Method for preparing tellurium film self-driven polarized photoelectric detector based on ALD (atomic layer deposition) process

Abstract

The invention belongs to the field of polarized photoelectric detectors, and particularly discloses a method for preparing a tellurium film self-driven polarized photoelectric detector based on an ALD (atomic layer deposition) process, which comprises the following steps of: depositing a tellurium film on an insulating substrate by adopting the ALD process; preparing a source electrode and a drain electrode at two ends of the tellurium film on the insulating substrate; depositing an Al2O3 thin film on the tellurium thin film close to one side of the source electrode by adopting an ALD (atomic layer deposition) process; and carrying out annealing process treatment to obtain the tellurium film self-driven polarized photoelectric detector. Compared with the prior art, the preparation method disclosed by the invention is controllable in process, low in thermal budget, higher in process compatibility and beneficial to realizing industrial and large-batch production; the tellurium film self-driven polarized photoelectric detector prepared by the invention has excellent polarized photoelectric detection capability and does not need any external voltage; therefore, the tellurium film self-driven polarized photoelectric detector prepared by the invention is excellent in self-driven polarization sensitivity, can be applied to the field of low-power-consumption polarized photoelectric detection, and has very strong market prospects and development potential.

Description

Technical Field

[0001] The present invention relates to the field of polarization photoelectric detectors, and in particular to a method for preparing a tellurium thin film self-driven polarization photoelectric detector 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, biomedical imaging, etc. Polarized light carries information about the direction of light wave vibration, which gives it unique advantages in signal processing and image analysis. At present, traditional polarization photodetection devices can be divided into four types: time-sharing type, amplitude-sharing type, focal plane-sharing type, and aperture-sharing type. Although they are currently widely used, there are still problems such as complex structure, high cost, cumbersome process, and high power consumption that need to be solved, which cannot meet the current development needs of low-power, integrated, high-performance optoelectronic devices.

[0003] In response to this problem, researchers have begun to explore 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 adjustable band gap, excellent photoelectric properties and high carrier mobility. However, the instability of black phosphorus in the air has greatly hindered its further development. In recent years, tellurium, as a new type of semiconductor material, has been regarded as a potential polarization photodetector channel layer material due to its high absorption coefficient in a wide band range, good environmental stability and excellent polarization photoelectric properties.

[0004] Patent application number CN202110716606.5 discloses a polarized light detector based on two-dimensional layered semiconductor materials and its preparation method. The polarized light detector is composed of an insulating substrate, a tellurium nanofilm prepared based on a hydrothermal synthesis technique, and a metal electrode from bottom to top. The polarized 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 polarized 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 preparation method, including a silicon substrate, a first SiO2 film, a two-dimensional Te film, a MAXene film and a back electrode, wherein the first SiO2 film is prepared 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 prepared on the surface of the SiO2:Au film or the surface of the second SiO2 film; a MAXene film is prepared on the surface of the two-dimensional Te film as the source and drain electrodes of the detector; and a back electrode is deposited on the back of the silicon substrate as a gate electrode. Although a tellurium nanolayer is also disclosed, its structure is too complicated and is not conducive to 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 purposes 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 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 one 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 the step S1, the insulating substrate is cleaned with one or more of acetone, isopropanol, ethanol, and deionized water, and dried 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 applied in the field of low-power polarization photodetection and has strong market prospects and development potential. BRIEF DESCRIPTION OF THE DRAWINGS

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

[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 Graph 1 shows 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 solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the invention.

[0031] Example 1

[0032] (1) Pre-treatment such as cleaning and drying the Si / SiO2 substrate 101 is performed, specifically: ultrasonically cleaning the substrate with acetone, isopropanol, ethanol, and deionized water for 15 minutes in sequence, and drying it with nitrogen for later use. The surface of the Si / SiO2 substrate 101 after treatment needs to be free of any visible impurities; the pre-treated Si / SiO2 substrate is placed in an atomic layer deposition chamber.

[0033] (2) Setting appropriate temperature gas flow and single introduction time of the tellurium precursor, and setting 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 s, purification time for 10 s, and Te(OEt)4 introduction for 1 s, purification time for 10 s; 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 processes, a source electrode 103 and a drain electrode 104 are prepared at both ends of the tellurium film 102 on the Si / SiO2 substrate 101. 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 until a clean tellurium film 102 with a source electrode 103 and a 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 to deposit an Al2O3 film 105 using a classic ALD Al2O3 deposition process, with a deposition thickness of 50 nm.

[0036] The above device is subjected to debonding and annealing processes, the annealing temperature is 500°C, and the annealing time is 10 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 achieve the preparation of the photodiode, so as to obtain 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, isopropanol, ethanol, and deionized water in sequence, and blown dry with nitrogen for later use. The surface of the Si / SiO2 substrate after treatment needs to be free of any visible impurities. The pre-treated Si / SiO2 substrate is placed in an atomic layer deposition chamber.

[0039] (2) Setting appropriate temperature gas flow and single introduction time of the tellurium precursor, and setting 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 purification time is 50 seconds, and Te(OEt)4 is introduced for 5 seconds, the purification time is 50 seconds; the above deposition process steps are continuously cycled so that the precursor is alternately adsorbed and reacted 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 processes, a source electrode 103 and a drain electrode 104 are prepared at both ends of the tellurium film 102 on the Si / SiO2 substrate 101. 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 until a clean tellurium film 102 with a source electrode 103 and a 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 source electrode side, and the device with the Al2O3 film deposition window is placed in an atomic layer deposition chamber to deposit the Al2O3 film 105 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, the annealing temperature is 200° C., and the annealing time is 60 min. 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 achieve the preparation of a photodiode, so as to obtain 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, isopropanol, ethanol, and deionized water in sequence, and blown dry with nitrogen for later use. The surface of the Si / SiO2 substrate after treatment needs to be free of any visible impurities. The pre-treated Si / SiO2 substrate is placed in an atomic layer deposition chamber.

[0045] (2) Setting appropriate temperature gas flow and single introduction time of the tellurium precursor, and setting 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, and repeat three times to introduce MeOH / Te(SiMe3)2 in batches for 0.5s at the same time, with a purge time of 10s each time, and introduce Te(OEt)4 for 3s, with a purge time of 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 dosing 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 prepared at both ends of the tellurium 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 debonded and cleaned by soaking in acetone solution. This is until a clean tellurium film 102 with a source electrode 103 and a 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 to deposit an Al2O3 film 105 using a 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, the annealing temperature is 300° C., and the annealing time is 30 min. 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 achieve the preparation of 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 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 under infrared (808nm) polarized light in different directions (0-360°) are tested respectively. The results are shown in Figure 4 As shown by Figure 4 It can be seen from (a) and (b) 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. All 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, placing it in an atomic layer deposition chamber, and depositing a tellurium thin film on the insulating substrate; S2, preparing a source electrode and a drain electrode at both ends of the tellurium 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 one side wall of the source electrode; 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.

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, isopropanol, ethanol, and deionized water, and 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: In the 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.

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

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: In the 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.

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 thickness of the Al2O3 film is smaller than the thickness of the source electrode and the drain electrode.

8. The method for preparing a tellurium thin film self-driven polarization photodetector based on the ALD process according to claim 1 or 7, 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.

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

10. A tellurium thin film self-driven polarization photodetector prepared by the method according to any one of claims 1 to 9.

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