Light receiving element and lidar device

Abstract

Disclosed in an embodiment of the present invention is a light-receiving element including: a semiconductor structure including a first electrode layer, a substrate provided on the first electrode layer, a first-conductivity-type semiconductor layer formed on the substrate, a second-conductivity-type semiconductor layer, and an active layer provided between the first-conductivity-type semiconductor layer and the second-conductivity-type semiconductor layer, and configured as a well structure; a second electrode layer provided on the semiconductor structure; and a first diffusion layer provided between the first-conductivity-type semiconductor layer and the active layer.

Description

Technical Field

[0001] According to embodiments of the present invention, there is a light receiving element and a LiDAR device. Background Technology

[0002] Advanced Driver Assistance Systems (ADAS) are advanced driver assistance systems designed to assist drivers in driving. They are configured to sense the situation ahead, make situation assessments based on the sensing results, and control the vehicle's behavior based on these assessments. For example, ADAS sensor devices detect vehicles ahead and identify lanes. Subsequently, when the target lane, target speed, and target ahead are determined, the system controls the vehicle's electronic stability control (ESC), engine management system (EMS), motor-driven power steering (MDPS), etc. Typical examples of ADAS implementations include automatic parking systems, low-speed city driving assistance systems, and blind spot warning systems.

[0003] In recent years, with the increasing interest in autonomous vehicles, the demand for LiDAR (Light Detection and Ranging) sensors, a core component, has increased. Currently, LiDAR is only used in high-specification, high-priced vehicles, but due to the reduction in manufacturing costs, it is expected to be applied to ordinary vehicles.

[0004] Ultra-small and ultra-lightweight LiDAR technology can be used not only in sensors for unmanned mobile devices, but also in satellites and aerospace for observing land terrain and environment, unmanned vehicles, and transport vehicles, cranes, and robots used in factories and shipyards. It is expected to emerge in the form of combinations or collaborative operations between mobile devices through integrated methods for land, aerospace, and marine industries. Therefore, there is an urgent need to develop ultra-small and ultra-lightweight optical systems to realize ultra-small and ultra-lightweight LiDAR. Summary of the Invention

[0005] Technical issues

[0006] Embodiments of the present invention aim to improve the diffusion and uniformity of electrons through a first diffusion layer, thereby realizing a light-receiving element and a LiDAR device with further improved electrical properties.

[0007] Furthermore, the embodiments can improve the diffusion of holes with low mobility through a second diffusion layer, thereby achieving optical receiving elements and LiDAR devices with improved response speed and improved power efficiency.

[0008] Furthermore, the embodiments aim to significantly improve hole movement by using a second diffusion layer with a thickness greater than that of the first diffusion layer, and to enable electron-hole pairs to be efficiently transferred to the first electrode layer even at the edges, thereby realizing a light-receiving element and LiDAR device with improved light sensitivity.

[0009] Furthermore, optical receiving elements and LiDAR devices with further improved current spreading can be achieved by increasing the thickness at the edges in the first or second diffusion layer.

[0010] The embodiments aim to realize a light receiving element and a LiDAR device, wherein the structure of the second conductivity type semiconductor layer overcomes the Schottky junction, facilitates the formation of ohmic contacts, and reduces contact resistance due to the reduction of energy barriers, thereby further improving electrical characteristics.

[0011] Furthermore, the embodiments can realize a light receiving element and a LiDAR device in which the occurrence of cracks in the stacked insulating layer or another component can be easily suppressed by adjusting the tilted surface and thickness, thereby improving reliability.

[0012] The problems to be solved by the embodiments are not limited thereto, and the purposes or effects that can be understood from the solutions or embodiments of the problems to be solved described below are also included.

[0013] Technical solution

[0014] According to an embodiment of the present invention, a light-receiving element includes: a first electrode layer; a substrate disposed on the first electrode layer; a semiconductor structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer formed on the substrate, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, wherein the semiconductor structure is formed as a well structure; a second electrode layer disposed on the semiconductor structure; and a first diffusion layer located between the first conductivity type semiconductor layer and the active layer.

[0015] The first diffusion layer may overlap with the first conductivity type semiconductor layer, the active layer, and the second conductivity type semiconductor layer in the stacking direction.

[0016] The active layer may include an open area on the upper surface that is exposed.

[0017] The opening region can be offset from the second electrode layer in the stacking direction.

[0018] The second electrode layer may include a first sub-electrode layer and a second sub-electrode layer spaced apart from each other.

[0019] The first diffusion layer may overlap with the first sub-electrode layer and the second sub-electrode layer in the stacking direction.

[0020] The first diffusion layer may include a first region that overlaps with the opening region in the stacking direction and a second region that overlaps with the second electrode layer.

[0021] The thickness of the first region can be less than the thickness of the second region.

[0022] The light receiving element may also include a second diffusion layer disposed between the substrate and the first electrode layer.

[0023] The second diffusion layer may include a third region that overlaps with the semiconductor structure in the stacking direction and a fourth region other than the third region.

[0024] The thickness of the third region can be less than the thickness of the fourth region.

[0025] The third region can overlap with the first and second regions.

[0026] The first conductivity type semiconductor layer may be doped with a first dopant, and the second conductivity type semiconductor layer and the active layer may be doped with a second dopant.

[0027] The doping concentration of the second conductivity type semiconductor layer can be greater than that of the active layer.

[0028] The LiDAR device according to an embodiment includes: a light emitting element configured to emit light; a light receiving element configured to receive light reflected from an object; and a controller configured to control the light emitting element and the light receiving element, wherein the light receiving element includes: a first electrode layer; a substrate disposed on the first electrode layer; a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer on the substrate, and formed in a well structure; a second electrode layer disposed on the semiconductor structure; and a first diffusion layer located between the first conductivity type semiconductor layer and the active layer.

[0029] The light receiving element according to an embodiment includes: a first electrode layer; a substrate disposed on the first electrode layer; a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer formed on the substrate, and formed in a well structure; and a second electrode layer disposed on the semiconductor structure, wherein the second electrode layer includes a contact region that contacts the second conductivity type semiconductor layer and a non-contact region that does not contact the second conductivity type semiconductor layer, and the lower surface of the contact region is located below the lower surface of the non-contact region.

[0030] The upper surface of the second conductivity type semiconductor layer may include a first inclined surface disposed along its edge and a bottom surface disposed inside the first inclined surface.

[0031] The first inclined surface can be located at a higher elevation than the bottom surface.

[0032] The active layer may include an open area on the upper surface that is exposed.

[0033] The exposed surface in the opening area can be located higher than the bottom surface.

[0034] The opening region can be offset from the second electrode layer in the stacking direction.

[0035] The second electrode layer may include a first opening region corresponding to the opening region.

[0036] The second electrode layer may include a first sub-electrode layer and a second sub-electrode layer spaced apart from each other.

[0037] The second electrode layer may include a second opening region between the first sub-electrode layer and the second sub-electrode layer.

[0038] In a plan view, the second opening region can surround the first sub-electrode layer and the opening region.

[0039] The second opening area can be a closed loop in the plan view.

[0040] The second conductivity type semiconductor layer may include a first sublayer and a second sublayer disposed on the first sublayer.

[0041] The doping concentration of the second sublayer can be greater than that of the first sublayer.

[0042] The first conductivity type semiconductor layer may be doped with a first dopant, and the second conductivity type semiconductor layer and the active layer may be doped with a second dopant, wherein the doping concentration of the second conductivity type semiconductor layer may be greater than the doping concentration of the active layer.

[0043] The LiDAR device according to an embodiment includes: a light emitting element configured to emit light; a light receiving element configured to receive light reflected from an object; and a controller configured to control the light emitting element and the light receiving element, wherein the light receiving element includes: a first electrode layer; a substrate disposed on the first electrode layer; a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer on the substrate, and formed in a well structure; and a second electrode layer disposed on the semiconductor structure, the second electrode layer including a contact region that contacts the second conductivity type semiconductor layer and a non-contact region that does not contact the second conductivity type semiconductor layer, and the contact region is located below the non-contact region.

[0044] Beneficial effects

[0045] Embodiments of the present invention provide a light-receiving element and a LiDAR device that have further improved electrical properties by improving the diffusion and uniformity of electrons through a first diffusion layer.

[0046] Furthermore, the embodiments can provide an optical receiving element and LiDAR device that have improved response speed and improved power efficiency by improving the diffusion of holes with low mobility through a second diffusion layer.

[0047] Furthermore, the embodiments can provide a light-receiving element and LiDAR device with improved light sensitivity by having a second diffusion layer having a thickness greater than that of the first diffusion layer, which significantly improves hole movement and enables electron-hole pairs to be efficiently transferred to the first electrode layer even at the edges.

[0048] Furthermore, by increasing the thickness at the edges in the first or second diffusion layer, it is possible to provide light-receiving elements and LiDAR devices with further improved current spreading.

[0049] The embodiments can provide a light receiving element and a LiDAR device, wherein the structure of the semiconductor layer of the second conductivity type overcomes the Schottky junction, facilitates the formation of ohmic contacts, and reduces contact resistance due to the reduction of energy barriers, thereby further improving electrical characteristics.

[0050] Furthermore, the embodiments can provide a light receiving element and a LiDAR device in which the occurrence of cracks in stacked insulating layers or other components can be easily suppressed by adjusting the tilted surface and thickness, thereby improving reliability.

[0051] The various beneficial advantages and effects of the present invention are not limited to those described above, and can be more readily understood in the process of describing specific embodiments of the invention. Attached Figure Description

[0052] Figure 1 This is a block diagram of a LiDAR device according to an embodiment of the present invention.

[0053] Figure 2 This is a view illustrating a LiDAR device and a system using the LiDAR device according to an embodiment.

[0054] Figure 3 This is a view used to describe the operation of a LiDAR device and a system applying the LiDAR device according to an embodiment.

[0055] Figure 4 This is a cross-sectional view of a light receiving element according to an embodiment of the present invention.

[0056] Figure 5 This is a plan view of the light receiving element according to the first embodiment.

[0057] Figure 6 It is along Figure 5 Cross-sectional view of line AA' in the diagram.

[0058] Figure 7 It is along Figure 5 Cross-sectional view of the BB' line in the diagram.

[0059] Figure 8 It is along Figure 5 Cross-sectional view of the CC' line in the diagram.

[0060] Figure 9 This is a plan view of the light receiving element according to the second embodiment.

[0061] Figure 10 It is along Figure 9 Cross-sectional view of the DD' line in the diagram.

[0062] Figure 11 yes Figure 10 Enlarged view of section K1.

[0063] Figure 12 yes Figure 10 Enlarged view of section K2.

[0064] Figure 13 This is a cross-sectional view of the light receiving element according to the third embodiment.

[0065] Figure 14 yes Figure 13 A magnified view of section K3.

[0066] Figure 15 This is a cross-sectional view of a light receiving element according to a fourth embodiment of the present invention.

[0067] Figure 16 This is a plan view of the light receiving element according to the fourth embodiment.

[0068] Figure 17 It is along Figure 16 Cross-sectional view of the EE' line in the diagram.

[0069] Figure 18 yes Figure 17 Enlarged view of section K4.

[0070] Figure 19 yes Figure 17 Enlarged view of section K5.

[0071] Figure 20 yes Figure 16 A magnified view of section K in the middle.

[0072] Figure 21 yes Figure 20 Enlarged view of section K6.

[0073] Figure 22 yes Figure 20 Enlarged view of section K7.

[0074] Figure 23 It is along Figure 16 Cross-sectional view of the FF' line in the diagram.

[0075] Figure 24 It is along Figure 16 Cross-sectional view of the GG' line in the diagram.

[0076] Figure 25 This is a view used to describe a method of manufacturing a light receiving element according to a fourth embodiment. Detailed Implementation

[0077] This invention can be modified in various ways and can have various embodiments, and therefore specific embodiments will be shown and described in the accompanying drawings. However, this is not intended to limit the invention to the specific embodiments, and it should be understood to include all modifications, equivalents, and substitutions that fall within the spirit and technical scope of the invention.

[0078] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0079] However, the technical concept of the present invention is not limited to the described embodiments, but can be implemented in various different forms, and one or more components in the embodiments can be selectively combined or substituted within the scope of the technical concept of the present invention.

[0080] Furthermore, the terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as having the meaning commonly understood by those skilled in the art, unless otherwise explicitly defined and stated, and common terms (such as terms defined in a dictionary) may be interpreted according to the context of the relevant art.

[0081] Furthermore, the terminology used in the embodiments of the present invention is for the purpose of describing the embodiments and is not intended to limit the invention. In this specification, unless otherwise specified in the phrase, the singular may also include the plural, and when described as "at least one (or one or more) of A, B, and C", it may include one or more of all possible combinations of A, B, and C.

[0082] Although various components may be described using terms including ordinal numbers such as "second" and "first," the components are not limited by these terms. These terms are used only to distinguish one component from another. For example, a second component may be named a first constituent element without departing from the scope of the invention, and similarly, a first component may be named a second component. The term "and / or" includes any combination of multiple related descriptive terms or any item of multiple related descriptive terms. These terms are used only to distinguish one component from another, and the nature, order, or sequence of such components are not limited by these terms.

[0083] Furthermore, when describing a component as being “connected,” “coupled,” or “linked” to another component, the component may include not only cases where it is directly connected, coupled, or linked to the other component, but also cases where it is “connected,” “coupled,” or “linked” because another component is provided between the component and the other component.

[0084] The terminology used in this application is for describing specific embodiments only and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as “comprising” or “having” are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0085] Furthermore, when describing each component as being "above" or "below" another component, the term "above" or "below" includes not only cases where the two components are in direct contact, but also cases where one or more other components are formed or positioned between the two components. Additionally, when expressed as "above" or "below," it can include both upward and downward directions based on a component.

[0086] In addition, the statement that component A is positioned between component B and component C should be understood to include the meaning that component A is positioned such that at least a portion thereof overlaps with components B and component C in the horizontal and / or vertical directions.

[0087] The descriptions involving directions include horizontal and vertical directions. The horizontal direction includes a first horizontal direction and a second horizontal direction perpendicular to the first horizontal direction. According to the Cartesian coordinate system, this is referred to as the first horizontal direction (X-axis), the second horizontal direction (Y-axis), and the vertical direction (Z-axis). The meaning of overlap in the horizontal direction should be understood as including overlap in the first horizontal direction and / or overlap in the second horizontal direction.

[0088] Furthermore, the meaning of "component A is exposed from component B" should be understood as component A being exposed from component B, not component A being exposed from the entire product. That is, when describing component A as being exposed from component B, it should be understood as at least a portion of component A being covered by component C.

[0089] Furthermore, when describing component A as "in contact" with component B, the component can include not only cases where it directly "in contact" with another component, but also cases where it "in contact" because another component is disposed between the component and the other component. Therefore, when it should be understood only as the case where component A and component B are "in contact" directly, it is described as "direct contact".

[0090] In addition, when describing component A as being "covered" by component B, it should be understood that the part of component A that achieves the expected function and purpose is covered by component B. Unless there are special circumstances, it should not be understood that the entire component A is necessarily covered by component B.

[0091] Unless otherwise defined, all terms used herein (including technical or scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms as defined in common dictionaries shall be interpreted as having the same meaning as they have in the context of the relevant art and shall not be interpreted in an idealized or overly formalized sense, unless otherwise expressly defined in this application.

[0092] Before describing the embodiments, the electronic devices of the light-receiving element and LiDAR device of the application embodiments will be briefly described. For example, the electronic device may be a smartphone, personal digital assistant, digital camcorder, digital camera, vehicle, high-performance server, network system, computer, monitor, tablet computer, laptop computer, netbook, television, video game, smartwatch, automotive equipment, etc.

[0093] Specifically, the electronic device can be a vehicle, and the light receiving element and LiDAR device can be used as electronic components to assist the driver.

[0094] However, the invention is not limited thereto, and can also be applied to the fields of satellites and aerospace, as well as to transport vehicles, cranes and robots used in factories and shipyards.

[0095] Figure 1 This is a block diagram of a LiDAR device according to an embodiment of the present invention. Figure 2 This is a view illustrating a LiDAR device according to an embodiment and a system using the LiDAR device, and Figure 3 This is a view used to describe the operation of a LiDAR device and a system applying the LiDAR device according to an embodiment.

[0096] Reference Figure 1 According to an embodiment, the LiDAR device 1000 can emit light toward a target and detect the light reflected from the target and returned to the LiDAR device 1000. The LiDAR device 1000 may include an emitter 1010. The emitter 1010 can adjust the emission direction of light emitted toward the outside of the LiDAR device 1000. The emitter 1010 can be a mechanical or non-mechanical (semiconductor type) beam device. The LiDAR device 1000 may include a light source unit disposed in the emitter 1010, or may include a light source unit disposed separately from the emitter 1010. The emitter 1010 may be a scanning type light-emitting device. However, the light-emitting device of the LiDAR device 1000 is not limited to the emitter 1010. In another example, the LiDAR device 1000 may further include a flash-type light-emitting device instead of the emitter 1010, or include a flash-type light-emitting device together with the emitter 1010. In the case of a flash, light can be emitted at once to an area encompassing the entire field of view.

[0097] Light guided by transmitter 1010 can be reflected by a target or object and returned to LiDAR device 1000. LiDAR device 1000 may include receiver 1030 for detecting light reflected by a target. Receiver 1030 may include multiple light receiving elements and may further include other optical components. Therefore, receiver 1030 may correspond to a "light detection unit". Furthermore, the multiple light receiving elements may include any of the avalanche light receiving elements described below.

[0098] Additionally, the LiDAR device 1000 may further include a controller 1020 connected to at least one of the transmitter 1010 and the receiver 1030. The controller 1020 may include a computing unit for acquiring and calculating data, and may further include a drive unit, a control unit, etc. Furthermore, the controller 1020 may further include a power supply, a memory, etc.

[0099] Although the LiDAR device 1000 is shown as including a transmitter 1010 and a receiver 1030 in one device, the transmitter 1010 and receiver 1030 may not be configured as a single device, but may be configured separately in separate devices. Furthermore, the controller 1020 may not be connected to the transmitter 1010 or receiver 1030 via wires, but may be connected wirelessly.

[0100] The LiDAR device 1000 described above according to the embodiments can be applied to various electronic devices. As an example, the LiDAR device 1000 can be applied to a LiDAR device. The LiDAR device can be a phase-shifting type or a time-of-flight (TOF) type device. In addition, the light receiving element according to the embodiments, or the LiDAR device 1000 including the light receiving element, can be installed in electronic devices such as smartphones, wearable devices (glasses-type devices for realizing augmented reality and virtual reality, etc.), Internet of Things (IoT) devices, home appliances, tablet personal computers (PCs), personal digital assistants (PDAs), portable multimedia players (PMPs), navigation systems, drones, robots, unmanned vehicles, autonomous vehicles, and advanced driver assistance systems (ADAS).

[0101] The following is a conceptual diagram illustrating an exemplary embodiment of a LiDAR device applied to a vehicle.

[0102] Reference Figure 2 and Figure 3 LiDAR device 1000 (or optical receiver element) (see...) Figure 1 This can be applied to vehicle 2000. Information about target 2020 can be obtained using a LiDAR device 1000 (or optical receiving element) applied to the vehicle. Vehicle 2000 can be a vehicle with autonomous driving capabilities.

[0103] The LiDAR device 1000 can detect a target 2020 or an object (e.g., a person) in the direction of travel of the vehicle 2000. The LiDAR device 1000 can use information such as the time difference between the transmitted and detected signals to measure the distance to the target 2020. The LiDAR device 1000 can acquire information about nearby objects 3010 and distant objects 3020 within its scanning range. The LiDAR device 1000 may include a light receiving element, which will be described below.

[0104] Furthermore, although the LiDAR device 1000 is shown positioned in front of the vehicle 2000 to detect the target 2020 in the direction of travel of the vehicle 2000, the present invention may not be limited thereto.

[0105] For example, the LiDAR device 1000 can radiate light 2010 forward and receive light 2030 to detect targets 2020. Furthermore, the LiDAR device 1000 can be positioned at multiple locations on the vehicle 2000 to detect all targets 2020 around the vehicle 2000. For example, four LiDAR devices 2010 can be positioned in front, behind, and on both sides of the vehicle 2000. In another example, the LiDAR device 1000 can be positioned on the roof of the vehicle 2000 and can rotate to detect targets 2020 around the vehicle 2000.

[0106] Specifically, the LiDAR device 1000 can calculate distance information based on time-of-flight measurements of light pulses emitted from a light source. Furthermore, it can illuminate a scene on a target surface associated with a specific range, and can use known information about the beam profile based on a specific design of the source and projector system to determine the positional information of the reflecting surface, thereby generating a complete three-dimensional image of the scene with x, y, z coordinates.

[0107] In other words, the point-by-point 3D map representation of the surrounding environment is a set of measurement data indicating the positional information of all surfaces illuminated from the source to the receiver within the field of view of the LiDAR device 1000. In this way, a 3D representation of an object can be obtained within the field of view of the LiDAR device 1000.

[0108] Additionally, a schematic diagram illustrating the two-dimensional field of view and distance requirements of a typical surrounding detection LiDAR device 1000 for vehicle 202 is shown. For example, adaptive cruise control functions may require a field of view and distance 2040 with a narrower field of view but longer distance requirements compared to viewing a "surround view" field of view and distance 2060. Typically, vehicle sensor functions can be achieved through a combination of LiDAR, radar, cameras, and ultrasonic sensors. This combination of sensor data that generates information about the surrounding environment is often referred to as "sensor fusion."

[0109] Although the present invention describes the LiDAR device 1000 in the vehicle context of LiDAR being widely used in autonomous, self-driving, or driver-assisted vehicles, it should be understood that embodiments can be applied to any vehicle. Other types of vehicles may include robots, tractors, trucks, airplanes, drones, boats, ships, etc.

[0110] Figure 4 This is a cross-sectional view of a light receiving element according to an embodiment of the present invention.

[0111] Reference Figure 4According to an embodiment of the present invention, the light-receiving element 100 may include a first electrode layer 111, a substrate 112, a semiconductor structure SS, a second electrode layer 116, a first diffusion layer 117, and an insulating layer 119. Furthermore, the semiconductor structure SS may include a first conductivity type semiconductor layer 113, an active layer 114, and a second conductivity type semiconductor layer 115 disposed on the substrate 112. Additionally, the semiconductor structure SS may have a well structure. For example, the second conductivity type semiconductor layer 115 may have a well structure, and the active layer 114 may have a well structure covering the second conductivity type semiconductor layer 115 with the well structure. Furthermore, the first conductivity type semiconductor layer 113 may cover the active layer 114 or be located below the active layer 114. The semiconductor structure SS may have a well structure relative to the upper surface of the substrate 112. Furthermore, the light-receiving element 100 may further include a second diffusion layer 118 located between the first electrode layer 111 and the substrate 112.

[0112] Apart from the first electrode layer 111, the second electrode layer 116, and the insulating layer 119, the remaining layers can be made of semiconductor materials. For example, semiconductor materials may include at least one of the following: group IV semiconductors such as silicon (Si) and germanium (Ge); group III-V compound semiconductors such as GaAs and GaP; group II-VI compound semiconductors such as CdS and ZnTe; group IV-VI compound semiconductors such as PbS; group IV-IV compound semiconductors such as SiC; oxide semiconductors such as indium gallium zinc oxide (IGZO); quantum dots; organic semiconductors; and semiconductors with a two-dimensional crystal structure having a band gap. A representative example of a semiconductor with a two-dimensional crystal structure is a transition metal dichalcogenide (TMD), which is a compound of a transition metal and a chalcogenide. For example, transition metal dichalcogenides may include MoS2, WS2, TaS2, HfS2, ReS2, TiS2, NbS2, SnS2, MoSe2, WSe2, TaSe2, HfSe2, ReSe2, TiSe2, NbSe2, SnSe2, MoTe2, WTe2, TaTe2, HfTe2, ReTe2, TiTe2, NbTe2, and SnTe2. In addition to transition metal dichalcogenides, semiconductors with two-dimensional crystal structures also exist. For example, semiconductors with two-dimensional crystal structures may further include TiO2. x NbO x MnO x VaO x , MnO3, TaO3, WO3, MoCl2, CrCl3, RuCl3, BiI3, PbCl4, GeS, GaS, GeSe, GaSe, PtSe2, In2Se3, GaTe, InS, InSe, InTe, etc.

[0113] Furthermore, the first electrode layer 111, the second diffusion layer 118, the substrate 112, the semiconductor structure SS, and the second electrode layer 116 can be sequentially disposed in the stacking direction (X-axis direction). Therefore, the second diffusion layer 118 can be located on the first electrode layer 111. The substrate 112 can be located on either the first electrode layer 111 or the second diffusion layer 118. The semiconductor structure SS can be located on the second diffusion layer 118. Furthermore, the second electrode layer 116 can be located on the semiconductor structure SS. Specifically, the second electrode layer 116 can be located on the second conductivity type semiconductor layer 115.

[0114] The first electrode layer 111 may be located on one side of the light receiving element 100. For example, the first electrode layer 111 may be located below the light receiving element 100. The light receiving element 100 may be electrically connected to an external circuit (e.g., a controller) through the first electrode layer 111. For example, holes may be moved to the external circuit through the first electrode layer 111.

[0115] Furthermore, the first electrode layer 111 can be made of a conductive metallic material. For example, the first electrode layer 111 can be made of a metal such as magnesium (Mg), aluminum (Al), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), zirconium (Zr), niobium (Nb), molybdenum (Mo), lead (Pd), silver (Ag), cadmium (Cd), indium (In), tin (Sn), lanthanum (La), hafnium (Hf), tantalum (Ta), tungsten (W), iridium (Ir), platinum (Pt), gold (Au), bismuth (Bi), or alloys thereof.

[0116] Furthermore, the first electrode layer 111 can be made of a transparent conductive material. For example, the first electrode layer 111 can be made of a transparent conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), or ZnO, or graphene.

[0117] A second diffusion layer 118 can be disposed on the first electrode layer 111 such that after electron-hole pairs (EHP) are generated in the semiconductor structure SS, all EHP reaches the first electrode layer 111, which serves as the lower electrode. That is, the second diffusion layer 118 enables more uniform charge carrier transport and prevents current concentration in specific regions. Therefore, a uniform current flow can be formed in the first electrode layer 111 not only in the region where the opening regions of the active layer 114 overlap, but also in a wider region. With this configuration, after EHP generation, the charge can flow uniformly instead of moving only along a specific path. Therefore, an optical receiving element with reduced signal distortion and loss and improved power efficiency can be provided. Furthermore, an optical receiving element with improved reliability can be provided by addressing the thermal imbalance caused by current concentration.

[0118] The second diffusion layer 118 may be doped with the first dopant. For example, the second diffusion layer 118 may be doped with a p-type dopant. For example, the second diffusion layer 118 may have up to 10 17 cm -3 The doping concentration.

[0119] Furthermore, the second diffusion layer 118 can have a larger area than the semiconductor structure SS. For example, the area of ​​the first electrode layer 111 can be less than 5% of the area of ​​the opening region of the active layer 114. Furthermore, the second diffusion layer 118 can have a larger area than the semiconductor structure SS and can be located on the entire upper surface of the first electrode layer 111. For example, the second diffusion layer 118 can be formed on the entire lower surface of the substrate 112. Therefore, even when the hole mobility is relatively slower than the electron mobility, current can diffuse more easily through the second diffusion layer 118. Thus, the improvement in the response speed of the light-receiving element can be further enhanced.

[0120] The substrate 112 may be located on the first electrode layer 111 and the second diffusion layer 118. The substrate 112 may include silicon (Si), germanium (Ge), or silicon-germanium (SiGe). The conductivity type of the substrate 112 may be n-type or p-type. When the conductivity type of the substrate 112 is n-type, the substrate 112 may include group V elements (e.g., phosphorus (P), arsenic (As), antimony (Sb), etc.), group VI elements, or group VII elements as impurities. For example, in an embodiment, the substrate 112 may be p-type. Therefore, the substrate 112 may include group III elements (e.g., boron (B), aluminum (Al), gallium (Ga), indium (In), etc.) or group II elements as impurities. Furthermore, the substrate 112 may be a semiconductor substrate and an epitaxial layer formed by an epitaxial growth process.

[0121] The substrate 112 can be electrically connected to a first conductivity type semiconductor layer 113 of the semiconductor structure SS, and can be mechanically supported by the semiconductor structure SS. Furthermore, an electric field distribution can be stably formed on the substrate 112. Additionally, depending on the applied voltage, a portion of the depletion region can extend within the substrate 112.

[0122] The semiconductor structure SS can be located in the substrate 112 as a well structure. For example, the semiconductor structure SS can be housed in the substrate 112.

[0123] Furthermore, as described above, the semiconductor structure SS may include a first conductivity type semiconductor layer 113, an active layer 114, and a second conductivity type semiconductor layer 115 disposed in the stacking direction (X-axis direction).

[0124] Furthermore, each of the first conductivity type semiconductor layer 113, the active layer 114, and the second conductivity type semiconductor layer 115 may be doped with a first dopant or a second dopant. The first conductivity type semiconductor layer 113, the active layer 114, and the second conductivity type semiconductor layer 115 may be implemented using III-V compound semiconductors, II-VI compound semiconductors, etc. Furthermore, the first conductivity type semiconductor layer 113 may be doped with a first dopant. For example, the first dopant may be a p-type dopant. The p-type dopant may be selected from Mg, Zn, Ca, Sr, Ba, etc., but is not limited thereto.

[0125] Furthermore, the active layer 114 and the second conductivity type semiconductor layer 115 may be doped with a second dopant. For example, the second dopant may be an n-type dopant. The n-type dopant may be selected from Si, Ge, Sn, Se, Te, etc., but is not limited thereto.

[0126] The first conductivity type semiconductor layer 113 may be located on the substrate 112. The first conductivity type semiconductor layer 113 may be located at the bottom of the semiconductor structure SS.

[0127] The first conductivity type semiconductor layer 113 may include an avalanche region. That is, avalanche multiplication can occur in the first conductivity type semiconductor layer 113. Therefore, a strong electric field can be applied to the first conductivity type semiconductor layer 113, and electron-hole pairs can be generated by the rapid movement of electrons and the resulting impact ionization.

[0128] The active layer 114 can be a light-absorbing layer. The active layer 114 can be doped with a second dopant. The active layer 114 can be formed as a single layer, multiple layers, etc.

[0129] The active layer 114 can be formed around a second conductivity type semiconductor layer 115 having a well structure. Furthermore, the active layer 114 can have an exposed region where its upper surface is exposed. Light can be supplied to the light-receiving element 100 through this exposed region. That is, the light supplied through this exposed region can be absorbed in the active layer 114. Additionally, at least a portion of the active layer 114 can correspond to a portion of the upper surface of the semiconductor structure SS.

[0130] The second conductivity type semiconductor layer 115 can be located on the active layer 114. The second conductivity type semiconductor layer 115 can be configured in the stacking direction to be offset from the opening region of the active layer 114.

[0131] Furthermore, the second conductivity type semiconductor layer 115 may be doped with a second dopant. The doping concentration of the second conductivity type semiconductor layer 115 may be greater than the doping concentration of the active layer 114.

[0132] Therefore, the second conductivity type semiconductor layer 115 can have low resistance and promote electron movement by having a high doping concentration. Thus, the second conductivity type semiconductor layer 115 can be used as an electron injection layer. Additionally, the second conductivity type semiconductor layer 115 can sense a strong electric field to improve avalanche multiplication in the photoreceiving element.

[0133] The second electrode layer 116 may be located on the second conductivity type semiconductor layer 115. Alternatively, the second electrode layer 116 may be located on the semiconductor structure SS. Alternatively, the second electrode layer 116 may be located on the second substrate 112.

[0134] The second electrode layer 116 may be located on the entire upper surface of the light receiving element 100. Furthermore, the second electrode layer 116 may not overlap with the opening region of the active layer 114. The second electrode layer 116 may include a first opening region and a second opening region. The first opening region may correspond to the opening region of the active layer. The first opening region may overlap with the opening region of the active layer 114 in the stacking direction (X-axis direction).

[0135] The second electrode layer 116 may be formed of a plurality of electrode layers spaced apart from each other. A detailed description thereof will be provided below.

[0136] Additionally, the first electrode layer 111 can be made of a conductive metallic material. For example, the second electrode layer 116 can be made of a metal such as magnesium (Mg), aluminum (Al), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), zirconium (Zr), niobium (Nb), molybdenum (Mo), lead (Pd), silver (Ag), cadmium (Cd), indium (In), tin (Sn), lanthanum (La), hafnium (Hf), tantalum (Ta), tungsten (W), iridium (Ir), platinum (Pt), gold (Au), bismuth (Bi), or alloys thereof.

[0137] Furthermore, the second electrode layer 116 can be made of a transparent conductive material. For example, the second electrode layer 116 can be made of a transparent conductive oxide such as ITO, IZO or ZnO, or graphene.

[0138] Furthermore, the second electrode layer 116 can be connected to an external circuit. Therefore, current can flow. For example, at least one of a plurality of spaced-apart second electrode layers 116 can be electrically connected to an external circuit. Additionally, the second electrode layer 116 can be in contact with a second conductivity type semiconductor layer 115 and can supply electrons. Electrons can move through the second electrode layer 116 into the photoreceiving element.

[0139] The first diffusion layer 117 may be located between the active layer 114 and the first conductivity type semiconductor layer 113. Therefore, the first diffusion layer 117 may be located below the active layer 114 and the second conductivity type semiconductor layer 115. Alternatively, the first diffusion layer 117 may be located on the first electrode layer 111, the second diffusion layer 118, or the substrate 112.

[0140] The first diffusion layer 117 may be doped with a second dopant. The first diffusion layer 117 can optimize the uniform injection and movement of electrons. That is, the first diffusion layer 117 can allow electrons to diffuse widely without avalanche multiplication occurring only at specific locations. The first diffusion layer 117 can improve current flow through charge, and the second diffusion layer 118 can improve current flow through electrons. Therefore, a light-receiving element with improved electrical properties such as charge diffusion and charge homogenization can be provided.

[0141] Therefore, through the first diffusion layer 117 and the second diffusion layer 118, which have low resistance and high transmittance, the electron-hole pairs generated in the first conductivity type semiconductor layer 113, which overlaps with the opening region OA of the active layer 114 in the stacking direction (X-axis direction), can easily reach the first electrode layer 111 and the second electrode layer 116 located below and above the light receiving element 100.

[0142] The insulating layer 119 may be located on the semiconductor structure SS or the substrate 112. The insulating layer 119 may be formed on the second electrode layer 116. In addition, the insulating layer 119 may be located on or above the outside of the light receiving element 100.

[0143] The insulating layer 119 can be made of an insulating material. For example, the insulating layer 119 can be formed of an insulating material and can include SiO2, SiO2, etc. x SiO x N y At least one of Si3N4, Al2O3 and TiO2.

[0144] This configuration protects the internal layers of the optical receiver 100 from external materials. Furthermore, it improves the reliability of the optical receiver.

[0145] Alternatively, the light-receiving element 100 can have the above-described structure by forming a second diffusion layer 118 under the substrate 112 and etching a portion of the substrate 112 to form a semiconductor structure SS and a first diffusion layer 117. Furthermore, a first electrode layer 111, a second electrode layer 116, and an insulating layer 119 can be formed to manufacture the light-receiving element 100.

[0146] Figure 5 This is a plan view of the light receiving element according to the first embodiment. Figure 6 It is along Figure 5Cross-sectional view of line AA' in the diagram. Figure 7 It is along Figure 5 The cross-sectional view of the BB' line in the diagram, and Figure 8 It is along Figure 5 Cross-sectional view of the CC' line in the diagram.

[0147] Reference Figures 5 to 8 In this embodiment, the first diffusion layer 117 may overlap with the semiconductor structure SS in the stacking direction (X-axis direction). That is, the first diffusion layer 117 may overlap with the first conductivity type semiconductor layer 113, the active layer 114, and the second conductivity type semiconductor layer 115 in the stacking direction (X-axis direction). Therefore, the first diffusion layer 117 can more effectively improve the movement of electrons in the current flow.

[0148] Additionally, as described above, the active layer 114 may include an opening region OA with its upper surface exposed. The opening region OA may be offset from the second electrode layer 116 in the stacking direction (X-axis direction). That is, the opening region OA may not overlap with the second electrode layer 116 in the stacking direction (X-axis direction). Therefore, the reception of light by the light-receiving element through the opening region OA can be achieved more efficiently.

[0149] Additionally, the first diffusion layer 117 may include a first region AR1 that overlaps with the opening region OA in the stacking direction (X-axis direction) and a second region AR2 that does not overlap with the opening region OA in the stacking direction or overlaps with the second conductivity type semiconductor layer 115 in the stacking direction (X-axis direction). The first region AR1 and the second region AR2 may be offset from each other.

[0150] Additionally, as described above, the plurality of second electrode layers 116 may be spaced apart from each other. For example, the second electrode layer 116 may include a first sub-electrode layer 116a and a second sub-electrode layer 116b. The first sub-electrode layer 116a and the second sub-electrode layer 116b may be physically separated.

[0151] Additionally, as described above, the second electrode layer 116 may include a first opening region OP1 and a second opening region OP2. The first opening region OP1 may correspond to the opening region of the active layer. The first opening region OP1 may overlap with the opening region OA of the active layer 114 in the stacking direction (X-axis direction).

[0152] The second opening region OP2 can be located outside the contact surface where the second electrode layer 116 and the second conductivity type semiconductor layer 115 contact each other. Therefore, the second opening region OP2 can overlap with the substrate 112, the active layer 114, etc. in the stacking direction. In addition, the first sub-electrode layer 116a and the second sub-electrode 116b can be separated from each other through the second opening region OP2. The first sub-electrode layer 116a and the second sub-electrode 116b can overlap with the active layer 114, the first diffusion layer 117, the first conductivity type semiconductor layer 113, the substrate 112, and the second diffusion layer 118 in the stacking direction (X-axis direction). With this configuration, smooth current flow can be achieved through the movement of electrons via the second electrode layer 116.

[0153] Additionally, the first opening region OP1 can be located inside the second opening region OP2. For example, the first opening region OP1 can be located inside the second opening region OP2, which is a closed loop in the plan view.

[0154] Furthermore, the thickness T1 of the first diffusion layer 117 can be smaller than the thickness T2 of the second diffusion layer 118. Therefore, the movement of holes with relatively low mobility can be significantly improved, thereby enabling a more effective improvement in power efficiency.

[0155] Figure 9 This is a plan view of the light receiving element according to the second embodiment. Figure 10 It is along Figure 9 Cross-sectional view of the DD' line in the diagram. Figure 11 yes Figure 10 An enlarged view of section K1, and Figure 12 yes Figure 10 Enlarged view of section K2.

[0156] Reference Figures 9 to 12 According to the second embodiment, the light-receiving element 100A may include a first electrode layer 111, a substrate 112, a semiconductor structure SS, a second electrode layer 116, a first diffusion layer 117, a second diffusion layer 118, and an insulating layer 119. Furthermore, the semiconductor structure SS may include a first conductivity type semiconductor layer 113, an active layer 114, and a second conductivity type semiconductor layer 115 disposed on the substrate 112. Additionally, the semiconductor structure SS may have a well structure.

[0157] In addition to the descriptions below, the descriptions of the first electrode layer 111, substrate 112, semiconductor structure SS, second electrode layer 116, first diffusion layer 117, second diffusion layer 118, and insulating layer 119 can be applied in the same way to those described in other embodiments.

[0158] In this embodiment, the first diffusion layer 117 may include a first region AR1 that overlaps with the opening region OA in the stacking direction (X-axis direction) and a second region AR2 that does not overlap with the opening region OA in the stacking direction or overlaps with the second conductivity type semiconductor layer 115 in the stacking direction (X-axis direction). The first region AR1 and the second region AR2 may be offset from each other.

[0159] Furthermore, the first diffusion layer 117 can have different thicknesses (length in the stacking direction) depending on the region. In an embodiment, the thickness T1b of the first region AR1 and the thickness T1a of the second region AR2 can be different. The thickness T1b of the first region AR1 can be less than the thickness T1a of the second region AR2. That is, the first diffusion layer 117 can have a greater thickness in the region where it overlaps with the second conductivity type semiconductor layer 115 in the stacking direction (X-axis direction) than in other regions. With this configuration, the relatively weakened current flow at the edges can be significantly improved. Therefore, a light-receiving element with improved electrical characteristics such as power efficiency (e.g., photosensitivity) can be provided.

[0160] Additionally, the second diffusion layer 118 may include a third region AR3 that overlaps with the semiconductor structure SS in the stacking direction (X-axis direction) and a fourth region AR4 other than the third region AR3. That is, the fourth region AR4 may be offset from the semiconductor structure SS in the stacking direction (X-axis direction).

[0161] Furthermore, the second diffusion layer 118 can have different thicknesses (length in the stacking direction) depending on the region. In the second diffusion layer 118 according to the embodiment, the thickness T2b of the third region AR3 can be different from the thickness T2a of the fourth region AR4. For example, the thickness T2b of the third region AR3 can be less than the thickness T2a of the fourth region AR4. That is, the second diffusion layer 118 can have a larger thickness in the region that overlaps with the semiconductor structure SS in the stacking direction (X-axis direction) than in other regions. With this configuration, the relatively weakened current flow at the edges can be significantly improved. Therefore, a light-receiving element with improved electrical characteristics such as power efficiency (e.g., photosensitivity) can be provided.

[0162] Additionally, the third region AR3 can overlap with the first region AR1 and the second region AR2 in the stacking direction (X-axis direction). Conversely, the fourth region AR4 can be set to be offset from the first region AR1 and the second region AR2 in the stacking direction (X-axis direction).

[0163] Furthermore, the thickness T2b of the third region AR3 can be greater than or less than the thickness T1a of the second region AR2.

[0164] Figure 13This is a cross-sectional view of the light receiving element according to the third embodiment, and Figure 14 yes Figure 13 Enlarged view of section K3.

[0165] The light-receiving element 100B according to the third embodiment may include a first electrode layer 111, a substrate 112, a semiconductor structure SS, a second electrode layer 116, a first diffusion layer 117, a second diffusion layer 118, and an insulating layer 119. Furthermore, the semiconductor structure SS may include a first conductivity type semiconductor layer 113, an active layer 114, and a second conductivity type semiconductor layer 115 disposed on the substrate 112. Additionally, the semiconductor structure SS may have a well structure.

[0166] In addition to the descriptions below, the descriptions of the first electrode layer 111, substrate 112, semiconductor structure SS, second electrode layer 116, first diffusion layer 117, second diffusion layer 118, and insulating layer 119 can be applied in the same way to those described in other embodiments.

[0167] In this embodiment, the first diffusion layer 117 may include a first region AR1 that overlaps with the opening region OA in the stacking direction (X-axis direction) and a second region AR2 that does not overlap with the opening region OA in the stacking direction or overlaps with the second conductivity type semiconductor layer 115 in the stacking direction (X-axis direction). The first region AR1 and the second region AR2 may be offset from each other.

[0168] Furthermore, the first diffusion layer 117 can have different thicknesses (length in the stacking direction) depending on the region. In an embodiment, the thickness T1b of the first region AR1 and the thickness T1a of the second region AR2 can be different. The thickness T1b of the first region AR1 can be less than the thickness T1a of the second region AR2. That is, the first diffusion layer 117 can have a greater thickness in the region where it overlaps with the second conductivity type semiconductor layer 115 in the stacking direction (X-axis direction) than in other regions. With this configuration, the relatively weakened current flow at the edges can be significantly improved. Therefore, a light-receiving element with improved electrical characteristics such as power efficiency (e.g., photosensitivity) can be provided.

[0169] Conversely, the second diffusion layer 118 can maintain a constant thickness. Therefore, the thickness of the second diffusion layer 118 can be greater than the thickness in the first region AR1 or the second region AR2 of the first diffusion layer 117.

[0170] With this configuration, the second diffusion layer 118 and the first electrode layer 111 located beneath the substrate 112 can have flat surfaces, thereby suppressing the occurrence of defects and minimizing stress generation. That is, a light-receiving element with improved reliability can be provided.

[0171] As a variation, the first diffusion layer 117 in the light-receiving element can have a constant thickness. That is, the first region AR1 and the second region AR2 of the first diffusion layer 117 can have the same thickness. Conversely, the second diffusion layer 118 can have different regions depending on its location. That is, the second diffusion layer 118 can have a greater thickness in the region that overlaps with the semiconductor structure SS in the stacking direction (X-axis direction) than in other regions. With this configuration, a light-receiving element with improved electrical characteristics (e.g., photosensitivity) can be provided.

[0172] Figure 15 This is a cross-sectional view of a light receiving element according to a fourth embodiment of the present invention.

[0173] Reference Figure 15 According to a fourth embodiment of the present invention, the light-receiving element 100C may include a first electrode layer 111, a substrate 112, a semiconductor structure SS, a second electrode layer 116, and an insulating layer 119. Furthermore, the semiconductor structure SS may include a first conductivity type semiconductor layer 113, an active layer 114, and a second conductivity type semiconductor layer 115 disposed on the substrate 112. Additionally, the semiconductor structure SS may have a well structure. For example, the second conductivity type semiconductor layer 115 may have a well structure, and the active layer 114 may have a well structure covering the second conductivity type semiconductor layer 115 with the well structure. Furthermore, the first conductivity type semiconductor layer 113 may cover the active layer 114 or may be located below it. The semiconductor structure SS may have a well structure relative to the upper surface of the substrate 112.

[0174] Apart from the first electrode layer 111, the second electrode layer 116, and the insulating layer 119, the remaining layers can be made of semiconductor materials. For example, semiconductor materials may include at least one of the following: group IV semiconductors such as silicon (Si) and germanium (Ge); group III-V compound semiconductors such as GaAs and GaP; group II-VI compound semiconductors such as CdS and ZnTe; group IV-VI compound semiconductors such as PbS; group IV-IV compound semiconductors such as SiC; oxide semiconductors such as IGZO; quantum dots; organic semiconductors; and semiconductors with a two-dimensional crystal structure having a band gap. A representative example of a semiconductor with a two-dimensional crystal structure is a transition metal dichalcogenide (TMD), which is a compound of a transition metal and a chalcogenide. For example, transition metal dichalcogenides may include MoS2, WS2, TaS2, HfS2, ReS2, TiS2, NbS2, SnS2, MoSe2, WSe2, TaSe2, HfSe2, ReSe2, TiSe2, NbSe2, SnSe2, MoTe2, WTe2, TaTe2, HfTe2, ReTe2, TiTe2, NbTe2, and SnTe2. In addition to transition metal dichalcogenides, semiconductors with two-dimensional crystal structures also exist. For example, semiconductors with two-dimensional crystal structures may further include TiO2. x NbO x MnO x VaO x , MnO3, TaO3, WO3, MoCl2, CrCl3, RuCl3, BiI3, PbCl4, GeS, GaS, GeSe, GaSe, PtSe2, In2Se3, GaTe, InS, InSe, InTe, etc.

[0175] Furthermore, the first electrode layer 111, substrate 112, semiconductor structure SS, and second electrode layer 116 can be sequentially disposed in the stacking direction (X-axis direction). The substrate 112 can be located on the first electrode layer 111. The semiconductor structure SS can be located on the substrate 112. Furthermore, the second electrode layer 116 can be located on the semiconductor structure SS. Specifically, the second electrode layer 116 can be located on the second conductivity type semiconductor layer 115.

[0176] The first electrode layer 111 may be located on one side of the light receiving element 100C. For example, the first electrode layer 111 may be located below the light receiving element 100C. The light receiving element 100C can be electrically connected to an external circuit (e.g., a controller) through the first electrode layer 111. For example, holes can move to the external circuit through the first electrode layer 111.

[0177] Furthermore, the first electrode layer 111 can be made of a conductive metallic material. For example, the first electrode layer 111 can be made of a metal such as magnesium (Mg), aluminum (Al), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), zirconium (Zr), niobium (Nb), molybdenum (Mo), lead (Pd), silver (Ag), cadmium (Cd), indium (In), tin (Sn), lanthanum (La), hafnium (Hf), tantalum (Ta), tungsten (W), iridium (Ir), platinum (Pt), gold (Au), bismuth (Bi), or alloys thereof.

[0178] Furthermore, the first electrode layer 111 can be made of a transparent conductive material. For example, the first electrode layer 111 can be made of a transparent conductive oxide such as ITO, IZO or ZnO, or graphene.

[0179] Substrate 112 may be located on the first electrode layer 111. Substrate 112 may include silicon (Si), germanium (Ge), or silicon-germanium (SiGe). The conductivity type of substrate 112 may be n-type or p-type. When the conductivity type of substrate 112 is n-type, substrate 112 may include group V elements (e.g., phosphorus (P), arsenic (As), antimony (Sb), etc.), group VI elements, or group VII elements as impurities. For example, in an embodiment, substrate 112 may be p-type. Therefore, substrate 112 may include group III elements (e.g., boron (B), aluminum (Al), gallium (Ga), indium (In), etc.) or group II elements as impurities. Furthermore, substrate 112 may be a semiconductor substrate and an epitaxial layer formed by an epitaxial growth process.

[0180] The substrate 112 can be electrically connected to a first conductivity type semiconductor layer 113 of the semiconductor structure SS, and can mechanically support the semiconductor structure SS. Furthermore, an electric field distribution can be stably formed on the substrate 112. Additionally, depending on the applied voltage, a portion of the depletion region can extend within the substrate 112.

[0181] The semiconductor structure SS can be located in the substrate 112 in a well structure. For example, the semiconductor structure SS can be housed in the substrate 112.

[0182] Furthermore, as described above, the semiconductor structure SS may include a first conductivity type semiconductor layer 113, an active layer 114, and a second conductivity type semiconductor layer 115 disposed in the stacking direction (X-axis direction).

[0183] Furthermore, each of the first conductivity type semiconductor layer 113, the active layer 114, and the second conductivity type semiconductor layer 115 may be doped with a first dopant or a second dopant. The first conductivity type semiconductor layer 113, the active layer 114, and the second conductivity type semiconductor layer 115 may be implemented using III-V compound semiconductors, II-VI compound semiconductors, etc. Furthermore, the first conductivity type semiconductor layer 113 may be doped with a first dopant. For example, the first dopant may be a p-type dopant. The p-type dopant may be selected from Mg, Zn, Ca, Sr, Ba, etc., but is not limited thereto.

[0184] Furthermore, the active layer 114 and the second conductivity type semiconductor layer 115 may be doped with a second dopant. For example, the second dopant may be an n-type dopant. The n-type dopant may be selected from Si, Ge, Sn, Se, Te, etc., but is not limited thereto.

[0185] The first conductivity type semiconductor layer 113 may be located on the substrate 112. The first conductivity type semiconductor layer 113 may be located at the bottom of the semiconductor structure SS.

[0186] The first conductivity type semiconductor layer 113 may include an avalanche region. That is, avalanche multiplication can occur in the first conductivity type semiconductor layer 113. Therefore, a strong electric field can be applied to the first conductivity type semiconductor layer 113, and thus electron-hole pairs can be generated by the rapid movement of electrons and the resulting impact ionization.

[0187] The active layer 114 can be a light-absorbing layer. The active layer 114 can be doped with a second dopant. The active layer 114 can be formed as a single layer, multiple layers, etc.

[0188] The active layer 114 can be formed around a second conductivity type semiconductor layer 115 having a well structure. Furthermore, the active layer 114 can have an exposed region where its upper surface is exposed. Light can be supplied to the light-receiving element 100C through this exposed region. That is, the light supplied through this exposed region can be absorbed in the active layer 114. Additionally, at least a portion of the active layer 114 can correspond to a portion of the upper surface of the semiconductor structure SS.

[0189] The second conductivity type semiconductor layer 115 can be located on the active layer 114. The second conductivity type semiconductor layer 115 can be configured in the stacking direction to be offset from the opening region of the active layer 114.

[0190] Furthermore, the second conductivity type semiconductor layer 115 may be doped with a second dopant. The doping concentration of the second conductivity type semiconductor layer 115 may be greater than the doping concentration of the active layer 114.

[0191] Therefore, the second conductivity type semiconductor layer 115 can have low resistance and promote electron movement by having a high doping concentration. Thus, the second conductivity type semiconductor layer 115 can be used as an electron injection layer. Additionally, the second conductivity type semiconductor layer 115 can sense strong electric fields to improve avalanche multiplication in the photoreceiving element.

[0192] The second electrode layer 116 may be located on the semiconductor layer 115 of the second conductivity type. Alternatively, the second electrode layer 116 may be located on the semiconductor structure SS. Alternatively, the second electrode layer 116 may be located on the substrate 112.

[0193] The second electrode layer 116 may be located on the entire upper surface of the light receiving element 100C. Furthermore, the second electrode layer 116 may not overlap with the opening region of the active layer 114. The second electrode layer 116 may include a first opening region and a second opening region. The first opening region may correspond to the opening region of the active layer. The first opening region may overlap with the opening region of the active layer 114 in the stacking direction (X-axis direction).

[0194] The second electrode layer 116 may be formed of a plurality of electrode layers spaced apart from each other. A detailed description thereof will be provided below.

[0195] Additionally, the second electrode layer 116 can be made of a conductive metallic material. For example, the second electrode layer 116 can be made of a metal such as magnesium (Mg), aluminum (Al), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), zirconium (Zr), niobium (Nb), molybdenum (Mo), lead (Pd), silver (Ag), cadmium (Cd), indium (In), tin (Sn), lanthanum (La), hafnium (Hf), tantalum (Ta), tungsten (W), iridium (Ir), platinum (Pt), gold (Au), bismuth (Bi), or alloys thereof.

[0196] Furthermore, the second electrode layer 116 can be made of a transparent conductive material. For example, the second electrode layer 116 can be made of a transparent conductive oxide such as ITO, IZO or ZnO, or graphene.

[0197] Furthermore, the second electrode layer 116 can be connected to an external circuit. Therefore, current can flow. For example, at least one of a plurality of spaced-apart second electrode layers 116 can be electrically connected to an external circuit. Additionally, the second electrode layer 116 can contact a second conductivity type semiconductor layer 115 to supply electrons. Electrons can move through the second electrode layer 116 into the photoreceiving element.

[0198] The insulating layer 119 may be located on the semiconductor structure SS or the substrate 112. The insulating layer 119 may be formed on the second electrode layer 116. In addition, the insulating layer 119 may be located on the outside or above the light receiving element 100C.

[0199] The insulating layer 119 can be made of an insulating material. For example, the insulating layer 119 can be formed of an insulating material and can include SiO2, SiO2, etc. x SiO x N y At least one of Si3N4, Al2O3 or TiO2.

[0200] This configuration protects the internal layers of the optical receiver 100C from external materials. Furthermore, it improves the reliability of the optical receiver.

[0201] Figure 16 This is a plan view of the light receiving element according to the fourth embodiment. Figure 17 It is along Figure 16 Cross-sectional view of the EE' line in the diagram. Figure 18 yes Figure 17 A magnified view of section K4. Figure 19 yes Figure 17 A magnified view of section K5. Figure 20 yes Figure 16 A magnified view of section K in the middle. Figure 21 yes Figure 20 Enlarged view of section K6 in the middle. Figure 22 yes Figure 20 Enlarged view of section K7 in the middle. Figure 23 It is along Figure 16 Cross-sectional view of the FF' line in the diagram. Figure 24 It is along Figure 16 The cross-sectional view of the GG' line in the diagram, and Figure 25 This is a view used to describe a method of manufacturing a light receiving element according to an embodiment.

[0202] Reference Figures 16 to 24 In the light-receiving element 100C according to an embodiment, the second electrode layer 116 may be in contact with the second conductivity type semiconductor layer 115. Furthermore, the second electrode layer 116 may include a contact region CA and a non-contact region NCA. The contact region CA is the area in the second electrode layer 116 where the second electrode layer 116 and the second conductivity type semiconductor layer 115 are in contact with each other. The non-contact region NCA is the area in the second electrode layer 116 where the second electrode layer 116 and the second conductivity type semiconductor layer 115 are not in contact with each other.

[0203] In this case, in the second electrode layer 116, the lower surface of the contact region CA can be located below the lower surface of the non-contact region NCA. In other words, in the second electrode layer 116, the lower surface of the contact region CA can be closer to the lower surface of the light-receiving element than the lower surface of the non-contact region NCA. For example, in the second electrode layer 116, the spacing between the lower surface of the contact region CA and the first conductivity type semiconductor layer 113 can be smaller than the spacing between the lower surface of the non-contact region NCA and the first conductivity type semiconductor layer 113.

[0204] Furthermore, the upper surface US of the second conductivity type semiconductor layer 115 may include a first inclined surface IS1 and a bottom surface BS1. The first inclined surface IS1 may be disposed along the edge of the upper surface US of the second conductivity type semiconductor layer 115. Additionally, the first inclined surface IS1 may correspond to the edge of the contact region CA on the upper surface US of the second conductivity type semiconductor layer 115. Furthermore, the bottom surface BS1 may be located inside the first inclined surface IS1 on the upper surface US of the second conductivity type semiconductor layer 115. Additionally, the first inclined surface IS1 may be located on the bottom surface BS1 on the upper surface US1 of the second conductivity type semiconductor layer 115.

[0205] Using this configuration, recesses or trenches can be formed towards the lower part or the second conductive semiconductor layer in the region where the second conductive semiconductor layer 115 and the second electrode layer 116 are in contact with each other. Therefore, the presence of insulating layers or other components other than the second conductive semiconductor layer can be easily prevented. Furthermore, the contact area between the second conductive semiconductor layer and the second electrode layer can be increased. In addition, dangling bonds can be easily prevented, Schottky junctions can be overcome, and ohmic contacts can be easily formed. Furthermore, the energy barrier can be lowered, thereby enabling smooth current flow. Therefore, the contact resistance between the second electrode layer 116 and the second conductive semiconductor layer 115 can be reduced. Therefore, a passive element with improved power efficiency and photosensitivity can be provided.

[0206] Furthermore, the height of the recess or trench can be less than the minimum thickness of the second electrode layer 116. That is, the height of the first inclined surface IS1 can be less than the minimum thickness of the second electrode layer 116. With this configuration, the occurrence of cracks or the like in the stacked insulating layers or lower components can be suppressed. Therefore, a passive component with improved reliability can be provided.

[0207] Since the bottom surface BS1 on the upper surface US of the second conductivity type semiconductor layer 115 is in contact with the lower surface of the contact region CA on the second electrode layer 116, the bottom surface BS1 on the upper surface US of the second conductivity type semiconductor layer 115 can correspond to the lower surface of the contact region CA on the second electrode layer 116. Furthermore, the lower surface of the non-contact region NCA on the second electrode layer 116 can correspond to the surface in contact with the active layer 114 or the surface in contact with the upper surface of the insulating layer 119.

[0208] Additionally, as described above, the active layer 114 may include an opening region OA with its upper surface exposed. The opening region OA may be offset from the second electrode layer 116 in the stacking direction (X-axis direction). That is, the opening region OA may not overlap with the second electrode layer 116 in the stacking direction (X-axis direction). Therefore, light reception by the light-receiving element through the opening region OA can be achieved more efficiently.

[0209] Furthermore, the surface EA exposed by the opening region OA in the active layer 114 can be located higher than the bottom surface BS1 of the second conductivity type semiconductor layer 115. Additionally, the opening region OA can be positioned offset from the second electrode layer 116 in the stacking direction (X-axis direction).

[0210] Additionally, as described above, the plurality of second electrode layers 116 can be configured to be spaced apart from each other. For example, the second electrode layers 116 may include a first sub-electrode layer 116a and a second sub-electrode layer 116b. The first sub-electrode layer 116a and the second sub-electrode layer 116b can be physically separated.

[0211] With this configuration, the electric field can be uniformly distributed without being concentrated in a specific region through the first sub-electrode layer 116a and the second sub-electrode layer 116b, which are spaced apart from each other. Therefore, the performance (e.g., signal-to-noise ratio, SNR) of the optical receiving element can be improved by blocking unwanted leakage current while stably maintaining the breakdown voltage.

[0212] Additionally, as described above, the second electrode layer 116 may include a first opening region OP1 and a second opening region OP2. The first opening region OP1 may correspond to the opening region OA of the active layer 114. The first opening region OP1 may overlap with the opening region OA of the active layer 114 in the stacking direction (X-axis direction).

[0213] The second opening region OP2 can be located outside the contact surface where the second electrode layer 116 and the second conductivity type semiconductor layer 115 contact each other. Therefore, the second opening region OP2 can overlap with the substrate 112, the active layer 114, etc. in the stacking direction. In addition, the first sub-electrode layer 116a and the second sub-electrode layer 116b can be separated from each other through the second opening region OP2. That is, the second opening region OP2 can be an opening region between the first sub-electrode layer 116a and the second sub-electrode layer 116b.

[0214] Furthermore, in the plan view, the second opening region OP2 can be configured to surround the first sub-electrode layer 116a and the opening region OA. Therefore, relative to the center of the opening region OA, the second opening region OP2 and the second sub-electrode 116b can be located outside the first sub-electrode layer 116a and the opening region OA. For example, in the plan view, the second opening region OP2 can be a closed loop.

[0215] The second opening region OP2 can surround the first sub-electrode layer 116a and the opening region OA. Therefore, the second sub-electrode layer 116b can be physically separated from the first sub-electrode layer 116a through the second opening region OP2.

[0216] Therefore, even if the contact area is formed to be small, the area of ​​the second electrode layer 116 can be increased, thereby maximizing the formation of the N-junction. Furthermore, the current will not be concentrated solely below the contact area, thus improving the reliability of the light-receiving element and easily extending its lifespan.

[0217] Furthermore, the first sub-electrode layer 116a and the second sub-electrode layer 116b can overlap with the active layer 114, the first conductivity type semiconductor layer 113, and the substrate 112 in the stacking direction (X-axis direction). With this configuration, smooth current flow can be achieved through the movement of electrons via the second electrode layer 116.

[0218] Additionally, the first opening region OP1 can be located inside the second opening region OP2. For example, the first opening region OP1 can be located inside the second opening region OP2, which is a closed loop in the plan view.

[0219] Additionally, in the light receiving element 100C according to the fourth embodiment, the second conductivity type semiconductor layer 115 may include a first sublayer 115a and a second sublayer 115b.

[0220] The first sublayer 115a and the second sublayer 115b can be stacked sequentially in the stacking direction (X-axis direction).

[0221] In this embodiment, the doping concentration of the first sublayer 115a may differ from the doping concentration of the second sublayer 115b. The doping concentration of the first sublayer 115a may be lower than that of the second sublayer 115b. That is, the second conductivity type semiconductor layer 115 may have a high doping concentration in the region adjacent to the second electrode layer 116. For example, the first sublayer 115a and the second sublayer 115b may be doped with an n-type dopant. Furthermore, the second sublayer 115b may have a doping concentration of 10... 19 atoms / cm 3 or higher doping concentrations.

[0222] This configuration improves the contact resistance between the second conductivity type semiconductor layer 115 and the second electrode layer 116, and enhances current flow. Therefore, a light-receiving element with improved power efficiency and improved light sensitivity can be provided. In other words, the detectable distance of the light-receiving element can be improved.

[0223] Additionally, at least a portion of the insulating layer 119 may be exposed by the second opening region OP2. The exposed area of ​​the insulating layer 119 may be spaced apart from the opening region OA and may also be offset from the contact region CA in the stacking direction (X-axis direction). The exposed area of ​​the insulating layer 119 may not overlap with the opening region OA and the contact region CA in the stacking direction.

[0224] Furthermore, the opening region OA and the contact region CA can be set to be spaced apart by a predetermined distance. Additionally, the insulating layer 119 can be located between the opening region OA and the contact region CA. Furthermore, the insulating layer 119 can be located outside the contact region CA.

[0225] Therefore, the insulating layer 119 can contact the second conductivity type semiconductor layer 115, the active layer 114, the substrate 112, etc.

[0226] Furthermore, the insulating layer 119 may have a structure extending upward from the upper portion of a recess or trench on the upper surface of the second conductivity type semiconductor layer to correspond to a recess or trench formed on the upper surface of the second conductivity type semiconductor layer 115. Therefore, at least a portion of the insulating layer 119 may be located between the second electrode layers 116 spaced apart in the stacking direction (X-axis direction). Alternatively, at least a portion of the insulating layer 119 may be positioned within the second electrode layers 116.

[0227] For example, in the region overlapping with the non-overlapping region NCA in the stacking direction (X-axis direction), the upper surface of the insulating layer 119 may be located below the upper surface of the insulating layer 119 in the region overlapping with the overlapping region CA in the stacking direction (X-axis direction). Furthermore, the insulating layer 119 may contact the second electrode layer 116 in the region overlapping with the overlapping region CA in the stacking direction (X-axis direction), but may contact the active layer 114 in the region overlapping with the non-overlapping region NCA in the stacking direction (X-axis direction).

[0228] Reference Figure 25 According to the embodiments, the light receiving element may include forming a substrate and a mask, forming a pattern of the mask, performing injection on the substrate, and forming a second electrode layer and an insulating layer.

[0229] like Figure 25 As shown in Figure A, a substrate 112 and a mask PR can be formed. Although the same content can be applied to the active layer 114 instead of the substrate 112, the following description will be based on the substrate 112. The mask PR can be formed on the upper surface of the substrate 112. For example, the mask PR may include a dry film, etc.

[0230] Subsequently, as Figure 25 As shown in Figure B, a portion of the mask can be removed by methods such as development to form a patterned mask PR'. Furthermore, the upper surface of the substrate 112 exposed by the mask PR' can be etched. An inclined surface and a bottom surface can be formed on the upper surface of the aforementioned second conductivity type semiconductor layer.

[0231] Subsequently, as Figure 25 As shown in Figure C, ion implantation can be performed on substrate 112. Therefore, the characteristics of the semiconductor substrate or device can be adjusted. Therefore, a semiconductor structure (or a second conductivity type semiconductor layer) can be formed. Therefore, recesses or trenches can be formed in the upper surface of the second conductivity type semiconductor layer.

[0232] Subsequently, as Figure 25 As shown in Figure D, a second electrode layer 116 and an insulating layer 119 can be formed on a second conductivity type semiconductor layer 115. At least a portion of the insulating layer 119 can be located inside the second electrode layer 116. Therefore, the upper and lower surfaces of the insulating layer 119 can be in contact with the second electrode layer 116 in certain regions.

[0233] The features, structures, effects, etc., described in the above embodiments are included in at least one embodiment, but are not necessarily limited to one embodiment. Furthermore, the features, structures, effects, etc., shown in the embodiments can be combined or modified by those skilled in the art for other embodiments. Therefore, matters related to these combinations and modifications should be interpreted as being included within the scope of the embodiments.

[0234] Although the above description has been carried out with reference to embodiments, it is merely illustrative and not intended to limit the embodiments. Those skilled in the art will understand that various modifications and applications not shown above can be made without departing from the essential characteristics of the embodiments. For example, each component specifically shown in the embodiments can be modified and implemented. Furthermore, differences associated with these modifications and applications should be interpreted as including within the scope of the embodiments as defined in the appended claims.

Claims

1. A light receiving element, comprising: First electrode layer; A substrate, wherein the substrate is disposed on the first electrode layer; A semiconductor structure comprising a first conductivity type semiconductor layer, a second conductivity type semiconductor layer formed on the substrate, and an active layer disposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, wherein the semiconductor structure is formed in a well structure. A second electrode layer is disposed on the semiconductor structure; as well as A first diffusion layer is located between the first conductivity type semiconductor layer and the active layer.

2. The optical receiving element according to claim 1, wherein, The first diffusion layer overlaps with the first conductivity type semiconductor layer, the active layer, and the second conductivity type semiconductor layer in the stacking direction.

3. The optical receiving element according to claim 1, wherein, The active layer includes an open area on its upper surface that is exposed.

4. The optical receiving element according to claim 3, wherein, The opening region is offset from the second electrode layer in the stacking direction.

5. The optical receiving element according to claim 3, wherein, The second electrode layer includes a first sub-electrode layer and a second sub-electrode layer spaced apart from each other.

6. The optical receiving element according to claim 5, wherein, The first diffusion layer overlaps with the first sub-electrode layer and the second sub-electrode layer in the stacking direction.

7. The optical receiving element according to claim 5, wherein, The first diffusion layer includes a first region that overlaps with the opening region in the stacking direction and a second region that overlaps with the second electrode layer.

8. The optical receiving element according to claim 7, wherein, The thickness of the first region is less than the thickness of the second region.

9. The optical receiving element according to claim 7, further comprising: A second diffusion layer is disposed between the substrate and the first electrode layer.

10. The optical receiving element according to claim 9, wherein, The second diffusion layer includes a third region that overlaps with the semiconductor structure in the stacking direction and a fourth region in addition to the third region.

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