Light-emitting element array, optical device, optical measurement device, and method for manufacturing the light-emitting element array

Abstract

To suppress the shape of a current passage region provided so as to correspond to each light-emitting element from being non-uniform by a block separation part.SOLUTION: A light-emitting element array 10 has: a semiconductor substrate; a plurality of light-emitting elements 50 arranged on the semiconductor substrate; a plurality of trench grooves 52; and a block separation groove 53. The plurality of trench grooves 52 are a plurality of constriction grooves provided around each of the plurality of light-emitting elements 50 and used for forming a current constriction layer which constricts a current flowing in a light-emitting layer provided below the light-emitting elements 50 by oxidizing the light-emitting layer. The block separation groove 53 is provided to curve along respective positions where the plurality of light-emitting elements 50 are arranged, so that at least one inflection point at which a sign of curvature changes is included.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a light-emitting element array, an optical device, an optical measurement device, and a method for manufacturing a light-emitting element array. [Background technology]

[0002] Patent Document 1 discloses that the size of the light-emitting region becomes non-uniform depending on the arrangement position between each of the VCSELs (Vertical Cavity Surface Emitting Lasers) that make up a VCSEL array.

[0003] Patent Document 2 discloses a light-emitting component including a substrate on which a second semiconductor layer is grown, via a tunnel junction layer or a III-V compound layer having metallic conductivity, on a first semiconductor laminate constituting a laser diode, which is an example of a light-emitting element, the second semiconductor layer including a setting thyristor and constituting a driving unit that drives a plurality of light-emitting elements to a state in which they can be sequentially switched to an ON state, a plurality of laser diodes, and a plurality of setting thyristors.

[0004] Patent Document 3 discloses a light-emitting component that includes a substrate, a plurality of light-emitting diodes that are provided on the substrate and emit light in a direction intersecting the surface of the substrate, and a plurality of setting thyristors that are stacked on the plurality of light-emitting diodes and that, when turned on, drive the light-emitting diodes to a state that enables them to transition to an on state, and the setting thyristors have openings in the path of light that travels from the light-emitting diodes to the setting thyristors.

[0005] Patent document 4 discloses a light emitting device in which a light emitting section has an array of multiple light emitting element groups, each having multiple light emitting elements, and the multiple light emitting elements included in each light emitting element group are sequentially set to an emitting or non-emitting state in parallel along the array. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent No. 10,250,012 [Patent Document 2] Patent No. 6245319 [Patent Document 3] Patent No. 6369613 [Patent Document 4] Japanese Patent Application Publication No. 2020-120018 Summary of the Invention [Problem to be solved by the invention]

[0007] In a light-emitting element array in which a plurality of light-emitting elements are formed, a configuration is sometimes used in which a plurality of narrowing grooves such as trench grooves are provided around each location where a light-emitting element is to be formed, and a current narrowing layer is formed by oxidizing the light-emitting layer from within this narrowing groove, thereby restricting the current flowing through the light-emitting layer to a current passing region corresponding to the position where the light-emitting element is provided.

[0008] In such a light-emitting element array, the light-emitting elements may be divided into a plurality of blocks, and light emission control may be performed on a block-by-block basis. When the light-emitting elements are divided into blocks in this manner, a block separator is provided between each block.

[0009] When a block separation groove is used, oxidation occurs more from the block separation groove than from the narrowing groove. As a result, there may be a difference between the area where oxidation occurs from the block separation groove and the area where oxidation occurs only from the narrowing groove. This is because, when the block separation grooves are continuous, the area of ​​the oxidized portion on the side of the block separation groove is larger than that of the narrowing groove, resulting in a faster oxidation rate. As a result, even if the distance between the block separation groove and the light-emitting element is the same as the distance between the narrowing groove and the light-emitting element, oxidation from the block separation groove occurs closer to the light-emitting element than oxidation from the narrowing groove. This may result in a decrease in the uniformity of the shape of the current passing region near the block separation portion, such as the block separation groove.

[0010] The object of the present invention is to provide a light-emitting element array, an optical device, an optical measuring device, and a method for manufacturing a light-emitting element array that can prevent the shape of the current passing region provided corresponding to each light-emitting element from becoming uneven due to block separation portions. [Means for solving the problem]

[0011] The light-emitting element array according to the first aspect of the present invention includes a substrate, a plurality of light-emitting elements disposed on the substrate; a plurality of constriction grooves provided around the plurality of light-emitting elements, respectively, for forming current constriction layers that oxidize the light-emitting layers to constrict a current flowing through the light-emitting layers; The light emitting element further includes a block separating portion that is formed to overlap with a part of the narrowing grooves in a plan view and separates the light emitting elements into a plurality of blocks.

[0012] A light-emitting element array according to a second aspect of the present invention is the light-emitting element array according to the first aspect, wherein the block separation portion includes a block separation groove; The narrowing groove and the block separating groove are configured so that the overlapping portion of the narrowing groove is deeper than the depth of either the narrowing groove or the block separating groove in the non-overlapping portion.

[0013] A light-emitting element array according to a third aspect of the present invention is the light-emitting element array according to the first aspect, wherein the light-emitting layer is not oxidized from a portion of the block separation section that does not overlap with the narrowing groove.

[0014] A light-emitting element array according to a fourth aspect of the present invention is the light-emitting element array according to the third aspect, wherein the block separation portion includes a block separation groove; The narrowing groove has a width wider than that of the block separating groove, and a step is formed at the overlapping portion of the narrowing groove where the width narrows from that of the narrowing groove to that of the block separating groove.

[0015] A light-emitting element array according to a fifth aspect of the present invention is the light-emitting element array according to any one of the first, second, and fourth aspects, wherein the block separation portion includes a block separation groove, The block separation groove is configured to pass through approximately the midpoint between two light emitting elements arranged in different blocks.

[0016] The light-emitting element array of the sixth aspect of the present invention is an light-emitting element array of any one of the first to fifth aspects, wherein the block separation portion is curved so as to include at least one inflection point where the sign of curvature changes along each position where the plurality of light-emitting elements are arranged.

[0017] The light-emitting element array of the seventh aspect of the present invention is a light-emitting element array of any one of the first to sixth aspects, in which a plurality of narrowing grooves are provided around the light-emitting element on a circle centered on the light-emitting element.

[0018] An eighth aspect of the light-emitting element array of the present invention is the light-emitting element array of the fifth aspect, wherein two adjacent light-emitting elements have at least one narrowing groove in common among the plurality of narrowing grooves provided around the periphery.

[0019] An optical device according to a ninth aspect of the present invention includes the light-emitting element array according to any one of the first to eighth aspects; a drive unit that drives the plurality of light-emitting elements configured on the light-emitting element array; and a control unit that controls the drive unit so that processing is performed using the light generated by the light-emitting element array.

[0020] An optical measurement device according to a tenth aspect of the present invention includes the light-emitting element array according to any one of the first to eighth aspects; a light receiving element that receives light that is emitted from the light emitting element array and reflected by an object; The light receiving device further includes a processing unit that processes information about the light received by the light receiving element to measure the distance from the light emitting element array to the object or the shape of the object.

[0021] A method for manufacturing a light-emitting element array according to an eleventh aspect of the present invention includes the steps of forming a plurality of narrowing grooves around each location on a substrate where light-emitting elements are to be disposed; a step of forming a current confinement layer that confines a current flowing through the light emitting layer by oxidizing a part of the light emitting layer that is exposed in the confinement groove; forming a block separation portion that separates the plurality of light emitting elements to be formed into a plurality of blocks; and forming a plurality of light-emitting elements by forming an emission aperture on the current passage region of the current confinement layer.

[0022] A twelfth aspect of the present invention relates to the method for manufacturing a light-emitting element array of the eleventh aspect, wherein the block separation portion includes a block separation groove; The block separation grooves are formed so as to overlap with parts of the plurality of trench grooves in a plan view. [Effects of the Invention]

[0023] According to the light-emitting element array of the first aspect of the present invention, it is possible to prevent the shape of the current passing region provided corresponding to each light-emitting element from becoming non-uniform due to the block separation portion.

[0024] According to the light-emitting element array of the second aspect of the present invention, it is possible to prevent the shape of the current passing region provided corresponding to each light-emitting element from becoming non-uniform due to the block separation portion.

[0025] According to the light-emitting element array of the third aspect of the present invention, by preventing the light-emitting layer from being oxidized from the block separation portion, it is possible to prevent the shape of the current passing region provided corresponding to each light-emitting element from becoming uneven due to the block separation portion.

[0026] According to the fourth aspect of the light-emitting element array of the present invention, by preventing the light-emitting layer from being oxidized from the block separation portion, it is possible to prevent the shape of the current passing region provided corresponding to each light-emitting element from becoming uneven due to the block separation portion.

[0027] According to the light-emitting element array of the fifth aspect of the present invention, the distance between two light-emitting elements arranged between different blocks can be minimized while preventing the shape of the current passing region from becoming uneven due to the block separation portion.

[0028] According to the light-emitting element array of the sixth aspect of the present invention, it is possible to suppress the influence of the block separation portion on the arrangement of the light-emitting elements.

[0029] According to the light-emitting element array of the seventh aspect of the present invention, the shape of the current passing region provided corresponding to each light-emitting element can be made nearly circular.

[0030] According to the light-emitting element array of the eighth aspect of the present invention, the distance between two light-emitting elements can be made shorter compared to when a narrowing groove is not provided in common for a plurality of light-emitting elements.

[0031] According to the optical device of the ninth aspect of the present invention, it is possible to prevent the shape of the current passing region provided corresponding to each light emitting element from becoming non-uniform due to the block separation portion.

[0032] According to the optical measurement device of the tenth aspect of the present invention, it is possible to prevent the shape of the current passing region provided corresponding to each light emitting element from becoming non-uniform due to the block separation portion.

[0033] According to the method for manufacturing a light-emitting element array of the eleventh aspect of the present invention, it is possible to prevent the shape of the current passing region provided corresponding to each light-emitting element from becoming non-uniform due to the block separation portion.

[0034] According to the method for manufacturing a light-emitting element array of the twelfth aspect of the present invention, it is possible to prevent the shape of the current passing region provided corresponding to each light-emitting element from becoming non-uniform due to the block separation portion. [Brief explanation of the drawings]

[0035] [Figure 1] 1 is a block diagram showing the configuration of an optical measurement device 100 according to an embodiment of the present invention. [Figure 2] 2 is a block diagram showing the configuration of a light emitting unit 40 in the optical measurement device 100 shown in FIG. [Figure 3] FIG. 1 is a block diagram showing a configuration of an optical device 110 according to an embodiment of the present invention. [Figure 4] 1 is a diagram showing a schematic configuration of a light-emitting element array 10 according to an embodiment of the present invention when viewed from above. [Figure 5] 5 is a schematic diagram of the structure of an enlarged portion of the light-emitting element array 10 shown in FIG. 4. [Figure 6] 6 is a cross-sectional view of the light-emitting element array 10 shown in FIG. 5 taken along the line XX'. [Figure 7] 6 is a cross-sectional view of the light-emitting element array 10 shown in FIG. 5 taken along line YY'. [Figure 8] 10 is a diagram for explaining the positional relationship between a block separation groove 53 and a trench groove 52. FIG. [Figure 9] FIG. 10 is a diagram showing a comparative example in which the block separation grooves 53 and the trench grooves 52 are not overlapped. [Figure 10] FIG. 10 is a diagram showing an example in which block separation grooves 53 are configured to be oblique. [Figure 11] FIG. 10 is a diagram showing an example in which the block separation grooves 53 are configured linearly. [Figure 12] FIG. 10 is a diagram showing an example in which the block separation grooves 53 are curved and configured so that the block separation grooves 53 and the trench grooves 52 do not overlap each other. [Figure 13] 1 is a flowchart showing the overall flow of a method for manufacturing a light-emitting element array 10 according to one embodiment of the present invention. [Figure 14] 1 is a diagram showing an example of a semiconductor laminated substrate in which each layer is formed in sequence by epitaxial growth on a GaAs substrate 60 when manufacturing a light emitting element array 10. FIG. [Figure 15] FIG. 10 is a cross-sectional view after the anode electrode 71 is formed in step S101. [Figure 16] FIG. 10 is a cross-sectional view after a gate electrode 72 is formed in step S102. [Figure 17] This is a cross-sectional view after the n-gate layer 82 and the p-gate layer 83 are removed in step S103. [Figure 18] FIG. 10 is a cross-sectional view after trench grooves 52 are formed in step S104. [Figure 19] FIG. 10 is a diagram showing an etching pattern when forming a trench groove 52 in the etching process of step S104. [Figure 20] FIG. 10 is a cross-sectional view after a current confinement layer 93 is formed in step S105. [Figure 21] FIG. 10 is a cross-sectional view after block separation grooves 53 are formed in step S106. [Figure 22] FIG. 10 is a diagram showing an etching pattern when forming block separation grooves 53 in the etching process of step S106. [Figure 23] FIG. 10 is a cross-sectional view after the emission opening 51 is formed in step S107. [Figure 24] FIG. 1 is a diagram showing an example of a light-emitting element array 10 in which a block division method is used in which a plurality of light-emitting elements 50 are divided into n blocks of n rows and 1 column. DETAILED DESCRIPTION OF THE INVENTION

[0036] Next, an embodiment of the present invention will be described in detail with reference to the drawings.

[0037] FIG. 1 is a diagram showing the configuration of an optical measurement device 100 according to one embodiment of the present invention. The optical measurement device 100 of this embodiment has the function of calculating the distance to the measurement object 200 and the three-dimensional shape of the measurement object 200 by irradiating light such as infrared light onto the measurement object 200, such as a human, and receiving the reflected light.

[0038] Here, the optical measurement device 100 uses a technology called time of flight (TOF) to measure the distance to the measurement object 200 from the time it takes for irradiated light to be reflected from the measurement object 200 and return, and the speed of light. Then, by using this technology to measure the distances to multiple points on the measurement object 200, the three-dimensional shape of the measurement object 200 can be calculated.

[0039] As shown in FIG. 1, the optical measurement device 100 of this embodiment includes a processing unit 30, a light emitting unit 40, and a light receiving unit 41.

[0040] The light-emitting unit 40 includes a light-emitting element array 10 having a plurality of light-emitting elements called VCSELs (Vertical Cavity Surface Emitting Lasers). The light-emitting element array 10 controls the lighting of each light-emitting element, and irradiates the object 200 to be measured with light from each light-emitting element.

[0041] The light receiving section 41 includes a light receiving element 20 that receives light that is emitted from the light emitting element array 10 and reflected by the object 200 to be measured.

[0042] The processing unit 30 processes information about the light received by the light receiving element 20 of the light receiving unit 41 to measure the distance from the light emitting element array 10 to the measurement object 200 or the shape of the measurement object 200 .

[0043] In this way, the optical measurement device 100 of this embodiment can be used in various systems that measure the distance to and three-dimensional shape of the measurement object 200, such as a system that measures the shape of a person's face to perform face authentication, or a system that is loaded onto a car to detect obstacles in front, behind, or to the side, etc.

[0044] In addition, the light-emitting element array 10 of this embodiment can also be used to configure a self-scanning light-emitting element array (SLED: Self-Scanning Light Emitting Device) to realize an LPH (LED Print Head) used in an electrophotographic system.

[0045] Next, the configuration of the light emitting unit 40 in the optical measurement device 100 shown in FIG. 1 is shown in a block diagram in FIG.

[0046] 2, the light-emitting unit 40 includes a light-emitting element array 10 and a driver 11. The light-emitting element array 10 is divided into 12 blocks of, for example, 3 rows and 4 columns. The driver 11 functions as a drive unit that drives a plurality of light-emitting elements configured on the light-emitting element array 10.

[0047] The configuration of an optical device 110 using the light emitting element array 10 of this embodiment is shown in the block diagram of FIG.

[0048] As shown in FIG. 3, the optical device 110 of this embodiment includes a light-emitting element array 10, a driver 11, and a control unit 12.

[0049] The control unit 12 controls the driver 11 so that processing using the light generated by the light emitting element array 10 is performed.

[0050] Next, FIG. 4 shows a schematic configuration of the light emitting element array 10 in this embodiment as viewed from above.

[0051] Referring to FIG. 4, the light-emitting element array 10 in this embodiment is composed of a plurality of light-emitting elements 50. The plurality of light-emitting elements 50 are divided into a plurality of blocks, and light emission control can be performed on a block-by-block basis. In this embodiment, the plurality of light-emitting elements in the same block are connected by thyristors, and the light-emitting elements in the same block can emit light at the same timing in response to a signal sent to the thyristor. Meanwhile, the thyristors in different blocks are insulated from each other due to the presence of block grooves, and a signal sent to the thyristors in different blocks will not cause the light-emitting elements in different blocks to emit light. FIG. 4 shows a case in which the plurality of light-emitting elements 50 are divided into 12 blocks arranged in 3 rows and 4 columns.

[0052] 4, when the plurality of light-emitting elements 50 are divided into blocks, a block separation groove 53 is provided between each block to separate the elements and ensure electrical insulation between different blocks. The block separation groove 53 is an example of a block separation portion in this embodiment.

[0053] In this embodiment, although the blocks are electrically insulated from each other, the anode electrodes 71 and back electrodes 73 are connected. However, since the thyristor portions are electrically insulated from each other, it is possible to make each block emit light at different times.

[0054] Next, FIG. 5 shows a schematic diagram of the structure of an enlarged portion of the light-emitting element array 10 shown in FIG.

[0055] In FIG. 5, for ease of explanation, the anode electrodes provided around each light emitting element 50 are omitted.

[0056] The light-emitting element array 10 includes a semiconductor substrate (described later) and a plurality of light-emitting elements 50 arranged on the semiconductor substrate. Each of the light-emitting elements 50 constituting the light-emitting element array 10 has an emission opening 51 for emitting laser light, and a plurality of trench grooves 52 are provided around each of the emission openings 51.

[0057] The multiple trench grooves 52 are provided around the multiple light-emitting elements 50, respectively, and are constriction grooves for forming a current constriction layer that oxidizes the light-emitting layer provided below the light-emitting element 50 to constrict the current flowing in the light-emitting layer.

[0058] The block separation grooves 53 are formed so as to overlap with parts of the trench grooves 52 in a plan view, and are provided so as to separate the light emitting elements 50 into a plurality of blocks.

[0059] Next, a cross-sectional view of the light-emitting element array 10 shown in FIG. 5 taken along line XX' is shown in FIG. 6, and a cross-sectional view of the light-emitting element array 10 taken along line YY' is shown in FIG.

[0060] The light emitting element array 10 of this embodiment is configured as a surface emission type semiconductor laminated structure using a distributed Bragg reflector (DBR) waveguide.

[0061] 6, the light-emitting element 50 is formed on a GaAs substrate 60, which is a compound semiconductor substrate, and has a structure in which a thyristor 80 that controls the on / off state of the light-emitting element 50 and a light-emitting layer 90 that generates laser light are coupled via a tunnel junction layer 91. A back electrode 73 is formed on the back side of the GaAs substrate 60.

[0062] The thyristor 80 is composed of an anode layer 81, an n-type n-gate layer 82, a p-type p-gate layer 83, and a cathode layer 84. The light-emitting layer 90 is composed of a p-type pDBR layer 92 and an n-type nDBR layer 95 formed above and below a resonator 94.

[0063] An anode electrode 71 is formed on the anode layer 81 of the thyristor 80. As shown in Fig. 7, a gate electrode 72 for controlling the on / off of the thyristor 80 is formed at a predetermined location on the n-gate layer 82. As mentioned above, the anode electrode 71 is not shown in the enlarged view shown in Fig. 5, but in reality it is formed to surround the periphery of the emission opening 51.

[0064] In the light-emitting layer 90, laser light is generated by the resonance of light of a specific wavelength between the upper pDBR layer 92 and the lower nDBR layer 95. The laser light generated in the light-emitting layer 90 is then emitted vertically from the emission opening 51.

[0065] A current confinement layer 93 is formed by oxidizing a portion of the pDBR layer 92. This current confinement layer 93 is formed to constrict the current path of the current flowing in the light-emitting element array 10, thereby causing the current flowing in the light-emitting element array 10 to pass through the central portion of the light-emitting element 50. Specifically, the current confinement layer 93 is formed such that the central portion of the light-emitting element 50 is formed as a current passing region α through which current can easily flow, and the surrounding portion is formed as a current blocking region through which current cannot easily flow.

[0066] By providing such a current confinement layer 93, the power consumed by non-radiative recombination is suppressed, thereby achieving lower power consumption and increased luminous efficiency.

[0067] As described above, the current confinement layer 93 is formed by oxidizing a portion of the pDBR layer 92. Forming the current confinement layer 93 by oxidizing a portion of the pDBR layer 92 is sometimes referred to as oxidation confinement. To oxidize the pDBR layer 92, a trench 52 is provided around the light-emitting element 50.

[0068] 5, a case will be described in which six trench grooves 52 are provided around the light emitting element 50 on a circle centered on the light emitting element 50. However, the number of trench grooves 52 provided for one light emitting element 50 is not limited, and a structure in which four, five, eight, etc. trench grooves are provided for one light emitting element may also be used.

[0069] The six trenches 52 surround the periphery of the emission opening 51 and are formed so as to remove the cathode layer 84, the tunnel junction layer 91, the pDBR layer 92, and the resonator 94. The pDBR layer 92 is oxidized through the trenches 52 to form a current confinement layer 93.

[0070] In this embodiment, the block separation groove 53 is formed so as to overlap with a portion of the plurality of trench grooves 52 in plan view. Specifically, in Fig. 6, the trench groove 52 provided on the right side of the light emitting element 50 is provided so as to overlap with the block separation groove 53. In contrast, in Fig. 6, the trench groove 52 provided on the left side of the light emitting element 50 is provided so as not to overlap with the block separation groove 53.

[0071] In this embodiment, after the trench grooves 52 are formed by etching, oxidation confinement is performed in the light-emitting layer 90, and then the block separation grooves 53 are formed by etching.

[0072] Therefore, the overlapping portions of the trench grooves 52 and the block separation grooves 53 are configured to be deeper than the non-overlapping portions of either the trench grooves 52 or the block separation grooves 53. In addition, in the overlapping portions of the trench grooves 52 and the block separation grooves 53, the block separation grooves 53 are configured to be composed of a plurality of grooves with different depths.

[0073] For example, if trench groove 52 is formed to a depth of 5 μm and then block separation groove 53 is formed to a depth of 5 μm, the depth of block separation groove 53 will be 10 μm where trench groove 52 and block separation groove 53 overlap. However, in reality, it is not a simple addition, and even under the above conditions, the depth of block separation groove 53 where trench groove 52 and block separation groove 53 overlap will be, for example, about 7 μm.

[0074] Here, when the oxidative confinement is performed on the light-emitting layer 90, the block separation groove 53 has not yet been formed, and therefore the light-emitting layer 90 is not oxidized from the portion of the block separation groove 53 that does not overlap with the trench groove 52. As a result, the light emission of the light-emitting element 50 is not affected by oxidation from the block separation groove 53.

[0075] Then, the trench grooves 52 and the block separation grooves 53 are each formed by two etching processes, with the width of the trench grooves 52 being wider than the width of the block separation grooves 53. As a result, as shown in Fig. 6, a step is formed in the portion where the trench grooves 52 and the block separation grooves 53 overlap, where the width of the trench grooves 52 narrows to the width of the block separation grooves 53.

[0076] Next, the positional relationship between the block separation grooves 53 and the trench grooves 52 will be described with reference to Fig. 8. For ease of understanding, the block separation grooves 53 are shown by black lines in Fig. 8.

[0077] As described above, in the light-emitting element array 10 of this embodiment, some of the multiple trench grooves 52, specifically the trench grooves 52 provided between two light-emitting elements 50 belonging to different blocks, are configured to overlap with the block separation grooves 53.

[0078] The block separation groove 53 is configured to pass through approximately the midpoint between two light emitting elements 50 arranged in different blocks.

[0079] Here, approximately midway between two light-emitting elements 50 means that on a line connecting the centers of the two light-emitting elements 50, the distance from either center is within 45 to 55% of the distance between the two centers.

[0080] As described above, in this embodiment, the block separation groove 53 is formed after forming the trench groove 52 and the current confinement layer 93. However, if the trench groove 52 and the block separation groove 53 are formed in the same etching process, and the distance between the block separation groove 53 and the light-emitting element 50 is short, the light-emitting layer 90 will also be oxidized and confined from the block separation groove 53, resulting in a non-uniform shape of the current passage region. Specifically, the shape of the current passage region will be non-uniform between a light-emitting element 50 having a block separation groove 53 formed nearby and a light-emitting element 50 having no block separation groove 53 formed nearby.

[0081] If the shape of the current passing region becomes non-uniform between the light emitting elements 50, the intensity of the emitted laser light will become non-uniform between the light emitting elements 50.

[0082] Therefore, when the block separation groove 53 and the trench groove 52 are formed by the same etching process, it is necessary to prevent the shape of the current passage region of the light emitting element 50 from being affected by oxidation constriction caused by the block separation groove 53. Specifically, the distance between the block separation groove 53 and the light emitting element 50 needs to be a predetermined distance or more.

[0083] FIG. 9 shows a comparative example in which the block separation grooves 53 and the trench grooves 52 are not overlapped.

[0084] 9, when the block separation grooves 53 and the trench grooves 52 are configured so as not to overlap each other and the distance between the block separation grooves 53 and the light emitting elements 50 is set to a predetermined distance or more, a certain amount of space is required between the plurality of light emitting elements 50 arranged in different blocks. By providing a certain amount of space between the plurality of light emitting elements 50 arranged in different blocks in this way, it is possible to make the block separation grooves 53 linear, and by setting the distance between the block separation grooves 53 and each light emitting element 50 to a predetermined distance or more, it is possible to prevent the current passing region from being shaped unevenly among the light emitting elements 50 having different shapes due to etching from the block separation grooves 53.

[0085] However, in the comparative example shown in Figure 9, by providing a certain amount of space between multiple light-emitting elements 50 arranged in different blocks, the number of light-emitting elements 50 that can be formed on a semiconductor substrate of the same area is reduced, resulting in a low arrangement density of the light-emitting elements 50.

[0086] Therefore, in this embodiment, as shown in Figure 8, even in a configuration in which the light-emitting elements 50 are arranged at equal intervals and at least one trench groove 52 among the multiple trench grooves 52 provided around two adjacent light-emitting elements 50 is commonly provided, by configuring the block separation groove 53 and the trench groove 52 to overlap in a planar view, it is possible to prevent the shape of the current passage region between the light-emitting elements 50 from becoming uneven.

[0087] Furthermore, the distance between the light emitting element 50 and the portion where the block separation groove 53 and the trench groove 52 do not overlap is longer than the distance between the trench groove 52 and the light emitting element 50. Therefore, even if oxidation of the light emitting layer 90 occurs from the block separation groove 53, the effect on the shape of the current passing region of each light emitting element 50 is suppressed.

[0088] In addition, in Figure 8, the light-emitting elements 50 are described as being arranged at equal intervals even at the boundaries between different blocks, but the present invention is not limited to such a configuration and can be similarly applied to cases where the light-emitting elements 50 are not arranged at equal intervals at the boundaries of the blocks.

[0089] Furthermore, in this embodiment, by providing a trench groove 52 in common between two adjacent light-emitting elements 50 and between light-emitting elements 50 in upper and lower rows, the block separation groove 53 is formed without affecting the arrangement of the light-emitting elements 50, even when the spacing between the light-emitting elements 50 is shortened and the arrangement density of the light-emitting elements 50 is increased.

[0090] 8, the block separation grooves 53 are curved to include at least one inflection point where the sign of the curvature changes along the positions of the light emitting elements 50. Therefore, even when the light emitting elements 50 are arranged with short intervals between them, the block separation grooves 53 are configured without disturbing the arrangement of the light emitting elements 50.

[0091] 8, the block separation groove 53 is formed along both an array (shown by a thick line in the figure) formed by three trench grooves 52a-52c arranged along the light emitting element 50A and an array (shown by a filled-in horizontal line in the figure) formed by three trench grooves 52c-52e arranged along the light emitting element 50B. The inflection point of the block separation groove 53 occurs at the portion where the line changes from the line formed by the three trench grooves 52a-52c to the line formed by the three trench grooves 52c-52e, that is, at the position where the trench groove 52c is arranged, where the two arrays overlap.

[0092] That is, the curvature of the block separation groove 53 follows the arrangement formed by the trench grooves 52 for the light emitting elements 50, and the inflection points occur when the block separation groove 53 follows the trench grooves 52 of different light emitting elements 50. These different light emitting elements 50 are light emitting elements 50 in different blocks.

[0093] In addition, in Figure 8, the block separation grooves 53 are curved, so that the distance between the light-emitting elements 50 is maintained, and even if oxidation of the light-emitting layer 90 occurs from the block separation grooves 53, the shape of the current passage region of each light-emitting element 50 is not affected.

[0094] In the light emitting element array 10 of this embodiment, as shown in FIG. 4, the block separation grooves 53 are provided in a lattice pattern.

[0095] However, the block separation grooves 53 are not limited to being provided in a grid pattern, and as shown in FIG. 10, the block separation grooves 53 may be configured to be oblique.

[0096] Furthermore, the block separation grooves 53 are not limited to being curved, and the block separation grooves 53 may be configured in a straight line as shown in Fig. 11. Fig. 11 shows an example of an arrangement in which four trench grooves 52 are arranged around one light emitting element 50, and the trench groove 52 is shared with other light emitting elements 50 above, below, and to the left and right.

[0097] Furthermore, an example in which the block separation grooves 53 are curved and configured so that the block separation grooves 53 and the trench grooves 52 do not overlap each other is shown in FIG.

[0098] 12 shows an example of an arrangement in which four trench grooves 52 are arranged around one light emitting element 50, and the trench grooves 52 are not shared with other light emitting elements 50 above, below, to the left, or to the right. In the example of the arrangement shown in FIG. 12, it can be seen that the block separation grooves 53 are arranged to be curved along the arrangement positions of the light emitting elements 50, so that the block separation grooves 53 are arranged without affecting the arrangement of the light emitting elements 50.

[0099] 12 illustrates a case where the distance between the two trenches 52 is large enough to form the block separation groove 53, but there are also cases where the distance between the two trenches 52 is too short to form the block separation groove 53. In such cases, the block separation groove 53 and the trenches 52 are configured to overlap each other.

[0100] Next, a method for manufacturing the light emitting element array 10 of this embodiment will be described.

[0101] The overall flow of the manufacturing method for the light-emitting element array 10 of this embodiment is shown in the flowchart of Fig. 13. Note that, although the flowchart of Fig. 13 explains only the main steps in the manufacturing method for the light-emitting element array 10, an actual manufacturing method may include steps that are not shown in the flowchart of Fig. 13.

[0102] First, when manufacturing the light-emitting element array 10, the nDBR layer 95, the resonator 94, the pDBR layer 92, the tunnel junction layer 91, the cathode layer 84, the p-gate layer 83, the n-gate layer 82, and the anode layer 81 are formed sequentially by epitaxial growth on the GaAs substrate 60, as shown in FIG.

[0103] 14, first, in step S101, a metal material that will become the anode electrode 71 is vapor-deposited to form the anode electrode 71. A cross-sectional view of the anode electrode 71 after being formed in this manner is shown in FIG.

[0104] Next, in step S102, a gate contact is formed by etching a portion of the anode layer 81, and a metal material is evaporated onto the formed gate contact to form the gate electrode 72. A cross-sectional view of the gate electrode 72 after it has been formed in this manner is shown in Figure 16. Note that the gate electrode 72 does not appear in the cross-sectional view of Figure 16, and therefore the cross section of the gate electrode 72 is not directly shown.

[0105] Next, in step S103, the n-gate layer 82 and the p-gate layer 83 are etched away from the region where the trench groove 52 is to be formed. A cross-sectional view of the structure after the n-gate layer 82 and the p-gate layer 83 have been removed in this manner is shown in FIG.

[0106] Next, in step S104, a plurality of trenches 52, which are narrowed grooves, are formed around the locations where the light-emitting elements 50 are to be disposed on the GaAs substrate 60. Specifically, in step S104, etching is performed using an etching gas to remove parts of the cathode layer 84, the tunnel junction layer 91, the pDBR layer 92, and the resonator 94, thereby forming the trenches 52. A cross-sectional view of the trenches 52 after they have been formed in this manner is shown in FIG.

[0107] FIG. 19 shows an etching pattern when forming trench grooves 52 in the etching process of step S104.

[0108] In the cross-sectional view shown in FIG. 18, the block separation grooves 53 have not yet been formed, so the trench grooves 52 on the left and right of the portion where the light emitting element 50 is to be formed have the same depth.

[0109] Then, in step S105, a current confinement layer 93 that confines the current flowing through the light-emitting layer 90 is formed by oxidizing the light-emitting layer 90 that is partially exposed in the trench 52. Specifically, in step S105, an oxidizing gas is supplied from the trench 52 to oxidize a portion of the pDBR layer 92, thereby forming the current confinement layer 93. A cross-sectional view of the current confinement layer 93 after it has been formed in this manner is shown in FIG.

[0110] Next, in step S106, etching is performed using a predetermined etching pattern to form block separation grooves 53 that separate the plurality of light emitting elements 50 into a plurality of blocks. A cross-sectional view of the block separation grooves 53 formed in this manner is shown in FIG.

[0111] FIG. 22 shows an etching pattern when forming the block separation grooves 53 in the etching process of step S106.

[0112] Referring to Figure 21, it can be seen that the trench groove 52 to the left of the area where the light-emitting element 50 is formed does not have a block separation groove 53 formed thereon, but the trench groove 52 to the right of the area where the light-emitting element 50 is formed has a block separation groove 53 formed thereon, resulting in a stepped shape.

[0113] Finally, in step S107, emission openings 51 are formed on the current passing regions of the current confinement layer 93 to form a plurality of light emitting elements 50. Specifically, in step S107, the anode layer 81, n-gate layer 82, p-gate layer 83, cathode layer 84, and tunnel junction layer 91 are removed in the regions where the light emitting elements 50 are to be formed, thereby forming the emission openings 51. A cross-sectional view of the emission openings 51 after they have been formed in this manner is shown in FIG.

[0114] It should be noted that the manufacturing method of the light-emitting element array 10 of this embodiment described above is only an outline, and therefore, descriptions of the actual generation of insulating films, electrode lead wiring, protective films, light-shielding films, etc. are omitted.

[0115] Finally, a rear electrode 73 is formed, thereby completing the light emitting element array 10 as shown in FIG.

[0116] 4 illustrates a case where the plurality of light-emitting elements 50 are divided into 12 blocks of 3 rows and 4 columns, but the block division method is not limited to this case, and other block division methods may be used to divide the plurality of light-emitting elements 50. For example, as shown in FIG. 24, a block division method may be used in which the plurality of light-emitting elements 50 are divided into n blocks of n rows and 1 column.

[0117] Furthermore, in this embodiment, the present invention has been described as being applied to a light-emitting element array 10 having a structure in which elements are isolated between blocks by forming block isolation grooves 53, but the present invention is not limited to this case. The present invention can also be applied to a light-emitting element array having a structure in which elements are isolated between light-emitting elements by separating the semiconductor laminate structure into multiple islands by mesa etching. A structure in which the semiconductor laminate structure is etched into islands like this is also called a post structure, and in a light-emitting element array having such a post structure, the periphery of each light-emitting element is removed in the shape of a continuous groove.

[0118] When the grooves formed in such a post structure are post grooves, the block separation grooves as described above may be formed so as to overlap with parts of the plurality of post grooves in a plan view.

[0119] Furthermore, in this embodiment, the light-emitting element array 10 having a layered structure of light-emitting elements and thyristors may be configured without thyristors. In this case, for example, an anode electrode 71 may be provided for each block so that current is supplied to each block, and a driving unit capable of driving control may be applied so that current is supplied to each block at different timings.

[0120] Furthermore, in this embodiment, an example has been shown in which one block includes a plurality of light emitting elements, but one block may be configured with one light emitting element.

[0121] Other structures include a VCSEL array that emits light to the back surface of the substrate, a thyristor structure itself that serves as a light emitting element, and a transistor instead of the thyristor.

[0122] In this embodiment, the present invention is applied to an optical measurement device, but it may also be applied to optical transmission by combining a light emitting device, an optical transmission path, and a light receiving means, or to biological detection in which light emitted from the light emitting device enters the inside of the object to be detected.

[0123] Furthermore, although a VCSEL is used as the light emitting element, an LED may also be used.

[0124] In this embodiment, linear block separation grooves, in which the entire groove is connected as a line, are shown as an example of block separation portions. However, dotted grooves may also be used. In this case, it is preferable to narrow the distance between the dots to a certain extent to prevent signals from reaching adjacent blocks. Furthermore, rather than separating blocks using grooves, ion implantation may be used to create insulating portions at the block separation positions. Since ion implantation does not create a step due to the grooves, it is applicable even when the distance between light-emitting points is narrow and it is difficult to ensure the size of the light-emitting points. Furthermore, oxidation does not occur at the separation separation portions formed by ion implantation, and non-uniformity due to the presence of block separation portions is suppressed. Furthermore, separation grooves and ion implantation may be used in combination. [Explanation of symbols]

[0125] 10 Light-emitting element array 11 Drivers 12 Control Unit 20 Photodetector 30 Processing section 40 Light-emitting part 41 Light receiving part 50 Light-emitting element 51 Exit opening 52 Trench 53 Block separation groove 60 GaAs substrate 71 Anode electrode 72 gate electrode 73 Back electrode 80 Thyristor 81 Anode layer 82 n-gate layer 83 p-gate layer 84 cathode layer 90 Light-emitting layer 91 Tunnel Junction Layer 92 pDBR layer 93 Current confinement layer 94 Resonator 95 nDBR layer 100 Optical measurement device 110 Optical equipment 200 Measurement object

Claims

1. A substrate; a plurality of light-emitting elements disposed on the substrate; a plurality of constriction grooves provided around the plurality of light-emitting elements, respectively, for forming current constriction layers that oxidize the light-emitting layers to constrict a current flowing through the light-emitting layers; a block separation portion that is formed so as to overlap a part of the narrowing grooves in a plan view and separates the light emitting elements into a plurality of blocks; the block separation portion includes a block separation groove, The narrowing groove and the block separating groove are configured so that the overlapping portion of the narrowing groove and the block separating groove is deeper than the non-overlapping portion of either the narrowing groove or the block separating groove. Light-emitting element array.

2. 2. The light-emitting element array according to claim 1, wherein the light-emitting layer is not oxidized from a portion of the block separating portion that does not overlap with the narrowing groove.

3. An light-emitting element array as described in claim 2, wherein the width of the narrowing groove is wider than the width of the block separation groove, and at the portion where the narrowing groove and the block separation groove overlap, a step is formed that narrows from the width of the narrowing groove to the width of the block separation groove.

4. An array of light-emitting elements as described in claim 1 or 3, wherein the block separation groove is configured to pass through approximately the midpoint between two light-emitting elements arranged in different blocks.

5. 5. The light-emitting element array according to claim 1, wherein the block separation portion is curved so as to include at least one inflection point where the sign of curvature changes along each position where the plurality of light-emitting elements are arranged.

6. 6. The light-emitting element array according to claim 1, wherein a plurality of narrowing grooves are provided around the light-emitting element on a circle centered on the light-emitting element.

7. 5. The light-emitting element array according to claim 4, wherein at least one narrowing groove among the plurality of narrowing grooves provided around the periphery of two adjacent light-emitting elements is provided in common.

8. The light-emitting element array according to any one of claims 1 to 7, a drive unit that drives the plurality of light-emitting elements configured on the light-emitting element array; a control unit that controls the drive unit so that a process using light generated by the light-emitting element array is performed; An optical device comprising:

9. The light-emitting element array according to any one of claims 1 to 7, a light receiving element that receives light that is emitted from the light emitting element array and reflected by an object; a processing unit that processes information about the light received by the light receiving element to measure the distance from the light emitting element array to the object or the shape of the object; An optical measurement device equipped with:

10. forming a plurality of narrowing grooves around each location on the substrate where the light emitting elements are to be disposed; a step of forming a current confinement layer that confines a current flowing through the light emitting layer by oxidizing a part of the light emitting layer that is exposed in the confinement groove; forming a block separation groove for separating the plurality of light emitting elements to be formed into a plurality of blocks; forming an emission aperture on a current passing region of the current confinement layer to form a plurality of light emitting elements; The narrowing groove and the block separating groove are configured so that the overlapping portion of the narrowing groove and the block separating groove is deeper than the non-overlapping portion of either the narrowing groove or the block separating groove. A method for manufacturing a light-emitting element array.

11. A method for manufacturing a light-emitting element array as described in Claim 10, wherein the block separation groove is formed so as to overlap a portion of the plurality of narrowing grooves in a planar view.

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