Optoelectronic angle measuring device based on planar structure

Abstract

The application discloses a photoelectric angle measuring instrument based on a plane structure, which uses an inorganic semiconductor material as a substrate, sets a doped area on the surface of the substrate, sets an ohmic electrode on one side of the doped area and a Schottky electrode on the other side, and the distance between the ohmic electrode and the Schottky electrode and the doped area is the same; the doped area between the two electrodes is used as an illumination area, when the incident angle of a light source changes, the ratio of photoelectric currents at a first wavelength and a second wavelength changes linearly, and thus, the incident angle of the light source is obtained based on the ratio of the photoelectric currents at the first wavelength and the second wavelength. The device of the application has a simple structure, a simple measuring method and an accurate measuring result.

Description

Technical Field

[0001] This invention relates to the field of photoelectric detectors, and more specifically to photoelectric angle measuring instruments. Background Technology

[0002] An angle measuring instrument is a crucial measuring device widely used in industrial automation, scientific research, aerospace, and construction engineering. Utilizing advanced optical technology and a precise measuring system, it can accurately measure the rotation and tilt angles of objects. [1-2] This provides crucial support and solutions for various precision measurement tasks. Common angle measurement methods include circular grating angle measurement, optical internal reflection small angle measurement, and laser interferometry. [3] These methods generally suffer from the following problems: they require high standards for the design and stability of the optical path; they are greatly affected by ambient light, resulting in low measurement accuracy.

[0003] References:

[0004] [1]Chen T, Zhang W, Xie Z, Zhang H, Wang F, Chang SA new angle detection method based on the compound parabolic collector (CPC): Design and simulation [J]. Optik, 2023, 284:6.

[0005] [2]Xue Y,Luo Y,Chen J,Li H,Wu Z,Liu M,et al.Rotation angle detection based on low-frequency giant magnetoimpedance effect[J].Sensors and ActuatorsA:Physical,2023,363:9.[3]Liang X,Lin J,Yang L,Wu T,Liu Y,Zhu J.SimultaneousMeasurement ofAbsolute Distance andAngle Based on Dispersive Interferometry[J]. IEEE Photonics Technology Letters, 2020, 32(8):449-52. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, this invention provides a photoelectric angle measuring instrument based on a planar structure, which aims to achieve angle measurement with a simple process and method. The device has a simpler structure, better stability, and the measurement method is easier to implement.

[0007] The present invention solves the technical problem by adopting the following technical solution:

[0008] The photoelectric angle measuring instrument based on a planar structure is characterized in that: the photoelectric angle measuring instrument uses an inorganic semiconductor material as a substrate, a doped region is set on the surface of the substrate, and an ohmic electrode is set on one side of the doped region and a Schottky electrode is set on the other side, and the ohmic electrode and the Schottky electrode are equidistant from the doped region; the doped region between the two electrodes is used as the illumination region, and when the incident angle of the light source changes, the ratio of the photocurrent at the first wavelength to the second wavelength of the device changes linearly. Therefore, the incident angle of the light source is obtained based on the ratio of the photocurrent at the first wavelength to the second wavelength.

[0009] Furthermore, the photoelectric angle measuring instrument of the present invention can use most inorganic semiconductor materials as substrates, including at least one of silicon, germanium, gallium arsenide, and indium phosphide. When the substrate is silicon, the material of the Schottky electrode forming the Schottky contact with it on the silicon includes one of Au, Ag, Al, Pt, Mo, Ni, Ti, and W. When the substrate is germanium, the material of the Schottky electrode forming the Schottky contact with it on the germanium includes one of Ti, Ni, Pt, Gr, and Al. When the substrate is gallium arsenide, the material of the Schottky electrode forming the Schottky contact with it on the gallium arsenide is one of graphene, Au, Ti, Ag, Pt, Al, and Gr. When the substrate is indium phosphide, the material of the Schottky electrode forming the Schottky contact with it on the indium phosphide is one of graphene, Au, Pt, Ti, and Pd.

[0010] Furthermore, the doped region is formed by high-temperature diffusion or ion implantation. When the substrate is silicon or germanium, the impurity doped into the doped region is at least one of Ag, Au, Al, As, Cu, Ni, Pt, Sb, Se, Zn, and Te. When the substrate is gallium arsenide, the impurity doped into the doped region is at least one of Au, Ag, Cu, S, and Te. When the substrate is indium phosphide, the impurity doped into the doped region is at least one of Ti, V, Cr, Mn, Fe, Co, and Ni.

[0011] Furthermore, an illuminated area is formed on the substrate surface by shielding the remaining areas. Even further, the light-shielding treatment is performed using insulating black tape, which covers the entire area except for the doped regions, and a transparent tape is placed between the insulating black tape and the substrate at the interval between the Schottky electrode and the doped region.

[0012] Furthermore, the incident angle of the light source refers to the angle between the incident direction of the light source and the thickness direction of the substrate (less than 90°). The second wavelength refers to the peak wavelength when the incident angle of the light source is 0°. The first wavelength is a light wavelength that is shorter than the second wavelength and whose ratio to the photocurrent at the second wavelength changes with the incident angle of the light source.

[0013] The method for manufacturing the photoelectric angle measuring instrument based on a planar structure described in this invention can be as follows:

[0014] 1) Provide an inorganic semiconductor wafer as a substrate, which also serves as a light-absorbing layer;

[0015] 2) The substrate surface is doped using high-temperature diffusion or ion implantation to form a doped region;

[0016] 3) Keep the morphology of the doped region unchanged, and control the size and spacing of the illuminated area on the substrate surface and the electrodes through a photomask;

[0017] 4) Two electrodes are fabricated using techniques such as electron beam evaporation, chemical vapor deposition, or magnetron sputtering;

[0018] 5) The remaining areas of the substrate surface, except for the light-illuminated areas, are shielded.

[0019] Compared with existing technologies, the beneficial effects of this invention are reflected in:

[0020] 1. This invention provides a photoelectric angle measuring instrument based on a planar structure. After doping the illumination area, the angle between the incident direction of the light source and the thickness direction of the substrate can be adjusted to achieve the control of photocurrent of different wavelengths of the device to realize angle measurement. The device has a simple structure, the measurement method is simple, and the measurement results are accurate.

[0021] 2. The photoelectric angle measuring instrument of the present invention has the characteristics of low manufacturing cost, simple manufacturing process and easy implementation.

[0022] 3. Compared with photoelectric angle measuring instruments based on organic materials, the photoelectric angle measuring instrument of this invention, constructed using inorganic semiconductors such as silicon, germanium, gallium arsenide, and indium phosphide, and metal thin films, has higher stability. Attached Figure Description

[0023] Figure 1This is a schematic diagram of a silicon-based photoelectric angle measuring instrument based on a planar structure provided in Embodiment 1 of the present invention. In the figure, the numbers are as follows: 1 is the substrate; 2 is the doped region; 3 is the ohmic electrode; 4 is the Schottky electrode; 5 is the insulating black tape; 6 is the illumination region; and 7 is the transparent tape.

[0024] Figure 2 The spectral response curve of the photoelectric angle measuring instrument provided in Embodiment 1 of the present invention after changing the incident angle of the light source.

[0025] Figure 3 The photoelectric angle measuring instrument provided in Embodiment 1 of the present invention displays the normalized spectral response curve of the device after changing the incident angle of the light source.

[0026] Figure 4 The curves showing the relationship between the photocurrent ratio and the incident angle of the light source at 840nm and 1100nm are provided by the photoelectric angle measuring instrument in Embodiment 1 of the present invention.

[0027] Figure 5 This is a schematic diagram of the device provided in Comparative Example 1 of the present invention.

[0028] Figure 6 The spectral response curve of the device provided in Comparative Example 1 of this invention is shown. Detailed Implementation

[0029] The embodiments of the present invention are described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.

[0030] Example 1

[0031] like Figure 1 As shown, this embodiment provides a silicon-based photoelectric angle measuring instrument based on a planar structure. A single-crystal silicon wafer is used as a substrate 1. A doped region 2 is set in the middle region of the substrate surface. An ohmic electrode 3 is set on the left side of the doped region and a Schottky electrode 4 is set on the right side of the doped region. The remaining areas on the substrate surface are shielded by insulating black tape 5 to form an illuminated region 6. The illuminated region is located between the ohmic electrode 3 and the Schottky electrode 4.

[0032] Specifically, in this embodiment, an n-type single-layer polished silicon wafer (thickness 500±10μm, resistivity 1-10Ω·cm, size 0.5cm×0.5cm) is used as the substrate to fabricate a photoelectric angle measuring instrument. The steps are as follows:

[0033] (1) Clean the n-type single-polished silicon wafers in an ultrasonic cleaner for 15 minutes each with acetone, ethanol and deionized water, and then dry them with nitrogen gas for later use.

[0034] (2) The doped region was located on the substrate surface using photolithography. A 2nm thick gold layer was deposited on the substrate surface using a SEM gold sputtering device, and then the substrate was immersed in an acetone solution to remove excess photoresist. The substrate was then transferred to an annealing furnace, and the annealing temperature was set to 500℃. Annealing was carried out for 30 minutes under a nitrogen atmosphere to achieve doping of the light-illuminated region.

[0035] (3) The Schottky electrode region is positioned on the substrate surface by photolithography, and then a 100 nm thick gold layer is deposited on the substrate as the Schottky electrode by electron beam deposition. The distance between the ohmic electrode 3 and the Schottky electrode 4 and the doped region 2 is 30 μm.

[0036] (4) The ohmic electrode region is positioned on the substrate surface by photolithography, and then a 100nm thick Ti is deposited on the substrate as an ohmic electrode by a magnetron sputtering system. The working conditions are: power 90W, working pressure 0.2Pa, and deposition time 300s.

[0037] (5) Due to the small size of the device, it needs to be fixed on a PCB board with a slightly larger area, and wires are led out from the two electrodes for easy testing. Then, transparent tape 7 is placed at the interval between the Schottky electrode 4 and the doped region 2, and the entire area of ​​the substrate surface except for the doped region 2 is covered with insulating black tape 5 to form the illumination area 6.

[0038] Figure 2 The figure shows the spectral response curve of the photoelectric angle measuring instrument obtained in this embodiment after changing the incident angle θ of the light source. As can be seen from the figure, after doping in the illuminated area, the peak wavelength at an incident angle of 0° is 1100nm. With the increase of the incident light angle, the recombination effect of the device on photogenerated carriers gradually weakens, and the device's response gradually strengthens. Compared to long-wavelength light, the device's response to short-wavelength light is significantly enhanced.

[0039] Figure 3 The figure shows the normalized spectral response curve of the photoelectric angle measuring instrument obtained in this embodiment after changing the incident angle of the light source. As can be seen from the figure, as the incident light angle increases, the recombination effect of the device on short-wavelength photogenerated carriers gradually weakens, and the peak value of the device's spectral response gradually blue-shifts from 1100nm to 920nm.

[0040] Figure 4 The graph shows the relationship between the photocurrent ratio at 840nm and 1100nm and the incident angle of the light source obtained by the photoelectric angle measuring instrument in this embodiment. It can be seen from the graph that the ratio I of the photocurrent at 840nm to that at 1100nm is... 840 / I 1100 The photocurrent is linearly related to the incident angle θ of the light source. Therefore, if the photocurrent of the detector at 840nm and 1100nm is measured, its current ratio I can be calculated.840 / I 1100 Then it can be from Figure 4 The incident angle of the light source is obtained from the relationship curve.

[0041] Comparative Example 1

[0042] The device structure provided in this comparative example is as follows: Figure 5 As shown, the difference between it and the photoelectric angle measuring instrument provided in Example 1 is that there is no transparent tape at the interval between the Schottky electrode 4 and the doped region 2, but instead, an insulating black tape 5 is directly used to cover it.

[0043] Figure 6 The figure shows the spectral response curve of the photodetector obtained in this embodiment. It can be seen from the figure that when no transparent tape is set, the device has a strong effect on the recombination of photogenerated carriers. When the incident angle of the light source changes, the light response of the device in the range of 750nm-1000nm does not change significantly.

[0044] Based on the above results, it can be seen that by placing transparent tape between the insulating black tape and the substrate at the interval between the Schottky electrode and the doped region, the ratio of photocurrent at the first wavelength to the second wavelength can be linearly changed when the incident angle of the light source is altered. This is because when there is a step formed by the transparent tape in this region, as the incident angle of the light source increases, the light source may illuminate this region. Furthermore, the number of defects in this region is small, resulting in a weak recombination effect on photogenerated carriers generated by short-wavelength light.

[0045] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A photoelectric angle measuring instrument based on a planar structure, characterized in that: The photoelectric angle measuring instrument uses an inorganic semiconductor material as a substrate, with a doped region on the substrate surface. An ohmic electrode is placed on one side of the doped region and a Schottky electrode is placed on the other side, with both the ohmic and Schottky electrodes at the same distance from the doped region. The doped region between the two electrodes is used as the illumination region. When the incident angle of the light source changes, the ratio of the photocurrent at the first wavelength to the second wavelength of the device changes linearly. Thus, the incident angle of the light source is obtained based on the ratio of the photocurrent at the first wavelength to the second wavelength. An illuminated area is formed on the surface of the substrate by shielding the remaining areas. The light is shielded by insulating black tape, which covers the entire area except for the doped region, and transparent tape is placed between the insulating black tape and the substrate at the interval between the Schottky electrode and the doped region. The incident angle of the light source refers to the angle between the incident direction of the light source and the thickness direction of the substrate; the second wavelength refers to the peak wavelength when the incident angle of the light source is 0°, and the first wavelength is a light wavelength that is shorter than the second wavelength and has a linear relationship with the photocurrent at the second wavelength when the incident angle of the light source changes.

2. The photoelectric angle measuring instrument according to claim 1, characterized in that: The doped regions are formed by high-temperature diffusion or ion implantation.

3. The photoelectric angle measuring instrument according to claim 1, characterized in that: The inorganic semiconductor material used as a substrate is at least one of silicon, germanium, gallium arsenide, and indium phosphide.

4. The photoelectric angle measuring instrument according to claim 1 or 3, characterized in that: When the substrate is silicon, the material of the Schottky electrode includes one of Au, Ag, Al, Pt, Mo, Ni, Ti, and W; when the substrate is germanium, the material of the Schottky electrode includes one of Ti, Ni, Pt, Gr, and Al; when the substrate is gallium arsenide, the material of the Schottky electrode is one of graphene, Au, Ti, Ag, Pt, Al, and Gr; when the substrate is indium phosphide, the material of the Schottky electrode is one of graphene, Au, Pt, Ti, and Pd.

5. The photoelectric angle measuring instrument according to claim 1 or 3, characterized in that: When the substrate is silicon or germanium, the impurity doped in the doped region is at least one of Ag, Au, Al, As, Cu, Ni, Pt, Sb, Se, Zn, and Te; when the substrate is gallium arsenide, the impurity doped in the doped region is at least one of Au, Ag, Cu, S, and Te; when the substrate is indium phosphide, the impurity doped in the doped region is at least one of Ti, V, Cr, Mn, Fe, Co, and Ni.

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