# US 8,569,804 B2 · Light receiving device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,569,804 B2 - Document ID: US8569804B2 - Status: Granted - Kind: B2 - Application number: 13/435,496 - Filed: 2012-03-30 - Published: 2012-10-04 - Granted: 2013-10-29 - Earliest claimed: 2011-03-31 - Assignees: Honda Motor Co., Ltd. - Applicants: Tomoyuki Kamiyama - Inventors: Tomoyuki Kamiyama - Web page: https://patentgrep.com/patent/US8569804B2 ## CPC - H10F 30/2877: {Field-effect phototransistors having PN heterojunction gates} - G01S 7/4863: Detector arrays, e.g. charge-transfer gates - G01S 17/894: Three-dimensional [3D] imaging with simultaneous measurement of time-of-flight at a two-dimensional [2D] array of receiver pixels, e.g. time-of-flight cameras or flash lidar - H04N 25/771: comprising storage means other than floating diffusion - H10F 39/803: {Pixels having integrated switching, control, storage or amplification elements} - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A light receiving device comprises a photoelectric conversion element formed on a first-conductivity-type semiconductor substrate, and further comprises a plurality of photoelectron distributors formed on the first-conductivity-type semiconductor substrate. The photoelectron distributor has a first transfer unit for transferring photoelectrons generated in the photoelectric conversion element, a photoelectron hold unit for temporarily holding the photoelectrons generated in the photoelectric conversion element, a second transfer unit for transferring the photoelectrons held in the photoelectron hold unit, and a floating diffusion layer for storing the transferred photoelectrons and converting the photoelectrons to a voltage. A first-conductivity-type impurity region, which has a first-level, first-conductivity-type impurity concentration higher than the first-conductivity-type impurity concentration of the first-conductivity-type semiconductor substrate, is formed in the vicinity of a surface of the first-conductivity-type semiconductor substrate in the photoelectron hold unit. ## Claims ### Claim 1 A light receiving device comprising a photoelectric conversion element for detecting a light to generate photoelectrons formed on a first-conductivity-type semiconductor substrate, wherein the light receiving device further comprises a plurality of photoelectron distributors formed on the first-conductivity-type semiconductor substrate, each of the photoelectron distributors has a first transfer unit for transferring the photoelectrons generated in the photoelectric conversion element, a photoelectron hold unit located on one side of the photoelectric conversion element with the first transfer unit interposed therebetween for temporarily holding the photoelectrons generated in the photoelectric conversion element, a second transfer unit located on one side of the first transfer unit with the photoelectron hold unit interposed therebetween for transferring the photoelectrons held in the photoelectron hold unit, and a floating diffusion layer located on one side of the photoelectron hold unit with the second transfer unit interposed therebetween for converting the transferred photoelectrons to a voltage, and a first-conductivity-type impurity region is formed so as to confront a hold gate of the photoelectron hold unit in the vicinity of a surface of the first-conductivity-type semiconductor substrate in the photoelectron hold unit and has a first-level, first-conductivity-type impurity concentration higher than the first-conductivity-type impurity concentration of the first-conductivity-type semiconductor substrate. ### Claim 2 (depends on 1) The light receiving device according to claim 1, wherein a second-conductivity-type impurity region is formed adjacent to the first-conductivity-type impurity region between a first transfer gate of the first transfer unit and the hold gate of the photoelectron hold unit and/or between the hold gate of the photoelectron hold unit and a second transfer gate of the second transfer unit in the vicinity of the surface of the first-conductivity-type semiconductor substrate. ### Claim 3 (depends on 2) The light receiving device according to claim 2, wherein the first-conductivity-type impurity region extends in a depth direction more than the second-conductivity-type impurity region formed between the first transfer gate of the first transfer unit and the hold gate of the photoelectron hold unit and/or between the hold gate of the photoelectron hold unit and the second transfer gate of the second transfer unit, and further extends beneath the second-conductivity-type impurity region. ### Claim 4 (depends on 1) The light receiving device according to claim 1, wherein a first-conductivity-type impurity layer is formed as an intermediate layer in the first-conductivity-type semiconductor substrate and has a second-level, first-conductivity-type impurity concentration higher than the first-conductivity-type impurity concentration of the first-conductivity-type semiconductor substrate. ### Claim 5 (depends on 1) The light receiving device according to claim 1, wherein a first-conductivity-type impurity layer is formed as an intermediate layer in the first-conductivity-type semiconductor substrate, and has a third-level, first-conductivity-type impurity concentration different from the first-conductivity-type impurity concentration of the first-conductivity-type semiconductor substrate, and the first-conductivity-type impurity concentration of the first-conductivity-type impurity layer decreases in a direction toward the surface of the first-conductivity-type semiconductor substrate. ### Claim 6 A light receiving device comprising a photoelectric conversion element for detecting a light to generate photoelectrons formed on a first-conductivity-type semiconductor substrate, wherein the light receiving device further comprises a plurality of photoelectron distributors formed on the first-conductivity-type semiconductor substrate, each of the photoelectron distributors has a first transfer unit for transferring the photoelectrons generated in the photoelectric conversion element, a photoelectron hold unit located on one side of the photoelectric conversion element with the first transfer unit interposed therebetween for temporarily holding the photoelectrons generated in the photoelectric conversion element, a second transfer unit located on one side of the first transfer unit with the photoelectron hold unit interposed therebetween for transferring the photoelectrons held in the photoelectron hold unit, and a floating diffusion layer located on one side of the photoelectron hold unit with the second transfer unit interposed therebetween for storing the transferred photoelectrons and converting the photoelectrons to a voltage, a second-conductivity-type impurity region is formed in the vicinity of a surface of the first-conductivity-type semiconductor substrate, and a first-conductivity-type impurity layer is formed as an intermediate layer in the first-conductivity-type semiconductor substrate below respective gates of the photoelectric conversion element, the first transfer unit, the photoelectron hold unit, and the second transfer unit, and the first-conductivity-type impurity layer has a fourth-level, first-conductivity-type impurity concentration higher than the first-conductivity-type impurity concentration of the first-conductivity-type semiconductor substrate. ### Claim 7 A light receiving device comprising a photoelectric conversion element for detecting a light to generate photoelectrons formed on a first-conductivity-type semiconductor substrate, wherein the light receiving device further comprises a plurality of photoelectron distributors formed on the first-conductivity-type semiconductor substrate, each of the photoelectron distributors has a first transfer unit for transferring the photoelectrons generated in the photoelectric conversion element, a photoelectron hold unit located on one side of the photoelectric conversion element with the first transfer unit interposed therebetween for temporarily holding the photoelectrons generated in the photoelectric conversion element, a second transfer unit located on one side of the first transfer unit with the photoelectron hold unit interposed therebetween for transferring the photoelectrons held in the photoelectron hold unit, and a floating diffusion layer located on one side of the photoelectron hold unit with the second transfer unit interposed therebetween for converting the transferred photoelectrons to a voltage, a second-conductivity-type impurity region is formed in the vicinity of a surface of the first-conductivity-type semiconductor substrate, a first-conductivity-type impurity layer is formed as an intermediate layer in the first-conductivity-type semiconductor substrate below respective gates of the photoelectric conversion element, the first transfer unit, the photoelectron hold unit, and the second transfer unit, the first-conductivity-type impurity layer has a fifth-level, first-conductivity-type impurity concentration different from the first-conductivity-type impurity concentration of the first-conductivity-type semiconductor substrate, and the first-conductivity-type impurity concentration of the first-conductivity-type impurity layer decreases in a direction toward the surface of the first-conductivity-type semiconductor substrate. ### Claim 8 (depends on 1) The light receiving device according to claim 1, wherein the photoelectric conversion element has a photogate structure, and the first transfer unit, the photoelectron hold unit, and the second transfer unit have an MOS diode structure.