WO2021131651A1 - 測距イメージセンサ及びその製造方法 - Google Patents
測距イメージセンサ及びその製造方法 Download PDFInfo
- Publication number
- WO2021131651A1 WO2021131651A1 PCT/JP2020/045535 JP2020045535W WO2021131651A1 WO 2021131651 A1 WO2021131651 A1 WO 2021131651A1 JP 2020045535 W JP2020045535 W JP 2020045535W WO 2021131651 A1 WO2021131651 A1 WO 2021131651A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- region
- image sensor
- semiconductor layer
- distance measuring
- pixels
- Prior art date
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 21
- 238000000034 method Methods 0.000 title claims description 15
- 238000012546 transfer Methods 0.000 claims abstract description 168
- 239000004065 semiconductor Substances 0.000 claims abstract description 161
- 238000009826 distribution Methods 0.000 claims abstract description 72
- 230000004888 barrier function Effects 0.000 claims description 48
- 239000000758 substrate Substances 0.000 claims description 23
- 239000004020 conductor Substances 0.000 claims 1
- 230000035945 sensitivity Effects 0.000 description 37
- 230000000903 blocking effect Effects 0.000 description 9
- 239000012535 impurity Substances 0.000 description 9
- 238000012545 processing Methods 0.000 description 7
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 5
- 229920005591 polysilicon Polymers 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- 230000003071 parasitic effect Effects 0.000 description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 230000005684 electric field Effects 0.000 description 2
- 239000011810 insulating material Substances 0.000 description 2
- 230000031700 light absorption Effects 0.000 description 2
- 239000007769 metal material Substances 0.000 description 2
- 238000004904 shortening Methods 0.000 description 2
- 229910052814 silicon oxide Inorganic materials 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000002366 time-of-flight method Methods 0.000 description 1
- 238000011282 treatment Methods 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/14609—Pixel-elements with integrated switching, control, storage or amplification elements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- 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
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/88—Lidar systems specially adapted for specific applications
- G01S17/89—Lidar systems specially adapted for specific applications for mapping or imaging
-
- G—PHYSICS
- G01—MEASURING; TESTING
- 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
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/88—Lidar systems specially adapted for specific applications
- G01S17/89—Lidar systems specially adapted for specific applications for mapping or imaging
- G01S17/894—3D imaging with simultaneous measurement of time-of-flight at a 2D array of receiver pixels, e.g. time-of-flight cameras or flash lidar
-
- G—PHYSICS
- G01—MEASURING; TESTING
- 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
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/481—Constructional features, e.g. arrangements of optical elements
- G01S7/4816—Constructional features, e.g. arrangements of optical elements of receivers alone
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/14603—Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/14609—Pixel-elements with integrated switching, control, storage or amplification elements
- H01L27/1461—Pixel-elements with integrated switching, control, storage or amplification elements characterised by the photosensitive area
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/14636—Interconnect structures
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14683—Processes or apparatus peculiar to the manufacture or treatment of these devices or parts thereof
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14683—Processes or apparatus peculiar to the manufacture or treatment of these devices or parts thereof
- H01L27/14689—MOS based technologies
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
- H01L31/10—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors characterised by potential barriers, e.g. phototransistors
- H01L31/101—Devices sensitive to infrared, visible or ultraviolet radiation
- H01L31/102—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier
- H01L31/107—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier the potential barrier working in avalanche mode, e.g. avalanche photodiodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/1463—Pixel isolation structures
Definitions
- This disclosure relates to a distance measuring image sensor and a manufacturing method thereof.
- a distance measuring image sensor that acquires a distance image of an object using an indirect TOF (Time of Flight) method
- a semiconductor layer provided with a light-sensitive region and a photogate electrode provided for each pixel on the semiconductor layer.
- transfer gate electrodes are known (see, for example, Patent Documents 1 and 2). According to such a ranging image sensor, the electric charge generated in the light-sensitive region due to the incident light can be transferred at high speed.
- the distance measuring image sensor it may be required to improve the light receiving sensitivity, for example, in order to increase the distance that can be measured.
- An object of the present disclosure is to provide a distance measuring image sensor capable of uniformly improving the light receiving sensitivity in a plurality of pixels and a method for manufacturing the same.
- the ranging image sensor on one side of the present disclosure has a first surface on the first side and a second surface on the second side opposite to the first side, and is arranged along the first surface.
- a semiconductor layer forming the plurality of pixels and an electrode layer provided on the first surface and forming the plurality of pixels are provided, and each of the plurality of pixels is a first conductive type formed in the semiconductor layer.
- a second conductive type charge distribution region formed on the first side of the semiconductor layer and connected to the second multiplication region, and a charge distribution region formed on the first side of the second multiplication region in the semiconductor layer and connected to the charge distribution region.
- the avalanche photomultiplier region is connected over a plurality of pixels or reaches a trench formed in a semiconductor layer so as to separate each of the plurality of pixels from each other.
- the avalanche multiplication region formed in the semiconductor layer is connected over a plurality of pixels, or is formed in a trench formed in the semiconductor layer so as to separate each of the plurality of pixels from each other. It has reached.
- high sensitivity is realized in each of the plurality of pixels in a state where the variation in the light receiving sensitivity among the plurality of pixels and the variation in the light receiving sensitivity depending on the location within one pixel are suppressed. Therefore, according to this distance measuring image sensor, it is possible to uniformly improve the light receiving sensitivity in a plurality of pixels.
- the trench is formed on the first surface, and the bottom surface of the trench may be located on the second side with respect to the avalanche multiplication region. As a result, it is possible to suppress the occurrence of crosstalk between adjacent pixels.
- the trench is formed on the first surface, and the bottom surface of the trench may be located within the avalanche multiplication region. As a result, it is possible to sufficiently suppress the occurrence of crosstalk between adjacent pixels while shortening the time for forming the trench.
- each of the plurality of pixels is formed on the first side of the second multiplication region in the semiconductor layer, and is formed with at least one of the first charge transfer region and the second charge transfer region. It further has a first conductive type well region constituting an electrically connected readout circuit, and a second conductive type barrier region formed between the second multiplying region and the well region in the semiconductor layer. You may. As a result, even if the depletion layer formed in the avalanche multiplication region spreads toward the first conductive type well region by applying a high voltage to the avalanche multiplication region, the second conductive type barrier region This prevents the depletion layer from reaching the first conductive type well region. That is, it is possible to suppress the flow of current between the avalanche multiplication region and the well region due to the depletion layer reaching the well region.
- the barrier region may include a well region when viewed from the thickness direction of the semiconductor layer. As a result, it is possible to suppress the flow of current between the avalanche multiplication region and the well region due to the depletion layer reaching the well region.
- each of the plurality of pixels has a second conductive sink region formed on the first side of the barrier region in the semiconductor layer and connected to the barrier region. May be good. As a result, the electric charge collected around the barrier region of the second conductive type is drawn into the sink region of the second conductive type, so that the electric charge collected around the barrier region can be suppressed from becoming noise as a parasitic charge. it can.
- the sink region may be connected to the second charge transfer region.
- the ranging image sensor on one side of the present disclosure may be further provided with a wiring layer provided on the first surface so as to cover the electrode layer and electrically connected to each of the plurality of pixels.
- a wiring layer provided on the first surface so as to cover the electrode layer and electrically connected to each of the plurality of pixels.
- the method for manufacturing the distance measuring image sensor is the method for manufacturing the distance measuring image sensor, wherein the avalanche multiplication region, the charge distribution region, the first charge transfer region, and the second charge transfer region are semiconductors.
- the semiconductor layer By forming the semiconductor layer on the substrate, the photogate electrode, the first transfer gate electrode, and the second transfer gate electrode are formed on the first surface of the semiconductor layer after the first step and the first step.
- an avalanche multiplication region is formed on the semiconductor substrate so as to be connected over a plurality of pixels.
- an avalanche multiplication region is formed on a semiconductor substrate so as to be connected over a plurality of pixels.
- the variation in the light receiving sensitivity among a plurality of pixels and the variation in the light receiving sensitivity depending on the location within one pixel are suppressed, and the light receiving sensitivity is high in each of the plurality of pixels. Sensitivity is realized. Therefore, according to this method of manufacturing a distance measuring image sensor, it is possible to obtain a distance measuring image sensor in which the light receiving sensitivity is uniformly improved in a plurality of pixels.
- the avalanche multiplication region may be formed on the semiconductor substrate, and then a trench may be formed on the first surface. As a result, it is possible to easily and surely obtain a configuration in which the avalanche multiplication region reaches the trench.
- a wiring layer is formed on the first surface so as to cover the electrode layer, and the wiring layer is electrically connected to each of a plurality of pixels.
- a fifth step may be further provided.
- a distance measuring image sensor capable of uniformly improving the light receiving sensitivity in a plurality of pixels and a method for manufacturing the same.
- FIG. 1 is a configuration diagram of a photodetector including the ranging image sensor of the first embodiment.
- FIG. 2 is a plan view of the pixel portion of the distance measuring image sensor of the first embodiment.
- FIG. 3 is a cross-sectional view taken along the line III-III shown in FIG.
- FIG. 4 is a cross-sectional view taken along the line IV-IV shown in FIG.
- FIG. 5 is a cross-sectional view for explaining a method of manufacturing the distance measuring image sensor of the first embodiment.
- FIG. 6 is a cross-sectional view for explaining a method of manufacturing the distance measuring image sensor of the first embodiment.
- FIG. 7 is a plan view of a part of the distance measuring image sensor of the second embodiment.
- FIG. 8 is a cross-sectional view taken along the line VIII-VIII shown in FIG.
- FIG. 9 is a plan view of a part of the distance measuring image sensor of the third embodiment.
- FIG. 10 is a cross-sectional view taken along the line XX shown in FIG.
- FIG. 11 is a plan view of a part of the distance measuring image sensor of the fourth embodiment.
- FIG. 12 is a cross-sectional view taken along the line XII-XII shown in FIG.
- FIG. 13 is a cross-sectional view taken along the line XIII-XIII shown in FIG.
- FIG. 14 is a plan view of a part of the distance measuring image sensor of the fifth embodiment.
- FIG. 15 is a cross-sectional view taken along the line XV-XV shown in FIG. FIG.
- FIG. 16 is a cross-sectional view of a distance measuring image sensor of a modified example.
- FIG. 17 is a cross-sectional view of a distance measuring image sensor of a modified example.
- FIG. 18 is a cross-sectional view of a distance measuring image sensor of a modified example.
- FIG. 19 is a cross-sectional view of a distance measuring image sensor of a modified example.
- FIG. 20 is a cross-sectional view of a distance measuring image sensor of a modified example.
- FIG. 21 is a cross-sectional view of a distance measuring image sensor of a modified example.
- FIG. 22 is a cross-sectional view of a distance measuring image sensor of a modified example.
- the photodetector 1 includes a light source 2, a ranging image sensor 10A, a signal processing unit 3, a control unit 4, and a display unit 5.
- the light detection device 1 is a device that acquires a distance image of an object OJ (an image including information on a distance d to the object OJ) by using an indirect TOF method.
- the light source 2 emits pulsed light L.
- the light source 2 is composed of, for example, an infrared LED or the like.
- the pulsed light L is, for example, near-infrared light, and the frequency of the pulsed light L is, for example, 10 kHz or more.
- the ranging image sensor 10A detects the pulsed light L emitted from the light source 2 and reflected by the object OJ.
- the distance measuring image sensor 10A is configured by monolithically forming a pixel unit 11 and a CMOS reading circuit unit 12 on a semiconductor substrate (for example, a silicon substrate).
- the ranging image sensor 10A is mounted on the signal processing unit 3.
- the signal processing unit 3 controls the pixel unit 11 and the CMOS reading circuit unit 12 of the distance measuring image sensor 10A.
- the signal processing unit 3 performs predetermined processing on the signal output from the ranging image sensor 10A to generate a detection signal.
- the control unit 4 controls the light source 2 and the signal processing unit 3.
- the control unit 4 generates a distance image of the object OJ based on the detection signal output from the signal processing unit 3.
- the display unit 5 displays a distance image of the object OJ generated by the control unit 4.
- the distance measuring image sensor 10A includes a semiconductor layer 20 and an electrode layer 40 in the pixel unit 11.
- the semiconductor layer 20 has a first surface 20a and a second surface 20b.
- the first surface 20a is a surface on one side of the semiconductor layer 20 in the thickness direction.
- the second surface 20b is the surface on the other side of the semiconductor layer 20 in the thickness direction.
- the electrode layer 40 is provided on the first surface 20a of the semiconductor layer 20.
- the semiconductor layer 20 and the electrode layer 40 constitute a plurality of pixels 11a arranged along the first surface 20a. In the distance measuring image sensor 10A, the plurality of pixels 11a are arranged two-dimensionally along the first surface 20a.
- the thickness direction of the semiconductor layer 20 is referred to as the Z direction
- one direction perpendicular to the Z direction is referred to as the X direction
- the direction perpendicular to both the Z direction and the X direction is referred to as the Y direction.
- one side in the Z direction is referred to as a first side
- the other side in the Z direction is referred to as a second side.
- the wiring layer 60 which will be described later, is not shown.
- each pixel 11a includes a semiconductor region 21, an avalanche multiplication region 22, a charge distribution region 23, a pair of first charge transfer regions 24 and 25, and a pair of second charge transfer regions. It has 26, 27, a plurality of charge blocking regions 28, a well region 31, a LOCOS (Local Oxidation of Silicon) region 33, a barrier region 34, and a pair of sink regions 35.
- the regions 21 to 28 and 31 to 35 are formed by performing various treatments (for example, etching, film formation, impurity injection, etc.) on a semiconductor substrate (for example, a silicon substrate).
- the semiconductor region 21 is a p-type (first conductive type) region, and is provided along the second surface 20b in the semiconductor layer 20.
- the semiconductor region 21 functions as a light absorption region (photoelectric conversion region).
- the semiconductor region 21 is a p-type region having a carrier concentration of 1 ⁇ 10 15 cm -3 or less, and the thickness of the semiconductor region 21 is about 10 ⁇ m.
- the avalanche multiplication region 22 and the like also function as a light absorption region (photomultiplier region).
- the avalanche multiplication region 22 includes a first multiplication region 22a and a second multiplication region 22b.
- the first multiplication region 22a is a p-type region and is formed on the first side of the semiconductor region 21 in the semiconductor layer 20.
- the first multiplying region 22a is a p-type region having a carrier concentration of 1 ⁇ 10 16 cm -3 or more, and the thickness of the first multiplying region 22a is about 1 ⁇ m.
- the second photomultiplier region 22b is an n-type (second conductive type) region and is formed on the first side of the first photomultiplier region 22a in the semiconductor layer 20.
- the second photomultiplier region 22b is an n-type region having a carrier concentration of 1 ⁇ 10 16 cm -3 or more, and the thickness of the second photomultiplier region 22b is about 1 ⁇ m.
- the first multiplying region 22a and the second multiplying region 22b form a pn junction.
- the charge distribution region 23 is an n-type region and is formed on the first side of the second photomultiplier region 22b in the semiconductor layer 20.
- the charge distribution region 23 is an n-type region having a carrier concentration of 5 ⁇ 10 15 to 1 ⁇ 10 16 cm -3 , and the thickness of the charge distribution region 23 is about 1 ⁇ m.
- Each of the first charge transfer regions 24 and 25 is an n-type region and is formed on the first side of the second photomultiplier region 22b in the semiconductor layer 20.
- the first charge transfer regions 24 and 25 are connected to the charge distribution region 23.
- the pair of first charge transfer regions 24 and 25 face each other in the X direction with the first side portion of the charge distribution region 23 interposed therebetween.
- each of the first charge transfer regions 24 and 25 is an n-type region having a carrier concentration of 1 ⁇ 10 18 cm -3 or more, and the thickness of each of the first charge transfer regions 24 and 25 is 0. It is about 2 ⁇ m.
- the second side portion of the charge distribution region 23 is inserted between the first charge transfer regions 24 and 25 and the second multiplication region 22b.
- the first charge transfer regions 24 and 25 function as charge storage regions.
- Each of the second charge transfer regions 26 and 27 is an n-type region and is formed on the first side of the second photomultiplier region 22b in the semiconductor layer 20.
- the second charge transfer regions 26 and 27 are connected to the charge distribution region 23.
- the pair of second charge transfer regions 26 and 27 face each other in the Y direction with the first side portion of the charge distribution region 23 interposed therebetween.
- each of the second charge transfer regions 26 and 27 is an n-type region having a carrier concentration of 1 ⁇ 10 18 cm -3 or more, and the thickness of each of the second charge transfer regions 26 and 27 is 0. It is about 2 ⁇ m.
- the second side portion of the charge distribution region 23 is inserted between the second charge transfer regions 26 and 27 and the second multiplication region 22b.
- the second charge transfer regions 26 and 27 function as charge discharge regions.
- Each charge blocking region 28 is a p-type region, and includes the first charge transfer regions 24 and 25 and the charge distribution region 23 (the second side portion of the charge distribution region 23) in the semiconductor layer 20. Is formed between.
- each charge blocking region 28 is a p-type region having a carrier concentration of 1 ⁇ 10 17 to 1 ⁇ 10 18 cm -3 , and the thickness of each charge blocking region 28 is about 0.2 ⁇ m. ..
- the well region 31 is a p-type region and is formed on the first side of the second photomultiplier region 22b in the semiconductor layer 20.
- the well region 31 surrounds the charge distribution region 23 when viewed from the Z direction.
- the LOCOS region 33 is formed on the first side of the well region 31 in the semiconductor layer 20.
- the LOCOS region 33 is connected to the well region 31.
- the well region 31 and the LOCOS region 33 form a plurality of read circuits (for example, a source follower amplifier, a reset transistor, etc.). Each readout circuit is electrically connected to each of the first charge transfer regions 24, 25.
- the well region 31 is a p-type region having a carrier concentration of 1 ⁇ 10 16 to 5 ⁇ 10 17 cm -3 , and the thickness of the well region 31 is about 1 ⁇ m.
- STI Shallow Trench Isolation
- the LOCOS region 33 may be used instead of the LOCOS region 33, or only the well region 31 is used. May be good.
- the barrier region 34 is an n-type region and is formed between the second multiplying region 22b and the well region 31 in the semiconductor layer 20.
- the barrier region 34 includes a well region 31 when viewed from the Z direction. That is, the well region 31 is located within the barrier region 34 when viewed from the Z direction.
- the barrier region 34 surrounds the charge distribution region 23.
- the concentration of n-type impurities in the barrier region 34 is higher than the concentration of n-type impurities in the second photomultiplier region 22b.
- the barrier region 34 is an n-type region having a carrier concentration from the carrier concentration of the second multiplying region 22b to about twice the carrier concentration of the second multiplying region 22b, and the thickness of the barrier region 34 is It is about 1 ⁇ m.
- Each sink region 35 is an n-type region and is formed on the first side of the barrier region 34 in the semiconductor layer 20.
- the second end of each sink region 35 is connected to the barrier region 34.
- the first end of each sink region 35 is connected to the second charge transfer regions 26, 27, respectively.
- the concentration of n-type impurities in the second charge transfer regions 26 and 27 is higher than the concentration of n-type impurities in each sink region 35, and the concentration of n-type impurities in each sink region 35 is the n-type impurities in the barrier region 34.
- concentration of p-type impurities in the well region 31 is an n-type region and is formed on the first side of the barrier region 34 in the semiconductor layer 20.
- the second end of each sink region 35 is connected to the barrier region 34.
- the first end of each sink region 35 is connected to the second charge transfer regions 26, 27, respectively.
- the concentration of n-type impurities in the second charge transfer regions 26 and 27 is higher than the concentration of n-type impur
- each sink region 35 is an n-type region having a carrier concentration equal to or higher than the carrier concentration of the well region 31, and the thickness of each sink region 35 is the second charge transfer regions 26, 27 and the barrier region 34, respectively. Depends on the distance between.
- Each pixel 11a has a photogate electrode 41, a pair of first transfer gate electrodes 42, 43, and a pair of second transfer gate electrodes 44, 45 in the electrode layer 40.
- the gate electrodes 41 to 45 are formed on the first surface 20a of the semiconductor layer 20 via the insulating film 46.
- the insulating film 46 is, for example, a silicon nitride film, a silicon oxide film, or the like.
- the photogate electrode 41 is formed on the first side of the charge distribution region 23 in the electrode layer 40.
- the photogate electrode 41 is made of a material having conductivity and light transmission (for example, polysilicon).
- the photogate electrode 41 has a rectangular shape having two sides facing each other in the X direction and two sides facing each other in the Y direction when viewed from the Z direction.
- the first transfer gate electrode 42 is formed on the first side of the charge distribution region 23 in the electrode layer 40 so as to be located on the first charge transfer region 24 side with respect to the photogate electrode 41.
- the first transfer gate electrode 43 is formed on the first side of the charge distribution region 23 in the electrode layer 40 so as to be located on the first charge transfer region 25 side with respect to the photogate electrode 41.
- Each of the first transfer gate electrodes 42, 43 is made of a material having conductivity and light transmission (for example, polysilicon).
- each of the first transfer gate electrodes 42 and 43 has a rectangular shape having two sides facing each other in the X direction and two sides facing each other in the Y direction when viewed from the Z direction.
- the second transfer gate electrode 44 is formed on the first side of the charge distribution region 23 in the electrode layer 40 so as to be located on the second charge transfer region 26 side with respect to the photogate electrode 41.
- the second transfer gate electrode 45 is formed on the first side of the charge distribution region 23 in the electrode layer 40 so as to be located on the second charge transfer region 27 side with respect to the photogate electrode 41.
- Each of the second transfer gate electrodes 44, 45 is made of a conductive and light transmissive material (eg polysilicon).
- each of the second transfer gate electrodes 44 and 45 has a rectangular shape having two sides facing each other in the X direction and two sides facing each other in the Y direction when viewed from the Z direction.
- the distance measuring image sensor 10A further includes a counter electrode 50 and a wiring layer 60 in the pixel portion 11.
- the counter electrode 50 is provided on the second surface 20b of the semiconductor layer 20.
- the counter electrode 50 includes a plurality of pixels 11a when viewed from the Z direction.
- the counter electrode 50 faces the electrode layer 40 in the Z direction.
- the counter electrode 50 is made of, for example, a metal material.
- the wiring layer 60 is provided on the first surface 20a of the semiconductor layer 20 so as to cover the electrode layer 40.
- the wiring layer 60 is electrically connected to each pixel 11a and the CMOS readout circuit unit 12 (see FIG. 1).
- a light incident opening 60a is formed in a portion of the wiring layer 60 facing the photogate electrode 41 of each pixel 11a.
- a trench 29 is formed in the semiconductor layer 20 so as to separate each pixel 11a from each other.
- the trench 29 is formed on the first surface 20a of the semiconductor layer 20.
- the bottom surface 29a of the trench 29 is located on the second side with respect to the avalanche multiplication region 22. That is, the trench 29 completely separates the avalanche multiplication region 22.
- An insulating material 47 such as silicon oxide is arranged in the trench 29.
- a metal material such as tungsten, polysilicon, or the like may be arranged in the trench 29.
- the avalanche multiplication region 22 reaches the trench 29.
- the avalanche multiplication region 22 is a region that causes an avalanche multiplication. That is, in each pixel 11a, the avalanche multiplication region 22 that can generate an electric field strength of 3 ⁇ 10 5 to 4 ⁇ 10 5 V / cm when a predetermined value of reverse bias is applied is surrounded by the trench 29. It spreads over the entire area.
- a negative voltage for example, ⁇ 50 V
- a reverse bias is applied to the junction to generate an electric field strength of 3 ⁇ 10 5 to 4 ⁇ 10 5 V / cm in the avalanche multiplication region 22.
- a reset voltage is first applied to the pair of second transfer gate electrodes 44 and 45 in each pixel 11a.
- the reset voltage is a positive voltage with reference to the potential of the photogate electrode 41.
- the electrons that have moved to the charge distribution region 23 are discharged from the pair of second charge transfer regions 26 and 27.
- a pulse voltage signal is applied to the pair of first transfer gate electrodes 42 and 43.
- the pulse voltage signal applied to the first transfer gate electrode 42 is a voltage signal in which positive voltage and negative voltage are alternately repeated with reference to the potential of the photogate electrode 41, and is the light source 2 (FIG. 1). It is a voltage signal having the same period, pulse width and phase as the intensity signal of the pulsed light L emitted from (see).
- the pulse voltage signal applied to the first transfer gate electrode 43 is the same voltage signal as the pulse voltage signal applied to the first transfer gate electrode 42, except that the phase is shifted by 180 °.
- the electrons that have moved to the charge distribution region 23 are alternately transferred to the pair of first charge transfer regions 24 and 25 at high speed.
- the electrons accumulated in the first charge transfer regions 24 and 25 by the transfer for a predetermined period are used as a signal in the CMOS readout circuit unit 12 (FIG. 1) via the readout circuit composed of the well regions 31 and the like and the wiring layer 60. See).
- a p-type semiconductor substrate 20s is prepared, and an avalanche multiplication region 22 and a charge distribution region 23 are formed on the semiconductor substrate 20s.
- the avalanche multiplication region 22 is formed on the semiconductor substrate 20s so as to be connected over the plurality of pixels 11a (see FIG. 5B).
- a trench 29 is formed on the first surface 20a of the semiconductor layer 20.
- FIG. 5A a p-type semiconductor substrate 20s is prepared, and an avalanche multiplication region 22 and a charge distribution region 23 are formed on the semiconductor substrate 20s.
- the avalanche multiplication region 22 is formed on the semiconductor substrate 20s so as to be connected over the plurality of pixels 11a (see FIG. 5B).
- a trench 29 is formed on the first surface 20a of the semiconductor layer 20.
- each region 24 to 28, 31 to 35 is formed on the semiconductor substrate 20s so that each pixel 11a has a LOCOS region 33, a barrier region 34, and a pair of sink regions 35.
- the semiconductor layer 20 in which the trench 29 is formed is formed (first step).
- the semiconductor region 21 is a region possessed by the semiconductor substrate 20s.
- each pixel 11a has a photogate electrode 41, a pair of first transfer gate electrodes 42, 43, and a pair of second transfer gate electrodes 44, 45.
- Each of the gate electrodes 41 to 45 is formed on the first surface 20a of the semiconductor layer 20.
- the electrode layer 40 is formed (second step).
- a wiring layer 60 is formed on the first surface 20a of the semiconductor layer 20 so as to cover the electrode layer 40, and the wiring layer 60 is electrically connected to each pixel 11a (the first). 3 steps).
- the counter electrode 50 is formed on the second surface 20b of the semiconductor layer 20.
- the CMOS readout circuit portion 12 is formed on the semiconductor substrate 20s. As described above, the distance measuring image sensor 10A is manufactured.
- the trench 29 is formed after the regions 24 to 28 and 31 to 35 are formed on the semiconductor substrate 20s and before the gate electrodes 41 to 45 are formed on the first surface 20a of the semiconductor layer 20. May be done. [Action and effect]
- the avalanche multiplication region 22 formed in the semiconductor layer 20 reaches the trench 29 formed in the semiconductor layer 20 so as to separate the pixels 11a from each other.
- high sensitivity is realized in each pixel 11a while the variation in the light receiving sensitivity among the plurality of pixels 11a and the variation in the light receiving sensitivity depending on the location in one pixel 11a are suppressed. Therefore, according to the distance measuring image sensor 10A, it is possible to uniformly improve the light receiving sensitivity in the plurality of pixels 11a.
- the bottom surface 29a of the trench 29 is located on the second side with respect to the avalanche multiplication region 22. As a result, it is possible to suppress the occurrence of crosstalk between adjacent pixels 11a.
- an n-type barrier region 34 is formed between the n-type second multiplying region 22b and the p-type well region 31 constituting the readout circuit.
- the barrier region 34 includes the well region 31 when viewed from the Z direction. As a result, it is possible to suppress the flow of current between the avalanche multiplication region 22 and the well region 31 due to the depletion layer reaching the well region 31.
- an n-type sink region 35 connected to the barrier region 34 is formed on the first side of the barrier region 34.
- the electrons collected around the n-type barrier region 34 are drawn into the n-type sink region 35, so that it is possible to suppress the electrons collected around the barrier region 34 from becoming noise as parasitic electrons. ..
- the impurity concentration in the region between the first charge transfer region 24 and each sink region 35 and the region between the first charge transfer region 25 and each sink region 35 the parasitic electrons are generated in each first. It is possible to form a potential state in which one is more likely to be drawn into the sink region 35 than the charge transfer regions 24 and 25.
- the sink region 35 is connected to the second charge transfer regions 26 and 27, respectively.
- the parasitic electrons drawn into the sink region 35 can be discharged to the second charge transfer regions 26 and 27, which function as unnecessary charge discharge regions.
- a wiring layer 60 is provided on the first surface 20a of the semiconductor layer 20 so as to cover the electrode layer 40, and the wiring layer 60 is electrically connected to each pixel 11a. Thereby, the input / output of the electric signal to each pixel 11a can be performed via the wiring layer 60.
- the avalanche multiplication region 22 is formed on the semiconductor substrate 20s so as to be connected over the plurality of pixels 11a.
- the manufacturing method of the distance measuring image sensor 10A it is possible to obtain the distance measuring image sensor 10A in which the light receiving sensitivity is uniformly improved in the plurality of pixels 11a.
- a trench 29 is formed on the first surface 20a of the semiconductor layer 20 after the formation of the avalanche multiplication region 22.
- the wiring layer 60 is formed on the first surface 20a of the semiconductor layer 20 so as to cover the electrode layer 40, and the wiring layer 60 is formed on each pixel. It is electrically connected to 11a.
- input / output of an electric signal to each pixel 11a can be performed via the wiring layer 60.
- the second charge transfer regions 26a, 26b, 27a, 27b are arranged on both sides of the charge distribution region 23 in the X direction, and X. It is mainly different from the above-mentioned ranging image sensor 10A in that a plurality of second transfer gate electrodes 44a, 44b, 45a, 45b are arranged on both sides of the photogate electrode 41 in the direction.
- the pair of second charge transfer regions 26a and 26b is one side of the charge distribution region 23 in the X direction, and is the first charge transfer region 24 in the Y direction. It is located on both sides.
- the pair of second charge transfer regions 27a and 27b are on the other side of the charge distribution region 23 in the X direction and are arranged on both sides of the first charge transfer region 25 in the Y direction.
- the second transfer gate electrode 44a is arranged between the photogate electrode 41 and the second charge transfer region 26a when viewed from the Z direction.
- the second transfer gate electrode 44b is arranged between the photogate electrode 41 and the second charge transfer region 26b when viewed from the Z direction.
- the second transfer gate electrode 45a is arranged between the photogate electrode 41 and the second charge transfer region 27a when viewed from the Z direction.
- the second transfer gate electrode 45b is arranged between the photogate electrode 41 and the second charge transfer region 27b when viewed from the Z direction.
- the avalanche multiplication region 22 formed in the semiconductor layer 20 is a trench formed in the semiconductor layer 20 so as to separate the pixels 11a from each other. It has reached 29.
- high sensitivity is realized in each pixel 11a while the variation in the light receiving sensitivity among the plurality of pixels 11a and the variation in the light receiving sensitivity depending on the location in one pixel 11a are suppressed. Therefore, according to the distance measuring image sensor 10B, it is possible to uniformly improve the light receiving sensitivity in the plurality of pixels 11a.
- the first charge transfer region 24 is arranged in the central portion of the charge distribution region 23, and the second charge transfer region 26 is formed in an annular shape. It is mainly different from the above-mentioned ranging image sensor 10A in that the electrodes 41, 42, and 44 are formed in an annular shape.
- the first charge transfer region 24 is arranged in the central portion of the charge distribution region 23 when viewed from the Z direction.
- the second charge transfer region 26 has, for example, a rectangular ring when viewed from the Z direction, and is arranged along the outer edge of the charge distribution region 23.
- the photogate electrode 41 has, for example, a rectangular ring shape when viewed from the Z direction, and is arranged outside the first charge transfer region 24 and inside the second charge transfer region 26.
- the first transfer gate electrode 42 has, for example, a rectangular ring shape when viewed from the Z direction, and is arranged outside the first charge transfer region 24 and inside the photogate electrode 41.
- the second transfer gate electrode 44 has, for example, a rectangular ring shape when viewed from the Z direction, and is arranged outside the photogate electrode 41 and inside the second charge transfer region 26.
- the avalanche multiplication region 22 formed in the semiconductor layer 20 is a trench formed in the semiconductor layer 20 so as to separate the pixels 11a from each other. It has reached 29.
- high sensitivity is realized in each pixel 11a while the variation in the light receiving sensitivity among the plurality of pixels 11a and the variation in the light receiving sensitivity depending on the location in one pixel 11a are suppressed. Therefore, according to the distance measuring image sensor 10C, it is possible to uniformly improve the light receiving sensitivity in the plurality of pixels 11a.
- the well region 31, the LOCOS region 33, the barrier region 34, and the sink region 35 are not formed in the semiconductor layer 20. Therefore, according to the distance measuring image sensor 10C, it is possible to increase the density of the plurality of pixels 11a and simplify the structure of the semiconductor layer 20. As an example, a semiconductor substrate on which a readout circuit for each pixel 11a and a CMOS readout circuit unit 12 are formed is joined to the distance measuring image sensor 10C from the first side.
- the first charge transfer region 24 is arranged in the central portion of the charge distribution region 23, and a plurality of second charge transfer regions. 26 is arranged along the outer edge of the charge distribution region 23, the photogate electrode 41 and the first transfer gate electrode 42 are formed in an annular shape, and the plurality of second transfer gate electrodes 44 are photogate electrodes.
- the above-mentioned distance measurement is performed in that the trench 29 is not formed in the semiconductor layer 20 and the avalanche multiplication region 22 is connected to the plurality of pixels 11a so as to surround the 41. It is mainly different from the image sensor 10A.
- the first charge transfer region 24 is arranged in the central portion of the charge distribution region 23 when viewed from the Z direction.
- the plurality of second charge transfer regions 26 are arranged along the outer edge of the charge distribution region 23 when viewed from the Z direction.
- Each second charge transfer region 26 is shared by two adjacent pixels 11a.
- the photogate electrode 41 has, for example, a rectangular ring shape when viewed from the Z direction, and is arranged outside the first charge transfer region 24 and inside the plurality of second charge transfer regions 26.
- the first transfer gate electrode 42 has, for example, a rectangular ring shape when viewed from the Z direction, and is arranged outside the first charge transfer region 24 and inside the photogate electrode 41.
- Each second transfer gate electrode 44 is arranged between the photogate electrode 41 and each second charge transfer region 26 when viewed from the Z direction.
- the well region 31 and the barrier region 34 are located on the intersections of a plurality of virtual lines arranged in a grid pattern so as to partition the plurality of pixels 11a when viewed from the Z direction. Have been placed. Therefore, the trench 29 is not formed in the semiconductor layer 20, and the avalanche multiplication region 22 is connected to the plurality of pixels 11a.
- the avalanche multiplication region 22 formed on the semiconductor layer 20 is connected over a plurality of pixels 11a.
- high sensitivity is realized in each pixel 11a while the variation in the light receiving sensitivity among the plurality of pixels 11a and the variation in the light receiving sensitivity depending on the location in one pixel 11a are suppressed. Therefore, according to the distance measuring image sensor 10D, it is possible to uniformly improve the light receiving sensitivity in the plurality of pixels 11a.
- the sink region 35 (see FIG. 3) is not formed on the semiconductor layer 20. This is because, in the distance measuring image sensor 10D, the barrier region 34 is separated from the first charge transfer region 24 as compared with the distance measuring image sensor 10A described above, and as a result, the electrons collected around the barrier region 34 are collected. This is because it becomes difficult to enter the first charge transfer region 24.
- the first charge transfer region 24 is arranged at the center of each pixel 11a, and the plurality of second charge transfer regions 26 are each pixel 11a.
- the points are arranged at the plurality of corners of the above, the points where the first transfer gate electrode 42 is formed in an annular shape, and the photogate electrodes 41 are arranged so as to avoid the central portion and the plurality of corners of each pixel 11a.
- the first charge transfer region 24 is arranged at the center of each pixel 11a when viewed from the Z direction.
- the plurality of second charge transfer regions 26 are arranged at a plurality of corners of each pixel 11a when viewed from the Z direction.
- the photogate electrode 41 is arranged so as to avoid the central portion and the plurality of corner portions of each pixel 11a (that is, avoid the first charge transfer region 24 and the plurality of second charge transfer regions 26).
- the photogate electrode 41 is connected to a plurality of pixels 11a.
- the first transfer gate electrode 42 has, for example, a rectangular ring shape when viewed from the Z direction, and is arranged outside the first charge transfer region 24 and inside the photogate electrode 41.
- Each second transfer gate electrode 44 is arranged between the photogate electrode 41 and each second charge transfer region 26 when viewed from the Z direction.
- each pixel 11a of the distance measuring image sensor 10E the corresponding second charge transfer region 26 and the second transfer gate electrode 44 are shared by four adjacent pixels 11a. Therefore, the trench 29 is not formed in the semiconductor layer 20, and the avalanche multiplication region 22 is connected to the plurality of pixels 11a.
- the avalanche multiplication region 22 formed on the semiconductor layer 20 is connected over a plurality of pixels 11a.
- high sensitivity is realized in each pixel 11a while the variation in the light receiving sensitivity among the plurality of pixels 11a and the variation in the light receiving sensitivity depending on the location in one pixel 11a are suppressed. Therefore, according to the distance measuring image sensor 10E, it is possible to uniformly improve the light receiving sensitivity in the plurality of pixels 11a.
- the well region 31, the LOCOS region 33, the barrier region 34, and the sink region 35 are not formed in the semiconductor layer 20. Therefore, according to the distance measuring image sensor 10E, it is possible to increase the density of the plurality of pixels 11a and simplify the structure of the semiconductor layer 20. As an example, a semiconductor substrate on which a readout circuit for each pixel 11a and a CMOS readout circuit unit 12 are formed is joined to the ranging image sensor 10E from the first side. [Modification example]
- the present disclosure is not limited to the above-mentioned first to fifth embodiments.
- the bottom surface 29a of the trench 29 may be located within the avalanche multiplication region 22. In that case, it is possible to sufficiently suppress the occurrence of crosstalk between adjacent pixels 11a while shortening the time for forming the trench 29.
- the bottom surface 29a of the trench 29 is located on the first side with respect to the avalanche multiplication region 22, and the avalanche multiplication region 22 is connected to the plurality of pixels 11a. May be good.
- the trench 29 may not be formed in the semiconductor layer 20, and the avalanche multiplication region 22 may be connected over the plurality of pixels 11a. Even in these cases, the light receiving sensitivity can be uniformly improved in the plurality of pixels 11a.
- each sink area 35 does not have to be connected to each of the second charge transfer areas 26 and 27.
- the sink region 35 may not be formed in the semiconductor layer 20.
- the well region 31 and the barrier region 34 may not be formed on the semiconductor layer 20.
- the charge blocking region 28 may not be formed on the semiconductor layer 20.
- the sink region 35 connected to the barrier region 34 may be formed in the semiconductor layer 20.
- a sink region 35 connected to each of the barrier region 34 and the second charge transfer region 26 may be formed in the semiconductor layer 20.
- the well region 31 and the barrier region 34 may not be formed on the semiconductor layer 20.
- the charge blocking region 28 may be formed in the semiconductor layer 20.
- the embedded region 36 may be formed in the semiconductor layer 20 of each pixel 11a.
- the embedded region 36 formed in the semiconductor layer 20 of each pixel 11a suppresses the generation of dark current in each pixel 11a.
- a point that a plurality of charge blocking regions 28 are not formed in the semiconductor layer 20 of each pixel 11a and an embedded region 36 in the semiconductor layer 20 of each pixel 11a are provided. It is mainly different from the above-mentioned ranging image sensor 10A in that it is formed.
- the configuration of the semiconductor layer 20 of each pixel 11a in the distance measuring image sensor 10A shown in FIGS. 16 and 17 is as follows.
- the charge distribution region 23 overlaps the photogate electrode 41 when viewed from the Z direction, and a plurality of transfer gate electrodes 42, 43, 44 when viewed from the Z direction. , 45 are formed so as not to overlap with each other.
- the embedded region 36 is a p-type region and is formed on the first side of the charge distribution region 23 in the semiconductor layer 20. That is, the charge distribution region 23 is embedded in the semiconductor layer 20 by the embedded region 36.
- the well region 31 surrounds the first side portion of the charge distribution region 23 and the embedded region 36. A part of the well region 31 is located between the embedded region 36 and the charge transfer regions 24, 25, 26, 27.
- the barrier region 34 surrounds the second side portion of the charge distribution region 23. When viewed from the Z direction, the inner edge of the barrier region 34 surrounding the charge distribution region 23 is located inside the inner edge of the well region 31 surrounding the charge distribution region 23 and the embedding region 36.
- the configuration of the semiconductor layer 20 of each pixel 11a in the distance measuring image sensor 10B shown in FIG. 18 is as follows.
- the charge distribution region 23 overlaps with the photogate electrode 41 when viewed from the Z direction, and a plurality of transfer gate electrodes 42, 43, 44a, 44b, when viewed from the Z direction. It is formed so as not to overlap with 45a and 45b (see FIG. 7).
- the embedded region 36 is a p-type region and is formed on the first side of the charge distribution region 23 in the semiconductor layer 20. That is, the charge distribution region 23 is embedded in the semiconductor layer 20 by the embedded region 36.
- the well region 31 surrounds the first side portion of the charge distribution region 23 and the embedded region 36. A part of the well region 31 is located between the embedded region 36 and the charge transfer regions 24, 25, 26a, 26b, 27a, 27b (see FIG. 7).
- the barrier region 34 surrounds the second side portion of the charge distribution region 23.
- the inner edge of the barrier region 34 surrounding the charge distribution region 23 is located inside the inner edge of the well region 31 surrounding the charge distribution region 23 and the embedding region 36.
- a well region 31 (hereinafter, “outer well region”) is formed in the semiconductor layer 20 so as to include a second charge transfer region 26 in each pixel 11a at a point where the region 31 (hereinafter referred to as “inner well region 31”) is formed. 31 ”) is formed, and the barrier region 34 is formed on the second side of each of the inner well region 31 and the outer well region 31.
- the configuration of the semiconductor layer 20 of each pixel 11a in the distance measuring image sensor 10C shown in FIG. 19 is as follows.
- the first side portion of the charge distribution region 23 overlaps with the photogate electrode 41 when viewed from the Z direction, and a plurality of transfer gate electrodes when viewed from the Z direction. It is formed so as not to overlap with 42 and 44.
- the embedded region 36 is a p-type region and is formed on the first side of the charge distribution region 23 in the semiconductor layer 20. That is, the charge distribution region 23 is embedded in the semiconductor layer 20 by the embedded region 36.
- the embedded region 36 has, for example, a rectangular ring shape when viewed from the Z direction, similar to the photogate electrode 41.
- the embedding region 36 surrounds the inner well region 31 when viewed from the Z direction.
- the outer well region 31 surrounds the embedding region 36 when viewed from the Z direction.
- the semiconductor layer is such that the embedded region 36 is formed in the semiconductor layer 20 of each pixel 11a and the first charge transfer region 24 is included in each pixel 11a.
- a well region 31 (hereinafter, referred to as “inner well region 31”) is formed in 20 and a well region 31 (hereinafter, referred to as “inner well region 31”) is formed in the semiconductor layer 20 so as to include a plurality of second charge transfer regions 26 in each pixel 11a.
- a barrier region 34 is formed on the second side of each of the inner well region 31 and the outer well region 31) at the point where the “outer well region 31”) is formed. It is mainly different from the distance image sensor 10D.
- the configuration of the semiconductor layer 20 of each pixel 11a in the distance measuring image sensor 10D shown in FIGS. 20 and 21 is as follows.
- the first portion of the charge distribution region 23 overlaps with the photogate electrode 41 when viewed from the Z direction, and a plurality of portions when viewed from the Z direction. It is formed so as not to overlap with the transfer gate electrodes 42 and 44.
- the embedded region 36 is a p-type region and is formed on the first side of the charge distribution region 23 in the semiconductor layer 20. That is, the charge distribution region 23 is embedded in the semiconductor layer 20 by the embedded region 36.
- the embedded region 36 has, for example, a rectangular ring shape when viewed from the Z direction, similar to the photogate electrode 41.
- the embedding region 36 surrounds the inner well region 31 when viewed from the Z direction.
- the outer well region 31 surrounds the embedding region 36 when viewed from the Z direction.
- the ranging image sensor 10E shown in FIG. 22 has a point where an embedded region 36 is formed in the semiconductor layer 20 of each pixel 11a, and a well in the semiconductor layer 20 so as to include a first charge transfer region 24 in each pixel 11a.
- the distance measurement described above is at the point where the outer well region 31 ”) is formed and the barrier region 34 is formed on the second side of each of the inner well region 31 and the outer well region 31. It is mainly different from the image sensor 10E.
- the configuration of the semiconductor layer 20 of each pixel 11a in the distance measuring image sensor 10E shown in FIG. 22 is as follows.
- the first side portion of the charge distribution region 23 overlaps with the photogate electrode 41 when viewed from the Z direction, and a plurality of transfer gate electrodes when viewed from the Z direction. It is formed so as not to overlap with 42 and 44.
- the embedded region 36 is a p-type region and is formed on the first side of the charge distribution region 23 in the semiconductor layer 20. That is, the charge distribution region 23 is embedded in the semiconductor layer 20 by the embedded region 36.
- the embedding region 36 surrounds the inner well region 31 when viewed from the Z direction.
- the counter electrode 50 may be formed of a material having conductivity and light transmission (for example, polysilicon).
- the electrode connected to the first multiplication region 22a side (the electrode on the first conductive type side) such as the electrode connected to the semiconductor region 21 is not limited to the counter electrode 50, and is from the first surface 20a of the semiconductor layer 20. It may be a through electrode reaching the semiconductor region 21, an electrode formed on the surface of the semiconductor region 21 reaching the first surface 20a of the semiconductor layer 20, or the like.
- any of the ranging image sensors 10A to 10E for one pixel 11a, at least one first charge transfer region, at least one second charge transfer region, at least one first transfer gate electrode, and at least one. It suffices if two second transfer gate electrodes are provided, how to apply a voltage to the first transfer gate electrode and the second transfer gate electrode, and to take out charges from the first charge transfer region and the second charge transfer region. The method and method of discharging are not limited to those described above. In any of the distance measuring image sensors 10A to 10E, the p-type and n-type conductive types may be opposite to those described above. In any of the distance measuring image sensors 10A to 10E, the plurality of pixels 11a may be one-dimensionally arranged along the first surface 20a of the semiconductor layer 20.
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Power Engineering (AREA)
- General Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Computer Hardware Design (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Computer Networks & Wireless Communication (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Solid State Image Pick-Up Elements (AREA)
- Light Receiving Elements (AREA)
Abstract
Description
[第1実施形態]
[光検出装置の構成]
[測距イメージセンサの構成]
[測距イメージセンサの製造方法]
[作用及び効果]
[第2実施形態]
[第3実施形態]
[第4実施形態]
[第5実施形態]
[変形例]
Claims (11)
- 第1側の第1表面、及び、前記第1側とは反対側である第2側の第2表面を有し、前記第1表面に沿って配置された複数の画素を構成する半導体層と、
前記第1表面に設けられ、前記複数の画素を構成する電極層と、を備え、
前記複数の画素のそれぞれは、
前記半導体層に形成された第1導電型の第1増倍領域、及び、前記半導体層において前記第1増倍領域の前記第1側に形成された第2導電型の第2増倍領域を含むアバランシェ増倍領域と、
前記半導体層において前記第2増倍領域の前記第1側に形成され、前記第2増倍領域と接続された第2導電型の電荷振分領域と、
前記半導体層において前記第2増倍領域の前記第1側に形成され、前記電荷振分領域と接続された第2導電型の第1電荷転送領域と、
前記半導体層において前記第2増倍領域の前記第1側に形成され、前記電荷振分領域と接続された第2導電型の第2電荷転送領域と、
前記電極層において前記電荷振分領域の前記第1側に形成されたフォトゲート電極と、
前記フォトゲート電極に対して前記第1電荷転送領域側に位置するように、前記電極層において前記電荷振分領域の前記第1側に形成された第1転送ゲート電極と、
前記フォトゲート電極に対して前記第2電荷転送領域側に位置するように、前記電極層において前記電荷振分領域の前記第1側に形成された第2転送ゲート電極と、有し、
前記アバランシェ増倍領域は、前記複数の画素に渡って繋がっているか、又は、前記複数の画素のそれぞれを互いに分離するように前記半導体層に形成されたトレンチに至っている、測距イメージセンサ。 - 前記トレンチは、前記第1表面に形成されており、
前記トレンチの底面は、前記アバランシェ増倍領域に対して前記第2側に位置している、請求項1に記載の測距イメージセンサ。 - 前記トレンチは、前記第1表面に形成されており、
前記トレンチの底面は、前記アバランシェ増倍領域内に位置している、請求項1に記載の測距イメージセンサ。 - 前記複数の画素のそれぞれは、
前記半導体層において前記第2増倍領域の前記第1側に形成され、前記第1電荷転送領域及び前記第2電荷転送領域の少なくとも一方と電気的に接続された読出し回路を構成する第1導電型のウェル領域と、
前記半導体層において前記第2増倍領域と前記ウェル領域との間に形成された第2導電型のバリア領域と、を更に有する、請求項1~3のいずれか一項に記載の測距イメージセンサ。 - 前記バリア領域は、前記半導体層の厚さ方向から見た場合に前記ウェル領域を含んでいる、請求項4に記載の測距イメージセンサ。
- 前記複数の画素のそれぞれは、
前記半導体層において前記バリア領域の前記第1側に形成され、前記バリア領域と接続された第2導電型のシンク領域を更に有する、請求項4又は5に記載の測距イメージセンサ。 - 前記シンク領域は、前記第2電荷転送領域と接続されている、請求項6に記載の測距イメージセンサ。
- 前記電極層を覆うように前記第1表面に設けられ、前記複数の画素のそれぞれと電気的に接続された配線層を更に備える、請求項1~7のいずれか一項に記載の測距イメージセンサ。
- 請求項1に記載の測距イメージセンサの製造方法であって、
前記アバランシェ増倍領域、前記電荷振分領域、前記第1電荷転送領域及び前記第2電荷転送領域を半導体基板に形成することで、前記半導体層を形成する第1工程と、
前記第1工程の後に、前記フォトゲート電極、前記第1転送ゲート電極及び前記第2転送ゲート電極を前記半導体層の前記第1表面に形成することで、前記電極層を形成する第2工程と、を備え、
前記第1工程においては、前記複数の画素に渡って繋がるように前記半導体基板に前記アバランシェ増倍領域を形成する、測距イメージセンサの製造方法。 - 前記第1工程においては、少なくとも前記アバランシェ増倍領域を前記半導体基板に形成した後に、前記第1表面に前記トレンチを形成する、請求項9に記載の測距イメージセンサの製造方法。
- 前記第2工程の後に、前記電極層を覆うように前記第1表面に配線層を形成し、前記配線層を前記複数の画素のそれぞれと電気的に接続する第3工程を更に備える、請求項10に記載の測距イメージセンサの製造方法。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE112020006344.5T DE112020006344T5 (de) | 2019-12-26 | 2020-12-07 | Range-Imaging-Sensor und Verfahren zur Herstellung dieses Sensors |
CN202080089284.XA CN114902418A (zh) | 2019-12-26 | 2020-12-07 | 测距图像传感器及其制造方法 |
US17/788,005 US20230026004A1 (en) | 2019-12-26 | 2020-12-07 | Ranging image sensor and method for manufacturing same |
KR1020227024969A KR20220119661A (ko) | 2019-12-26 | 2020-12-07 | 측거 이미지 센서 및 그 제조 방법 |
JP2021521315A JP6913840B1 (ja) | 2019-12-26 | 2020-12-07 | 測距イメージセンサ及びその製造方法 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2019236237 | 2019-12-26 | ||
JP2019-236237 | 2019-12-26 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2021131651A1 true WO2021131651A1 (ja) | 2021-07-01 |
Family
ID=76573990
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2020/045535 WO2021131651A1 (ja) | 2019-12-26 | 2020-12-07 | 測距イメージセンサ及びその製造方法 |
Country Status (6)
Country | Link |
---|---|
US (1) | US20230026004A1 (ja) |
JP (2) | JP6913840B1 (ja) |
KR (1) | KR20220119661A (ja) |
CN (1) | CN114902418A (ja) |
DE (1) | DE112020006344T5 (ja) |
WO (1) | WO2021131651A1 (ja) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2024028045A (ja) * | 2022-08-19 | 2024-03-01 | ソニーセミコンダクタソリューションズ株式会社 | 光検出装置 |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2008004547A1 (fr) * | 2006-07-03 | 2008-01-10 | Hamamatsu Photonics K.K. | Ensemble photodiode |
JP2009014460A (ja) * | 2007-07-03 | 2009-01-22 | Hamamatsu Photonics Kk | 裏面入射型測距センサ及び測距装置 |
JP2009047661A (ja) * | 2007-08-22 | 2009-03-05 | Hamamatsu Photonics Kk | 測距装置 |
JP2011222893A (ja) * | 2010-04-14 | 2011-11-04 | Hamamatsu Photonics Kk | 半導体光検出素子 |
US20170192090A1 (en) * | 2015-12-30 | 2017-07-06 | Stmicroelectronics (Crolles 2) Sas | Time-of-flight detection pixel |
WO2018174090A1 (ja) * | 2017-03-22 | 2018-09-27 | ソニーセミコンダクタソリューションズ株式会社 | 撮像装置及び信号処理装置 |
JP2018530176A (ja) * | 2015-07-08 | 2018-10-11 | ザ コモンウェルス オブ オーストラリアThe Commonwealth Of Australia | Spadアレイ構造及び動作方法 |
JP2019004149A (ja) * | 2017-06-15 | 2019-01-10 | 三星電子株式会社Samsung Electronics Co.,Ltd. | 距離測定のためのイメージセンサ |
JP2019079968A (ja) * | 2017-10-26 | 2019-05-23 | ソニーセミコンダクタソリューションズ株式会社 | フォトダイオード、画素回路、および、フォトダイオードの製造方法 |
US20190187260A1 (en) * | 2016-08-12 | 2019-06-20 | Sony Depthsensing Solutions Sa/Nv | A demodulator with a carrier generating pinned photodiode and a method for operating it |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5558999B2 (ja) | 2009-11-24 | 2014-07-23 | 浜松ホトニクス株式会社 | 距離センサ及び距離画像センサ |
US9134401B2 (en) | 2012-03-27 | 2015-09-15 | Hamamatsu Photonics K. K. | Range sensor and range image sensor |
-
2020
- 2020-12-07 US US17/788,005 patent/US20230026004A1/en active Pending
- 2020-12-07 WO PCT/JP2020/045535 patent/WO2021131651A1/ja active Application Filing
- 2020-12-07 CN CN202080089284.XA patent/CN114902418A/zh active Pending
- 2020-12-07 JP JP2021521315A patent/JP6913840B1/ja active Active
- 2020-12-07 KR KR1020227024969A patent/KR20220119661A/ko unknown
- 2020-12-07 DE DE112020006344.5T patent/DE112020006344T5/de active Pending
-
2021
- 2021-07-09 JP JP2021114410A patent/JP2021182627A/ja active Pending
Patent Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2008004547A1 (fr) * | 2006-07-03 | 2008-01-10 | Hamamatsu Photonics K.K. | Ensemble photodiode |
JP2009014460A (ja) * | 2007-07-03 | 2009-01-22 | Hamamatsu Photonics Kk | 裏面入射型測距センサ及び測距装置 |
JP2009047661A (ja) * | 2007-08-22 | 2009-03-05 | Hamamatsu Photonics Kk | 測距装置 |
JP2011222893A (ja) * | 2010-04-14 | 2011-11-04 | Hamamatsu Photonics Kk | 半導体光検出素子 |
JP2018530176A (ja) * | 2015-07-08 | 2018-10-11 | ザ コモンウェルス オブ オーストラリアThe Commonwealth Of Australia | Spadアレイ構造及び動作方法 |
US20170192090A1 (en) * | 2015-12-30 | 2017-07-06 | Stmicroelectronics (Crolles 2) Sas | Time-of-flight detection pixel |
US20190187260A1 (en) * | 2016-08-12 | 2019-06-20 | Sony Depthsensing Solutions Sa/Nv | A demodulator with a carrier generating pinned photodiode and a method for operating it |
WO2018174090A1 (ja) * | 2017-03-22 | 2018-09-27 | ソニーセミコンダクタソリューションズ株式会社 | 撮像装置及び信号処理装置 |
JP2019004149A (ja) * | 2017-06-15 | 2019-01-10 | 三星電子株式会社Samsung Electronics Co.,Ltd. | 距離測定のためのイメージセンサ |
JP2019079968A (ja) * | 2017-10-26 | 2019-05-23 | ソニーセミコンダクタソリューションズ株式会社 | フォトダイオード、画素回路、および、フォトダイオードの製造方法 |
Also Published As
Publication number | Publication date |
---|---|
DE112020006344T5 (de) | 2022-10-27 |
US20230026004A1 (en) | 2023-01-26 |
JP2021182627A (ja) | 2021-11-25 |
CN114902418A (zh) | 2022-08-12 |
KR20220119661A (ko) | 2022-08-30 |
JP6913840B1 (ja) | 2021-08-04 |
JPWO2021131651A1 (ja) | 2021-07-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2020202880A1 (ja) | アバランシェフォトダイオードセンサおよびセンサ装置 | |
US20070187724A1 (en) | Image sensor with large-area, high-sensitivity and high-speed pixels | |
JP4304927B2 (ja) | 固体撮像素子及びその製造方法 | |
TWI539585B (zh) | Solid state camera device | |
JP6351097B2 (ja) | 電磁波検出素子及び固体撮像装置 | |
JP6913840B1 (ja) | 測距イメージセンサ及びその製造方法 | |
WO2021215066A1 (ja) | 光検出器及び電子機器 | |
JPS61133660A (ja) | 固体イメ−ジセンサ | |
JP6913841B1 (ja) | 測距イメージセンサ | |
WO2021149650A1 (ja) | フォトセンサ及び距離測定システム | |
JP6913793B1 (ja) | 光センサ | |
JP6895595B1 (ja) | 測距装置、及び測距センサの駆動方法 | |
WO2021131399A1 (ja) | 測距装置、及び測距センサの駆動方法 | |
WO2021225036A1 (ja) | 光検出装置、及び光センサの駆動方法 | |
US20230035346A1 (en) | Light detection device and method for driving photosensor | |
WO2022054341A1 (ja) | 距離画像取得装置及び距離画像取得方法 | |
WO2023108527A1 (en) | Soi-jfet pixel and method of fabricating the same | |
US20230283866A1 (en) | Imaging device | |
WO2022210149A1 (ja) | 固体撮像素子および固体撮像素子の製造方法 | |
TW202218105A (zh) | 感測器裝置及感測模組 | |
JPH04233760A (ja) | 固体撮像装置 | |
JPH02106070A (ja) | 固体撮像装置 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
ENP | Entry into the national phase |
Ref document number: 2021521315 Country of ref document: JP Kind code of ref document: A |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 20907605 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 20227024969 Country of ref document: KR Kind code of ref document: A |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 20907605 Country of ref document: EP Kind code of ref document: A1 |