A method for manufacturing a visible light detector

Abstract

The application discloses a preparation method of a visible light detector, which comprises the following steps: depositing a metal layer of a group III element on an InGaN substrate by electron beam evaporation coating; taking a first powder of a group VI element as a precursor; and making the metal layer react to form a group III-VI compound film, i.e., a compound layer, by chemical vapor deposition, so that a large-area group III-VI compound film is formed on the InGaN substrate, the light absorption capacity of the visible light detector in a visible light band is improved, and the performance of the visible light detector is improved; and the electrode layer is prepared on the compound layer and a first substrate layer to prepare an InGaN-based heterojunction visible light detector, the high carrier mobility of the group III-VI compound film and the heterojunction structure are utilized, the photo-generated carriers in the visible light detector are separated quickly, and the performance of the visible light detector is further improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a method for fabricating a visible light detector. Background Technology

[0002] The rapid development of new solid-state lighting technologies in recent years has driven the advancement of visible light communication technology. Visible light communication is a wireless optical communication technology based on white light-emitting diode (LED) technology. It can simultaneously achieve both lighting and high-speed data transmission, and features high signal density coverage, high security, resistance to electromagnetic interference, and a wide spectrum range, enabling high-speed, stable, and secure communication transmission. As an unrestricted blank spectrum region, visible light communication does not interfere with traditional radio waves in terms of signal strength.

[0003] Compared to silicon-based detectors, novel two-dimensional detectors offer advantages such as small size, portability, ease of integration, and high breakdown electric field, thus promoting the further development of visible light detectors. III-VI compounds, as novel two-dimensional van der Waals semiconductor materials, possess characteristics such as high carrier mobility, high thermal stability, good chemical stability, and adjustable bandgap with the number of layers, achieving an adjustable bandgap of 2-2.7 eV. Theoretically, visible light detection at wavelengths of 460-620 nm can be achieved based on III-VI compounds. However, conventional chemical vapor deposition techniques are difficult to use for large-area growth of III-VI compounds, and the growth process of III-VI compounds is complex and uncontrollable. Currently, there are no reports on wafer-level III-VI compound thin films, hindering improvements in the performance of visible light detectors. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for fabricating a visible light detector.

[0005] The technical solution adopted in the embodiments of the present invention is as follows:

[0006] A method for fabricating a visible light detector includes the following steps:

[0007] A first substrate layer is prepared, wherein the first substrate layer is an InGaN substrate;

[0008] A metal layer is deposited on one side of the first substrate by electron beam evaporation deposition, wherein the metal material selected for the metal layer is a group III element;

[0009] Using the first powder as a precursor, chemical vapor deposition is used to react the metal layer to generate a compound layer, wherein the compound layer is a III-VI compound film, and the material of the first powder corresponds to a group VI element.

[0010] Electrode layers are fabricated on the side of the compound layer away from the first substrate layer and on the side of the first substrate layer where the compound layer is fabricated, thereby completing the fabrication of the visible light detector.

[0011] As an optional implementation, the fabrication of the first substrate layer includes:

[0012] A silicon substrate was selected as the second substrate layer;

[0013] An InGaN buffer layer is prepared on one side of the second substrate layer;

[0014] An InGaN epitaxial layer is prepared on the side of the InGaN buffer layer away from the second substrate layer, thus completing the preparation of the first substrate layer.

[0015] As an optional implementation, the fabrication of an InGaN buffer layer on one side of the second substrate layer includes:

[0016] The InGaN buffer layer is prepared on one side of the second substrate layer using a growth temperature of 780-850℃.

[0017] As an optional implementation, the step of fabricating an InGaN epitaxial layer on the side of the InGaN buffer layer away from the second substrate layer includes:

[0018] The InGaN epitaxial layer is prepared on the side of the InGaN buffer layer away from the second substrate layer using a growth temperature of 800-850℃.

[0019] As an optional implementation, the InGaN buffer layer uses InGaN with an In content of 5-20%, and the InGaN epitaxial layer uses InGaN with an In content of 5-30%.

[0020] As an optional implementation, the deposition of a metal layer on one side of the first substrate using electron beam evaporation includes:

[0021] The metal layer is deposited on the side of the InGaN epitaxial layer away from the InGaN buffer layer using electron beam evaporation deposition.

[0022] As an optional implementation, the step of using a first powder as a precursor and employing chemical vapor deposition to react the metal layer to form a compound layer includes:

[0023] Using the first powder as a precursor, the metal layer is reacted to generate the compound layer in a tube furnace CVD using chemical vapor deposition.

[0024] As an optional implementation, the material of the first powder includes any one of sulfur, selenium and tellurium.

[0025] As an optional implementation, the thickness of the compound layer is 50-300 nm.

[0026] As an optional implementation, the electrode layer is a Ti electrode layer and an Au electrode layer, wherein the thickness of the Ti electrode layer is 30-100 nm and the thickness of the Au electrode layer is 60-200 nm.

[0027] The visible light detector fabrication method of this invention involves depositing a metal layer of group III elements on an InGaN substrate using electron beam evaporation deposition, and then using a first powder of group VI elements as a precursor, reacting the metal layer with chemical vapor deposition to generate a group III-VI compound thin film, i.e., a compound layer. This achieves the generation of a large area of ​​group III-VI compound thin film on the InGaN substrate, improving the light absorption capability of the visible light detector in the visible light band, thereby enhancing the performance of the visible light detector. Furthermore, by fabricating an electrode layer on the compound layer and the first substrate layer to prepare an InGaN-based heterojunction visible light detector, the high carrier mobility of the group III-VI compound thin film and the heterojunction structure enable rapid separation of photogenerated carriers in the visible light detector, further improving the performance of the visible light detector. Attached Figure Description

[0028] Figure 1 This is a flowchart illustrating the fabrication method of a visible light detector according to an embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of the visible light detector according to an embodiment of the present invention;

[0030] Figure 3 This is a scanning electron microscope (SEM) characterization image of the visible light detector according to an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the XPS test results of the compound layer of the visible light detector in an embodiment of the present invention. Detailed Implementation

[0032] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0033] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0034] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0035] Compared to silicon-based detectors, novel two-dimensional detectors offer advantages such as small size, portability, ease of integration, and high breakdown electric field, thus promoting the further development of visible light detectors. III-VI compounds, as novel two-dimensional van der Waals semiconductor materials, possess characteristics such as high carrier mobility, high thermal stability, good chemical stability, and adjustable bandgap with the number of layers, achieving an adjustable bandgap of 2-2.7 eV. Theoretically, visible light detection at wavelengths of 460-620 nm can be achieved based on III-VI compounds. However, conventional chemical vapor deposition techniques are difficult to use for large-area growth of III-VI compounds, and the growth process of III-VI compounds is complex and uncontrollable. Currently, there are no reports on wafer-level III-VI compound thin films, hindering improvements in the performance of visible light detectors. To address this, this invention proposes a method for fabricating a visible light detector. This method involves depositing a metal layer of group III elements on an InGaN substrate using electron beam evaporation. Then, using a first powder of group VI elements as a precursor, chemical vapor deposition is employed to react the metal layer and generate a group III-VI compound thin film, i.e., a compound layer. This achieves the formation of a large-area group III-VI compound thin film on the InGaN substrate, enhancing the light absorption capability of the visible light detector in the visible light band, thereby improving the performance of the visible light detector. Furthermore, by fabricating an electrode layer on the compound layer and the first substrate layer to prepare an InGaN-based heterojunction visible light detector, the high carrier mobility of the group III-VI compound thin film and the heterojunction structure enable rapid separation of photogenerated carriers in the visible light detector, further improving its performance.

[0036] like Figure 1As shown in the figure, an embodiment of the present invention proposes a method for fabricating a visible light detector, which includes the following steps S101-S104:

[0037] S101, Prepare the first substrate layer;

[0038] The first substrate layer is an InGaN substrate.

[0039] In an embodiment of the present invention, the first substrate layer includes a second substrate layer, an InGaN buffer layer, and an InGaN epitaxial layer.

[0040] Step S101 specifically includes:

[0041] 1) Select a silicon substrate as the second substrate layer;

[0042] Optionally, in one embodiment of the present invention, the thickness of the second substrate layer is 300-400 μm and the orientation is (111).

[0043] 2) An InGaN buffer layer is prepared on one side of the second substrate layer;

[0044] Specifically, in an embodiment of the present invention, an InGaN buffer layer is prepared on one side of the second substrate at a growth temperature of 780-850°C. Optionally, the growth thickness of the InGaN buffer layer is 1-2 μm.

[0045] 3) Prepare an InGaN epitaxial layer on the side of the InGaN buffer layer away from the second substrate layer to complete the preparation of the first substrate layer.

[0046] Specifically, in an embodiment of the present invention, an InGaN epitaxial layer is prepared on the side of the InGaN buffer layer away from the second substrate layer at a growth temperature of 800-850°C. Optionally, the growth thickness of the InGaN epitaxial layer is 1-3 μm.

[0047] In embodiments of the present invention, the InGaN buffer layer uses InGaN with an In content of 5-20%, and the InGaN epitaxial layer uses InGaN with an In content of 5-30%.

[0048] S102. A metal layer is deposited on one side of the first substrate by electron beam evaporation deposition.

[0049] The metal material used for the metal layer is a group III element.

[0050] Specifically, in an embodiment of the present invention, an electron beam evaporation deposition method is used to deposit a metal layer on the side of the InGaN epitaxial layer away from the InGaN buffer layer.

[0051] Optionally, in one embodiment of the present invention, the metal layer is selected as In metal. A spin coater is used for spin coating, followed by photolithography, development, and electron beam evaporation to deposit an In metal layer on one side of the first substrate. After removing the photoresist, a rapid annealing furnace is used for rapid annealing to complete the preparation of the In metal layer. In the rapid annealing process, the annealing temperature is 100-200℃, the annealing time is 10-30 min, the gas atmosphere is argon, and the gas pressure is one standard atmosphere.

[0052] Optionally, in one embodiment of the present invention, the thickness of the metal layer is 50-300 nm.

[0053] The metal layer in this embodiment of the invention is disposed of (111) after annealing.

[0054] S103. Using the first powder as a precursor, chemical vapor deposition is used to react the metal layer to generate a compound layer.

[0055] The compound layer is a III-VI group compound film, and the material of the first powder corresponds to a group VI element.

[0056] Optionally, in an embodiment of the present invention, the first powder is a chalcogenide powder, and the corresponding element includes any one of sulfur, selenium and tellurium.

[0057] Specifically, after generating the compound layer using chemical vapor deposition, the compound layer is annealed. Optionally, in some embodiments, the annealing temperature is 150-200°C, the annealing time is 10-60 min, the gas atmosphere is an inert gas, such as argon and nitrogen, and the gas pressure is one standard atmosphere.

[0058] In the embodiments of the present invention, the thickness of the prepared compound layer is 50-300 nm.

[0059] S104. An electrode layer is prepared on the side of the compound layer away from the first substrate layer and on the side of the first substrate layer where the compound layer is prepared, thereby completing the preparation of the visible light detector.

[0060] In an embodiment of the present invention, the electrode layer is a Ti electrode layer and an Au electrode layer, wherein the thickness of the Ti electrode layer is 30-100 nm and the thickness of the Au electrode layer is 60-200 nm.

[0061] Specifically, electrode layers are fabricated on the side of the compound layer away from the first substrate layer and on the side of the first substrate layer where the compound layer is formed, using processes such as spin coating, photolithography, development, and electron beam evaporation deposition. The unexposed photoresist in the electrode layers is then stripped and cleaned to obtain the InGaN-based visible light detector of this embodiment of the invention. Figure 2 As shown.

[0062] Figure 3 The image shows the SEM characterization of a visible light detector prepared by a method for preparing a visible light detector through steps S101-S104.

[0063] Figure 4 This is an XPS test image of the compound layer (In2S3) of the visible light detector according to an embodiment of the present invention. Figure 4 Based on the bonding energy intensity of the In orbitals and S orbitals, a method for fabricating a visible light detector according to an embodiment of the present invention successfully generated a large-area III-VI compound thin film on the first substrate layer.

[0064] In summary, the visible light detector fabrication method of this invention involves depositing a metal layer of group III elements on an InGaN substrate using electron beam evaporation deposition, and then using a first powder of group VI elements as a precursor, reacting the metal layer with chemical vapor deposition to generate a group III-VI compound thin film, i.e., a compound layer. This achieves the formation of a large-area group III-VI compound thin film on the InGaN substrate, improving the light absorption capability of the visible light detector in the visible light band, thereby enhancing the performance of the visible light detector. Furthermore, by fabricating an electrode layer on the compound layer and the first substrate layer to fabricate an InGaN-based heterojunction visible light detector, the high carrier mobility of the group III-VI compound thin film and the heterojunction structure enable rapid separation of photogenerated carriers in the visible light detector, further improving the performance of the visible light detector.

[0065] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A method for fabricating a visible light detector, characterized in that, Includes the following steps: A first substrate layer is prepared, wherein the first substrate layer is an InGaN substrate; A metal layer is deposited on one side of the first substrate by electron beam evaporation deposition, wherein the metal material selected for the metal layer is a group III element; Using the first powder as a precursor, chemical vapor deposition is used to react the metal layer to generate a compound layer, wherein the compound layer is a III-VI compound film, and the material of the first powder corresponds to a group VI element. Electrode layers are fabricated on the side of the compound layer away from the first substrate layer and on the side of the first substrate layer where the compound layer is fabricated, thereby completing the fabrication of the visible light detector; The preparation of the first substrate layer includes: A silicon substrate was selected as the second substrate layer; An InGaN buffer layer is fabricated on one side of the second substrate layer, including: The InGaN buffer layer is prepared on one side of the second substrate layer using a growth temperature of 780-850℃; An InGaN epitaxial layer is fabricated on the side of the InGaN buffer layer away from the second substrate layer to complete the fabrication of the first substrate layer; The second substrate layer has a thickness of 300-400 μm and an orientation of (111). The InGaN buffer layer uses InGaN with an In content of 5-20%, and the InGaN epitaxial layer uses InGaN with an In content of 5-30%. The method of depositing a metal layer on one side of the first substrate using electron beam evaporation includes: The metal layer is deposited on the side of the InGaN epitaxial layer away from the InGaN buffer layer using electron beam evaporation deposition. After removing the photoresist, a rapid annealing furnace is used for rapid annealing. In the rapid annealing process, the annealing temperature is 100-200℃, the annealing time is 10-30min, the gas atmosphere is argon, and the gas pressure is one standard atmosphere. The process of using a first powder as a precursor and employing chemical vapor deposition to react the metal layer to form a compound layer includes: Using the first powder as a precursor, the metal layer is reacted to generate the compound layer in a tube furnace CVD using chemical vapor deposition. After generating the compound layer using chemical vapor deposition, the compound layer is annealed at a temperature of 150-200℃ for 10-60 minutes in an inert atmosphere, including argon and nitrogen, at a pressure of one standard atmosphere.

2. The method for fabricating a visible light detector according to claim 1, characterized in that, The step of fabricating an InGaN epitaxial layer on the side of the InGaN buffer layer away from the second substrate layer includes: The InGaN epitaxial layer is prepared on the side of the InGaN buffer layer away from the second substrate layer using a growth temperature of 800-850℃.

3. The method for fabricating a visible light detector according to claim 1, characterized in that, The element corresponding to the material of the first powder includes any one of sulfur, selenium and tellurium.

4. The method for fabricating a visible light detector according to claim 1, characterized in that, The thickness of the compound layer is 50-300 nm.

5. The method for fabricating a visible light detector according to claim 1, characterized in that, The electrode layer is a Ti electrode layer and an Au electrode layer, the thickness of the Ti electrode layer is 30-100nm, and the thickness of the Au electrode layer is 60-200nm.

Images