: a photoelectric conversion element; a front-stage charge holding region; a rear-stage charge holding region having a different capacity from the front-stage charge holding region; a front-stage transfer transistor that transfers a 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 that transfers the charge from the rear-stage charge holding region to a floating diffusion region; an intermediate transfer transistor that 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; a light-shielding wall that prevents the charge from leaking from the photoelectric conversion element to the rear-stage charge holding region; and a signal processing circuit that processes a pixel signal in accordance with an amount of charge transferred to the floating diffusion region. ### Claim 13 A method for controlling a solid-state imaging element comprising: a front-stage transfer procedure of transferring 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 procedure of transferring the charge from the rear-stage charge holding region in which leakage of charge to the photoelectric conversion element is prevented by a light-shielding wall to a floating diffusion region; and an intermediate transfer procedure of transferring 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.