Optical detection device, optical detection system, lidar device, moving body, inspection method, and semiconductor device manufacturing method

Abstract

To provide a light detection device, a light detection system, a rider device, a movable body, an inspection method, and a manufacturing method of a semiconductor device, capable of more easily performing an inspection.SOLUTION: A light detection device according to an embodiment includes a first region, a second region, a first electrode, and a second electrode. The first region includes a plurality of first semiconductor light detection elements, and a plurality of first lenses respectively provided on the plurality of first semiconductor light detection elements. The second region includes a plurality of second semiconductor light detection elements, no lens being located directly above the plurality of second semiconductor light detection elements at a position in a first direction that is the same direction of the plurality of first lenses. The first direction is a direction from one of the plurality of first semiconductor light detection elements toward one of the plurality of first lenses. The first electrode is electrically connected to the plurality of first semiconductor light detection elements. The second electrode is electrically connected to the plurality of second semiconductor light detection elements.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] Embodiments of the present invention relate to a light detection device, a light detection system, a lidar device, a moving object, an inspection method, and a method for manufacturing a semiconductor device. [Background technology]

[0002] There are photodetection devices that detect light, and there is a demand for technology that can more easily inspect these photodetection devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-72347 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the embodiments of the present invention, a light detection device, a light detection system, a lidar device, a moving object, an inspection method, and a method for manufacturing a semiconductor device are provided, which allow for easier inspection. [Means for solving the problem]

[0005] A photodetector device according to an embodiment includes a first region, a second region, a first electrode, and a second electrode. The first region includes a plurality of first semiconductor photodetector elements and a plurality of first lenses respectively provided on the plurality of first semiconductor photodetector elements. The second region includes a plurality of second semiconductor photodetector elements. No lenses are provided directly above the plurality of second semiconductor photodetector elements at the same positions in the first direction as the first lenses. The first direction is a direction from one of the plurality of first semiconductor photodetector elements to one of the plurality of first lenses. The first electrode is electrically connected to the plurality of first semiconductor photodetector elements. The second electrode is electrically connected to the plurality of second semiconductor photodetector elements. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic plan view showing a light detection device according to an embodiment. [Figure 2] FIG. 2 is an enlarged plan view of a portion A of FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along the line B1-B2 of FIG. [Figure 4] FIG. 4 is an enlarged plan view of a portion C of FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along line D1-D2 of FIG. [Figure 6] FIG. 6 is a flowchart showing the inspection method according to the first embodiment. [Figure 7] FIG. 7 is a graph illustrating an output from the photodetection device according to the first embodiment. [Figure 8] FIG. 8 is a flowchart showing the specific process of the inspection. [Figure 9] FIG. 9 is a flowchart showing another inspection method according to the first embodiment. [Figure 10] FIG. 10 is a flowchart showing another inspection method according to the first embodiment. [Figure 11] FIG. 11 is a schematic plan view showing a light detection device according to a first modified example of the first embodiment. [Figure 12] FIG. 12 is an enlarged plan view of a portion A of FIG. [Figure 13] FIG. 13 is a cross-sectional view taken along the line B1-B2 of FIG. [Figure 14] FIG. 14 is a schematic plan view showing a light detection device according to a second modified example of the first embodiment. [Figure 15] FIG. 15 is an enlarged plan view of a portion A in FIG. [Figure 16] FIG. 16 is a cross-sectional view taken along the line B1-B2 of FIG. [Figure 17] FIG. 17 is a schematic plan view showing a light detection device according to a third modified example of the first embodiment. [Figure 18] FIG. 18 is an enlarged plan view of a portion A in FIG. [Figure 19] FIG. 19 is a schematic plan view showing another light detection device according to the third modified example of the first embodiment. [Figure 20] FIG. 20 is a schematic cross-sectional view showing a part of the light detection device according to the first embodiment. [Figure 21] FIG. 21 is a schematic diagram illustrating an active quench circuit. [Figure 22] 22(a) and 22(b) are schematic diagrams illustrating the test object. [Figure 23] FIG. 23 is a schematic plan view showing the light detection device according to the second embodiment. [Figure 24] FIG. 24 is a flowchart showing a manufacturing method according to the third embodiment. [Figure 25] FIG. 25 is a schematic diagram illustrating a wafer map. [Figure 26] FIG. 26 is a flowchart showing a manufacturing method according to a first modified example of the third embodiment. [Figure 27] FIG. 27 is a schematic diagram showing a hardware configuration. [Figure 28] FIG. 28 is a schematic diagram illustrating a LIDAR device according to the fourth embodiment. [Figure 29] FIG. 29 is a diagram for explaining detection of a detection target by a LIDAR device. [Figure 30] FIG. 30 is a schematic top view of a moving body equipped with a LIDAR device according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Even when the same part is shown, the dimensions and ratios may be different depending on the drawing. In the present specification and the drawings, elements similar to those already explained are given the same reference numerals and detailed explanations will be omitted as appropriate. In the following description and drawings, n + and p + , p, p - The notation indicates the relative level of each impurity concentration. That is, a notation with a "+" indicates a relatively higher impurity concentration than a notation with neither a "+" nor a "-" and a notation with a "-" indicates a relatively lower impurity concentration than a notation with neither. When both p-type and n-type impurities are contained in each region, these notations indicate the relative level of the net impurity concentration after the impurities compensate for each other. In each of the embodiments described below, the p-type and n-type of each semiconductor region may be reversed to implement each embodiment.

[0008] [First embodiment] FIG. 1 is a schematic plan view showing a light detection device according to an embodiment. 1, the photodetector 100 includes a first region 10, a second region 20, a pad electrode 51 (first electrode), and a pad electrode 52 (second electrode). The pad electrode 51 and the pad electrode 52 are located on the front surface side of the photodetector 100. The pad electrode 51 is provided to extract an output from the first region 10. The pad electrode 52 is provided to extract an output from the second region 20.

[0009] The pad electrode 52 is separated from the pad electrode 51 and electrically isolated from the pad electrode 51. Therefore, the output from the first region 10 and the output from the second region 20 can be extracted independently through the pad electrodes 51 and 52. The second region 20 may be separated from the first region 10 or may be adjacent to the first region 10.

[0010] Fig. 2 is an enlarged plan view of a portion A in Fig. 1. Fig. 3 is a cross-sectional view taken along line B1-B2 in Fig. 2. 2 and 3, the first region 10 includes a first semiconductor photodetector element 11, a first lens 12, a first quenching portion 13, a first wiring 14, and an insulating layer 15. Note that the insulating layer 15 is omitted in FIG. 2.

[0011] For the sake of explanation, the direction from the first semiconductor photodetector element 11 to the first lens 12 is referred to as the Z direction (first direction). Two directions that are perpendicular to the Z direction and intersect with each other are referred to as the X direction and the Y direction. Furthermore, the direction from the first semiconductor photodetector element 11 to the first lens 12 is referred to as "up," and the opposite direction is referred to as "down." These directions are based on the relative positional relationship between the first semiconductor photodetector element 11 and the first lens 12, and are unrelated to the direction of gravity.

[0012] The first semiconductor photodetector element 11 includes a p-type (first conductivity type) semiconductor region 1 (first semiconductor region) and an n + n type (second conductivity type) semiconductor region 2 (second semiconductor region). + The p-type semiconductor region 2 is provided on the p-type semiconductor region 1 and is in contact with the p-type semiconductor region 1. + A pn junction is formed between the semiconductor region 2 and the semiconductor region 3 .

[0013] The insulating layer 15 is optically transparent and is provided on the first semiconductor photodetector element 11. The first lens 12 is provided on the insulating layer 15 and is located above the first semiconductor photodetector element 11. The upper surface of the first lens 12 is convex upward. The lower surface of the first lens 12 is parallel to the XY plane. The first lens 12 collects light toward the corresponding first semiconductor photodetector element 11.

[0014] n of the first semiconductor photodetector element 11 + The semiconductor region 2 is electrically connected to the first quench portion 13 via a contact plug 13a, a wiring 13b, and a contact plug 13c. The first quench portion 13 is electrically connected to the first wiring 14 via a contact plug (not shown). In other words, the first quench portion 13 is electrically connected between the first semiconductor photodetector element 11 and the first wiring 14.

[0015] A plurality of first semiconductor photodetector elements 11 are provided in the X and Y directions. The first quenching portion 13 is electrically connected to one or more first semiconductor photodetector elements 11. A plurality of first wirings 14 are provided in the Y direction. Each first wiring 14 is electrically connected to a plurality of first semiconductor photodetector elements 11 lined up in the X direction. The plurality of first wirings 14 are electrically connected to pad electrodes 51.

[0016] In the illustrated example, the insulating portion 5 is formed between the p-type semiconductor region 1 and the n-type semiconductor region 2 in the XY plane. + The insulating portions 5 are provided around the semiconductor region 2. For example, a plurality of insulating portions 5 spaced apart from each other are provided around the plurality of first semiconductor photodetector elements 11, respectively.

[0017] Fig. 4 is an enlarged plan view of a portion C in Fig. 1. Fig. 5 is a cross-sectional view taken along line D1-D2 in Fig. 4. As shown in FIGS. 4 and 5, the second region 20 includes a second semiconductor photodetector element 21, a second quenching portion 23, a second wiring 24, and an insulating layer 25.

[0018] The second semiconductor photodetector element 21, like the first semiconductor photodetector element 11, has a p-type semiconductor region 1 and an n-type semiconductor region 2. + The insulating portion 5 is formed between the p-type semiconductor region 1 and the n-type semiconductor region 2 in the XY plane. + The insulating layer 25 is optically transparent and is provided on the second semiconductor photodetector element 21. No lens is provided directly above the second semiconductor photodetector element 21 at the same position in the Z direction as the first lens 12. The second region 20 does not include a lens.

[0019] Alternatively, the second region 20 may include another lens that is larger than the first lens 12, and the another lens may be provided directly above the second semiconductor photodetector elements 21. In this case, the another lens is located directly above the plurality of second semiconductor photodetector elements 21. In other words, in either case, no lens corresponding to each of the second semiconductor photodetector elements 21 is provided in the second region 20. The position of the another lens in the Z direction may be the same as or different from the position of the first lens 12 in the Z direction.

[0020] n of the second semiconductor photodetector element 21 + The semiconductor region 2 is electrically connected to the second quench portion 23 via the contact plug 23a, the wiring 23b, and the contact plug 23c. The second quench portion 23 is electrically connected to the second wiring 24. In other words, the second quench portion 23 is electrically connected between the second semiconductor photodetector element 21 and the second wiring 24.

[0021] A plurality of second semiconductor photodetector elements 21 are provided in the X and Y directions. The second quench portion 23 is electrically connected to one or more second semiconductor photodetector elements 21. A plurality of second wirings 24 are provided in the Y direction. Each second wiring 24 is electrically connected to a plurality of second semiconductor photodetector elements 21 lined up in the X direction. The plurality of second wirings 24 are electrically connected to pad electrodes 52.

[0022] The first semiconductor photodetector element 11 and the second semiconductor photodetector element 21 have substantially the same characteristics. For example, the p-type impurity concentration, thickness, and width of the p-type semiconductor region 1 of the first semiconductor photodetector element 11 are the same as the p-type impurity concentration, thickness, and width of the p-type semiconductor region 1 of the second semiconductor photodetector element 21, respectively. + The n-type impurity concentration, thickness and width of the n-type semiconductor region 2 are respectively the same as those of the n-type semiconductor light-detecting element 21. + The n-type impurity concentration, thickness, and width are the same as those of the n-type semiconductor region 2. The thickness is the dimension in the Z direction. The width is the dimension in the X or Y direction.

[0023] As shown in FIGS. 3 and 5, the first region 10 and the second region 20 are p + The semiconductor layer 61 (first semiconductor layer) and p - The semiconductor layer 62 is provided on the insulating layer 64. - The semiconductor layer 62 is p + The insulating layer 61 is provided on the insulating layer 62. - The p-type impurity concentration of the p-type semiconductor layer 62 is p + The p-type impurity concentration of the p-type semiconductor region 1 is lower than that of the p-type semiconductor layer 61. -The p-type impurity concentration of the p-type semiconductor layer 62 is higher than that of the p-type semiconductor layer 62.

[0024] The p-type semiconductor region 1 is p - p through the semiconductor layer 62 + It is electrically connected to the semiconductor layer 61. + A back electrode may be provided under the semiconductor layer 61. + By applying a voltage between the semiconductor layer 61 and the pad electrode 51, a voltage is applied to the plurality of first semiconductor light-detecting elements 11. + By applying a voltage between the semiconductor layer 61 and the pad electrode 52, a voltage is applied to the plurality of second semiconductor light detecting elements 21.

[0025] p-type semiconductor region 1 and n + A reverse voltage is applied between the p-type semiconductor region 1 and the n-type semiconductor region 2. For example, the first semiconductor photodetector element 11 and the second semiconductor photodetector element 21 function as a PiN diode or an avalanche photodiode (APD). + A voltage significantly exceeding the breakdown voltage may be applied between the first semiconductor photodetector element 11 and the second semiconductor photodetector element 2. That is, the first semiconductor photodetector element 11 and the second semiconductor photodetector element 21 may be APDs that operate in Geiger mode. By operating in Geiger mode, a pulsed signal is output with a high multiplication factor. This improves the light receiving sensitivity of the first semiconductor photodetector element 11 and the second semiconductor photodetector element 21.

[0026] Each of the first semiconductor photodetector elements 11 and each of the second semiconductor photodetector elements 21 can detect light. The first semiconductor photodetector element 11 detects light that is collected by the first lens 12 and incident on the first semiconductor photodetector element 11. The second semiconductor photodetector element 21 detects light that is incident on the second semiconductor photodetector element 21 without passing through a lens. When light is incident on the first semiconductor photodetector element 11 or the second semiconductor photodetector element 21 from above, p + Semiconductor layer 61, p - Charges are generated in the p-type semiconductor layer 62 or the p-type semiconductor region 1. The charges flow to the pad electrodes, generating a current. The incidence of light on the first region 10 or the second region 20 can be detected from the current based on the charges.

[0027] When the first semiconductor photodetector element 11 and the second semiconductor photodetector element 21 operate in Geiger mode, the first quench portion 13 and the second quench portion 23 are electrically connected, as shown in Figures 2 to 5. When the first semiconductor photodetector element 11 and the second semiconductor photodetector element 21 do not operate in Geiger mode or are PiN diodes, the first quench portion 13 and the second quench portion 23 can be omitted.

[0028] The first quench portion 13 and the second quench portion 23 are provided to suppress the continuation of avalanche breakdown when it occurs. The electrical resistance of the first quench portion 13 and the electrical resistance of the second quench portion 23 are each greater than the electrical resistance of the contact plug, wiring, etc. The electrical resistance of the first quench portion 13 and the electrical resistance of the second quench portion 23 are preferably 50 kΩ or more and 6 MΩ or less. When avalanche breakdown occurs and a current flows through the first quench portion 13 or the second quench portion 23, a voltage drop occurs according to the electrical resistance. The voltage drop causes a current to flow between the p-type semiconductor region 1 and the n-type semiconductor region 2. + The potential difference between the first semiconductor photodetector element 11 and the second semiconductor photodetector element 21 decreases, and the avalanche breakdown stops. This allows the first semiconductor photodetector element 11 and the second semiconductor photodetector element 21 to respond quickly with a short time constant, and they can again detect the next incident light.

[0029] In the photodetector 100, the area of ​​the first region 10 is larger than the area of ​​the second region 20. In other words, the number of first semiconductor photodetector elements 11 provided in the first region 10 is greater than the number of second semiconductor photodetector elements 21 provided in the second region 20. The first region 10, which includes the first lenses 12, is the main region for photodetection. The second region 20 is provided as a reference region for inspection.

[0030] An example of the material for each element will be described below. p-type semiconductor region 1, n + Semiconductor region 2, p + The semiconductor layer 61 and the p -The n-type semiconductor layer 62 includes at least one semiconductor material selected from the group consisting of silicon, silicon carbide, gallium arsenide, and gallium nitride. For example, when these semiconductor regions include silicon, phosphorus, arsenic, or antimony is used as an n-type impurity. Boron or boron fluoride is used as a p-type impurity.

[0031] p + The semiconductor layer 61 is, for example, a part of a semiconductor substrate. - The semiconductor layer 62 is p + The p-type semiconductor region 1 and the n-type semiconductor region 2 are layers formed by epitaxial growth on the p-type semiconductor layer 61. + The semiconductor region 2 is p - The semiconductor layer 62 is formed by ion implantation.

[0032] The insulating portion 5, the insulating layer 15, and the insulating layer 25 include an insulating material. For example, the insulating portion 5, the insulating layer 15, and the insulating layer 25 include silicon oxide or silicon nitride. The first quenching portion 13 and the second quenching portion 23 include polysilicon. The first quenching portion 13 and the second quenching portion 23 may be doped with n-type impurities or p-type impurities. The pad electrode 51, the pad electrode 52, each contact plug, and each wiring include a metal material such as tungsten, titanium, copper, or aluminum.

[0033] The first lens 12 contains a light-transmitting resin. The resin has a refractive index different from that of the semiconductor material. The resin is preferably an acrylic resin. The acrylic resin may be a resin mixed with propylene glycol monomethyl ether acetate.

[0034] FIG. 6 is a flowchart showing the inspection method according to the first embodiment. In the inspection method IM1 shown in FIG. 6, a first voltage is applied to a plurality of first semiconductor photodetector elements 11 of the photodetector 100, and a first output value is measured when each element is irradiated with light through a first lens 12 (step S1). A first voltage is applied to a plurality of second semiconductor photodetector elements 21 of the photodetector 100, and a second output value is measured when each element is irradiated with light without passing through a lens (step S2). In steps S1 and S2, light of the same intensity is irradiated onto the first region 10 and the second region 20. Step S2 may be performed before step S1. Steps S1 and S2 may be performed simultaneously. The photodetector 100 is inspected using the measured first and second output values ​​(step S3).

[0035] FIG. 7 is a graph illustrating an output from the photodetection device according to the first embodiment. In FIG. 7, the horizontal axis represents voltage V, and the vertical axis represents current I. The solid line represents first output values ​​OP1 from the plurality of first semiconductor photodetector elements 11. The dashed line represents second output values ​​OP2 from the plurality of second semiconductor photodetector elements 21. FIG. 7 shows the output when the applied voltage to the first semiconductor photodetector elements 11 and the second semiconductor photodetector elements 21 is increased while the first region 10 and the second region 20 are irradiated with light of the same intensity. Light is collected by the first lens 12 onto the first semiconductor photodetector element 11. Therefore, the first output value OP1 from the plurality of first semiconductor photodetector elements 11 is greater than the second output value OP2 from the plurality of second semiconductor photodetector elements 21.

[0036] The first output value OP1 and the second output value OP2 depend on the number of first semiconductor photodetecting elements 11 and the number of second semiconductor photodetecting elements 21, respectively. If the number of second semiconductor photodetecting elements 21 is different from the number of first semiconductor photodetecting elements 11, one of the first output value OP1 or the second output value OP2 is corrected. For example, if the number of first semiconductor photodetecting elements 11 is N times the number of second semiconductor photodetecting elements 21, the first output value OP1 is multiplied by (1 / N). FIG. 7 shows the corrected first output value OP1 and second output value OP2.

[0037] The corrected first output value OP1 is approximately expressed by the following Equation 1. Ia (V) =A×(DCR (V) )×(Gain (V) )+B×(PDE (V) )×(Gain (V) ) ···(1)

[0038] Ia (V) is the current output from the plurality of first semiconductor photodetecting elements 11 when the voltage is V, and corresponds to the first output value OP1. A and B are coefficients that are set appropriately depending on the measurement environment, such as the intensity of the irradiated light, and the characteristics of the photodetecting device 100. (V) is the number of thermal noise (dark counts) generated per unit time at voltage V. Gain (V) is the multiplication factor at voltage V. DCR (V) and Gain (V) The current (dark current) caused by thermal noise generated in the first region 10 can be approximately expressed by the value obtained by multiplying the product of PDE by A, which is a unit conversion coefficient. (V) is the photodetection efficiency at voltage V. (V) and Gain (V) The current (light current) generated in the first region 10 due to the light detection can be approximately expressed by the value obtained by multiplying the product of ∇ ...

[0039] The second output value OP2 is approximately expressed by the following Equation 2. Ib (V) =A×(DCR (V) )×(Gain (V) )+B×(1 / M)×(PDE (V) )×(Gain (V) ) ···(2)

[0040] Ib (V)is the current output from the plurality of second semiconductor photodetecting elements 21 when the voltage is V, and corresponds to the second output value OP2. M indicates the rate of increase in detection efficiency amplified by the first lens 12, and is calculated in advance. No lens is provided above the second semiconductor photodetecting elements 21. Therefore, the photodetection efficiency of the second semiconductor photodetecting elements 21 is (1 / M) times the photodetection efficiency of the first semiconductor photodetecting elements 11. Furthermore, the second semiconductor photodetecting elements 21 have substantially the same characteristics as the first semiconductor photodetecting elements 11. Therefore, the DCR in Equation 2 (V) , Gain (V) , PDE (V) , A, and B are the DCRs in Eq. (V) , Gain (V) , PDE (V) , A, and B, respectively.

[0041] The term before Equation 1 is the same as the term before Equation 2. The term after Equation 1 is M times the term after Equation 2. Here, the terms before Equations 1 and 2 are called "reference values." The value of the term after Equation 1 is called "first inspection value." The value of the term after Equation 2 is called "second inspection value." The reference values ​​are obtained in advance from the measurement results of the photodetection device 100 being inspected.

[0042] If the plurality of first semiconductor photodetecting elements 11, the plurality of first lenses 12, the plurality of second semiconductor photodetecting elements 21, etc. are formed according to pre-designed conditions and are normal, the first inspection value will be approximately M times the second inspection value. For example, an acceptable range for the first inspection value is set based on M times the second inspection value. In step S3, if the first inspection value is within the acceptable range, the plurality of first semiconductor photodetecting elements 11 and the plurality of first lenses 12 are determined to be normal. In other words, the main region is determined to be normal, and the photodetecting device 100 is determined to be normal. If the first inspection value is outside the acceptable range, the plurality of first semiconductor photodetecting elements 11 or the plurality of first lenses 12 are abnormal, and the photodetecting device 100 is determined to be abnormal (not normal). The acceptable range is set depending on the variation in each output value, the allowable variation in characteristics, etc.

[0043] According to the inspection method IM1, even if some of the plurality of second semiconductor photodetecting elements 21 are abnormal and the second output value is abnormal, it can be determined that the photodetecting device 100 is abnormal. The purpose of this embodiment is to easily and accurately find a photodetecting device 100 that may be abnormal. Therefore, according to the inspection method IM1, it can be determined that the photodetecting device 100 is abnormal both when the second output value is abnormal and when the first output value is abnormal.

[0044] FIG. 8 is a flowchart showing the specific process of the inspection. 8 shows a specific inspection procedure for the photodetector 100. The first output value is corrected according to the ratio between the number of first semiconductor photodetector elements 11 and the number of second semiconductor photodetector elements 21 (step S3a). A first inspection value is calculated as the difference between the corrected first output value and a reference value (step S3b). A second inspection value is calculated as the difference between the second output value and the reference value (step S3c). An allowable range is set based on the second inspection value (step S3d). It is determined whether the first inspection value is within the allowable range (step S3e). If the first inspection value is within the allowable range, the photodetector 100 is determined to be normal (step S3f). If the first inspection value is outside the allowable range, the photodetector 100 is determined to be abnormal (step S3g).

[0045] When the output values ​​vary widely, the average of the output values ​​obtained at multiple voltages may be calculated. For example, first output values ​​from the multiple first semiconductor photodetector elements 11 are measured at multiple different voltages. Similarly, second output values ​​from the multiple second semiconductor photodetector elements 21 are measured at multiple different voltages. A first inspection value is calculated as the difference between the average of the multiple first output values ​​and a reference value. A second inspection value is calculated as the difference between the average of the multiple second output values ​​and the reference value. The photodetector device 100 is inspected using the first inspection value, the second inspection value, and the increase rate M.

[0046] In the above example, the allowable range is set based on the second test value, and the first test value is compared with the allowable range. However, the present invention is not limited to this example; the allowable range may be set based on (1 / M) times the first test value, and the second test value may be compared with the allowable range.

[0047] Multiple acceptable ranges may be set. For example, a first range and a second range wider than the first range may be set based on M times the second inspection value. If the first inspection value is within the second range, the light detection device 100 is determined to be normal and a good product. Furthermore, if the first inspection value is within the first range, the light detection device 100 is determined to be normal and a good product.

[0048] As shown in Figure 7, the output increases when it exceeds the breakdown voltage Vbd. The difference between the first output value OP1 and the second output value OP2 also increases. Therefore, it is preferable that the first voltage set when measuring the first output value OP1 and the second output value OP2 be greater than the breakdown voltage. In particular, applying a first voltage that allows each semiconductor photodetector element to operate in Geiger mode can further increase the output.

[0049] The advantages of the light detection device according to the first embodiment will be described. The photodetector 100 includes a first region 10 including a first lens 12, and a second region 20 not including a lens. Pad electrodes 51 and 52 are provided to obtain output from the first region 10 and output from the second region 20, respectively. By providing the pad electrodes 51 and 52, it is possible to obtain separate outputs from the first region 10 and the second region 20. These outputs can be used to easily inspect the first region 10, which is the main region. According to the first embodiment, a photodetector 100 that can be easily inspected is provided.

[0050] The advantages of the inspection method according to the first embodiment will be described. One method for inspecting photodetectors involves repeatedly measuring the output waveform of a semiconductor photodetector element without any light and then irradiating it with extremely weak light, approximately one photon per element. This method analyzes a large amount of measured data to separate characteristics of the photodetector, such as its light detection capability, noise characteristics, and the magnitude of the output signal (output characteristics) during detection, and inspects the photodetector based on each characteristic. However, this inspection method requires an excessively long inspection time. When using the inspection method according to the reference example, in mass-produced photodetectors, this inspection method can only be applied to inspecting a portion of the photodetectors, such as through sampling inspection. A simpler inspection method that can inspect a larger number (e.g., all) of the photodetectors during mass production is needed.

[0051] In the inspection method according to the first embodiment, a first output value is measured when a first voltage is applied to a plurality of first semiconductor photodetector elements 11 and light is irradiated through a plurality of first lenses 12. A second output value is measured when light is irradiated without passing through a lens to a plurality of second semiconductor photodetector elements 21 to which the same first voltage is applied. If the photodetector 100 is normal, the difference between these output values ​​corresponds to the rate of increase M of light detection efficiency due to the lens, as described above. The photodetector 100 can be easily inspected by using the first output value and the second output value. According to the first embodiment, an inspection method capable of easily inspecting a larger number of photodetector devices is provided.

[0052] 9 and 10 are flowcharts showing another inspection method according to the first embodiment. The inspection method IM2 shown in Fig. 9 further includes step S11 compared to the inspection method IM1 shown in Fig. 6. In step S11, a first reference value is measured for the plurality of first semiconductor photodetector elements 11 to which a first voltage is applied when no light is irradiated.

[0053] When no light is irradiated, no current caused by light flows through the first semiconductor photodetector elements 11. In Equation 1, the value of coefficient B, which is related to the intensity of the irradiated light, is zero. The output from the pad electrode 51, corrected according to the ratio between the number of first semiconductor photodetector elements 11 and the number of second semiconductor photodetector elements 21, is approximately expressed by the following Equation 3. I C (V) =A×(DCR (V) )×(Gain (V) ) ···(3)

[0054] Current Ic (V) corresponds to the value of the previous term in Equations 1 and 2. That is, in inspection method IM2, reference values ​​for obtaining the first inspection value and the second inspection value are measured.

[0055] In the inspection method IM2, the output of the second semiconductor photodetector elements 21 to which the first voltage is applied may be measured when no light is irradiated. This output may be used as the first reference value, because the first semiconductor photodetector elements 11 and the second semiconductor photodetector elements 21 have substantially the same characteristics.

[0056] 9, the inspection method IM3 shown in Fig. 10 further includes step S12. In step S11, a first reference value is measured for the plurality of first semiconductor photodetector elements 11 to which a first voltage is applied when no light is irradiated. In step S12, a second reference value is measured for the plurality of second semiconductor photodetector elements 21 to which a first voltage is applied when no light is irradiated.

[0057] In the first test in step S3, the process shown in Fig. 8 is performed. At this time, the first test value is the difference between the first output value and the first reference value. The second test value is the difference between the second output value and the second reference value.

[0058] In the second test in step S4, the photodetector 100 is tested using the first and second reference values. As described above, the first semiconductor photodetector element 11 and the second semiconductor photodetector element 21 have substantially the same characteristics. Therefore, if the photodetector 100 is normal, the difference between the corrected first and second reference values ​​will be small. For example, the difference between the corrected first and second reference values ​​is compared with a preset threshold. If the difference is less than the threshold, the photodetector 100 is determined to be normal. If the difference is greater than or equal to the threshold, the photodetector 100 is determined to be abnormal.

[0059] According to inspection method IM3, the output when no light is irradiated is used to further inspect the light detection device 100. Therefore, compared to inspection methods IM1 and IM2, the inspection accuracy can be further improved.

[0060] (First Modification) FIG. 11 is a schematic plan view showing a light detection device according to a first modified example of the first embodiment. 11 , compared to the photodetector 100, the photodetector 110 according to the first modification further includes a third region 30 and a pad electrode 53 (third electrode). The structure of the third region 30 in the photodetector 110 is the same as the structure of the first region 10 in the photodetector 100. The area of ​​the first region 10 in the photodetector 110 is smaller than the area of ​​the first region 10 in the photodetector 100. The number of first semiconductor photodetector elements 11 provided in the first region 10 is the same as the number of second semiconductor photodetector elements 21 provided in the second region 20.

[0061] Fig. 12 is an enlarged plan view of a portion A in Fig. 11. Fig. 13 is a cross-sectional view taken along B1-B2 in Fig. 12. As shown in Figures 12 and 13, the third region 30 includes a plurality of third semiconductor photodetector elements 31, a plurality of second lenses 32, a plurality of third quenching portions 33, a plurality of third wirings 34, and an insulating layer 35.

[0062] The third semiconductor photodetector elements 31 have substantially the same characteristics as the first semiconductor photodetector elements 11 and the second semiconductor photodetector elements 21. Each third semiconductor photodetector element 31 has a p-type semiconductor region 1 and an n-type semiconductor region 21. + The insulating portion 5 is formed between the p-type semiconductor region 1 and the n-type semiconductor region 2 in the XY plane. + The insulating layer 35 is provided around the semiconductor region 2. The insulating layer 35 is optically transparent and is provided on the plurality of third semiconductor photodetector elements 31. The second lenses 32 are provided on the insulating layer 35 and are positioned above the third semiconductor photodetector elements 31. The second lenses 32 focus light toward the corresponding third semiconductor photodetector elements 31.

[0063] n of the third semiconductor photodetector element 31 + The semiconductor region 2 is electrically connected to the third wiring 34 via the contact plug 33a, the wiring 33b, the contact plug 33c, and the third quench portion 33. Each of the third wirings 34 is electrically connected to a plurality of third semiconductor photodetector elements 31 arranged in the X direction, and is also electrically connected to the pad electrode 53.

[0064] The pad electrode 53 is provided on the front surface side of the photodetector device 110. Output values ​​from the plurality of third semiconductor photodetector elements 31 can be measured through the pad electrode 53. The pad electrode 53 is separated from the pad electrodes 51 and 52 and is electrically isolated from the pad electrodes 51 and 52.

[0065] The third region 30 is p - The p-type semiconductor region 1 of the third semiconductor photodetector element 31 is formed on the p-type semiconductor layer 62. - p through the semiconductor layer 62 + It is electrically connected to the semiconductor layer 61. + By applying a voltage between the shaped semiconductor layer 61 and the pad electrode 53, a voltage is applied to the plurality of third semiconductor photodetector elements 31. For example, the third semiconductor photodetector elements 31 are PiN diodes or APDs. Preferably, the third semiconductor photodetector elements 31 are APDs operating in Geiger mode.

[0066] The specific structures of the first region 10 and the second region 20 in the light detection device 110 are the same as those shown in FIGS.

[0067] In the photodetector device 110, the area of ​​the third region 30 is larger than the area of ​​the first region 10 and larger than the area of ​​the second region 20. In other words, the number of third semiconductor photodetector elements 31 provided in the third region 30 is greater than the number of first semiconductor photodetector elements 11 provided in the first region 10 and is greater than the number of second semiconductor photodetector elements 21 provided in the second region 20. In the photodetector device 110, the third region 30 is a main region for photodetection. The first region 10 and the second region 20 are reference regions for inspection.

[0068] 6 is performed on the photodetector 110. That is, first output values ​​from the plurality of first semiconductor photodetector elements 11 are measured (step S1). Second output values ​​from the plurality of second semiconductor photodetector elements 21 are measured (step S2). The photodetector 110 is inspected using the measured first and second output values ​​(step S3).

[0069] When inspecting the photodetector 110, the inspection results using the plurality of first semiconductor photodetector elements 11 and the plurality of first lenses 12 are regarded as inspection results for the plurality of third semiconductor photodetector elements 31 and the plurality of second lenses 32. That is, if the plurality of first semiconductor photodetector elements 11 and the plurality of first lenses 12 are determined to be normal, the plurality of third semiconductor photodetector elements 31 and the plurality of second lenses 32 are also deemed to be normal, and the photodetector 110 is determined to be normal. If the plurality of first semiconductor photodetector elements 11 and the plurality of first lenses 12 are determined to be abnormal, the plurality of third semiconductor photodetector elements 31 and the plurality of second lenses 32 are also deemed to be abnormal, and the photodetector 110 is determined to be abnormal.

[0070] As shown in FIG. 11, the first region 10, the second region 20, and the third region 30 have the same p + The semiconductor layer 61 and p -The first region 10, the second region 20, and the third region 30 are provided on the semiconductor layer 62. In other words, the first region 10, the second region 20, and the third region 30 are provided in the same chip. During mass production, if an abnormality is found in any of the first region 10, the second region 20, and the third region 30, it is highly likely that an abnormality will also exist in the other regions. Therefore, the inspection results of the multiple first semiconductor photodetector elements 11 and the multiple first lenses 12 can be considered as the inspection results of the photodetector device 110.

[0071] In the photodetector device 100, the first region 10 is the main region, and its area is larger than that of the second region 20. Therefore, the variation in output from each first semiconductor photodetector element 11 in the first region 10 is larger than the variation in output from each second semiconductor photodetector element 21 in the second region 20. For example, the variation is caused by differences in the amount of incident light between the center and the periphery of the first region 10, differences in the angle of incidence of light, etc. Even if the output from each first semiconductor photodetector element 11 in the center of the first region 10 is the same as the output from each second semiconductor photodetector element 21 in the second region 20, the output from each first semiconductor photodetector element 11 on the periphery of the first region 10 may be smaller than the output from each second semiconductor photodetector element 21. Therefore, even if the output value is corrected according to the ratio between the number of first semiconductor photodetector elements 11 and the number of second semiconductor photodetector elements 21, an appropriate value for testing may not be obtained.

[0072] In the photodetector device 110, the number of first semiconductor photodetector elements 11 provided in the first region 10 is the same as the number of second semiconductor photodetector elements 21 provided in the second region 20. Both the first region 10 and the second region 20 are provided as reference regions. Therefore, there is no need to correct the output from the pad electrode 51 or the output from the pad electrode 52 during testing. Furthermore, the number of first semiconductor photodetector elements 11 provided in the first region 10 and the number of second semiconductor photodetector elements 21 provided in the second region 20 are fewer than the number of third semiconductor photodetector elements 31 provided in the third region 30. Therefore, the variation in the output from each semiconductor photodetector element in these regions is smaller than the variation in the output from each third semiconductor photodetector element 31 in the third region 30. By using the output from the pad electrode 51 and the output from the pad electrode 52 for testing, the accuracy of the test can be improved.

[0073] (Second Modification) FIG. 14 is a schematic plan view showing a light detection device according to a second modified example of the first embodiment. As shown in FIG. 14, the photodetector 120 according to the second modification further includes a fourth region 40 and a pad electrode 54 in comparison with the photodetector 110.

[0074] Fig. 15 is an enlarged plan view of a portion A in Fig. 14. Fig. 16 is a cross-sectional view taken along B1-B2 in Fig. 15. Except for the lenses, the structure of the fourth region 40 is the same as the structure of the first region 10. As shown in Figures 15 and 16, the fourth region 40 includes a plurality of fourth semiconductor photodetector elements 41, a plurality of third lenses 42, a plurality of fourth quenching portions 43, a plurality of fourth wirings 44, and an insulating layer 45.

[0075] Each fourth semiconductor photodetector element 41 has a p-type semiconductor region 1 and an n-type semiconductor region 2. + The insulating portion 5 is formed between the p-type semiconductor region 1 and the n-type semiconductor region 2 in the XY plane. + The insulating layer 45 is optically transparent and is provided on the plurality of fourth semiconductor photodetector elements 41.

[0076] n of the fourth semiconductor photodetector element 41+ The semiconductor region 2 is electrically connected to the fourth wiring 44 via the contact plug 43a, the wiring 43b, the contact plug 43c, and the fourth quench portion 43. Each of the fourth wirings 44 is electrically connected to the plurality of fourth semiconductor photodetector elements 41 arranged in the X direction, and is electrically connected to a pad electrode 54.

[0077] The pad electrode 54 is provided on the front surface side of the light-detecting device 110. The output values ​​of the plurality of fourth semiconductor light-detecting elements 41 can be measured through the pad electrode 54. The pad electrode 54 is separated from the pad electrodes 51 to 53 and is electrically isolated from them.

[0078] The fourth region 40 is p - The p-type semiconductor region 1 of the fourth semiconductor photodetector element 41 is provided on the p-type semiconductor layer 62. - through the semiconductor layer 62, + It is electrically connected to the semiconductor layer 61. + By applying a voltage between the semiconductor layer 61 and the pad electrode 54, a voltage is applied to the plurality of fourth semiconductor photodetector elements 41. For example, the fourth semiconductor photodetector elements 41 are PiN diodes or APDs. Preferably, the fourth semiconductor photodetector elements 41 are APDs operating in Geiger mode.

[0079] The third lens 42 is provided on the insulating layer 45 and is positioned above the fourth semiconductor photodetector element 41. The optical properties of the third lens 42 are different from the optical properties of the second lens 32. For example, the diameter of the third lens 42 shown in FIGS. 15 and 16 is smaller than the diameter of the second lens 32 shown in FIGS. 12 and 13. The curvature of the upper surface of the third lens 42 may be different from the curvature of the upper surface of the second lens 32. The material of the third lens 42 may be different from that of the second lens 32.

[0080] Alternatively, the optical characteristics of the third lens 42 may be the same as those of the second lens 32, and the third lens 42 may be offset from the fourth semiconductor photo-detecting element 41. For example, in the first region 10, the center of the first semiconductor photo-detecting element 11 in the XY plane and the vertex of the first lens 12 are aligned in the Z direction. Similarly, in the third region 30, the center of the third semiconductor photo-detecting element 31 in the XY plane and the vertex of the second lens 32 are aligned in the Z direction. In the fourth region 40, the center of the fourth semiconductor photo-detecting element 41 in the XY plane and the vertex of the second lens 32 are not aligned in the Z direction.

[0081] In either case, the amount of light collected by the third lens 42 toward the fourth semiconductor photodetector elements 41 is smaller than the amount of light collected by the first lens 12 toward the first semiconductor photodetector elements 11, and is smaller than the amount of light collected by the second lens 32 toward the third semiconductor photodetector elements 31. Therefore, when light of the same intensity is irradiated onto the first region 10, the second region 20, and the fourth region 40, the output from each fourth semiconductor photodetector element 41 is smaller than the output from each first semiconductor photodetector element 11, and is smaller than the output from each second semiconductor photodetector element 21.

[0082] The number of fourth semiconductor photodetector elements 41 provided in the fourth region 40 is the same as the number of first semiconductor photodetector elements 11 provided in the first region 10, and is the same as the number of second semiconductor photodetector elements 21 provided in the second region 20.

[0083] In the test of the light detection device 120, in addition to the first output value and the second output value, a third output value is measured when the plurality of fourth semiconductor light detection elements 41 to which the first voltage is applied are irradiated with light. (V) is approximately expressed by the following Equation 4. Id (V) =A×(DCR (V) )×(Gain (V) )+B×(L / M)×(PDE (V) )×(Gain (V) ) ···(4)

[0084] Id (V) is the current output from the plurality of fourth semiconductor photodetector elements 41 when the voltage is V. L indicates the rate of increase in the detection efficiency amplified by the third lens 42, and is calculated in advance. The rate of increase L is smaller than the rate of increase M. The fourth semiconductor photodetector elements 41 have substantially the same characteristics as the first semiconductor photodetector elements 11. Therefore, the DCR in Equation 4 (V) , Gain (V) , PDE (V) , A, and B are the DCRs in Eq. (V) , Gain (V) , PDE (V) , A, and B, respectively.

[0085] A third test value is calculated as the difference between the third output value and the reference value. If the light detection device 120 is normal, the third test value is (L / M) times the second test value. For example, an acceptable range for the third test value is set based on (L / M) times the second test value. If the third test value is outside the acceptable range, the light detection device 120 is determined to be abnormal.

[0086] According to the second modification, more indices can be used to inspect the light detection device 120. This makes it possible to further improve the inspection accuracy.

[0087] (Third Modification) Fig. 17 is a schematic plan view showing a light-detecting device according to a third modified example of embodiment 1. Fig. 18 is an enlarged plan view of a portion A of Fig. 17. 17, a photodetector 130 according to the third modification includes a first region 10, a second region 20, and pad electrodes 51 and 52, similar to the photodetector 100. However, as shown in Fig. 18, the photodetector 130 differs from the photodetector 100 in that a lens 22 is provided in the second region 20. For example, the position of the lens 22 in the Z direction is the same as the position of the first lens 12 in the Z direction.

[0088] The optical properties of the lens 22 are different from those of the first lens 12. For example, the diameter of the lens 22 is smaller than the diameter of the first lens 12. The curvature of the upper surface of the lens 22 may be different from that of the upper surface of the first lens 12. The material of the lens 22 may be different from that of the first lens 12. Alternatively, the optical properties of the lens 22 may be the same as those of the first lens 12, and the lens 22 may be offset from the second semiconductor photodetector element 21.

[0089] FIG. 19 is a schematic plan view showing another light detection device according to the third modified example of the first embodiment. 18, the lens 22 may be larger than the first lens 12, as shown in Fig. 19. For example, one lens 22 is located directly above a plurality of second semiconductor photodetector elements 21. In this case, the number of lenses 22 is different from the number of second semiconductor photodetector elements 21.

[0090] In either case, the amount of light collected by the lens 22 toward the second semiconductor photodetector elements 21 is smaller than the amount of light collected by the first lens 12 toward the first semiconductor photodetector elements 11. When the first region 10 and the second region 20 are irradiated with light of the same intensity, the output from each second semiconductor photodetector element 21 is smaller than the output from each first semiconductor photodetector element 11.

[0091] 6 can be performed on the photodetector 130. For example, when the rate of increase in detection efficiency amplified by the lens 22 is L, the second output value from the plurality of second semiconductor photodetector elements 21 is expressed as Id (V) The increase rate L is smaller than the increase rate M. When the light detection device 130 is normal, the first test value is (M / L) times the second test value. For example, an allowable range for the first test value is set based on (M / L) times the second test value. When the first test value is within the allowable range, the light detection device 130 is determined to be normal. When the first test value is outside the allowable range, the light detection device 130 is determined to be abnormal.

[0092] Even when a lens 22 is provided in the second region 20, as in the photodetector 130, inspection can be performed as long as there is a difference in the amount of light collected between the first lens 12 and the lens 22. However, to improve inspection accuracy, it is preferable that the difference between the first output value and the second output value is large. Therefore, to improve inspection accuracy, it is preferable that no lens is provided in the second region 20.

[0093] FIG. 20 is a schematic cross-sectional view showing a part of the light detection device according to the first embodiment. In this application, a "lens" refers to a component having a curvature on its upper surface that focuses light toward the semiconductor photodetector element. For example, in the second region 20, as shown in FIG. 18, a resin layer 70 may be provided above the second semiconductor photodetector element 21. The upper and lower surfaces of the resin layer 70 are aligned with the XY plane and are flat. Therefore, the resin layer 70 is not a "lens." Alternatively, the photodetector device 100 may be provided with a filter or the like that transmits only light of a specific wavelength. If the upper and lower surfaces are substantially flat, the component is not a "lens."

[0094] FIG. 21 is a schematic diagram illustrating an active quench circuit. When each semiconductor photodetector element operates in Geiger mode, a resistor that generates a voltage drop is provided as the quench unit, as described above. A switching element may be provided instead of a resistor. That is, an active quench circuit for generating a voltage drop may be provided as the quench unit.

[0095] As shown in Fig. 21, the active quench circuit includes a switching array SWA. The switching array SWA includes a plurality of switching elements SW. For example, as shown in Fig. 21, in the first region 10, one switching element SW may be provided for one first semiconductor photodetector element 11. Alternatively, one switching element SW may be provided for a plurality of first semiconductor photodetector elements 11. For example, +One switching element SW is provided between the semiconductor region 2 and the first wiring 14. Alternatively, the switching element SW may be provided between the first wiring 14 and the pad electrode 51. In regions other than the first region 10, a switching element SW can be provided, similar to the first region 10.

[0096] 22(a) and 22(b) are schematic diagrams illustrating the test object. The photodetector 100 inspected by the inspection method according to the first embodiment may be divided into individual pieces, as shown in Fig. 22(a). As shown in Fig. 22(b), inspection may be performed on one or more of the multiple photodetector devices 100 formed on a semiconductor wafer W. Similarly, inspection can also be performed on the photodetector devices 110 to 130.

[0097] [Second embodiment] FIG. 23 is a schematic plan view showing the light detection device according to the second embodiment. The photodetector 200 according to the second embodiment further includes a processing circuit 90 in comparison with the photodetector according to the first embodiment. The processing circuit 90 includes a pad electrode 51, a pad electrode 52, and a p + The insulating layer 62 is electrically connected to the insulating layer 61 .

[0098] The processing circuit 90 executes the inspection method according to the first embodiment. The processing circuit 90 applies a first voltage to the plurality of first semiconductor light detecting elements 11. The processing circuit 90 measures a first output value when light is irradiated onto the plurality of first semiconductor photodetector elements 11 through the first lens 12. The processing circuit 90 applies a first voltage to the plurality of second semiconductor photodetector elements 21. The processing circuit 90 measures a second output value when light is irradiated onto the plurality of second semiconductor photodetector elements 21. The processing circuit 90 inspects the plurality of first semiconductor photodetector elements 11 and the plurality of first lenses 12 using the first output value and the second output value.

[0099] 23, a processing circuit 90 for performing the test may be incorporated into the photodetector 200. By incorporating the processing circuit 90 into the photodetector 200, it is not necessary to prepare a measuring device and take out an output from the photodetector 200. The test can be performed easily.

[0100] [Third embodiment] FIG. 24 is a flowchart showing a manufacturing method according to the third embodiment. The manufacturing method MM shown in FIG. 24 is a method for manufacturing a semiconductor device that covers the formation of photodetectors on a semiconductor wafer. The manufacturing method MM for a semiconductor device includes steps S21 to S23. In step S21, a plurality of photodetectors are formed on a semiconductor wafer. In step S22, an inspection is performed on each photodetector. In step S22, one of inspection methods IM1 to IM3 is performed. In step S23, a wafer map is created based on the inspection results for each photodetector.

[0101] FIG. 25 is a schematic diagram illustrating a wafer map. The wafer map 300 shows the position of each photodetector on a semiconductor wafer and the inspection results of each photodetector. For example, as shown in FIG. 25, multiple photodetectors formed on a semiconductor wafer are shown. The display mode of each photodetector is determined according to the inspection results. In the example of FIG. 25, each photodetector is ranked on a three-level scale based on the inspection. A photodetector with no hatching indicates the best quality. The denser the hatching, the worse the quality.

[0102] The created wafer map 300 is linked to the inspected semiconductor wafer W. According to the manufacturing method MM, a semiconductor wafer is obtained to which the inspection results of each light detection device are linked.

[0103] (First Modification) FIG. 26 is a flowchart showing a manufacturing method according to a first modified example of the third embodiment. Manufacturing method MM1 shown in Figure 26 relates to a method for manufacturing a photodetector. Compared to manufacturing method MM, manufacturing method MM1 includes step S24 instead of step S23. In step S24, the semiconductor wafer is diced. This separates the photodetector devices contained in the semiconductor wafer. Thereafter, photodetector devices that are determined to be normal and non-defective in the inspection are packaged through a packaging process.

[0104] Photodetectors that are found to be abnormal and defective during testing are not packaged and are discarded. Alternatively, the testing conditions may be adjusted for defective products. For example, if a higher operating voltage can be used to achieve higher photodetection sensitivity, a photodetector determined to be defective may be determined to be a product that meets a different testing standard, or may be considered to have slightly lower performance than a non-defective product. Alternatively, defective products may be recycled, and at least some of the materials may be recovered. Manufacturing method MM1 allows photodetectors to be manufactured while evaluating quality in a short period of time.

[0105] FIG. 27 is a schematic diagram showing a hardware configuration. The processing circuit 90 includes, for example, the configuration shown in Fig. 27. The processing circuit 90 includes a CPU 91, a ROM 92, a RAM 93, a storage device 94, an input interface 95, an output interface 96, and a communication interface 97.

[0106] The ROM 92 stores a program that controls the operation of the processing circuit 90. The ROM 92 stores a program required to cause the processing circuit 90 to perform each of the above-mentioned processes. The RAM 93 functions as a storage area in which the program stored in the ROM 92 is expanded.

[0107] The CPU 91 includes a processing circuit. The CPU 91 uses a RAM 93 as a work memory and executes a program stored in at least one of a ROM 92 and a storage device 94. During program execution, the CPU 91 controls each component via a system bus 98 and executes various processes.

[0108] The storage device 94 stores data necessary for executing the program and data obtained by executing the program.

[0109] An input interface (I / F) 95 is provided to connect the processing circuit 90 to an external input device. The CPU 91 can read various data from the external input device via the input I / F 95. An output interface (I / F) 96 is provided to connect the processing circuit 90 to an external output device. The CPU 91 can transmit data to the external output device via the output I / F 96. A communication interface (I / F) 97 is provided to connect the processing circuit 90 to an external server.

[0110] [Fourth embodiment] FIG. 28 is a schematic diagram illustrating a LIDAR (Laser Imaging Detection and Ranging) device according to the fourth embodiment. This embodiment is configured with a line light source and a lens and can be applied to a long-range object detection system (LIDAR), etc. The LIDAR device 5001 includes a light projection unit T that projects laser light toward an object 411, and a light receiving unit R (also called a light detection system) that receives the laser light from the object 411, measures the time it takes for the laser light to travel to and from the object 411, and converts it into distance.

[0111] In the light-projecting unit T, a light source 404 emits light. For example, the light source 404 includes a laser oscillator and emits laser light. A drive circuit 403 drives the laser oscillator. An optical system 405 extracts a portion of the laser light as reference light, and irradiates the remaining laser light onto an object 411 via a mirror 406. A mirror controller 402 controls the mirror 406 to project the laser light onto the object 411. Here, "projecting light" means to apply light.

[0112] In the light receiving unit R, a photodetector 409 for reference light detects the reference light extracted by the optical system 405. A photodetector 410 receives reflected light from an object 411. A distance measurement circuit 408 measures the distance to the object 411 based on the reference light detected by the photodetector 409 for reference light and the reflected light detected by the photodetector 410. An image recognition system 407 recognizes the object 411 based on the result of measurement by the distance measurement circuit 408.

[0113] The LIDAR device 5001 employs optical time-of-flight ranging, which measures the time it takes for laser light to travel to and from the target 411 and converts the measured time into distance. The LIDAR device 5001 is applied to in-vehicle drive-assist systems, remote sensing, and the like. When the light detection device according to the above-described embodiment is used as the light detection device 410, it exhibits good sensitivity, particularly in the near-infrared region. This makes it possible for the LIDAR device 5001 to be applied to a light source in a wavelength band invisible to humans. The LIDAR device 5001 can be used, for example, for obstacle detection for moving objects.

[0114] FIG. 29 is a diagram for explaining detection of a detection target by a LIDAR device. A light source 3000 emits light 412 toward an object 600 to be detected. A light detection device 3001 detects light 413 that is transmitted through, reflected from, or diffused by the object 600.

[0115] The photodetector 3001 can achieve high-sensitivity detection by using, for example, the semiconductor device according to this embodiment described above. It is preferable to provide multiple sets of photodetectors 410 and light sources 404 and set their relative positions in advance in software (although a circuit may also be used). The sets of photodetectors 410 and light sources 404 are preferably arranged at equal intervals, for example. This allows the output signals of the photodetectors 410 to complement each other, thereby generating an accurate three-dimensional image.

[0116] FIG. 30 is a schematic top view of a moving body equipped with a LIDAR device according to the fourth embodiment. 30, the moving body is a car. Vehicle 700 according to this embodiment is equipped with LIDAR devices 5001 at the four corners of vehicle body 710. By providing LIDAR devices at the four corners of the vehicle body, the vehicle according to this embodiment can detect the environment in all directions of the vehicle using the LIDAR devices.

[0117] The moving object may be a drone, a robot, or the like, in addition to the car shown in Figure 30. The robot may be, for example, an automated guided vehicle (AGV). By providing LIDAR devices at the four corners of these moving objects, the LIDAR devices can detect the environment in all directions around the moving object.

[0118] Embodiments may include the following aspects. (Appendix 1) a first region including a plurality of first semiconductor photodetector elements and a plurality of first lenses respectively provided on the plurality of first semiconductor photodetector elements; a second region including a plurality of second semiconductor photodetector elements, wherein no lens is provided directly above the second semiconductor photodetector elements at the same position in a first direction as the plurality of first lenses, and the first direction is a direction from one of the plurality of first semiconductor photodetector elements to one of the plurality of first lenses; a first electrode electrically connected to the plurality of first semiconductor photodetector elements; a second electrode electrically connected to the plurality of second semiconductor photodetector elements; A light detection device comprising: (Appendix 2) a third region including a plurality of third semiconductor photodetector elements and a plurality of second lenses respectively provided on the plurality of third semiconductor photodetector elements; a third electrode electrically connected to the plurality of third semiconductor photodetector elements; 2. The optical detection device of claim 1, further comprising: (Appendix 3) 3. The light-detecting device according to claim 2, wherein the number of the first semiconductor light-detecting elements provided in the first region is smaller than the number of the third semiconductor light-detecting elements provided in the third region. (Appendix 4) 4. The photodetection device according to claim 2, wherein the number of the first semiconductor photodetection elements provided in the first region is the same as the number of the second semiconductor photodetection elements provided in the second region. (Appendix 5) Further comprising a first semiconductor layer; 5. The light-detecting device according to any one of claims 1 to 4, wherein the first region, the second region, the first electrode, and the second electrode are provided on the first semiconductor layer. (Appendix 6) The photodetection device according to any one of appendixes 1 to 5, wherein a resistor or a switching element is electrically connected between one or more of the plurality of first semiconductor photodetection elements and the first electrode, and between one or more of the plurality of second semiconductor photodetection elements and the second electrode. (Appendix 7) 7. The photodetector according to claim 1, wherein each of the plurality of first semiconductor photodetector elements and the plurality of second semiconductor photodetector elements is a PiN diode or an avalanche photodiode. (Appendix 8) 8. The light detection device of claim 7, wherein each of the plurality of first semiconductor light detection elements and the plurality of second semiconductor light detection elements is an avalanche photodiode operating in Geiger mode. (Appendix 9) 9. The light detection device according to any one of claims 1 to 8, wherein the first electrode and the second electrode are pad electrodes provided at a distance from each other, and different outputs can be extracted independently from each other. (Appendix 10) A photodetector according to any one of claims 1 to 9; a distance measurement circuit that calculates a time of flight of light from an output signal of the light detection device; An optical detection system comprising: (Appendix 11) a light source that irradiates light onto an object; 11. The light detection system of claim 10, which detects light reflected by the object; A lidar device comprising: (Appendix 12) 12. The LIDAR device of claim 11, further comprising an image recognition system that generates a three-dimensional image based on the positional relationship between the light source and the light detection device. (Appendix 13) A moving object equipped with the LIDAR device according to claim 11 or 12. (Appendix 14) applying a first voltage to a plurality of first semiconductor photodetecting elements of the photodetecting device and measuring first output values ​​when light is irradiated through a plurality of first lenses; applying the first voltage to a plurality of second semiconductor photodetector elements of the photodetector device, and measuring second output values ​​when irradiated with light without passing through a lens; an inspection method for inspecting the light detection device using the first output value and the second output value; (Appendix 15) further measuring a reference value when no light is irradiated onto the plurality of first semiconductor photodetector elements or the plurality of second semiconductor photodetector elements to which the first voltage is applied; 15. The inspection method of claim 14, further comprising inspecting the light detection device using the first output value, the second output value, and the reference value. (Appendix 16) In the test, calculating a first inspection value that is a difference between the first output value and the reference value; calculating a second inspection value that is a difference between the second output value and the reference value; inspecting the light detection device using the first inspection value, the second inspection value, and an increase rate of detection efficiency of one of the plurality of first semiconductor light detection elements due to one of the plurality of first lenses; Testing method described in Appendix 15. (Appendix 17) further measuring a first reference value when no light is irradiated onto the plurality of first semiconductor photodetector elements to which the first voltage is applied, and a second reference value when no light is irradiated onto the plurality of second semiconductor photodetector elements to which the first voltage is applied, 15. The inspection method of claim 14, wherein the first output value, the second output value, the first reference value, and the second reference value are used to inspect the light detection device. (Appendix 18) 18. The inspection method according to any one of appendices 14 to 17, wherein the first voltage is greater than a breakdown voltage. (Appendix 19) forming a plurality of the photodetector devices on a semiconductor wafer; A method for manufacturing a semiconductor device, comprising inspecting each of the plurality of photodetectors by the inspection method according to any one of appendices 14 to 18. (Appendix 20) evaluating each of the plurality of light sensing devices based on results of the testing; 20. The method of claim 19, further comprising generating a wafer map indicative of the evaluation of each of the plurality of photodetectors. (Appendix 21) 21. The method for manufacturing a semiconductor device according to claim 19, further comprising dicing the semiconductor wafer to separate the plurality of photodetectors.

[0119] According to the embodiments described above, a light detection device, a light detection system, a LIDAR device, a moving object, an inspection method, and a method for manufacturing a semiconductor device are provided, which allow for easier inspection.

[0120] In this specification, "vertical" and "parallel" do not only mean strictly vertical and strictly parallel, but also include variations in the manufacturing process, and may mean substantially vertical and substantially parallel.

[0121] The embodiments of the present invention have been described above with reference to specific examples. However, the embodiments of the present invention are not limited to these specific examples. For example, the specific configurations of each element included in the photodetector, such as the semiconductor photodetector element, insulating portion, lens, contact plug, wiring, insulating layer, quenching portion, and pad electrode, are within the scope of the present invention as long as a person skilled in the art can implement the present invention in a similar manner and obtain similar effects by appropriately selecting them from known ranges.

[0122] Furthermore, any combination of two or more elements of each specific example within the scope of technical feasibility is also included within the scope of the present invention as long as it includes the gist of the present invention.

[0123] In addition, all optical detection devices, optical detection systems, LIDAR devices, moving bodies, inspection methods, and semiconductor device manufacturing methods that can be implemented by a person skilled in the art by making appropriate design modifications based on the optical detection devices, optical detection systems, LIDAR devices, moving bodies, inspection methods, and semiconductor device manufacturing methods described above as embodiments of the present invention also fall within the scope of the present invention, as long as they include the gist of the present invention.

[0124] In addition, within the scope of the concept of the present invention, a person skilled in the art may come up with various modifications and alterations, and it will be understood that these modifications and alterations also fall within the scope of the present invention.

[0125] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0126] 1: p-type semiconductor region, 2: n +semiconductor region, 5: insulating portion, 10: first region, 11: first semiconductor photodetector element, 12: first lens, 13: first quench portion, 13a: contact plug, 13b: wiring, 13c: contact plug, 14: first wiring, 15: insulating layer, 20: second region, 21: second semiconductor photodetector element, 22: lens, 23: second quench portion, 23a: contact plug, 23b: wiring, 23c: contact plug, 24: second wiring, 25: insulating layer, 30: third region, 31: third semiconductor photodetector element, 32: second lens, 33: third quench portion, 33a: contact plug, 33b: wiring, 33c: contact plug, 34: third wiring, 35: insulating layer, 40: fourth region, 41: fourth semiconductor light detecting element, 42: third lens, 43: fourth quenching portion, 43a: contact plug, 43b: wiring, 43c: contact plug, 44: fourth wiring, 45: insulating layer, 51: pad electrode, 52: pad electrode, 53: pad electrode, 54: pad electrode, 61: p + Semiconductor layer, 62:p - Semiconductor layer, 70: Resin layer, 90: Processing circuit, 91: CPU, 92: ROM, 93: RAM, 94: Storage device, 95: Input interface, 96: Output interface, 97: Communication interface, 98: System bus, 100-130, 200: Optical detection device, 300: Wafer map, 402: Mirror controller, 403: Drive circuit, 404: Light source, 405: Optical system, 406: Mirror, 407: Image recognition system, 408: Distance measurement circuit, 409: Optical detection device for reference light, 410: Optical detection device, 411: Object, 412: Light, 413: Light, 600: Object, 700: Vehicle, 710: Vehicle body, 3000: Light source, 3001: Optical detection device, 5001: Lidar device, IM1 to IM3: inspection method, MM, MM1: manufacturing method, OP1: first output value, OP2: second output value, R: light receiving unit, SW: switching element, SWA: switching array, T: light emitting unit, W: semiconductor wafer

Claims

1. a first region including a plurality of first semiconductor photodetector elements and a plurality of first lenses respectively provided on the plurality of first semiconductor photodetector elements; a second region including a plurality of second semiconductor photodetector elements, wherein no lens is provided directly above the plurality of second semiconductor photodetector elements at the same position in the first direction as the plurality of first lenses, and the first direction is a direction from one of the plurality of first semiconductor photodetector elements to one of the plurality of first lenses; a first electrode electrically connected to the plurality of first semiconductor light-detecting elements; a second electrode electrically connected to the plurality of second semiconductor light-detecting elements; Equipped with the first electrode and the second electrode are pad electrodes provided separately from each other, and different outputs can be independently extracted from each other; the first electrode is capable of extracting outputs from the plurality of first semiconductor photodetector elements, the outputs corresponding to the number of the plurality of first semiconductor photodetector elements; the second electrode is capable of extracting outputs from the plurality of second semiconductor light-detecting elements, the outputs corresponding to the number of the plurality of second semiconductor light-detecting elements; Light detection device.

2. a third region including a plurality of third semiconductor photodetector elements and a plurality of second lenses respectively provided on the plurality of third semiconductor photodetector elements; a third electrode electrically connected to the plurality of third semiconductor light-detecting elements; The optical sensing device of claim 1 further comprising:

3. 3. The light-detecting device according to claim 2, wherein the number of the first semiconductor light-detecting elements provided in the first region is smaller than the number of the third semiconductor light-detecting elements provided in the third region.

4. 3. The light-detecting device according to claim 2, wherein the number of the first semiconductor light-detecting elements provided in the first region is the same as the number of the second semiconductor light-detecting elements provided in the second region.

5. Further comprising a first semiconductor layer; The light-sensing device of claim 1 , wherein the first region, the second region, the first electrode, and the second electrode are provided on the first semiconductor layer.

6. 2. The light detection device according to claim 1, wherein a resistor or a switching element is electrically connected between one or more of the plurality of first semiconductor light detection elements and the first electrode, and between one or more of the plurality of second semiconductor light detection elements and the second electrode.

7. 2. The light-sensing device according to claim 1, wherein each of the plurality of first semiconductor light-sensing elements and the plurality of second semiconductor light-sensing elements is a PiN diode or an avalanche photodiode.

8. 8. The light-sensing device of claim 7, wherein each of the first plurality of semiconductor light-sensing elements and the second plurality of semiconductor light-sensing elements is an avalanche photodiode operating in Geiger mode.

9. A photodetector according to any one of claims 1 to 8; a distance measurement circuit that calculates a time of flight of light from an output signal of the light detection device; An optical detection system comprising:

10. a light source that irradiates light onto an object; a light detection system according to claim 9, which detects light reflected from the object; A lidar device comprising:

11. The LIDAR device of claim 10 , further comprising an image recognition system that generates a three-dimensional image based on the relative positions of the light source and the light detection device.

12. A moving object equipped with the LIDAR device according to claim 10.

13. applying a first voltage to a plurality of first semiconductor photodetector elements of the photodetector device, and measuring first output values ​​corresponding to the number of the plurality of first semiconductor photodetector elements, the first output values ​​being outputs from the plurality of first semiconductor photodetector elements when light is irradiated through a plurality of first lenses; applying the first voltage to a plurality of second semiconductor photodetector elements of the photodetector device, and measuring second output values ​​corresponding to the number of the plurality of second semiconductor photodetector elements, the second output values ​​being outputs from the plurality of second semiconductor photodetector elements when irradiated with light not passing through a lens; and testing the light detection device using the first output value and the second output value.

14. further measuring a reference value when no light is irradiated onto the plurality of first semiconductor photodetector elements or the plurality of second semiconductor photodetector elements to which the first voltage is applied; The inspection method of claim 13 , further comprising inspecting the light-sensing device using the first output value, the second output value, and the reference value.

15. In the test, calculating a first inspection value that is a difference between the first output value and the reference value; calculating a second inspection value that is a difference between the second output value and the reference value; inspecting the light detection device using the first inspection value, the second inspection value, and an increase rate of detection efficiency of one of the plurality of first semiconductor light detection elements due to one of the plurality of first lenses; The inspection method according to claim 14.

16. further measuring a first reference value which is an output from the plurality of first semiconductor photodetector elements when no light is irradiated and which corresponds to the number of the plurality of first semiconductor photodetector elements, and a second reference value which is an output from the plurality of second semiconductor photodetector elements when no light is irradiated and which corresponds to the number of the plurality of second semiconductor photodetector elements, and The method of claim 13 , further comprising testing the light-sensing device using the first output value, the second output value, the first reference value, and the second reference value.

17. The method of claim 13 , wherein the first voltage is greater than a breakdown voltage.

18. forming a plurality of the photodetector devices on a semiconductor wafer; A method for manufacturing a semiconductor device, wherein each of the plurality of photodetectors is inspected by the inspection method according to any one of claims 13 to 17.

19. evaluating each of the plurality of light sensing devices based on results of the testing; The method of claim 18 further comprising generating a wafer map indicative of said evaluation of each of said plurality of light sensing devices.

20. The method for manufacturing a semiconductor device according to claim 18, further comprising dicing the semiconductor wafer to separate the plurality of photodetectors into individual pieces.

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