Light-receiving element and lidar device

Abstract

Disclosed in an embodiment of the present invention is a light-receiving element comprising: a semiconductor structure, which includes a first electrode layer, a substrate disposed on the first electrode layer, a first conductive semiconductor layer formed on the substrate, a second conductive semiconductor layer, and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer, and which is structured as a well; a second electrode layer disposed on the semiconductor structure; and a first diffusion layer disposed between the first conductive semiconductor layer and the active layer.

Description

Photodetector and lidar device

[0001] An embodiment according to the present invention relates to a light receiving element and a lidar device.

[0002] ADAS (Advanced Driving Assistance System) is an advanced driver assistance system that assists the driver in driving. It consists of sensing the situation ahead, judging the situation based on the sensed results, and controlling the vehicle's behavior based on the situation judgment. For example, ADAS sensor devices detect a vehicle ahead and recognize lanes. After the target lane, target speed, and forward target are determined, the vehicle's ESC (Electrical Stability Control), EMS (Engine Management System), and MDPS (Motor Driven Power Steering) are controlled. Representative examples of ADAS can be implemented as automatic parking systems, low-speed city driving assistance systems, and blind spot warning systems.

[0003] With the recent surge in interest in autonomous vehicles, demand for LiDAR (Light Detection And Ranging) sensors, a key component of autonomous vehicles, is growing. Currently, LiDAR is used only in high-end, expensive vehicles, but its adoption in general-purpose vehicles is expected to increase as manufacturing costs decline.

[0004] Ultra-small and ultra-light lidar technology can be used not only as a sensor for unmanned mobile devices, but also in satellites and aerospace for observing the Earth's topography and environment, unmanned vehicles, transporters, cranes, and robots used in factories and shipyards, and it is expected to appear in the form of complex or cooperative operation between mobile devices through an integrated approach in the land, aviation, and marine industries. Therefore, the development of an optical system for ultra-small and ultra-light lidar to implement ultra-small and ultra-light lidar is urgent.

[0005] An embodiment of the present invention seeks to implement a light-receiving element and a lidar device with improved electrical characteristics by improving the diffusion and uniformity of electrons through a first diffusion layer.

[0006] In addition, the embodiment can implement a light-receiving element and a lidar device with improved response speed and improved power efficiency by improving diffusion for low-mobility holes through a second diffusion layer.

[0007] In addition, the embodiment can realize a light-receiving element and a lidar device with improved light sensitivity by significantly improving hole movement through a second diffusion layer having a larger thickness than the first diffusion layer and by transmitting electron-hole pairs to the first electrode layer with high efficiency even at the edge.

[0008] Additionally, by increasing the thickness at the edge of the first or second diffusion layer, a light-receiving element and a lidar device with improved current spreading can be implemented.

[0009] The embodiment aims to implement a light-receiving element and a lidar device with improved electrical characteristics by overcoming Schottky junctions and easily forming ohmic contacts through the structure of a second conductive semiconductor layer, and reducing contact resistance through a reduction in energy barriers, etc.

[0010] In addition, the embodiment can implement a light-receiving element and a lidar device with improved reliability by easily suppressing cracks in a laminated insulating layer or other components by controlling the slope and thickness.

[0011] The problem to be solved in the embodiment is not limited to this, and it can be said that the purpose or effect that can be understood from the solution or implementation form of the problem described below is also included.

[0012] A light-receiving element according to an embodiment of the present invention comprises: a first electrode layer; a substrate disposed on the first electrode layer; a first conductive semiconductor layer formed on the substrate; a second conductive semiconductor layer; and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer; and a semiconductor structure having a well structure; a second electrode layer disposed on the semiconductor structure; and a first diffusion layer positioned between the first conductive semiconductor layer and the active layer.

[0013] The first diffusion layer may overlap the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer in the stacking direction.

[0014] The above active layer may include an open region with an exposed upper surface.

[0015] The above open area may be misaligned with the second electrode layer in the lamination direction.

[0016] The second electrode layer may include a first sub-electrode layer and a second sub-electrode layer spaced apart from each other.

[0017] The first diffusion layer may overlap the first sub-electrode layer and the second sub-electrode layer in the stacking direction.

[0018] The first diffusion layer may include a first region overlapping the open region in the stacking direction and a second region overlapping the second electrode layer.

[0019] The thickness of the first region may be smaller than the thickness of the second region.

[0020] It may further include a second diffusion layer disposed between the substrate and the first electrode layer.

[0021] The second diffusion layer may include a third region overlapping the semiconductor structure in the stacking direction and a fourth region other than the third region.

[0022] The thickness of the third region may be smaller than the thickness of the fourth region.

[0023] The third region may overlap with the first region and the second region.

[0024] The first conductive semiconductor layer may be doped with a first dopant, and the second conductive semiconductor layer and the active layer may be doped with a second dopant.

[0025] The doping concentration of the second conductive semiconductor layer may be greater than the doping concentration of the active layer.

[0026] A lidar device according to an embodiment includes a light-emitting element that emits light; a light-receiving element that receives the light reflected by an object; and a control unit that controls 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 conductive semiconductor layer formed on the substrate; a second conductive semiconductor layer; and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer; and a semiconductor structure having a well structure; a second electrode layer disposed on the semiconductor structure; and a first diffusion layer positioned between the first conductive semiconductor layer and the active layer.

[0027] A light-receiving element according to an embodiment comprises: a first electrode layer; a substrate disposed on the first electrode layer; a first conductive semiconductor layer formed on the substrate; a second conductive semiconductor layer; and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer; a semiconductor structure having a well structure; and a second electrode layer disposed on the semiconductor structure; wherein the second electrode layer comprises a contact region in contact with the second conductive semiconductor layer and a non-contact region not in contact with the second conductive semiconductor layer; and a lower surface of the contact region is located below a lower surface of the non-contact region.

[0028] The upper surface of the second conductive semiconductor layer may include a first inclined surface arranged along an edge and a lower surface arranged inside the first inclined surface.

[0029] The above first inclined surface may be positioned higher than the above bottom surface.

[0030] The above active layer may include an open region with an exposed upper surface.

[0031] The surface exposed to the above open area may be located above the above bottom surface.

[0032] The above open area may be misaligned with the second electrode layer in the lamination direction.

[0033] The second electrode layer may include a first opening area corresponding to the open area.

[0034] The second electrode layer may include a first sub-electrode layer and a second sub-electrode layer spaced apart from each other.

[0035] The second electrode layer may include a second opening region formed between the first sub-electrode layer and the second sub-electrode layer.

[0036] The second opening area can surround the first sub-electrode layer and the open area in a plane.

[0037] The above second opening area may be a closed loop in a plane.

[0038] The second conductive semiconductor layer may include a first sub-layer and a second sub-layer disposed on top of the first sub-layer.

[0039] The doping concentration of the second sublayer may be greater than the doping concentration of the first sublayer.

[0040] The first conductive semiconductor layer is doped with a first dopant, the second conductive semiconductor layer and the active layer are doped with a second dopant, and the doping concentration of the second conductive semiconductor layer may be greater than the doping concentration of the active layer.

[0041] A lidar device according to an embodiment includes a light-emitting element that emits light; a light-receiving element that receives the light reflected by an object; and a control unit that controls 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 conductive semiconductor layer formed on the substrate; a second conductive semiconductor layer; and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer; a semiconductor structure having a well structure; and a second electrode layer disposed on the semiconductor structure, wherein the second electrode layer includes a contact region in contact with the second conductive semiconductor layer and a non-contact region not in contact with the second conductive semiconductor layer, wherein the contact region is located below the non-contact region.

[0042] An embodiment of the present invention provides a light-receiving element and a lidar device having improved electrical characteristics by improving electron diffusion and uniformity through a first diffusion layer.

[0043] In addition, the embodiment can provide a light-receiving element and a lidar device with improved response speed and improved power efficiency by improving diffusion for low-mobility holes through a second diffusion layer.

[0044] In addition, the embodiment can provide a light-receiving element and a lidar device with improved light sensitivity by significantly improving hole movement through a second diffusion layer having a larger thickness than the first diffusion layer and by allowing electron-hole pairs to be transferred to the first electrode layer with high efficiency even at the edge.

[0045] In addition, by increasing the thickness at the edge of the first diffusion layer or the second diffusion layer, a light-receiving element and a lidar device with improved current spreading can be provided.

[0046] The embodiment provides a light-receiving element and a lidar device with improved electrical characteristics by overcoming Schottky junctions and easily forming ohmic contacts through the structure of a second conductive semiconductor layer, and reducing contact resistance through a reduction in energy barriers, etc.

[0047] In addition, the embodiment can provide a light receiving element and a lidar device with improved reliability by easily suppressing crack occurrence in a laminated insulating layer or other components by controlling the slope and thickness.

[0048] The various advantageous and beneficial effects of the present invention are not limited to the above-described contents, and will be more easily understood in the course of explaining specific embodiments of the present invention.

[0049] Figure 1 is a block diagram of a lidar device according to an embodiment of the present invention.

[0050] Figure 2 is a drawing of a lidar device according to an embodiment and a system applying the same.

[0051] Figure 3 is a drawing explaining the operation of a lidar device and a system applying the same according to an embodiment.

[0052] Fig. 4 is a cross-sectional view of a light-receiving element according to an embodiment of the present invention;

[0053] Fig. 5 is a plan view of a light receiving element according to the first embodiment,

[0054] Figure 6 is a cross-sectional view taken along line AA' in Figure 5.

[0055] Fig. 7 is a cross-sectional view taken along line BB' in Fig. 5,

[0056] Fig. 8 is a cross-sectional view taken along line CC' in Fig. 5,

[0057] Fig. 9 is a plan view of a light receiving element according to the second embodiment,

[0058] Fig. 10 is a cross-sectional view taken along line DD' in Fig. 9,

[0059] Figure 11 is an enlarged view of part K1 in Figure 10,

[0060] Figure 12 is an enlarged view of the K2 portion in Figure 10,

[0061] Fig. 13 is a cross-sectional view of a light-receiving element according to the third embodiment,

[0062] Figure 14 is an enlarged view of part K3 in Figure 13,

[0063] Fig. 15 is a cross-sectional view of a light receiving element according to the fourth embodiment of the present invention.

[0064] Fig. 16 is a plan view of a light receiving element according to the fourth embodiment,

[0065] Fig. 17 is a cross-sectional view taken along line EE' in Fig. 16,

[0066] Figure 18 is an enlarged view of the K4 portion in Figure 17,

[0067] Figure 19 is an enlarged view of part K5 in Figure 17,

[0068] Figure 20 is an enlarged view of part K in Figure 16,

[0069] Figure 21 is an enlarged view of part K6 in Figure 20,

[0070] Figure 22 is an enlarged view of part K7 in Figure 20,

[0071] Fig. 23 is a cross-sectional view taken along the line FF' in Fig. 16,

[0072] Fig. 24 is a cross-sectional view taken along line GG' in Fig. 16,

[0073] Fig. 25 is a drawing explaining a method for manufacturing a light-receiving element according to the fourth embodiment.

[0074] The present invention can be modified in various ways and has various embodiments, and specific embodiments are illustrated and described in the drawings. However, this is not to be construed as a specific embodiment of the present invention.

[0075] It is not intended to be limited to the embodiments, and should be understood to include all modifications, equivalents, or substitutes included in the spirit and technical scope of the present invention.

[0076] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0077] However, the technical idea of ​​the present invention is not limited to some of the embodiments described, but can be implemented in various different forms, and within the scope of the technical idea of ​​the present invention, one or more of the components between the embodiments can be selectively combined or substituted for use.

[0078] In addition, terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as having a meaning that can be generally understood by a person of ordinary skill in the technical field to which the present invention belongs, unless explicitly and specifically defined and described, and terms that are commonly used, such as terms defined in a dictionary, may be interpreted in consideration of the contextual meaning of the relevant technology.

[0079] In addition, the terms used in the embodiments of the present invention are for the purpose of describing the embodiments and are not intended to limit the present invention. In this specification, the singular may also include the plural unless specifically stated in the phrase, and when it is described as “and (and) at least one (or more) of B, C,” it may include one or more of all combinations that can be combined with A, B, and C.

[0080] Terms that include ordinal numbers, such as "second," "first," etc., may be used to describe various components, but the components are not limited by the terms. The terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a second component may be referred to as a "first component," and similarly, a first component may also be referred to as a "second component." The terms "and / or" include a combination of multiple related items described herein or any of multiple related items described herein. These terms are only used to distinguish the component from other components and are not limited by the nature, order, or sequence of the component.

[0081] And, when a component is described as being 'connected', 'coupled' or 'connected' to another component, it may include not only cases where the component is directly connected, coupled or connected to the other component, but also cases where the component is 'connected', 'coupled' or 'connected' by another component between the component and the other component.

[0082] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0083] Additionally, when it is described as being formed or arranged "above or below" each component, "above" or "below" includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or arranged between the two components. Also, when it is expressed as "above" or "below", it can include the meaning of the downward direction as well as the upward direction based on one component.

[0084] Additionally, the expression that configuration A is positioned between configurations B and C should also include the meaning that configuration A is positioned so that it overlaps configurations B and C at least partially in the horizontal and / or vertical directions.

[0085] Expressions referring to directions include horizontal directions, vertical directions, and include a first horizontal direction and a second horizontal direction perpendicular to the first horizontal direction. These are referred to as a first horizontal direction (X-axis), a second horizontal direction (Y-axis), and a vertical direction (Z-axis) according to the Cartesian coordinate system, and the meaning of overlapping along the horizontal direction should also include the meaning of overlapping along the first horizontal direction and / or overlapping along the second horizontal direction.

[0086] Additionally, the statement that component A is exposed from component B should be understood to mean that component A is exposed from component B, not that component A is exposed from the entire product. That is, when it is stated that component A is exposed from component B, it should be understood to mean that component A is at least partially covered by component C.

[0087] Furthermore, when it is described that a component A is in "contact" with a component B, it may include not only cases where that component is in "contact" with the other component directly, but also cases where that component is "contacted" by another component between that component and the other component. Thus, if a component A is to be understood only as being in "direct contact" with a component B, it is described as being in "direct contact."

[0088] In addition, when it is written that configuration A is 'covered' by configuration B, it should be understood that configuration A is covered by configuration B, and that the part for the function and purpose to be solved is covered, and unless there are special circumstances, it should not be understood that the entire configuration A is covered by configuration B.

[0089] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0090] Before describing the embodiments, an electronic device to which the light-receiving element and lidar device of the embodiments are applied will be briefly described. For example, the electronic device may be a smart phone, a personal digital assistant, a digital video camera, a digital still camera, a vehicle, a high-performance server, a network system, a computer, a monitor, a tablet, a laptop, a netbook, a television, a video game, a smart watch, an automotive device, etc.

[0091] In particular, electronic devices can be used as electronic components for assisting drivers, etc. in vehicles, such as photodetectors and lidar devices.

[0092] However, it is not limited to this, and it can be applied to transporters, cranes, robots, etc. used in satellite and aerospace fields, factories, and shipyards.

[0093] FIG. 1 is a block diagram of a lidar device according to an embodiment of the present invention, FIG. 2 is a drawing of a lidar device according to an embodiment and a system applying the same, and FIG. 3 is a drawing explaining the operation of a lidar device according to an embodiment and a system applying the same.

[0094] Referring to FIG. 1, a lidar device (1000) according to an embodiment can irradiate light toward a subject and detect light that is reflected by the subject and returns to the lidar device (1000). The lidar device (1000) can include a transmitter (1010). The transmitter (1010) can adjust the irradiation direction of light emitted outside the lidar device (1000). The transmitter (1010) can be a mechanical or non-mechanical (semiconductor) beam device. The lidar device (1000) can include a light source within the transmitter (1010) or a light source provided separately from the transmitter (1010). The transmitter (1010) can be a scanning type light emitting device. However, the light emitting device of the lidar device (1000) is not limited to the transmitter (1010). In another example, the lidar device (1000) may further include a flash-type light emitting device instead of or in addition to the transmitter (1010). In the case of a flash, light can be irradiated to an area encompassing the entire field of view at once.

[0095] The light steered by the transmitter (1010) may be reflected by a subject or object and return to the lidar device (1000). The lidar device (1000) may include a receiver (1030) for detecting the light reflected by the subject. The receiver (1030) may include a plurality of light-receiving elements and may further include other optical members. Accordingly, the receiver (1030) may correspond to a 'light detection unit'. In addition, the plurality of light-receiving elements may include any one of the avalanche light-receiving elements described below.

[0096] In addition, the lidar device (1000) may further include a control unit (1020) connected to at least one of the transmitter unit (1010) and the receiver unit (1030). The control unit (1020) may include a calculation unit that acquires and calculates data, and may further include a driving unit and a control unit, etc. In addition, the control unit (1020) may further include a power supply unit and a memory, etc.

[0097] Although the lidar device (1000) is illustrated as including a transmitter (1010) and a receiver (1030) within a single device, the transmitter (1010) and the receiver (1030) may not be provided as a single device, but may be provided separately in separate devices. In addition, the control unit (1020) may not be connected to the transmitter (1010) or the receiver (1030) by wire, but may be connected via wireless communication.

[0098] The LiDAR device (1000) according to the embodiment described above can be applied to various electronic devices. For example, the LiDAR device (1000) can be applied to a LiDAR (Light Detection And Ranging) device. The LiDAR device can be a phase-shift type or a time-of-flight (TOF) type device. In addition, the light-receiving element according to the embodiment or the LiDAR device (1000) including the same can be mounted on electronic devices such as a smartphone, a wearable device (such as an augmented reality and virtual reality implementation glasses-type device), an Internet of Things (IoT) device, a home appliance, a tablet PC (Personal Computer), a PDA (Personal Digital Assistant), a PMP (Portable Multimedia Player), a navigation system, a drone, a robot, an unmanned vehicle, an autonomous vehicle, an Advanced Drivers Assistance System (ADAS), and the like.

[0099] The following are conceptual diagrams showing a case where a LiDAR device is applied to a vehicle according to an exemplary embodiment.

[0100] Referring to FIGS. 2 and 3, a lidar device (or light receiving element) (1000, see FIG. 1) may be applied to a vehicle (2000). Information about a subject (2020) may be acquired using the lidar device (1000) (or light receiving element) applied to the vehicle. The vehicle (2000) may be an automobile having an autonomous driving function.

[0101] The lidar device (1000) can detect a subject or object (e.g., a person) (2020) in the direction in which the vehicle (2000) is traveling. The lidar device (1000) can measure the distance to the subject (2020) by using information such as the time difference between the transmitted signal and the detected signal. The lidar device (1000) can obtain information about a nearby subject (3010) and a distant subject (3020) within the scan range. The lidar device (1000) can include a light-receiving element described below.

[0102] Additionally, although a lidar device (1000) is shown positioned at the front of the vehicle (2000) to detect a subject (2020) in the direction in which the vehicle (2000) is moving, it may not be limited thereto.

[0103] For example, the LiDAR device (1000) can detect a subject (2020) by emitting and receiving light forward (2010, 2030). Furthermore, the LiDAR device (1000) can be placed at multiple locations on the vehicle (2000) so as to detect all subjects (2020) around the vehicle (2000). For example, four LiDAR devices (2010) can be placed at the front, rear, and both sides of the vehicle (2000), respectively. In another example, the LiDAR device (1000) can be placed on the roof of the vehicle (2000) and rotate to detect subjects (2020) around the vehicle (2000).

[0104] Specifically, the lidar device (1000) calculates range information based on time-of-flight measurements of light pulses emitted from a light source. Additionally, the scene is illuminated at a target plane associated with a particular range, and known information about the light beam profile based on the particular design of the source and projector system is used to determine position information about the reflective surface, thereby generating a complete x, y, z, or 3D picture of the scene.

[0105] In other words, the point-by-point 3D map of the surrounding environment represents a collection of measurement data representing positional information from all surfaces reflecting light 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 in the field of view of the lidar device (1000) is obtained.

[0106] Also shown is a schematic diagram illustrating the two-dimensional field of view and range requirements of a typical surround view LIDAR device (1000) for a vehicle (202). For example, adaptive cruise control functions may require a field of view and range (2040) with a narrower field of view compared to a side view "surround view" field of view and range (2060), but with a long range requirement. Typically, the sensor functions of a vehicle may be enabled by a combination of LIDAR, radar, cameras, and ultrasonic sensors. The combination of these sensor data to generate information about the surrounding environment is often referred to as "sensor fusion."

[0107] While the present invention describes the lidar device (1000) in the context of an automobile, where LIDAR is widely used for autonomous, self-driving, or driver-assisted vehicles, it should be understood that the embodiments can be applied to any vehicle. Other types of vehicles may include robots, tractors, trucks, airplanes, drones, boats, ships, and the like.

[0108] Figure 4 is a cross-sectional view of a light-receiving element according to an embodiment of the present invention.

[0109] Referring to FIG. 4, a light-receiving element (100) according to an embodiment of the present invention 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). The semiconductor structure (SS) may include a first conductive semiconductor layer (113), an active layer (114), and a second conductive semiconductor layer (115) disposed on the substrate (112). The semiconductor structure (SS) may have a well structure. For example, the second conductive semiconductor layer (115) may have a well structure, and the active layer (114) may have a well structure covering the second conductive semiconductor layer (115) of the well structure. The first conductive semiconductor layer (113) may cover or be positioned below the active layer (114). The semiconductor structure (SS) may have a well structure with respect to the upper surface of the substrate (112). Furthermore, the light-receiving element (100) may further include a second diffusion layer (118) positioned between the first electrode layer (111) and the substrate (112).

[0110] Except for the first electrode layer (111), the second electrode layer (116), and the insulating layer (119), the remaining layers may be formed of semiconductor materials. For example, the semiconductor material may include at least one of a group IV semiconductor such as silicon (Si) or germanium (Ge), a group III-V compound semiconductor such as GaAs or GaP, a group II-VI compound semiconductor such as CdS or ZnTe, a group IV-VI compound semiconductor such as PbS, a group IV-IV compound semiconductor such as SiC, an oxide semiconductor such as IGZO, a quantum dot, an organic semiconductor, and a semiconductor having a two-dimensional crystal structure with a band gap. A representative example of a semiconductor having a two-dimensional crystal structure is a transition metal dichalcogenide (TMD), which is a compound of a transition metal and a chalcogen element. 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, SnTe2. In addition, in addition to transition metal dichalcogenides, there are semiconductors with a two-dimensional crystal structure. For example, semiconductors with a two-dimensional crystal structure may further include TiOx, NbOx, MnOx, VaOx, MnO3, TaO3, WO3, MoCl2, CrCl3, RuCl3, BiI3, PbCl4, GeS, GaS, GeSe, GaSe, PtSe2, In2Se3, GaTe, InS, InSe, InTe, etc.

[0111] And in the stacking direction (X-axis direction), 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 positioned. Accordingly, the second diffusion layer (118) can be positioned on the first electrode layer (111). The substrate (112) can be positioned on the first electrode layer (111) or the second diffusion layer (118). The semiconductor structure (SS) can be positioned on the second diffusion layer (118). And the second electrode layer (116) can be positioned on the semiconductor structure (SS). In particular, the second electrode layer (116) can be positioned on the second conductive semiconductor layer (115).

[0112] The first electrode layer (111) may be positioned on one side of the light-receiving element (100). For example, the first electrode layer (111) may be positioned below the light-receiving element (100). The light-receiving element (100) may be electrically connected to an external circuit (e.g., a control unit) through the first electrode layer (111). For example, holes may move to the external circuit through the first electrode layer (111).

[0113] And the first electrode layer (111) may be made of a conductive metal material. For example, the first electrode layer (111) may 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), etc., or an alloy thereof.

[0114] Furthermore, the first electrode layer (111) may be made of a transparent conductive material. For example, the first electrode layer (111) may be made of a transparent conductive oxide such as ITO, IZO, ZnO, or graphene.

[0115] The second diffusion layer (118) is arranged on the first electrode layer (111) so that electron-hole pairs (EHP) generated in the semiconductor structure (SS) can all reach the first electrode layer (111), which is the lower electrode. In other words, the second diffusion layer (118) can make the transport of charge carriers more uniform and prevent the current from being concentrated in a specific area. Accordingly, the first electrode layer (111) can form a uniform current flow not only in the area overlapping the open area of ​​the active layer (114), but also in a wider area. By this configuration, after the electron-hole pairs are generated, the charges can flow uniformly rather than moving only in a specific path. This reduces signal distortion and loss and improves power efficiency, making it possible to provide a light-receiving element. In addition, thermal imbalance due to current concentration can also be resolved, making it possible to provide a light-receiving element with improved reliability.

[0116] The second diffusion layer (118) may be doped with a 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 a doping concentration of 10 17 cm -3 It can be achieved up to .

[0117] Furthermore, the second diffusion layer (118) may have a larger area than the semiconductor structure (SS). For example, the first electrode layer (111) may have an area of ​​5% or less of the open area of ​​the active layer (114). Furthermore, the second diffusion layer (118) may have a larger area than the semiconductor structure (SS) and may be positioned on the entire upper surface of the first electrode layer (111). For example, the second diffusion layer (118) may be formed on the entire lower surface of the substrate (112). Accordingly, even if the mobility of holes is relatively slow compared to that of electrons, the current may be more easily diffused by the second diffusion layer (118). As a result, the response speed of the light-receiving element may be further improved.

[0118] The substrate (112) may be positioned 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, it may include a Group 5 element (e.g., phosphorus (P), arsenic (As), antimony (Sb), etc.), a Group 6 element, or a Group 7 element as an impurity. For example, in the embodiment, the substrate (112) may be p-type. Accordingly, the substrate (112) may include a Group 3 element (e.g., boron (B), aluminum (Al), gallium (Ga), indium (In), etc.) or a Group 2 element as an impurity. Additionally, the substrate (112) may be a semiconductor substrate and may be an epi layer formed by an epitaxial growth process.

[0119] The substrate (112) can be electrically connected to the first conductive semiconductor layer (113) of the semiconductor structure (SS) and can mechanically perform a supporting role. Furthermore, the substrate (112) can stably form an electric field distribution. Furthermore, depending on the voltage application, a portion of the depletion region in the substrate (112) can expand.

[0120] The semiconductor structure (SS) may be positioned in a well structure in the substrate (112). For example, the semiconductor structure (SS) may be accommodated within the substrate (112).

[0121] And as described above, the semiconductor structure (SS) may include a first conductive semiconductor layer (113), an active layer (114), and a second conductive semiconductor layer (115) positioned in the stacking direction (X-axis direction).

[0122] And each of the first conductive semiconductor layer (113), the active layer (114), and the second conductive semiconductor layer (115) may be doped with a first dopant or a second dopant. The first conductive semiconductor layer (113), the active layer (114), and the second conductive semiconductor layer (115) may be implemented with a compound semiconductor of group IIIⅤ, group IIⅥ, etc. And the first conductive semiconductor layer (113) may be doped with the 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.

[0123] And the active layer (114) and the second conductive semiconductor layer (115) can be doped with a second dopant. For example, the second dopant can be an n-type dopant. The n-type dopant can be selected from Si, Ge, Sn, Se, Te, etc., but is not limited thereto.

[0124] The first conductive semiconductor layer (113) may be positioned on the substrate (112). The first conductive semiconductor layer (113) may be positioned at the lowest portion of the semiconductor structure (SS).

[0125] The first conductive semiconductor layer (113) may include an avalanche region. That is, avalanche amplification may occur in the first conductive semiconductor layer (113). Accordingly, a strong electric field is applied to the first conductive semiconductor layer (113), and as electrons move rapidly, collision ionization may occur, thereby generating electron-hole pairs.

[0126] The active layer (114) may be a light-absorbing layer. The active layer (114) may be doped with a second dopant. The active layer (114) may be formed of a single layer or multiple layers.

[0127] The active layer (114) may be formed to surround the second conductive semiconductor layer (115) of the well structure. In addition, the active layer (114) may have an exposed region with an exposed upper surface. Light may be provided to the light-receiving element (100) through the exposed region. That is, light provided through the exposed region may be absorbed in the active layer (114). In addition, at least a portion of the active layer (114) may correspond to a portion of the upper surface of the semiconductor structure (SS).

[0128] The second conductive semiconductor layer (115) may be positioned on the active layer (114). The second conductive semiconductor layer (115) may be positioned so as to be misaligned with the open area of ​​the active layer (114) in the stacking direction.

[0129] Additionally, the second conductive semiconductor layer (115) may be doped with a second dopant. The doping concentration of the second conductive semiconductor layer (115) may be greater than the doping concentration of the active layer (114).

[0130] Accordingly, the second conductive semiconductor layer (115) has a high doping concentration, thereby achieving low resistance and facilitating electron movement. Accordingly, the second conductive semiconductor layer (115) can function as an electron injection layer. In addition, the second conductive semiconductor layer (115) can induce a strong electric field, thereby enhancing the avalanche amplification of the light-receiving element.

[0131] The second electrode layer (116) may be positioned on the second conductive semiconductor layer (115). In addition, the second electrode layer (116) may be positioned on the semiconductor structure (SS). In addition, the second electrode layer (116) may be positioned on the second substrate (112).

[0132] The second electrode layer (116) may be positioned on the entire upper surface of the light-receiving element (100). In addition, the second electrode layer (116) may not overlap with the open area of ​​the active layer (114). The second electrode layer (116) may include a first opening area and a second opening area. The first opening area may correspond to the open area of ​​the active layer. The first opening area may overlap with the open area of ​​the active layer (114) in the stacking direction (X-axis direction).

[0133] The second electrode layer (116) may be composed of a plurality of electrode layers spaced apart from each other. A detailed description thereof will be provided later.

[0134] In addition, the second electrode layer (116) may be made of a conductive metal material. For example, the first electrode layer (111) may 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 an alloy thereof.

[0135] Furthermore, the second electrode layer (116) may be made of a transparent conductive material. For example, the second electrode layer (116) may be made of a transparent conductive oxide such as ITO, IZO, ZnO, or graphene.

[0136] And the second electrode layer (116) can be connected to an external circuit. Accordingly, current can flow. For example, at least one of the plurality of spaced second electrode layers (116) can be electrically connected to an external circuit. And the second electrode layer (116) can be in contact with the second conductive semiconductor layer (115) and supply electrons. The electrons can move into the light-receiving element through the second electrode layer (116).

[0137] The first diffusion layer (117) may be positioned between the active layer (114) and the first conductive semiconductor layer (113). Accordingly, the first diffusion layer (117) may be positioned below the active layer (114) and the second conductive semiconductor layer (115). In addition, the first diffusion layer (117) may be positioned above the first electrode layer (111), the second diffusion layer (118), or the substrate (112).

[0138] 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) allows electrons to diffuse widely without avalanche amplification occurring only at a specific location. The first diffusion layer (117) can improve current flow through charges, and the second diffusion layer (118) can improve current flow through electrons. Accordingly, a light-receiving element with improved electrical characteristics, such as charge diffusion and charge uniformity, can be provided.

[0139] In this way, through the first diffusion layer (117) and the second diffusion layer (118) having low resistance and high permeability, electron-hole pairs generated in the first conductive semiconductor layer (113) overlapping the open area (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 at the bottom and top of the light-receiving element (100).

[0140] The insulating layer (119) may be positioned on the semiconductor structure (SS) or the substrate (112). The insulating layer (119) may be formed on the second electrode layer (116). Furthermore, the insulating layer (119) may be positioned on the outside or top of the light-receiving element (100).

[0141] The insulating layer (119) may be made of an insulating material. For example, the insulating layer (119) may be formed of an insulating material, for example, SiO2, SiO x , SiO x N y ,Si3N4, Al2O3, or TiO 2　 may include at least one of

[0142] By this configuration, the inner layer of the light receiving element (100) can be protected from external substances, etc. Furthermore, the reliability of the light receiving element can be improved.

[0143] In addition, the light receiving element (100) can have the structure described above by forming a second diffusion layer (118) at the bottom of the substrate (112) and etching a portion of the substrate (112) to form a semiconductor structure (SS) and a first diffusion layer (117). Furthermore, the light receiving element (100) can be manufactured by forming a first electrode layer (111), a second electrode layer (116), and an insulating layer (119).

[0144] FIG. 5 is a plan view of a light receiving element according to the first embodiment, FIG. 6 is a cross-sectional view taken along line AA' in FIG. 5, FIG. 7 is a cross-sectional view taken along line BB' in FIG. 5, and FIG. 8 is a cross-sectional view taken along line CC' in FIG. 5.

[0145] Referring to FIGS. 5 to 8, in the 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 conductive semiconductor layer (113), the active layer (114), and the second conductive semiconductor layer (115) in the stacking direction (X-axis direction). Accordingly, the first diffusion layer (117) may more effectively improve the movement of electrons in the current flow.

[0146] In addition, the active layer (114) may include an open area (OA) with an exposed upper surface as described above. The open area (OA) may be misaligned with the second electrode layer (116) in the lamination direction (X-axis direction). That is, the open area (OA) may not overlap with the second electrode layer (116) in the lamination direction (X-axis direction). Accordingly, light reception by the light-receiving element through the open area (OA) may be implemented more effectively.

[0147] Additionally, the first diffusion layer (117) may include a first region (AR1) that overlaps the open region (OA) in the stacking direction (X-axis direction) and a second region (AR2) that does not overlap the open region (OA) in the stacking direction or overlaps the second conductive semiconductor layer (115) in the stacking direction (X-axis direction). The first region (AR1) and the second region (AR2) may be misaligned with each other.

[0148] Additionally, the second electrode layer (116) may be spaced apart from each other in multiple pieces as described above. 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 (116b) may be physically separated.

[0149] In addition, as described above, the second electrode layer (116) may include a first opening area (OP1) and a second opening area (OP2). The first opening area (OP1) may correspond to an open area of ​​the active layer. The first opening area (OP1) may overlap with the open area (OA) of the active layer (114) in the stacking direction (X-axis direction).

[0150] The second opening region (OP2) may be located outside the contact surface where the second electrode layer (116) and the second conductive semiconductor layer (115) come into contact. Accordingly, the second opening region (OP2) may overlap with the substrate (112) or the active layer (114) in the stacking direction. In addition, the first sub-electrode layer (116a) and the second sub-electrode (116b) may be separated from each other by the second opening region (OP2). The first sub-electrode layer (116a) and the second sub-electrode (116b) may overlap with the active layer (114), the first diffusion layer (117), the first conductive semiconductor layer (113), the substrate (112), and the second diffusion layer (118) in the stacking direction (X-axis direction). By this configuration, current flow can be smoothly achieved by electron movement through the second electrode layer (116).

[0151] Additionally, the first opening area (OP1) may be located inside the second opening area (OP2). For example, the first opening area (OP1) may be located inside the second opening area (OP2), which is a closed loop on a plane.

[0152] Additionally, the thickness (T1) of the first diffusion layer (117) may be smaller than the thickness (T2) of the second diffusion layer (118). Accordingly, the movement of holes with relatively low mobility is greatly improved, so that power efficiency improvement can be more effectively implemented.

[0153] FIG. 9 is a plan view of a light-receiving element according to the second embodiment, FIG. 10 is a cross-sectional view taken along line DD' in FIG. 9, FIG. 11 is an enlarged view of part K1 in FIG. 10, and FIG. 12 is an enlarged view of part K2 in FIG. 10.

[0154] Referring to FIGS. 9 to 12, a light-receiving element (100A) according to the second 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). In addition, the semiconductor structure (SS) may include a first conductive semiconductor layer (113), an active layer (114), and a second conductive semiconductor layer (115) disposed on the substrate (112). In addition, the semiconductor structure (SS) may have a well structure.

[0155] Except for the contents described below, the description of the first electrode layer (111), the substrate (112), the semiconductor structure (SS), the second electrode layer (116), the first diffusion layer (117), the second diffusion layer (118), and the insulating layer (119) can be equally applied to the contents described in other embodiments.

[0156] In the present embodiment, the first diffusion layer (117) may include a first region (AR1) that overlaps the open region (OA) in the stacking direction (X-axis direction) and a second region (AR2) that does not overlap the open region (OA) in the stacking direction or overlaps the second conductive semiconductor layer (115) in the stacking direction (X-axis direction). The first region (AR1) and the second region (AR2) may be misaligned with each other.

[0157] And the first diffusion layer (117) may have a different thickness (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) may be different from each other. The thickness (T1b) of the first region (AR1) may be smaller than the thickness (T1a) of the second region (AR2). That is, the first diffusion layer (117) may have a larger thickness in a region overlapping the second conductive semiconductor layer (115) in the stacking direction (X-axis direction) than in other regions. By this configuration, the current flow, which is relatively lowered at the edge, can be greatly improved. Therefore, a light-receiving element with improved electrical characteristics (e.g., photosensitivity) such as power efficiency can be provided.

[0158] Additionally, the second diffusion layer (118) may include a third region (AR3) that overlaps 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 misaligned with the semiconductor structure (SS) in the stacking direction (X-axis direction).

[0159] And the second diffusion layer (118) may have a different thickness (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) may be different from the thickness (T2a) of the fourth region (AR4). For example, the thickness (T2b) of the third region (AR3) may be smaller than the thickness (T2a) of the fourth region (AR4). That is, the second diffusion layer (118) may have a greater thickness in the region overlapping the semiconductor structure (SS) in the stacking direction (X-axis direction) than in other regions. By this configuration, the current flow, which is relatively lowered at the edge, can be greatly improved. Therefore, a light-receiving element with improved electrical characteristics (e.g., photosensitivity) such as power efficiency can be provided.

[0160] Additionally, the third region (AR3) may overlap with the first region (AR1) and the second region (AR2) in the stacking direction (X-axis direction). Conversely, the fourth region (AR4) may be positioned offset from the first region (AR1) and the second region (AR2) in the stacking direction (X-axis direction).

[0161] Furthermore, the thickness (T2b) of the third region (AR3) may be greater or less than the thickness (T1a) of the second region (AR2).

[0162] Fig. 13 is a cross-sectional view of a light-receiving element according to the third embodiment, and Fig. 14 is an enlarged view of part K3 in Fig. 13.

[0163] A 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). In addition, the semiconductor structure (SS) may include a first conductive semiconductor layer (113), an active layer (114), and a second conductive semiconductor layer (115) disposed on the substrate (112). In addition, the semiconductor structure (SS) may have a well structure.

[0164] Except for the contents described below, the description of the first electrode layer (111), the substrate (112), the semiconductor structure (SS), the second electrode layer (116), the first diffusion layer (117), the second diffusion layer (118), and the insulating layer (119) can be equally applied to the contents described in other embodiments.

[0165] In this example, the first diffusion layer (117) may include a first region (AR1) that overlaps the open region (OA) in the stacking direction (X-axis direction) and a second region (AR2) that does not overlap the open region (OA) in the stacking direction or overlaps the second conductive semiconductor layer (115) in the stacking direction (X-axis direction). The first region (AR1) and the second region (AR2) may be misaligned with each other.

[0166] And the first diffusion layer (117) may have a different thickness (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) may be different from each other. The thickness (T1b) of the first region (AR1) may be smaller than the thickness (T1a) of the second region (AR2). That is, the first diffusion layer (117) may have a larger thickness in a region overlapping the second conductive semiconductor layer (115) in the stacking direction (X-axis direction) than in other regions. By this configuration, the current flow, which is relatively lowered at the edge, can be greatly improved. Therefore, a light-receiving element with improved electrical characteristics (e.g., photosensitivity) such as power efficiency can be provided.

[0167] In contrast, the thickness of the second diffusion layer (118) can be maintained constant. Accordingly, the thickness of the second diffusion layer (118) can be greater than the thickness of the first diffusion layer (117) in the first region (AR1) or the second region (AR2).

[0168] By this configuration, the second diffusion layer (118) and the first electrode layer (111) located under the substrate (112) have flat surfaces, thereby suppressing the occurrence of defects and minimizing the occurrence of stress. In other words, a light-receiving element with improved reliability can be provided.

[0169] As a variation, the first diffusion layer (117) in the light-receiving element may have a constant thickness. That is, the first region (AR1) and the second region (AR2) in the first diffusion layer (117) may have the same thickness. In contrast, the second diffusion layer (118) may have different regions depending on the location. That is, the second diffusion layer (118) may have a greater thickness in a region overlapping the semiconductor structure (SS) in the stacking direction (X-axis direction) than in other regions. By this configuration, a light-receiving element with improved electrical characteristics (e.g., photosensitivity) may be provided.

[0170] Fig. 15 is a cross-sectional view of a light receiving element according to a fourth embodiment of the present invention.

[0171] Referring to FIG. 15, a light-receiving element (100C) according to a fourth embodiment of the present invention may include a first electrode layer (111), a substrate (112), a semiconductor structure (SS), a second electrode layer (116), and an insulating layer (119). The semiconductor structure (SS) may include a first conductive semiconductor layer (113), an active layer (114), and a second conductive semiconductor layer (115) disposed on the substrate (112). The semiconductor structure (SS) may have a well structure. For example, the second conductive semiconductor layer (115) may have a well structure, and the active layer (114) may have a well structure covering the second conductive semiconductor layer (115) of the well structure. The first conductive semiconductor layer (113) may cover or be positioned below the active layer (114). The semiconductor structure (SS) may have a well structure with respect to the upper surface of the substrate (112).

[0172] Except for the first electrode layer (111), the second electrode layer (116), and the insulating layer (119), the remaining layers may be formed of semiconductor materials. For example, the semiconductor material may include at least one of a group IV semiconductor such as silicon (Si) or germanium (Ge), a group III-V compound semiconductor such as GaAs or GaP, a group II-VI compound semiconductor such as CdS or ZnTe, a group IV-VI compound semiconductor such as PbS, a group IV-IV compound semiconductor such as SiC, an oxide semiconductor such as IGZO, a quantum dot, an organic semiconductor, and a semiconductor having a two-dimensional crystal structure with a band gap. A representative example of a semiconductor having a two-dimensional crystal structure is a transition metal dichalcogenide (TMD), which is a compound of a transition metal and a chalcogen element. 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, SnTe2. In addition, in addition to transition metal dichalcogenides, there are semiconductors with a two-dimensional crystal structure. For example, semiconductors with a two-dimensional crystal structure may further include TiOx, NbOx, MnOx, VaOx, MnO3, TaO3, WO3, MoCl2, CrCl3, RuCl3, BiI3, PbCl4, GeS, GaS, GeSe, GaSe, PtSe2, In2Se3, GaTe, InS, InSe, InTe, etc.

[0173] And, in the stacking direction (X-axis direction), a first electrode layer (111), a substrate (112), a semiconductor structure (SS), and a second electrode layer (116) can be sequentially positioned. The substrate (112) can be positioned on the first electrode layer (111). The semiconductor structure (SS) can be positioned on the substrate (112). And, the second electrode layer (116) can be positioned on the semiconductor structure (SS). In particular, the second electrode layer (116) can be positioned on the second conductive semiconductor layer (115).

[0174] The first electrode layer (111) may be positioned on one side of the light-receiving element (100C). For example, the first electrode layer (111) may be positioned below the light-receiving element (100C). Through the first electrode layer (111), the light-receiving element (100C) may be electrically connected to an external circuit (e.g., a control unit). For example, holes may move to the external circuit through the first electrode layer (111).

[0175] And the first electrode layer (111) may be made of a conductive metal material. For example, the first electrode layer (111) may 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), etc., or an alloy thereof.

[0176] Furthermore, the first electrode layer (111) may be made of a transparent conductive material. For example, the first electrode layer (111) may be made of a transparent conductive oxide such as ITO, IZO, ZnO, or graphene.

[0177] The substrate (112) may be positioned on the first electrode layer (111). 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, it may include a Group 5 element (e.g., phosphorus (P), arsenic (As), antimony (Sb), etc.), a Group 6 element, or a Group 7 element as an impurity. For example, in the embodiment, the substrate (112) may be p-type. Accordingly, the substrate (112) may include a Group 3 element (e.g., boron (B), aluminum (Al), gallium (Ga), indium (In), etc.) or a Group 2 element as an impurity. Additionally, the substrate (112) may be a semiconductor substrate and may be an epi layer formed by an epitaxial growth process.

[0178] The substrate (112) can be electrically connected to the first conductive semiconductor layer (113) of the semiconductor structure (SS) and can mechanically perform a supporting role. Furthermore, the substrate (112) can stably form an electric field distribution. Furthermore, depending on the voltage application, a portion of the depletion region in the substrate (112) can expand.

[0179] The semiconductor structure (SS) may be positioned in a well structure in the substrate (112). For example, the semiconductor structure (SS) may be accommodated within the substrate (112).

[0180] And as described above, the semiconductor structure (SS) may include a first conductive semiconductor layer (113), an active layer (114), and a second conductive semiconductor layer (115) positioned in the stacking direction (X-axis direction).

[0181] And each of the first conductive semiconductor layer (113), the active layer (114), and the second conductive semiconductor layer (115) may be doped with a first dopant or a second dopant. The first conductive semiconductor layer (113), the active layer (114), and the second conductive semiconductor layer (115) may be implemented with a compound semiconductor of group IIIⅤ, group IIⅥ, etc. And the first conductive semiconductor layer (113) may be doped with the 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.

[0182] And the active layer (114) and the second conductive semiconductor layer (115) can be doped with a second dopant. For example, the second dopant can be an n-type dopant. The n-type dopant can be selected from Si, Ge, Sn, Se, Te, etc., but is not limited thereto.

[0183] The first conductive semiconductor layer (113) may be positioned on the substrate (112). The first conductive semiconductor layer (113) may be positioned at the lowest portion of the semiconductor structure (SS).

[0184] The first conductive semiconductor layer (113) may include an avalanche region. That is, avalanche amplification may occur in the first conductive semiconductor layer (113). Accordingly, a strong electric field is applied to the first conductive semiconductor layer (113), and as electrons move rapidly, collision ionization may occur, thereby generating electron-hole pairs.

[0185] The active layer (114) may be a light-absorbing layer. The active layer (114) may be doped with a second dopant. The active layer (114) may be formed of a single layer or multiple layers.

[0186] The active layer (114) may be formed to surround the second conductive semiconductor layer (115) of the well structure. In addition, the active layer (114) may have an exposed region with an exposed upper surface. Light may be provided to the light-receiving element (100C) through the exposed region. That is, light provided through the exposed region may be absorbed in the active layer (114). In addition, at least a portion of the active layer (114) may correspond to a portion of the upper surface of the semiconductor structure (SS).

[0187] The second conductive semiconductor layer (115) may be positioned on the active layer (114). The second conductive semiconductor layer (115) may be positioned so as to be misaligned with the open area of ​​the active layer (114) in the stacking direction.

[0188] Additionally, the second conductive semiconductor layer (115) may be doped with a second dopant. The doping concentration of the second conductive semiconductor layer (115) may be greater than the doping concentration of the active layer (114).

[0189] Accordingly, the second conductive semiconductor layer (115) has a high doping concentration, thereby achieving low resistance and facilitating electron movement. Accordingly, the second conductive semiconductor layer (115) can function as an electron injection layer. In addition, the second conductive semiconductor layer (115) can induce a strong electric field, thereby enhancing the avalanche amplification of the light-receiving element.

[0190] The second electrode layer (116) may be positioned on the second conductive semiconductor layer (115). In addition, the second electrode layer (116) may be positioned on the semiconductor structure (SS). In addition, the second electrode layer (116) may be positioned on the substrate (112).

[0191] The second electrode layer (116) may be positioned on the entire upper surface of the light-receiving element (100C). In addition, the second electrode layer (116) may not overlap with the open area of ​​the active layer (114). The second electrode layer (116) may include a first opening area and a second opening area. The first opening area may correspond to the open area of ​​the active layer. The first opening area may overlap with the open area of ​​the active layer (114) in the stacking direction (X-axis direction).

[0192] The second electrode layer (116) may be composed of a plurality of electrode layers spaced apart from each other. A detailed description thereof will be provided later.

[0193] In addition, the second electrode layer (116) may be made of a conductive metal material. For example, the first electrode layer (111) may 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 an alloy thereof.

[0194] Furthermore, the second electrode layer (116) may be made of a transparent conductive material. For example, the second electrode layer (116) may be made of a transparent conductive oxide such as ITO, IZO, ZnO, or graphene.

[0195] And the second electrode layer (116) can be connected to an external circuit. Accordingly, current can flow. For example, at least one of the plurality of spaced second electrode layers (116) can be electrically connected to an external circuit. And the second electrode layer (116) can be in contact with the second conductive semiconductor layer (115) and supply electrons. The electrons can move into the light-receiving element through the second electrode layer (116).

[0196] The insulating layer (119) may be positioned on the semiconductor structure (SS) or the substrate (112). The insulating layer (119) may be formed on the second electrode layer (116). Furthermore, the insulating layer (119) may be positioned on the outside or top of the light-receiving element (100C).

[0197] The insulating layer (119) may be made of an insulating material. For example, the insulating layer (119) may be formed of an insulating material, for example, SiO2, SiO x , SiO x N y ,Si3N4, Al2O3, or TiO 2　 may include at least one of

[0198] By this configuration, the inner layer of the light receiving element (100C) can be protected from external substances, etc. Furthermore, the reliability of the light receiving element can be improved.

[0199] FIG. 16 is a plan view of a light-receiving element according to the fourth embodiment, FIG. 17 is a cross-sectional view taken along line EE' in FIG. 16, FIG. 18 is an enlarged view of part K4 in FIG. 17, FIG. 19 is an enlarged view of part K5 in FIG. 17, FIG. 20 is an enlarged view of part K in FIG. 16, FIG. 21 is an enlarged view of part K6 in FIG. 20, FIG. 22 is an enlarged view of part K7 in FIG. 20, FIG. 23 is a cross-sectional view taken along line FF' in FIG. 16, FIG. 24 is a cross-sectional view taken along line GG' in FIG. 16, and FIG. 25 is a drawing explaining a manufacturing method of a light-receiving element according to another embodiment.

[0200] Referring to FIGS. 16 to 24, in the light-receiving element (100C) according to the embodiment, the second electrode layer (116) may be in contact with the second conductive semiconductor layer (115). And the second electrode layer (116) may include a contact area (CA) and a non-contact area (NCA). The contact area (CA) is an area in the second electrode layer (116) where the second electrode layer (116) and the second conductive semiconductor layer (115) are in contact. And the non-contact area (NCA) may be an area in the second electrode layer (116) where the second electrode layer (116) and the second conductive semiconductor layer (115) are not in contact.

[0201] At this time, the lower surface of the contact area (CA) in the second electrode layer (116) may be positioned lower than the lower surface of the non-contact area (NCA). In other words, the lower surface of the contact area (CA) in the second electrode layer (116) may be positioned closer to the lower surface of the light-receiving element than the lower surface of the non-contact area (NCA). For example, the distance between the lower surface of the contact area (CA) in the second electrode layer (116) and the first conductive semiconductor layer (113) may be smaller than the distance between the lower surface of the non-contact area (NCA) in the second electrode layer (116) and the first conductive semiconductor layer (113).

[0202] Furthermore, the upper surface (US) of the second conductive semiconductor layer (115) may include a first inclined surface (IS1) and a lower surface (BS1). The first inclined surface (IS1) of the upper surface (US) of the second conductive semiconductor layer (115) may be arranged along the edge of the upper surface (US) of the second conductive semiconductor layer (115). In addition, the first inclined surface (IS1) of the upper surface (US) of the second conductive semiconductor layer (115) may correspond to the edge of the contact area (CA). In addition, the lower surface (BS1) of the upper surface (US) of the second conductive semiconductor layer (115) may be located on the inner side of the first inclined surface (IS1). In addition, the first inclined surface (IS1) of the upper surface (US1) of the second conductive semiconductor layer (115) may be located above the lower surface (BS1).

[0203] By this configuration, a recess or trench can be formed in the area where the second conductive semiconductor layer (115) and the second electrode layer (116) come into contact, toward the lower portion or the second conductive semiconductor layer. Accordingly, the residue of an insulating layer or other components other than the second conductive semiconductor layer can be easily prevented. In addition, the contact area between the second conductive semiconductor layer and the second electrode layer can be increased. Furthermore, dangling bonds can be easily prevented, Schottky junctions can be overcome, and ohmic contacts can be easily formed. In addition, the energy barrier can be reduced, so that current flow can be smoothly achieved. As a result, the contact resistance between the second electrode layer (116) and the second conductive semiconductor layer (115) can be reduced. Therefore, a passive device with improved power efficiency and photosensitivity can be provided.

[0204] Furthermore, the height of such recesses or trenches may be smaller than the minimum thickness of the second electrode layer (116). That is, the height of the first inclined surface (IS1) may be smaller than the minimum thickness of the second electrode layer (116). By this configuration, cracks in the laminated insulating layer or underlying components may be suppressed. Accordingly, a passive element with improved reliability may be provided.

[0205] Since the lower surface (BS1) of the upper surface (US) of the second conductive semiconductor layer (115) is in contact with the lower surface of the contact area (CA) of the second electrode layer (116), the lower surface (BS1) of the upper surface (US) of the second conductive semiconductor layer (115) may correspond to the lower surface of the contact area (CA) of the second electrode layer (116). In addition, the lower surface of the non-contact area (NCA) of the second electrode layer (116) may 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).

[0206] In addition, the active layer (114) may include an open area (OA) with an exposed upper surface as described above. The open area (OA) may be misaligned with the second electrode layer (116) in the lamination direction (X-axis direction). That is, the open area (OA) may not overlap with the second electrode layer (116) in the lamination direction (X-axis direction). Accordingly, light reception by the light-receiving element through the open area (OA) may be implemented more effectively.

[0207] And the surface (EA) exposed through the open area (OA) in the active layer (114) may be located above the bottom surface (BS1) of the second conductive semiconductor layer (115). And the open area (OA) may be positioned to be misaligned with the second electrode layer (116) in the stacking direction (X-axis direction).

[0208] Additionally, the second electrode layer (116) may be spaced apart from each other in multiple pieces as described above. 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 (116b) may be physically separated.

[0209] By this configuration, the electric field can be uniformly distributed without being concentrated in a specific area by the spaced first sub-electrode layer (116a) and second sub-electrode layer (116b). Accordingly, the performance (e.g., signal-to-noise ratio, SNR) of the light-receiving element can be improved by blocking unnecessary leakage current while stably maintaining the breakdown voltage.

[0210] In addition, as described above, the second electrode layer (116) may include a first opening area (OP1) and a second opening area (OP2). The first opening area (OP1) may correspond to the open area (OA) of the active layer (114). The first opening area (OP1) may overlap with the open area (OA) of the active layer (114) in the stacking direction (X-axis direction).

[0211] The second opening region (OP2) may be located outside the contact surface where the second electrode layer (116) and the second conductive semiconductor layer (115) come into contact. Accordingly, the second opening region (OP2) may overlap with the substrate (112) or the active layer (114) in the lamination direction. In addition, the first sub-electrode layer (116a) and the second sub-electrode (116b) may be separated from each other by the second opening region (OP2). That is, the second opening region (OP2) may be an opened region between the first sub-electrode layer (116a) and the second sub-electrode layer (116b).

[0212] Furthermore, the second opening area (OP2) may be positioned to surround the first sub-electrode layer (116a) and the open area (OA) in a planar manner. Accordingly, the second opening area (OP2) may be positioned so that the second sub-electrode (116b) is positioned outside the first sub-electrode layer (116a) and the open area (OA) with respect to the center of the open area (OA). For example, the second opening area (OP2) may be a closed loop in a planar manner.

[0213] A second opening area (OP2) may surround the first sub-electrode layer (116a) and the open area (OA). Accordingly, the second sub-electrode layer (116b) may be physically separated from the first sub-electrode layer (116a) by the second opening area (OP2).

[0214] In this way, 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 an N-junction. In addition, since the current is not concentrated only in the lower part of the contact area (CA), the reliability of the light-receiving element is improved, and its lifespan can be easily extended.

[0215] In addition, the first sub-electrode layer (116a) and the second sub-electrode (116b) may overlap with the active layer (114), the first conductive semiconductor layer (113), and the substrate (112) in the stacking direction (X-axis direction). By this configuration, current flow can be smoothly achieved through electron movement through the second electrode layer (116).

[0216] Additionally, the first opening area (OP1) may be located inside the second opening area (OP2). For example, the first opening area (OP1) may be located inside the second opening area (OP2), which is a closed loop on a plane.

[0217] Additionally, in the light-receiving element (100C) according to the fourth embodiment, the second conductive semiconductor layer (115) may include a first sub-layer (115a) and a second sub-layer (115b).

[0218] The first sub-layer (115a) and the second sub-layer (115b) can be sequentially stacked in the stacking direction (X-axis direction).

[0219] In an embodiment, the doping concentration of the first sub-layer (115a) may be different from the doping concentration of the second sub-layer (115b). The doping concentration of the first sub-layer (115a) may be lower than the doping concentration of the second sub-layer (115b). That is, the second conductive semiconductor layer (115) may have a high doping concentration in a region adjacent to the second electrode layer (116). For example, the first sub-layer (115a) and the second sub-layer (115b) may be doped with an n dopant. And the second sub-layer (115b) may have a doping concentration of 10 19 atoms / cm 3 The doping concentration can be as above.

[0220] By this configuration, the contact resistance between the second conductive semiconductor layer (115) and the second electrode layer (116) can be improved, and the current flow can be enhanced. As a result, a light-receiving element with improved power efficiency and photosensitivity can be provided. In other words, the detectable distance of the light-receiving element can be improved.

[0221] Additionally, the insulating layer (119) may be at least partially exposed by the second opening area (OP2). The exposed area of ​​the insulating layer (119) may be spaced apart from the open area (OA) and may be misaligned with the contact area (CA) in the lamination direction (X-axis direction). The exposed area of ​​the insulating layer (119) may not overlap with the open area (OA) and the contact area (CA) in the lamination direction.

[0222] And the open area (OA) and the contact area (CA) can be spaced apart from each other by a predetermined distance. Furthermore, the insulating layer (119) can be positioned between the open area (OA) and the contact area (CA). In addition, the insulating layer (119) can be positioned on the outside of the contact area (CA).

[0223] Accordingly, the insulating layer (119) can be in contact with the second conductive semiconductor layer (115), the active layer (114), the substrate (9112), etc.

[0224] And the insulating layer (119) may have a structure extending upward from the top of the recess or trench formed on the upper surface of the second conductive semiconductor layer (115), corresponding to the recess or trench formed on the upper surface of the second conductive semiconductor layer. Accordingly, at least a portion of the insulating layer (119) may be positioned 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 layer (116).

[0225] For example, the insulating layer (119) may be positioned lower than the upper surface in the region where the upper surface overlaps the overlapping area (CA) in the stacking direction (X-axis direction) with the non-overlapping area (NCA). In addition, the insulating layer (119) may be in contact with the second electrode layer (116) in the region where the overlapping area (CA) overlaps with the stacking direction (X-axis direction), but may be in contact with the active layer (114) in the region where the non-overlapping area (NCA) overlaps with the stacking direction (X-axis direction).

[0226] Referring to FIG. 25, a light-receiving element according to an embodiment may include a step of forming a substrate and a mask, a step of forming a pattern of the mask, a step of performing an implant on the substrate, and a step of forming a second electrode layer and an insulating layer.

[0227] As shown in Fig. 25(a), a substrate (112) and a mask (PR) can be formed. Although the same can be applied to the active layer (114) other than the substrate (112), the following description will be based on the substrate (112). A mask (PR) can be formed on the upper surface of the substrate (112). For example, the mask (PR) may include a dry film or the like.

[0228] Next, as shown in Fig. 25(b), a patterned mask (PR') can be formed by removing a portion of the mask through development or the like. Then, etching can be performed on the upper surface of the substrate (112) exposed by the mask (PR'). An inclined surface and a bottom surface can be formed on the upper surface of the second conductive semiconductor layer described above.

[0229] Next, as shown in Fig. 25(c), ion implantation can be performed on the substrate (112). This allows for controlling the characteristics of the semiconductor substrate or device. This allows for the formation of a semiconductor structure (or a second conductive semiconductor layer). This allows for the formation of a recess or trench on the upper surface of the second conductive semiconductor layer.

[0230] Next, as in Fig. 25(d), a second electrode layer (116) and an insulating layer (119) can be formed on the second conductive semiconductor layer (115). At least a portion of the insulating layer (119) can be located inside the second electrode layer (116). Accordingly, the upper and lower surfaces of the insulating layer (119) can be in contact with the second electrode layer (116) in some areas.

[0231] The features, structures, effects, etc. described in the embodiments above are included in at least one embodiment, and are not necessarily limited to just one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified in other embodiments by those skilled in the art to which the embodiments pertain. Therefore, the contents related to such combinations and modifications should be construed as being included within the scope of the embodiments.

[0232] Although the above description focuses on examples, these are merely examples and are not intended to limit the examples. Those skilled in the art will appreciate that various modifications and applications not exemplified above are possible without departing from the essential characteristics of the present examples. For example, each component specifically shown in the examples can be modified and implemented. In addition, differences related to such modifications and applications should be interpreted as being included within the scope of the embodiments set forth in the appended claims.

Claims

1. First electrode layer; A substrate disposed on the first electrode layer; A semiconductor structure comprising a first conductive semiconductor layer formed on the substrate; a second conductive semiconductor layer; and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer, the semiconductor structure having a well structure; A second electrode layer disposed on the semiconductor structure; and A light-receiving element comprising a first diffusion layer positioned between the first conductive semiconductor layer and the active layer.

2. In paragraph 1, A light-receiving element in which the first diffusion layer overlaps the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer in the stacking direction.

3. In paragraph 1, A light-receiving element including an open area with an exposed upper surface of the active layer.

4. In paragraph 3, The above open area is a light-receiving element that is misaligned with the second electrode layer in the lamination direction.

5. In paragraph 3, A light-receiving element comprising a first sub-electrode layer and a second sub-electrode layer spaced apart from each other, wherein the second electrode layer is a second electrode layer.

6. In paragraph 5, A light-receiving element in which the first diffusion layer overlaps the first sub-electrode layer and the second sub-electrode layer in the lamination direction.

7. In paragraph 5, A light-receiving element including a first region overlapping the open region in the stacking direction and a second region overlapping the second electrode layer; 8. In paragraph 7, A light-receiving element wherein the thickness of the first region is smaller than the thickness of the second region.

9. In paragraph 7, A light-receiving element further comprising a second diffusion layer disposed between the substrate and the first electrode layer.

10. In paragraph 9, A light-receiving element in which the second diffusion layer includes a third region overlapping the semiconductor structure in the stacking direction and a fourth region other than the third region.

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