A method for preparing a tellurium thin film self-driven polarization photodetector based on an ALD process

Abstract

The application belongs to the field of polarized photoelectric detectors, and specifically discloses a method for preparing a tellurium thin film self-driven polarized photoelectric detector based on an ALD process, which comprises the following steps: depositing a tellurium thin film on an insulating substrate by using the ALD process; preparing a source electrode and a drain electrode at both ends of the tellurium thin film on the insulating substrate; depositing an Al2O3 thin film on the tellurium thin film close to the source electrode by using the ALD process; and performing an annealing process to obtain the tellurium thin film self-driven polarized photoelectric detector. Compared with the prior art, the preparation method used in the application is controllable, has a low thermal budget, and has higher process compatibility, which is conducive to industrialization and mass production. The tellurium thin film self-driven polarized photoelectric detector prepared by the application has excellent polarized photoelectric detection capability and does not require any external voltage. Therefore, the tellurium thin film self-driven polarized photoelectric detector prepared by the application has excellent self-driven polarization sensitivity and can be applied in the field of low-power-consumption polarized photoelectric detection, and has strong market prospects and development potential.

Description

Technical Field

[0001] The present invention relates to the field of polarization photodetectors, and in particular to a method for preparing a tellurium thin film self-driven polarization photodetector based on an ALD process. Background Art

[0002] In the field of modern optoelectronics, the detection of polarized light is crucial for a variety of applications, such as optical communications, remote sensing, military tracking, and biomedical imaging. Polarized light carries information about the direction of light wave vibration, which gives it unique advantages in signal processing and image analysis. Currently, traditional polarization photodetection devices can be divided into four types: time-sharing, amplitude-sharing, focal plane-sharing, and aperture-sharing. Although they are currently widely used, they still have problems that need to be solved, such as complex structure, high cost, cumbersome process, and high power consumption. They cannot meet the current development needs of low-power, integrated, high-performance optoelectronic devices.

[0003] To address this issue, researchers have begun exploring two-dimensional material systems to realize low-power polarization photodetectors in recent years. Black phosphorus is a typical semiconductor material with broken inversion symmetry. It has received extensive research and attention due to its tunable band gap, excellent optoelectronic properties, and high carrier mobility. However, the instability of black phosphorus in air has greatly hindered its further development. In recent years, tellurium, as a new semiconductor material, has been regarded as a potential channel layer material for polarization photodetectors due to its high absorption coefficient over a wide wavelength range, good environmental stability, and excellent polarization photoelectric properties.

[0004] Patent application number CN202110716606.5 discloses a polarization light detector based on two-dimensional layered semiconductor materials and its preparation method. The polarization light detector consists of an insulating substrate, a tellurium nanofilm prepared based on hydrothermal synthesis technology, and a metal electrode from bottom to top. The polarization light detector is prepared by hydrothermal synthesis of tellurium materials, dry transfer of polyvinyl alcohol (PVA) to construct a heterojunction, photolithography, evaporation and other technologies. The tellurium nanofilm self-driven polarization photodetector disclosed in this patent still has problems such as uncontrollable process and lack of industrial production potential.

[0005] Patent application number CN202211617224.8 discloses a polarized light detector and its fabrication method. The device comprises a silicon substrate, a first SiO2 film, a two-dimensional Te film, a MAXene film, and a back electrode. The first SiO2 film is deposited on the surface of the silicon substrate; a SiO2:Au film is deposited on the surface of the first SiO2 film, or an Au nanolayer and a second SiO2 film are sequentially deposited on the surface of the first SiO2 film; a two-dimensional Te film is deposited on the surface of the SiO2:Au film or the surface of the second SiO2 film; a MAXene film is deposited on the surface of the two-dimensional Te film and serves as the detector source and drain electrodes; and a back electrode is deposited on the back of the silicon substrate and serves as the gate electrode. Although a tellurium nanolayer is also disclosed, its structure is too complex to be suitable for large-scale production. Summary of the Invention

[0006] The purpose of the present invention is to solve the deficiencies in the prior art and provide a method for preparing a tellurium thin film self-driven polarization photodetector based on the ALD process.

[0007] To achieve the above object, the present invention is implemented according to the following technical solutions:

[0008] One of the objectives of the present invention is to provide a method for preparing a tellurium thin film self-driven polarization photodetector based on an ALD process, comprising the following steps:

[0009] S1, after cleaning and drying the insulating substrate, placing it in an atomic layer deposition chamber, and depositing a tellurium thin film on the insulating substrate;

[0010] S2, preparing a source electrode and a drain electrode at both ends of the tellurium thin film on the insulating substrate;

[0011] S3, setting an Al2O3 film deposition window on the tellurium film near the source electrode, placing the film in an atomic layer deposition chamber, and depositing an Al2O3 film on the tellurium film in the Al2O3 film deposition window, with one side wall of the Al2O3 film connected to a side wall of the source electrode;

[0012] S4. After depositing the Al2O3 film, an annealing process is performed in a nitrogen or argon atmosphere. The annealing temperature is 200-500°C and the annealing time is 10-60 minutes. The Al ions in the Al2O3 film are used to dope the tellurium film with n-type electrons to obtain a tellurium film self-driven polarization photodetector.

[0013] Preferably, the insulating substrate is one of a Si / SiO2 substrate, a sapphire substrate, and a quartz substrate.

[0014] Furthermore, in step S1, the insulating substrate is cleaned with one or more of acetone, isopropyl alcohol, ethanol, and deionized water, and blown dry with Ar gas or nitrogen gas.

[0015] Furthermore, in step S1, the tellurium precursor used in the process of depositing the tellurium thin film is one or more of Te(SiMe3)2, Te(OEt)4, Te(OMe)4, and MeOH, the reaction chamber heating temperature of the atomic layer deposition chamber is 10-100°C, the pressure is 10-100mTorr, the flow rate of the tellurium precursor is 20-300sccm, and the single introduction time is 0.1-5s.

[0016] Preferably, the tellurium thin film deposition thickness is 10-50 nm.

[0017] Furthermore, a source electrode and a drain electrode are prepared at both ends of the tellurium thin film on the insulating substrate by using a photolithography process and a metal plating process.

[0018] Furthermore, the thickness of the Al2O3 film is smaller than the thickness of the source electrode and the drain electrode.

[0019] Preferably, the source electrode and the drain electrode are made of one or more of Au, Ti, Cr, and Pt, and the metal thickness of the source electrode and the drain electrode is 50-200 nm.

[0020] Preferably, the Al2O3 thin film deposition thickness is 10-100 nm.

[0021] A second object of the present invention is to provide a tellurium thin film self-driven polarization photodetector prepared by the above method.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The preparation method used in the present invention has controllable process, low thermal budget, higher process compatibility, and is conducive to industrialization and mass production.

[0024] The tellurium thin film self-driven polarization photodetector prepared by the present invention has excellent polarization photodetection capability and does not require any external voltage; therefore, the tellurium thin film self-driven polarization photodetector prepared by the present invention can be used in the field of low-power polarization photodetection and has strong market prospects and development potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a flow chart of the method for preparing a tellurium thin film self-driven polarization photodetector based on the ALD process of the present invention.

[0026] Figure 2 This is a schematic structural diagram of a tellurium thin film self-driven polarization photodetector prepared by the present invention.

[0027] Figure 3 This is a test schematic diagram of a tellurium thin film self-driven polarization photodetector prepared by the present invention.

[0028] Figure 4 Self-driven photocurrent transient curves and corresponding photocurrent polarization diagrams of a tellurium thin film self-driven polarization photodetector prepared in the present invention under infrared (808nm) polarized light in different directions (0-360°): (a) is the self-driven photocurrent transient curve; (b) is the photocurrent polarization diagram.

[0029] Figure 5 : The photocurrent anisotropy ratio of the tellurium thin film self-driven polarization photodetector under polarized light according to different embodiments of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. The specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] Example 1

[0032] (1) The Si / SiO2 substrate 101 is pre-treated by cleaning and drying. Specifically, the substrate is ultrasonically cleaned for 15 minutes using acetone, isopropyl alcohol, ethanol, and deionized water in sequence, and blown dry with nitrogen for later use. The surface of the treated Si / SiO2 substrate 101 must be free of any visible impurities. The pre-treated Si / SiO2 substrate is placed in an atomic layer deposition chamber.

[0033] (2) Setting an appropriate temperature gas flow rate and single introduction time of the tellurium precursor, and setting an appropriate temperature and pressure in the reaction chamber, wherein the heating temperature of the reaction chamber is 100°C and the pressure is 10 mTorr; the deposition process is Te(SiMe3)2 introduction for 1 second and the purge time is 10 seconds, and Te(OEt)4 introduction for 1 second and the purge time is 10 seconds; continuously cycling the above deposition process steps so that the precursors are alternately adsorbed and reacted in the deposition area until the expected tellurium film 102 with a thickness of 10 nm is achieved.

[0034] (3) Using photolithography and metal plating, a source electrode 103 and a drain electrode 104 are formed on both ends of the tellurium thin film 102 on the Si / SiO2 substrate 101. Specifically, the source and drain electrode windows are defined using photolithography, and a 50-200 nm thick Cr / Au electrode is deposited using metal plating. The film is then stripped and cleaned by immersion in acetone solution until a clean, impurity-free tellurium thin film 102 with the source electrode 103 and drain electrode 104 is obtained.

[0035] (4) Using the photolithography process again, an Al2O3 film deposition window is set on the tellurium film 102 on one side of the source electrode 103, and the device with the Al2O3 film deposition window is placed in an atomic layer deposition chamber and an Al2O3 film 105 is deposited using the classic ALD Al2O3 deposition process, with a deposition thickness of 50 nm.

[0036] The above device was subjected to a debonding and annealing process at a temperature of 500°C for 10 minutes. The Al ions in the Al2O3 film 105 were used to perform n-type electron doping on the tellurium film on the source electrode side to prepare a photodiode, thereby obtaining a tellurium film self-driven polarization photodetector.

[0037] Example 2

[0038] (1) The Si / SiO2 substrate 101 is pre-treated by cleaning and drying. Specifically, the substrate is ultrasonically cleaned for 15 minutes using acetone, isopropyl alcohol, ethanol, and deionized water in sequence, and blown dry with nitrogen for later use. The surface of the treated Si / SiO2 substrate must be free of any visible impurities. The pre-treated Si / SiO2 substrate is placed in an atomic layer deposition chamber.

[0039] (2) Setting an appropriate temperature gas flow rate and single introduction time of the tellurium precursor, and setting an appropriate temperature and pressure in the reaction chamber, wherein the heating temperature of the reaction chamber is 10°C and the pressure is 100 mTorr; the deposition process is to introduce MeOH for 10 seconds as a chemical adsorbent to optimize the substrate nucleation site, MeOH / Te(SiMe3)2 are introduced simultaneously for 5 seconds, the purge time is 50 seconds, and Te(OEt)4 is introduced for 5 seconds, the purge time is 50 seconds; the above deposition process steps are continuously cycled so that the precursor alternately adsorbs and reacts in the deposition area, and has a higher nucleation density and surface coverage, until the expected tellurium film 102 with a thickness of 50 nm is achieved.

[0040] (3) Using photolithography and metal plating, a source electrode 103 and a drain electrode 104 are formed on both ends of the tellurium thin film 102 on the Si / SiO2 substrate 101. Specifically, the source and drain electrode windows are defined using photolithography, and a 50-200 nm thick Cr / Au electrode is deposited using metal plating. The film is then stripped and cleaned by immersion in acetone solution until a clean, impurity-free tellurium thin film 102 with the source electrode 103 and drain electrode 104 is obtained.

[0041] (4) Using the photolithography process again, an Al2O3 film deposition window is set on the tellurium film 102 on the side of the source electrode, and the device with the Al2O3 film deposition window is placed in an atomic layer deposition chamber and an Al2O3 film 105 is deposited using the classic ALD Al2O3 deposition process, with a deposition thickness of 50 nm.

[0042] (5) The above device is subjected to a debonding and annealing process at a temperature of 200° C. for 60 min. The Al ions in the Al 2 O 3 film 105 are used to perform n-type electron doping on the tellurium film on the source electrode side to prepare a photodiode, thereby obtaining a tellurium film self-driven polarization photodetector.

[0043] Example 3

[0044] (1) The Si / SiO2 substrate 101 is pre-treated by cleaning and drying. Specifically, the substrate is ultrasonically cleaned for 15 minutes using acetone, isopropyl alcohol, ethanol, and deionized water in sequence, and blown dry with nitrogen for later use. The surface of the treated Si / SiO2 substrate must be free of any visible impurities. The pre-treated Si / SiO2 substrate is placed in an atomic layer deposition chamber.

[0045] (2) Setting the appropriate temperature gas flow rate and single introduction time of the tellurium precursor, and setting the appropriate temperature and pressure in the reaction chamber, wherein the heating temperature of the reaction chamber is 70°C and the pressure is 80 mTorr; the deposition process is to introduce MeOH for 3s as a chemical adsorbent to optimize the substrate nucleation site, repeating three times to introduce MeOH / Te(SiMe3)2 in batches simultaneously for 0.5s, each purification time is 10s, and Te(OEt)4 is introduced for 3s, and the purification time is 20s; continuously cycle the above deposition process steps so that the precursors are alternately adsorbed and reacted in the deposition area, and further optimize the nucleation density and film surface roughness by repeated dosage method until the expected optimized tellurium film 102 with a thickness of 30nm is achieved.

[0046] (3) Using photolithography and metal plating processes, a source electrode (103) and a drain electrode (104) are respectively prepared at both ends of the tellurium thin film on the Si / SiO2 substrate. Specifically, the source electrode and drain electrode windows are defined by photolithography, a Cr / Au electrode with a thickness of 50-200 nm is deposited by metal plating, and then the film is stripped and cleaned by soaking in acetone solution. This is done until a clean and impurity-free tellurium thin film 102 with the source electrode 103 and the drain electrode 104 is obtained.

[0047] (4) Using the photolithography process again, an Al2O3 film deposition window is set on the tellurium film 102 on one side of the source electrode 103, and the device with the Al2O3 film deposition window is placed in an atomic layer deposition chamber and an Al2O3 film 105 is deposited using the classic ALD Al2O3 deposition process, with a deposition thickness of 50 nm.

[0048] (5) The above device is subjected to a debonding and annealing process at a temperature of 300°C for 30 minutes. The Al ions in the Al2O3 film 105 are used to perform n-type electron doping on the tellurium film on the source electrode side to prepare a photodiode, thereby obtaining a tellurium film self-driven polarization photodetector.

[0049] Take the tellurium thin film self-driven polarization photodetector prepared in Examples 1 to 3 as an example. Figure 3 As shown in the figure, the laser light emitted by the laser light source is transmitted through the polarizer and then irradiated onto the tellurium thin film self-driven polarization photodetector. The self-driven photocurrent transient curve and the corresponding photocurrent polarization diagram are tested under infrared (808nm) polarized light in different directions (0-360°). The results are shown in the figure. Figure 4 As shown by Figure 4 It can be seen from (a) and (b) in the figure that the device of Example 3 has fast photoelectric response characteristics under different polarization angles, and the device has the largest photocurrent value (12.3nA) under 0° / 180° polarized light, and the smallest photocurrent value (3nA) under 90° / 270° polarized light, and its photocurrent anisotropy ratio is as high as 4.1. This shows that the tellurium thin film self-driven polarization photodetector prepared by the present invention has excellent self-driven polarization photoelectric performance. The photocurrent anisotropy of the tellurium thin film self-driven polarization photodetector under polarized light of Examples 1 to 3 is as follows: Figure 5 As shown by Figure 5 As shown, the devices of Examples 1 to 3 all have excellent photocurrent anisotropy ratios, demonstrating the feasibility of realizing tellurium thin film self-driven polarization photodetectors by n-type doping of aluminum oxide.

[0050] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. Any technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing a tellurium thin film self-driven polarization photodetector based on an ALD process, characterized in that: The following steps are involved: S1. After cleaning and drying the insulating substrate, place it in an atomic layer deposition chamber and deposit a tellurium thin film on the insulating substrate. The tellurium precursor used in the deposition of the tellurium thin film is two components of Te(SiMe3)2 and Te(OEt)4, or three components of Te(SiMe3)2, Te(OEt)4 and MeOH. The reaction chamber of the atomic layer deposition chamber is heated at a temperature of 10-100°C, a pressure of 10-100 mTorr, a flow rate of the tellurium precursor is 20-300 sccm, and a single injection time is 0.1-5 s. S2, preparing a source electrode and a drain electrode at both ends of the tellurium thin film on the insulating substrate; S3. Setting an Al2O3 film deposition window on the tellurium film near the source electrode, placing the film in an atomic layer deposition chamber, and depositing an Al2O3 film on the tellurium film in the Al2O3 film deposition window, with one side wall of the Al2O3 film connected to a side wall of the source electrode; the thickness of the Al2O3 film is smaller than the thickness of the source electrode and the drain electrode; S4. After depositing the Al2O3 film, an annealing process is performed in a nitrogen or argon atmosphere at a temperature of 200-500°C for 10-60 min. The Al ions in the Al2O3 film are used to dope the tellurium film with n-type electrons to obtain a tellurium film self-driven polarization photodetector.

2. The method for preparing a tellurium thin film self-driven polarization photodetector based on the ALD process according to claim 1, characterized in that: The insulating substrate is one of a Si / SiO2 substrate, a sapphire substrate and a quartz substrate.

3. The method for preparing a tellurium thin film self-driven polarization photodetector based on the ALD process according to claim 1, characterized in that: In the step S1, the insulating substrate is cleaned with one or more of acetone, isopropyl alcohol, ethanol, and deionized water, and then dried with Ar gas or nitrogen gas.

4. The method for preparing a tellurium thin film self-driven polarization photodetector based on the ALD process according to claim 1, characterized in that: The tellurium thin film deposition thickness is 10-50 nm.

5. The method for preparing a tellurium thin film self-driven polarization photodetector based on the ALD process according to claim 1, characterized in that: In step S2, a source electrode and a drain electrode are prepared at both ends of the tellurium thin film on the insulating substrate by using a photolithography process and a metal plating process.

6. The method for preparing a tellurium thin film self-driven polarization photodetector based on the ALD process according to claim 1, characterized in that: The source electrode and the drain electrode are made of one or more of Au, Ti, Cr, and Pt, and the metal thickness of the source electrode and the drain electrode is 50-200 nm.

7. The method for preparing a tellurium thin film self-driven polarization photodetector based on the ALD process according to claim 1, characterized in that: The Al2O3 thin film deposition thickness is 10-100 nm.

8. A tellurium thin film self-driven polarization photodetector prepared by the method according to any one of claims 1 to 7.

Images