Infrared device and method for manufacturing an infrared device

Abstract

A high-performance infrared device and a method for manufacturing the infrared device are provided. [Solution] The infrared device comprises a substrate (10), a semiconductor laminate (20) provided on the substrate and having a first semiconductor layer (21), an active layer (23), and a second semiconductor layer (25), and an electrical barrier layer (30) located between the substrate and the semiconductor laminate (20) to suppress leakage current. With the surface of the substrate on the side on which the semiconductor laminate is provided as a reference plane, the first angle formed by the side surface of the first semiconductor layer with a plane parallel to the reference plane and the second angle formed by the side surface of the electrical barrier layer with a plane parallel to the reference plane are different, and the side surface of the first semiconductor layer and the side surface of the electrical barrier layer are in contact.

Description

[Technical Field] 【0001】 This disclosure relates to an infrared device and a method for manufacturing an infrared device. [Background technology] 【0002】 For example, infrared radiation with wavelengths of approximately 2 to 15 μm contains many absorption bands specific to gas molecules, and is therefore used in non-dispersive infrared absorption type gas concentration measuring devices. Infrared devices used in gas concentration measuring devices are important components that greatly affect key performance characteristics such as detection resolution, and high emission intensity or light-receiving sensitivity at desired wavelengths is required. Here, an infrared device is an infrared light-emitting element or an infrared light-receiving element, and is used as a general term for these. For example, a light-emitting diode (LED) is used as the light-emitting element. Also, for example, a photodiode (PD) is used as the light-receiving element. Such infrared devices using semiconductors can emit and receive light at desired wavelength bands depending on the material design, and are used in gas concentration measuring devices that detect specific gases. An example of a gas concentration measuring device is an NDIR (non-dispersive infrared) type gas sensor (for example, Patent Document 1). An NDIR type gas sensor can measure gas concentration using an infrared light-receiving element that receives infrared radiation in the absorption wavelength band corresponding to the gas to be detected and an infrared light-emitting element that emits infrared radiation in the same absorption wavelength band. [Prior art documents] [Patent Documents] 【0003】 [Patent Document 1] Japanese Patent Publication No. 2004-271518 [Overview of the Initiative] [Problems that the invention aims to solve] 【0004】 Here, infrared devices are required to further improve their light emission intensity or detection sensitivity. If there is current leaking into the substrate, the light emission intensity or detection sensitivity of the infrared device will decrease. Also, when infrared devices and other components such as ICs are mounted on the same substrate, current leakage to the other components may affect them. 【0005】 This disclosure is made in view of these circumstances and aims to provide a high-performance infrared device and a method for manufacturing an infrared device. [Means for solving the problem] 【0006】 (1) An infrared device according to one embodiment of the present disclosure is circuit board and A semiconductor laminate is provided on the substrate and has a first semiconductor layer, an active layer, and a second semiconductor layer. It comprises an electrical barrier layer located between the substrate and the semiconductor laminate to suppress leakage current, Using the surface of the substrate on the side where the semiconductor stack is provided as the reference surface, The first angle formed by the side surface of the first semiconductor layer with a plane parallel to the reference plane and the second angle formed by the side surface of the electrical barrier layer with a plane parallel to the reference plane are different. The side surface of the first semiconductor layer and the side surface of the electrical barrier layer are in contact. 【0007】 (2) As one embodiment of the present disclosure, in (1), The aforementioned electrical barrier layer is an amorphous or polymer layer. 【0008】 (3) As one embodiment of the present disclosure, in (2), The aforementioned electrical barrier layer is a layer of silicon nitride, silicon dioxide, aluminum oxide, thermal silicon nitride, silica gel, silicon monoxide, epoxy resin, or polyimide. 【0009】 (4) In one embodiment of the present disclosure, in any of (1) to (3), The electric barrier layer is present in a first region that is a region between the plurality of semiconductor stacked portions, and the thickness of the electric barrier layer in the stacking direction in the first region is smaller than the thickness of the electric barrier layer in the stacking direction in a second region that is not the first region. 【0010】 (5) As one embodiment of the present disclosure, in any one of (1) to (4), The second angle is not perpendicular to the reference plane. 【0011】 (6) As one embodiment of the present disclosure, in any one of (1) to (5), The thickness of the electric barrier layer in the stacking direction is 500 nm or more. 【0012】 (7) As one embodiment of the present disclosure, in any one of (1) to (6), The refractive index of the electric barrier layer is lower than the average refractive index of the semiconductor stacked portions. 【0013】 (8) As one embodiment of the present disclosure, in any one of (1) to (7), Wavelength λ p [nm] has an optical characteristic having a peak, When the thickness of the semiconductor stacked portions in the stacking direction is t [nm] and an integer of 0 or more is m, the following formula (1) is satisfied. 【Equation】 【0014】 (9) As one embodiment of the present disclosure, in (1), The electric barrier layer is a semiconductor layer. 【0015】 (10) As one embodiment of the present disclosure, in (9), For the electric barrier layer, a material having a larger energy gap than the material of the first semiconductor layer is used. 【0016】 (11) As one embodiment of the present disclosure, in (9) or (10), The electric barrier layer has a conductivity type different from that of the first semiconductor layer. 【0017】 (12) As one embodiment of the present disclosure, in any one of (9) to (11), A material having an energy gap smaller than that of the substrate material is used for the electric barrier layer. 【0018】 (13) As one embodiment of the present disclosure, in any one of (9) to (12), The electric barrier layer has a conductivity type different from that of the substrate. 【0019】 (14) As one embodiment of the present disclosure, in any one of (1) to (13), The first semiconductor layer is in direct contact with the active layer, and the material of the layer of the first semiconductor layer that contacts the active layer has an energy gap larger than that of the active layer. 【0020】 (15) As one embodiment of the present disclosure, in any one of (1) to (14), The second semiconductor layer is in direct contact with the active layer, and the material of the layer of the second semiconductor layer that contacts the active layer has an energy gap larger than that of the active layer. 【0021】 (16) As one embodiment of the present disclosure, in any one of (1) to (15), The side where infrared rays are emitted or incident has an n-type conductivity type. 【0022】 (17) A method for manufacturing an infrared device according to an embodiment of the present disclosure is On a substrate A sacrificial layer and a semiconductor laminated film are laminated, The sacrificial layer is removed, An electric barrier layer made of amorphous or polymer is formed on a substrate different from the substrate, The semiconductor laminated film is bonded onto the electric barrier layer, The semiconductor laminated film is etched to form a semiconductor laminated portion, which is a method for manufacturing an infrared device. The infrared device to be manufactured is The aforementioned substrate, The semiconductor laminate is provided on the substrate and has a first semiconductor layer, an active layer, and a second semiconductor layer. It comprises an electrical barrier layer located between the substrate and the semiconductor laminate to suppress leakage current, Using the surface of the substrate on the side where the semiconductor stack is provided as the reference surface, The first angle formed by the side surface of the first semiconductor layer with a plane parallel to the reference plane and the second angle formed by the side surface of the electrical barrier layer with a plane parallel to the reference plane are different. The side surface of the first semiconductor layer and the side surface of the electrical barrier layer are in contact. [Effects of the Invention] 【0023】 This disclosure provides a high-performance infrared device and a method for manufacturing an infrared device. [Brief explanation of the drawing] 【0024】 [Figure 1] Figure 1 shows an example configuration of an infrared device according to one embodiment of the present disclosure. [Figure 2] Figure 2 shows another example configuration of an infrared device. [Figure 3] Figure 3 shows another example configuration of an infrared device. [Figure 4] Figure 4 shows another example configuration of an infrared device. [Figure 5] Figure 5 is a partial cross-sectional view of an infrared device, showing an example of the side angles of the first semiconductor layer and the side angles of the electrical barrier layer. [Figure 6] Figure 6 is a partial cross-sectional view of an infrared device, illustrating the angle of the side surface of the electrical barrier layer. [Figure 7] Figure 7 is a diagram illustrating the thickness in the stacking direction of the semiconductor stacked portion. [Figure 8]Figure 8 is a partial cross-sectional view of an infrared device, showing an example of the side angles of the first semiconductor layer and the side angles of the electrical barrier layer. [Figure 9] Figure 9 is a partial cross-sectional view of an infrared device, illustrating the angle of the side surface of the electrical barrier layer. [Figure 10A] Figure 10A is a diagram illustrating a method for manufacturing an infrared device according to one embodiment of the present disclosure. [Figure 10B] Figure 10B is a diagram illustrating a method for manufacturing an infrared device according to one embodiment of the present disclosure. [Figure 10C] Figure 10C is a diagram illustrating a method for manufacturing an infrared device according to one embodiment of the present disclosure. [Figure 10D] Figure 10D is a diagram illustrating a method for manufacturing an infrared device according to one embodiment of the present disclosure. [Figure 10E] Figure 10E is a diagram illustrating a method for manufacturing an infrared device according to one embodiment of the present disclosure. [Figure 11] Figure 11 is a diagram illustrating the difference in light reflection due to the relationship between the side surface of the first semiconductor layer and the side surface of the electrical barrier layer. [Figure 12] Figure 12 is a diagram illustrating the difference in light reflection due to the relationship between the side surface of the first semiconductor layer and the side surface of the electrical barrier layer. [Figure 13] Figure 13 is a partial cross-sectional view of an infrared device, showing an example of the side angles of the first semiconductor layer and the side angles of the electrical barrier layer. [Modes for carrying out the invention] 【0025】 <Infrared device> Figure 1 is a diagram showing an example configuration of an infrared device according to one embodiment of the present disclosure. The infrared device according to this embodiment has a wavelength λ p The optical properties may have a peak at a certain wavelength. The optical properties of an infrared device may have multiple peaks, for example, at a wavelength λ. pThis may be any one of several peaks of the optical properties. The infrared device comprises a substrate 10, a semiconductor laminate 20, and an electrical barrier layer 30. The semiconductor laminate 20 has a first angle in which the side surface of the first semiconductor layer 21 makes contact with a plane parallel to the reference plane, and a second angle in which the side surface of the electrical barrier layer 30 makes contact with a plane parallel to the reference plane, with the surface of the substrate 10 on the side on which the semiconductor laminate 20 is provided as the reference plane. In addition, the side surface of the first semiconductor layer 21 and the side surface of the electrical barrier layer 30 are in contact. 【0026】 Here, "infrared device" refers to an infrared light-emitting element or an infrared light-receiving element, and is a collective term for both. An infrared light-emitting element is realized with the structure of the infrared device described below, and an infrared light-receiving element is realized with the same structure. When the infrared device is an infrared light-emitting element, it may specifically be a light-emitting diode (LED). When the infrared device is an infrared light-receiving element, it may specifically be a photodiode (PD). 【0027】 <Circuit board> The infrared device according to this embodiment includes a substrate 10. The substrate 10 is not particularly limited as long as it is a substrate that supports the semiconductor laminate 20. Examples include GaAs substrates, InP substrates, GaN substrates, Si substrates, quartz substrates, aluminum substrates, oxide substrates, aluminum nitride substrates, and polyimide flexible substrates. For example, the substrate 10 may be a Si-based substrate containing IC circuits. 【0028】 In the infrared device according to this embodiment, the electrical barrier layer 30 can suppress the current leaking from the semiconductor laminate 20 to the substrate 10 (hereinafter referred to as "leakage current"). By using a substrate 10 with a low impurity concentration (carrier concentration) or a semi-insulating substrate 10, the leakage current can be further suppressed. In addition, free electron absorption by electrons or holes may become significant in the mid-infrared long wavelength range. For example, by using a substrate 10 with a low impurity concentration or a semi-insulating substrate 10, the effect of suppressing free electron absorption can be enhanced. 【0029】 Here, the reference surface 10a shown in Figure 1 is the surface of the substrate 10 on which the semiconductor stacked portion 20 is provided. 【0030】 <Semiconductor laminated section> The infrared device according to this embodiment includes a semiconductor laminate 20 provided on a substrate 10. The semiconductor laminate 20 has, from the substrate 10 side, a first semiconductor layer 21, an active layer 23, and a second semiconductor layer 25. The first semiconductor layer 21 and the second semiconductor layer 25 are directly connected to the active layer 23. The semiconductor laminate 20 and the electrode section 50 constitute a unit element. Multiple semiconductor laminates 20 can be used. In that case, if the infrared device is an infrared light-emitting element, multiple unit elements can be connected in series or parallel to obtain the required light emission intensity and to realize appropriate driving voltage and current. In this embodiment, the unit element constitutes one light-emitting diode. Also, if the infrared device is an infrared light-receiving element, multiple unit elements can be connected in series or parallel to achieve a resistance value that is easy to handle when amplifying the output signal with an amplification circuit. In this embodiment, the unit element constitutes one photodiode. 【0031】 In the following description, the direction in which the first semiconductor layer 21, the active layer 23, and the second semiconductor layer 25 are stacked on the substrate 10 may be referred to as the "stacking direction." In this embodiment, the stacking direction is perpendicular to the reference plane 10a. 【0032】 <First semiconductor layer> The first semiconductor layer 21 is a semiconductor layer of a first conductivity type. In this embodiment, the first conductivity type is n-type. The constituent material of the first semiconductor layer 21 can be InSb, GaAs, InAs, InGaAs, InAlSb, GaAsSb, or InGaP, but is not limited to these. The first semiconductor layer 21 may also be composed of a laminated structure of multiple materials. The above materials are doped with impurities to control the impurity concentration (carrier concentration). 【0033】 Here, examples of impurities include Sn and Te used as n-type doping materials, and Zn, Be, and Ge used as p-type doping materials. Si can also be used as an n-type or p-type doping material depending on the base semiconductor. However, the materials of the impurities are not limited to these. The impurity concentration can be evaluated, for example, by secondary ion mass spectrometry (SIMS). Furthermore, it is preferable that the first semiconductor layer 21 is doped to be n-type or p-type with donor or acceptor impurities, but it does not have to be doped if it has a first conductivity type. The first semiconductor layer 21 may also include a dislocation filter layer. Furthermore, the first semiconductor layer 21 may consist of multiple layers. Here, when the first semiconductor layer 21 is in direct contact with the active layer 23, from the viewpoint of reducing diffusion current, it is preferable that the material of the layer of the first semiconductor layer 21 that is in contact with the active layer 23 has a larger energy gap than the active layer 23. 【0034】 <Active layer> The active layer 23 is a light-emitting layer or a light-receiving layer. While materials such as InAsSb are used for the active layer 23, it is not limited to these. Here, the active layer 23 may be an intrinsic semiconductor or may be p-type doped. In particular, when the energy gap is narrow, the active layer 23 may be slightly doped to the p-type. As an example of slight doping, 10 16 / cm 3 from 10 18 / cm 3 The impurities are doped into the solution. 【0035】 <Second semiconductor layer> The second semiconductor layer 25 is a semiconductor layer of a second conductivity type. The second conductivity type may be different from or the same as the first conductivity type. In this embodiment, the second conductivity type is a p-type, which is different from the first conductivity type. As another example, the first conductivity type may be p-type and the second conductivity type may be n-type. InSb, GaAs, InAs, InGaAs, InAlSb, GaAsSb, or InGaP are used as constituent materials for the second semiconductor layer 25, but are not limited to these. The second semiconductor layer 25 may also be composed of a laminated structure of multiple materials. Here, when the second semiconductor layer 25 is in direct contact with the active layer 23, from the viewpoint of reducing diffusion current, it is preferable that the material of the layer of the second semiconductor layer 25 that is in contact with the active layer 23 has a larger energy gap than the active layer 23. Also, the direction of infrared emission in the light-emitting element or the direction of infrared incidence in the photodetector may be either the top or bottom of the substrate 10. From the viewpoint of improving infrared transmittance due to the Berstein-Moss effect of the infrared element, it is preferable that the side from which infrared radiation is emitted or incident is of type n conductivity. 【0036】 <Electrode part> For the electrode portion 50, a material with high reflectivity in the mid-infrared long wavelength range is preferred. For example, Au and Al can be used as the material for the electrode portion 50. Furthermore, different electrode materials can be laminated in the electrode portion 50 to reduce contact resistance, improve adhesion, and prevent mutual diffusion between the electrode material and the semiconductor material. For example, Ti, Pt, Ni, Cr, and Cu can also be used. However, the electrode material is not limited to these. 【0037】 The electrode portion 50 is electrically connected (in contact) with the first semiconductor layer 21 in its first portion, and can inject or extract current from the first semiconductor layer 21. The electrode portion 50 is electrically connected (in contact) with the second semiconductor layer 25 in its second portion, and can inject or extract current from the second semiconductor layer 25. 【0038】 <Electrical barrier layer> The electrical barrier layer 30 is located between the substrate 10 and the semiconductor laminate 20 and contributes to increasing the electrical resistance between the substrate 10 and the semiconductor laminate 20. Because leakage current is suppressed by the electrical barrier layer 30, a high-performance infrared device is realized that does not reduce the light emission intensity or detection sensitivity. From the viewpoint of insulation, the thickness of the electrical barrier layer 30 in the lamination direction is preferably 500 nm or more. 【0039】 The electrical barrier layer 30 may be an amorphous or polymer layer. For example, the electrical barrier layer 30 can be a layer of silicon nitride (SiN), silicon dioxide (SiO2), aluminum oxide (Al2O3), thermal silicon nitride, silica gel, silicon monoxide (SiO), epoxy resin, or polyimide. When the material of the electrical barrier layer 30 is amorphous or polymer, an infrared device is manufactured by connecting a pre-formed semiconductor laminate 20 to the substrate 10 via the electrical barrier layer 30 and connecting adjacent semiconductor laminates 20 with electrode portions 50. 【0040】 Here, if the material of the electrical barrier layer 30 is amorphous or polymer, it is difficult to form the semiconductor laminated portion 20 on the electrical barrier layer 30 using MBE or MOCVD. MBE and MOCVD are methods for growing crystals by inheriting the crystal information of the underlying layer. Since the underlying amorphous or polymer is noncrystalline, it does not contain crystal information (orientation, interatomic spacing, etc.). The method for manufacturing an infrared device according to one embodiment of this disclosure is as follows. First, a sacrificial layer b, which will be removed later, is laminated on a substrate a (see Figure 10A) separate from the substrate 10 (see Figure 10B), and then a semiconductor laminated film X is formed (see Figure 10C). Methods of formation include MBE or MOCVD. Next, the sacrificial layer b is removed, and only the semiconductor laminated film X is peeled off, and the semiconductor laminated film X is bonded to the substrate 10 via the electrical barrier layer 30 (see Figure 10D). Here, bonding to the substrate 10 is performed, for example, by bonding. Methods for removing the sacrificial layer b include etching. Methods for joining the electrical barrier layer 30 and the semiconductor multilayer film X include atomic diffusion bonding and surface activation bonding. The surface of the semiconductor multilayer film X that is joined to the substrate 10 may be the surface c that was in contact with the sacrificial layer b, or the surface d opposite to the surface c that was in contact with the sacrificial layer b. This makes it possible to form a structure e on the substrate 10 in which the electrical barrier layer 30 and the semiconductor multilayer film X are stacked (see Figure 10E). Subsequently, the semiconductor multilayer film X of structure e can be appropriately etched to form a semiconductor stacked portion 20. The layer used as a mask during this etching may be used as a protective layer for the infrared device. Subsequently, an appropriate protective layer is formed and adjacent semiconductor stacked portions 20 are connected by an electrode portion 50 to manufacture the infrared device. 【0041】 Furthermore, the electrical barrier layer 30 may be a semiconductor layer. In this case, the infrared device is manufactured by known semiconductor manufacturing methods. When the material of the electrical barrier layer 30 is a semiconductor, in order to reduce leakage current, the electrical barrier layer 30 may be made of a material with a larger energy gap (band gap) than the material of the first semiconductor layer 21. By utilizing the fact that a potential barrier is formed between a material with a larger energy gap and a material with a smaller energy gap, the inflow of carriers from the first semiconductor layer 21 with a small energy gap to the electrical barrier layer 30 with a large energy gap can be restricted, thereby reducing leakage current. Here, the electrical barrier layer 30 may be made of a material with a smaller energy gap than the material of the substrate 10. This restricts the inflow of carriers from the electrical barrier layer 30 with a small energy gap to the substrate 10 with a large energy gap, thereby reducing leakage current. Furthermore, the electrical barrier layer 30 may have a different conductivity type than the first semiconductor layer 21. Furthermore, the electrical barrier layer 30 may have a different conductivity type than the substrate 10. This is because a potential barrier is formed in different conductivity types, which restricts the inflow of carriers and reduces leakage current. 【0042】 Here, as shown in Figure 2, the region between the semiconductor stacked portions 20 is defined as the "first region," and the region that is not the first region is defined as the "second region." In other words, the second region is the region where the main part of the above-mentioned unit element is formed, and the connection region between adjacent unit elements is the first region. The electrical barrier layer 30 is provided in at least the second region. The electrical barrier layer 30 does not have to be present in the first region, as shown in Figure 2. As another example, as shown in Figure 3, the electrical barrier layer 30 may be formed to be present in the first region. Also, as shown in Figure 4, the electrical barrier layer 30 may be present in the first region and further formed to divide the first protective film 31. Here, the first protective film 31 is a film formed on the side and top surfaces of the semiconductor stacked portion 20 to protect the semiconductor stacked portion 20. As the first protective film 31, for example, silicon oxide, silicon nitride, aluminum oxide, titanium oxide, zinc oxide, hafnium oxide, etc. can be selected. Furthermore, silicone resin, polyimide resin, epoxy resin, etc., can be selected. If the electrical barrier layer 30 is formed so that it is also present in the first region, the coverage is improved, and the effect of suppressing leakage current is further enhanced. 【0043】 Here, the first protective film 31 may be formed to be in direct contact with the side and top surfaces of the semiconductor laminate 20, or it may be formed to be in contact via the second protective film 32. The infrared device in Figure 2 includes the second protective film 32, and the configuration of the electrical barrier layer 30 corresponds to that in Figure 1. 【0044】 Furthermore, as shown in Figure 3, the electrical barrier layer 30 may be located in the first region, and the thickness of the electrical barrier layer 30 in the stacking direction (h1) in the first region may be thinner than the thickness of the electrical barrier layer 30 in the stacking direction (h2) in the second region. In this case, since the thickness of the electrical barrier layer 30 changes at the boundary between the first and second regions, the distance along the surface of the electrical barrier layer 30 (creepage distance) can be extended. By extending the creepage distance, the ESD (Electro Static Discharge) resistance with adjacent unit elements can be improved. Here, as shown in Figure 4, the electrical barrier layer 30 may be formed to divide the first protective film 31. 【0045】 Furthermore, it is preferable to extend the creepage distance on the side portion of the semiconductor stacked portion 20. Figure 5 is a partial cross-sectional view of an infrared device, showing an example of the angles of the side surface of the first semiconductor layer 21 and the side surface of the electrical barrier layer 30. The first angle (θ1) formed by the side surface of the first semiconductor layer 21 with a plane parallel to the reference plane 10a and the second angle (θ2) formed by the side surface of the electrical barrier layer 30 with a plane parallel to the reference plane 10a are different, and the second angle may be larger than the first angle. By making the first angle different from the second angle, the creepage distance of the side portion of the first semiconductor layer 21 can be extended compared to the case where the first angle is aligned with the second angle. By extending the creepage distance, ESD resistance with adjacent unit elements or other components on the same substrate can be further improved. The second angle does not have to be perpendicular to the reference plane 10a. Here, as shown in Figure 6, if the electrical barrier layer 30 has a thin portion in the stacking direction, the second angle is determined excluding the thin portion. Also, as shown in Figures 8 and 9, the second angle may be smaller than the first angle. When the second angle is smaller than the first angle, the adhesion between the first semiconductor layer 21 and the electrical barrier layer 30 can be improved when forming electrodes and protective layers on top of the first semiconductor layer 21 and the electrical barrier layer 30. Here, if the angles of the sides of the first semiconductor layer 21 or the sides of the electrical barrier layer 30 are not all the same but have multiple angles, it is acceptable for one of the angles of the sides of the first semiconductor layer 21 and the sides of the electrical barrier layer 30 to be different from the others. For example, as shown in Figure 13, if the sides of the first semiconductor layer 21 have angles θ1 and θ1' with respect to the reference plane but are not uniform, it is acceptable for either angle θ1 or θ1' to be different from the angle θ2 of the side of the electrical barrier layer 30. Furthermore, the contact between the side surface of the first semiconductor layer 21 and the side surface of the electrical barrier layer 30 improves the optical properties compared to the case where the side surface of the first semiconductor layer 21 and the side surface of the electrical barrier layer 30 are not in contact. For example, when an infrared device is an infrared photodetector, if light perpendicular to the reference plane 10a is incident on the substrate from the substrate 10 side, and the side surface of the first semiconductor layer 21 and the side surface of the electrical barrier layer 30 are not in contact, the light will not be reflected and will leak to the outside of the infrared photodetector. This is undesirable because it reduces the amount of light reaching the active layer 23 (Figure 11).On the other hand, when the side surface of the first semiconductor layer 21 is in contact with the side surface of the electrical barrier layer 30, the amount of light reaching the active layer 23 can be improved by reflecting off the side surface of the first semiconductor layer 21 or the side surface of the electrical barrier layer 30 (Figure 12). 【0046】 In this embodiment, the refractive index of the electrical barrier layer 30 may be lower than the average refractive index of the semiconductor laminate 20. For example, if the average refractive index of the semiconductor laminate 20 is 3 to 4, the refractive index of the electrical barrier layer 30 may be less than 1.5. Also, the refractive index of the substrate 10 may be, for example, 3 to 4. Furthermore, since the electrodes on the upper surface of the semiconductor laminate 20 (part of the electrode portion 50) function as mirrors, the infrared device can take on a resonant structure, and therefore the wavelength λ p It may have optical properties with a peak at [nm]. Here, when applied to a gas sensor, the peak corresponds to the absorption of a specific gas (so-called function as a filter). The full width at half maximum of the optical properties with a peak (in other words, the emission spectrum or the light-receiving sensitivity spectrum) is preferably 2 μm or less, and more preferably 1 μm or less. Here, a configuration with multiple peaks can be made to be sensitive to multiple gases. Also, it is preferable that light is incident on or emitted from the substrate side so that the resonance effect is efficiently generated. Furthermore, it is preferable that the upper surface of the semiconductor laminate 20 has a high proportion of area covered by electrodes. This proportion is preferably 50% or more, and more preferably 75% or more. When the thickness of the semiconductor laminate 20 in the stacking direction is t [nm] and m is an integer of 0 or more, the following equation (1) is satisfied. 【0047】 【number】 【0048】 To explain in detail, the thickness (t) of the semiconductor stacked portion 20 in the stacking direction is calculated by the following equation (2), where "n" is the average refractive index of the semiconductor stacked portion 20. 【0049】 【number】 【0050】 Here, the average refractive index refers to the average value obtained by weighting the refractive index of each layer of the semiconductor volume portion by the film thickness. Here, FIG. 7 shows the thickness in the stacking direction of the semiconductor stacked portion 20 and the magnitude of the energy of the light confined inside the resonance structure (|E| 2 ).) The relationship. In the resonance structure, as shown in FIG. 7, a fixed end is located at the interface between the metal and the semiconductor stacked portion 20, and a free end is located at the interface between the semiconductor stacked portion and the electric barrier layer 30. The thickness t in the stacking direction of the semiconductor stacked portion 20 and the wavelength λ p are in the relational expression as shown in Equation (2). Here, the emission intensity or the light reception sensitivity can be improved by confining the energy of the light in a narrow region. Therefore, m in Equation (2) is preferably 3 or less, and more preferably 2 or less. On the other hand, from the viewpoint of the controllability of etching (the viewpoint of exposing the first semiconductor layer 21 or the second semiconductor layer 25), m in Equation (2) is preferably 0 or more, and more preferably 1 or more. Further, by substituting the average refractive index (3 to 4) of the semiconductor stacked portion 20 in the present embodiment into Equation (2), Equation (1) is obtained. The infrared device according to the present embodiment can have optical characteristics having a peak at a desired wavelength λ p by designing the thickness of the stacked structure so as to satisfy Equation (1). 【0051】 As described above, the embodiments have been described based on the drawings and examples. It should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these modifications and corrections are included in the scope of the present disclosure. For example, the functions included in each member, each means, etc. can be rearranged so as not to be logically contradictory, and a plurality of means, etc. can be combined into one or divided. 【Explanation of Signs】 【0052】 10 Substrate The semiconductor stacked portion 20 21 The first semiconductor layer 23 Active layer 25 The second semiconductor layer 30 Electrical barrier layer 31. First protective film 32. Second protective layer 50 Electrode section

Claims

[Claim 1] circuit board and A semiconductor laminate is provided on the substrate and has a first semiconductor layer, an active layer, and a second semiconductor layer. It comprises an electrical barrier layer located between the substrate and the semiconductor laminate to suppress leakage current, Using the surface of the substrate on the side where the semiconductor stack is provided as the reference surface, The first angle formed by the side surface of the first semiconductor layer with a plane parallel to the reference plane and the second angle formed by the side surface of the electrical barrier layer with a plane parallel to the reference plane are different. An infrared device in which the side surface of the first semiconductor layer and the side surface of the electrical barrier layer are in contact. [Claim 2] The infrared device according to claim 1, wherein the electrical barrier layer is an amorphous or polymer layer. [Claim 3] The infrared device according to claim 2, wherein the electrical barrier layer is a layer of silicon nitride, silicon dioxide, aluminum oxide, thermal silicon nitride, silica gel, silicon monoxide, epoxy resin, or polyimide. [Claim 4] The infrared device according to any one of claims 1 to 3, wherein the electrical barrier layer is located in a first region which is a region between a plurality of semiconductor stacked portions, and the thickness of the electrical barrier layer in the stacking direction in the first region is thinner than the thickness of the electrical barrier layer in the stacking direction in a second region which is not the first region. [Claim 5] The infrared device according to claim 1, wherein the second angle is not perpendicular to the reference plane. [Claim 6] The infrared device according to any one of claims 1 to 3, wherein the thickness of the electrical barrier layer in the stacking direction is 500 nm or more. [Claim 7] The infrared device according to any one of claims 1 to 3, wherein the refractive index of the electrical barrier layer is lower than the average refractive index of the semiconductor laminate. [Claim 8] wavelength λ ｐ It has optical properties with a peak at [nm], The infrared device according to any one of claims 1 to 3, wherein when the thickness of the semiconductor stacked portion in the stacking direction is t [nm] and m is an integer of 0 or more, the following formula (1) is satisfied. [Math 1] [Claim 9] The infrared device according to claim 1, wherein the electrical barrier layer is a semiconductor layer. [Claim 10] The infrared device according to claim 9, wherein the electrical barrier layer is made of a material with a larger energy gap than the material of the first semiconductor layer. [Claim 11] The infrared device according to claim 9 or 10, wherein the electrical barrier layer has a different conductivity type from the first semiconductor layer. [Claim 12] The infrared device according to claim 9 or 10, wherein the electrical barrier layer is made of a material having a smaller energy gap than the substrate material. [Claim 13] The infrared device according to claim 9 or 10, wherein the electrical barrier layer has a different conductivity type from the substrate. [Claim 14] The infrared device according to any one of claims 1 to 3, wherein the first semiconductor layer is in direct contact with the active layer, and the material of the layer of the first semiconductor layer that is in contact with the active layer has a larger energy gap than the active layer. [Claim 15] The infrared device according to any one of claims 1 to 3, wherein the second semiconductor layer is in direct contact with the active layer, and the material of the layer of the second semiconductor layer that is in contact with the active layer has a larger energy gap than the active layer. [Claim 16] An infrared device according to any one of claims 1 to 3, wherein the side from which infrared radiation is emitted or incident is of type n conductivity. [Claim 17] On the circuit board A sacrificial layer and a semiconductor multilayer film are stacked, Remove the aforementioned sacrificial layer, An amorphous or polymer electrical barrier layer is formed on a substrate other than the aforementioned substrate. The semiconductor multilayer film is bonded onto the electrical barrier layer, A method for manufacturing an infrared device, comprising etching the aforementioned semiconductor laminated film to form a semiconductor laminated portion, The infrared device to be manufactured is The aforementioned substrate, The semiconductor laminate is provided on the substrate and has a first semiconductor layer, an active layer, and a second semiconductor layer. It comprises an electrical barrier layer located between the substrate and the semiconductor laminate to suppress leakage current, Using the surface of the substrate on the side where the semiconductor stack is provided as the reference surface, The first angle formed by the side surface of the first semiconductor layer with a plane parallel to the reference plane and the second angle formed by the side surface of the electrical barrier layer with a plane parallel to the reference plane are different. A method for manufacturing an infrared device, wherein the side surface of the first semiconductor layer and the side surface of the electrical barrier layer are in contact.

Images