Photoelectric sensor and preparation method thereof

Abstract

The invention discloses a photoelectric sensor and a preparation method thereof, the photoelectric sensor comprises a substrate, the substrate is provided with a photoelectric conversion area, and the photoelectric conversion area comprises a trapezoidal groove and a second plane; the preparation method comprises the following steps: step 1, processing an isolation groove; 2, preparing a second isolation layer; step 3, processing a trapezoidal groove; 4, preparing a shielding layer; 5, preparing an N-type semiconductor; step 6, preparing a P-type semiconductor; 7, preparing a first isolation layer; 8, preparing an electrode; the light incident plane adopts the design that the trapezoidal groove is combined with the second plane, so that three planes with different angles are constructed, the incident angle of the light can be obtained by calculating and analyzing electric signals on the PN junction assembly corresponding to the three planes, and the design has the advantages of small size and low cost; the method covers the fine operation process of each production link of the sensor, and a solid and reliable foundation is provided for efficient and high-quality production of the sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to a photoelectric sensor and a preparation method thereof. Background Art

[0002] Photoelectric sensors can convert light signals into electrical signals. They mainly measure physical quantities or detect the existence, position, and motion state of objects by detecting changes in light intensity, color, frequency, and other characteristics. When detecting the incident angle of light, existing photoelectric sensors need to use multiple photoelectric sensors to form an array. The hardware cost of this sensor array is high and the data processing is complex. In addition, since multiple sensors and their supporting circuits occupy a large space, it is difficult to meet the installation requirements in some application scenarios with strict space requirements, such as miniaturized electronic devices and micro robots. Therefore, a photoelectric sensor and a preparation method thereof are proposed. Summary of the invention

[0003] The object of the present invention is to provide a photoelectric sensor and a method for preparing the same, so as to solve the problems raised in the above background technology.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a photoelectric sensor, comprising a substrate, a photoelectric conversion region is arranged on the substrate, the photoelectric conversion region comprises a trapezoidal groove and a second plane, a plurality of trapezoidal grooves are evenly distributed on the upper surface of the substrate, a second plane is arranged between two adjacent trapezoidal grooves, the trapezoidal groove is composed of a first plane, a first inclined plane and a second inclined plane, PN junction components are arranged at positions corresponding to the first plane, the first inclined plane, the second inclined plane and the second plane in the substrate, a plurality of isolation grooves are evenly distributed in the substrate, and the isolation grooves are arranged at the bottom end of the connection between the first plane, the first inclined plane, the second inclined plane and the second plane, and a second isolation layer is fixedly connected in the isolation grooves.

[0005] Preferably, a shielding layer is provided on the upper surface of the substrate, and a first isolation layer is fixedly connected to the lower surface of the substrate.

[0006] Preferably, the PN junction component includes a first doped region, a second doped region, a P-type semiconductor, an N-type semiconductor, a first electrode and a second electrode, and the first doped region and the second doped region are arranged in a substrate, the first doped region is provided with a P-type semiconductor, and the second doped region is provided with an N-type semiconductor.

[0007] Preferably, a first through groove is formed on the first isolation layer at a position corresponding to the P-type semiconductor, and a second through groove is formed on the first isolation layer at a position corresponding to the N-type semiconductor.

[0008] Preferably, a first electrode is fixedly connected in the first through groove, and the first electrode is fixedly connected to the P-type semiconductor, and a second electrode is fixedly connected in the second through groove, and the second electrode is fixedly connected to the N-type semiconductor.

[0009] A method for preparing a photoelectric sensor, comprising step 1, processing an isolation groove; step 2, preparing a second isolation layer; step 3, processing a trapezoidal groove; step 4, preparing a shielding layer; step 5, preparing an N-type semiconductor; step 6, preparing a P-type semiconductor; step 7, preparing a first isolation layer; step 8, preparing an electrode;

[0010] In the above step 1, a clean substrate is taken, a photoresist is coated on the lower surface of the substrate, and after exposure and development, a regional pattern of the isolation groove is obtained, and a directional ion reaction etching technology is used to process the lower surface of the substrate, and then the photoresist on the substrate is removed to obtain the isolation groove;

[0011] In the above step 2, SiO2 is deposited on the upper and lower surfaces of the substrate using a low-pressure chemical vapor deposition method, and SiO2 is filled in the isolation groove to form a second isolation layer;

[0012] In the above step 3, Si3N4 is deposited on the upper and lower surfaces of the substrate by using a low-pressure chemical vapor deposition method, and then a photoresist is coated on the upper surface of the substrate. After exposure and development, a regional pattern of a trapezoidal groove is obtained, and a reactive ion etching technique is used to remove SiO2 and Si3N4 in the regional pattern, and then a reactive ion etching technique is used to process the upper surface of the substrate to obtain a trapezoidal groove;

[0013] In the above step 4, a reactive ion etching technique is used to remove SiO2 and Si3N4 on the upper and lower surfaces of the substrate, and an ion implantation technique is used to implant phosphorus ions on the upper surface of the substrate to obtain a shielding layer;

[0014] In the above step 5, a photoresist is coated on the lower surface of the substrate, and after exposure and development, a regional pattern of the second doping region is obtained, and then phosphorus ions are implanted on the lower surface of the substrate by ion implantation technology, and the photoresist on the substrate is removed to obtain an N-type semiconductor, wherein the width of the N-type semiconductor is 10 μm and the thickness is 0.6 μm;

[0015] In the above step 6, a photoresist is coated on the lower surface of the substrate, and after exposure and development, a regional pattern of the first doped region is obtained, and boron ions are implanted on the lower surface of the substrate using an ion implantation technique, and the photoresist on the substrate is removed to obtain a P-type semiconductor, wherein the width of the P-type semiconductor is 110 μm and the thickness is 0.6 μm;

[0016] In the above step 7, Si3N4 is deposited on the lower surface of the substrate by plasma enhanced chemical vapor deposition to obtain a first isolation layer;

[0017] In the above step eight, a photoresist is coated on the lower surface of the substrate, and after exposure and development, a regional pattern of the first electrode and the second electrode is obtained, and a reactive ion etching technique is used to remove Si3N4 in the regional pattern. A physical vapor deposition technique is used to sputter metal aluminum on the lower surface of the substrate, and the photoresist on the substrate is stripped off to obtain the first electrode and the second electrode.

[0018] Preferably, in step 1, the isolation groove has a depth of 70 μm and a width of 5 μm.

[0019] Preferably, in step three, the depth of the trapezoidal groove is 250 μm, the angle between the first plane and the first inclined surface of the trapezoidal groove is 135°, and the angle between the first plane and the second inclined surface is 45°.

[0020] Preferably, in step 4, the thickness of the shielding layer is 1 μm.

[0021] Preferably, in step seven, the thickness of the first isolation layer is 100 nm.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: the light incident surface of the present invention adopts a trapezoidal groove combined with a second plane design to construct three planes with different angles, and the incident angle of the light can be obtained by calculating and analyzing the electrical signals on the PN junction components corresponding to the three planes. The design has the advantages of small size and low cost. The method of the present invention covers the fine operation process of each production link of the sensor, and provides a solid and reliable foundation for the efficient and high-quality production of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall three-dimensional structure of the present invention;

[0024] Figure 2 It is a schematic diagram of the main cutaway structure of the photoelectric conversion region of the present invention;

[0025] Figure 3 This is a schematic diagram of the main cutaway structure of the first isolation layer of the present invention;

[0026] Figure 4 It is a schematic diagram of the three-dimensional structure of the trapezoidal groove of the present invention;

[0027] Figure 5 is a flow chart of the method of the present invention;

[0028] Figure 6 (a)-(c) in it is a flow chart of step 1 of the present invention;

[0029] Figure 7 is a flow chart of step 2 of the present invention;

[0030] Figure 8(d)-(f) in FIG. 1 is a flow chart of step three of the present invention;

[0031] Fig. 9 (g)-(h) in FIG. 1 is a flow chart of step 4 of the present invention;

[0032] Fig.10 (i)-(k) in FIG. 1 is a flow chart of step five of the present invention;

[0033] Fig.11 (l)-(n) in FIG. 1 is a flow chart of step six of the present invention;

[0034] Fig.12 This is a flow chart of step seven of the present invention;

[0035] Fig.13 (o)-(q) in FIG. 1 is a flow chart of step eight of the present invention.

[0036] In the figure: 1, substrate; 2, photoelectric conversion region; 21, trapezoidal groove; 211, first plane; 212, first inclined plane; 213, second inclined plane; 22, second plane; 23, shielding layer; 24, first isolation layer; 241, first through groove; 242, second through groove; 25, PN junction component; 251, first doped region; 252, second doped region; 253, P-type semiconductor; 254, N-type semiconductor; 255, first electrode; 256, second electrode; 26, isolation groove; 27, second isolation layer. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Please see attached Figure 1 -Attached Figure 4, an embodiment of the present invention: a photoelectric sensor, comprising a substrate 1, a photoelectric conversion region 2 is arranged on the substrate 1, the photoelectric conversion region 2 comprises a trapezoidal groove 21 and a second plane 22, a plurality of trapezoidal grooves 21 are uniformly distributed on the upper surface of the substrate 1, a second plane 22 is arranged between two adjacent trapezoidal grooves 21, the trapezoidal groove 21 is composed of a first plane 211, a first inclined surface 212 and a second inclined surface 213, a PN junction component 25 is arranged at positions corresponding to the first plane 211, the first inclined surface 212, the second inclined surface 213 and the second plane 22 in the substrate 1, a plurality of isolation grooves 26 are uniformly distributed in the substrate 1, and the isolation grooves 26 are arranged on the first plane 2 11, the bottom of the connection between the first inclined surface 212, the second inclined surface 213 and the second plane 22, the second isolation layer 27 is fixedly connected in the isolation groove 26, the photoelectric conversion area 2 is the irradiation area of ​​the light, the trapezoidal groove 21 and the second plane 22 constitute the light incident surface, the PN junction assembly 25 is used to realize the photoelectric conversion, the isolation groove 26 is used to accommodate the second isolation layer 27, and the second isolation layer 27 is used to separate the areas corresponding to the first plane 211, the first inclined surface 212, the second inclined surface 213 and the second plane 22 on the substrate 1; the shielding layer 23 is provided on the upper surface of the substrate 1, and the first isolation layer 24 is fixedly connected to the lower surface of the substrate 1, and the shielding layer 23 is the field Shielding floating P well; PN junction component 25 includes a first doping region 251, a second doping region 252, a P-type semiconductor 253, an N-type semiconductor 254, a first electrode 255 and a second electrode 256, and the first doping region 251 and the second doping region 252 are arranged in the substrate 1, the first doping region 251 is provided with a P-type semiconductor 253, the second doping region 252 is provided with an N-type semiconductor 254, the first doping region 251 is used to dope boron ions to form a P-type semiconductor 253, the second doping region 252 is used to dope phosphorus ions to form an N-type semiconductor 254, and the P-type semiconductor 253 is combined with the N-type semiconductor 254 to achieve photoelectric conversion; A first through groove 241 is provided on the first isolation layer 24 at a position corresponding to the P-type semiconductor 253, and a second through groove 242 is provided on the first isolation layer 24 at a position corresponding to the N-type semiconductor 254; a first electrode 255 is fixedly connected in the first through groove 241, and the first electrode 255 is fixedly connected to the P-type semiconductor 253, a second electrode 256 is fixedly connected in the second through groove 242, and the second electrode 256 is fixedly connected to the N-type semiconductor 254, the first through groove 241 is used to accommodate the first electrode 255, the second through groove 242 is used to accommodate the second electrode 256, the first electrode 255 is a negative electrode, and the second electrode 256 is a positive electrode.

[0039] Please see attached Figure 5 -Attached Fig.13, an embodiment provided by the present invention: a method for preparing a photoelectric sensor, comprising step 1, processing an isolation groove; step 2, preparing a second isolation layer; step 3, processing a trapezoidal groove; step 4, preparing a shielding layer; step 5, preparing an N-type semiconductor; step 6, preparing a P-type semiconductor; step 7, preparing a first isolation layer; step 8, preparing an electrode;

[0040] In the above step 1, a clean substrate 1 is taken, a photoresist is coated on the lower surface of the substrate 1, and after exposure and development, a regional pattern of the isolation groove 26 is obtained, and a directional ion reaction etching technology is used to process the lower surface of the substrate 1, and then the photoresist on the substrate 1 is removed to obtain the isolation groove 26, and the isolation groove 26 has a depth of 70 μm and a width of 5 μm;

[0041] In the above step 2, SiO2 is deposited on the upper and lower surfaces of the substrate 1 using a low pressure chemical vapor deposition method, and SiO2 is filled in the isolation groove 26 to form a second isolation layer 27;

[0042] In the above step three, Si3N4 is deposited on the upper and lower surfaces of the substrate 1 by a low-pressure chemical vapor deposition method, and then a photoresist is coated on the upper surface of the substrate 1. After exposure and development, a regional pattern of the trapezoidal groove 21 is obtained, and a reactive ion etching technique is used to remove SiO2 and Si3N4 in the regional pattern, and then a reactive ion etching technique is used to process the upper surface of the substrate 1 to obtain a trapezoidal groove 21, the depth of the trapezoidal groove 21 is 250 μm, the angle between the first plane 211 of the trapezoidal groove 21 and the first inclined surface 212 is 135°, and the angle between the first plane 211 and the second inclined surface 213 is 45°;

[0043] In the above step 4, the SiO2 and Si3N4 on the upper and lower surfaces of the substrate 1 are removed by reactive ion etching technology, and phosphorus ions are implanted on the upper surface of the substrate 1 by ion implantation technology to obtain a shielding layer 23, and the thickness of the shielding layer 23 is 1 μm;

[0044] In the above step 5, a photoresist is coated on the lower surface of the substrate 1, and after exposure and development, a regional pattern of the second doping region 252 is obtained, and then phosphorus ions are implanted on the lower surface of the substrate 1 by ion implantation technology to remove the photoresist on the substrate 1 to obtain an N-type semiconductor 254, wherein the width of the N-type semiconductor 254 is 10 μm and the thickness is 0.6 μm;

[0045] In the above step 6, a photoresist is coated on the lower surface of the substrate 1, and after exposure and development, a regional pattern of the first doped region 251 is obtained, and boron ions are implanted on the lower surface of the substrate 1 by ion implantation technology, and the photoresist on the substrate 1 is removed to obtain a P-type semiconductor 253, wherein the width of the P-type semiconductor 253 is 110 μm and the thickness is 0.6 μm;

[0046] In the above step 7, Si3N4 is deposited on the lower surface of the substrate 1 by plasma enhanced chemical vapor deposition to obtain a first isolation layer 24, and the thickness of the first isolation layer 24 is 100 nm;

[0047] In the above step eight, a photoresist is coated on the lower surface of the substrate 1, and after exposure and development, a regional pattern of the first electrode 255 and the second electrode 256 is obtained, and a reactive ion etching technique is used to remove Si3N4 in the regional pattern. A physical vapor deposition technique is used to sputter metal aluminum on the lower surface of the substrate 1, and after stripping and removing the photoresist on the substrate 1, the first electrode 255 and the second electrode 256 are obtained.

[0048] Based on the above, the advantage of the present invention is that when the present invention is used, sunlight irradiates the photoelectric conversion area 2 of the substrate 1 and enters through the shielding layer 23. The PN junction component 25 receives the sunlight to generate photogenerated carriers. The light intensity can be measured according to the signal of the photogenerated current. Since the sunlight incident surface is composed of a trapezoidal groove 21 combined with a second plane 22, when the incident light angle changes, the projection areas of the three planes at different angles perpendicular to the light path will be different. The incident angle of the light can be determined according to the electrical signals on the PN junction component 25 under the three angle planes; wherein the trapezoidal groove 21 is composed of the first plane and the second plane. The substrate 1 is composed of a first through groove 241 and a second through groove 242. The first through groove 241 is used to accommodate the first electrode 255, the second through groove 242 is used to accommodate the second electrode 256, and the first isolation layer 24 is used to isolate the substrate 1, the first electrode 255 and the second electrode 256.

[0049] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A photoelectric sensor, comprising a substrate (1), characterized in that: The substrate (1) is provided with a photoelectric conversion region (2), the photoelectric conversion region (2) comprising a trapezoidal groove (21) and a second plane (22), a plurality of trapezoidal grooves (21) are evenly distributed on the upper surface of the substrate (1), a second plane (22) is provided between two adjacent trapezoidal grooves (21), the trapezoidal groove (21) is composed of a first plane (211), a first inclined plane (212) and a second inclined plane (213), a PN junction assembly (25) is provided at positions corresponding to the first plane (211), the first inclined plane (212), the second inclined plane (213) and the second plane (22) in the substrate (1), a plurality of isolation grooves (26) are evenly distributed in the substrate (1), and the isolation grooves (26) are provided at the bottom end of the connection between the first plane (211), the first inclined plane (212), the second inclined plane (213) and the second plane (22), and a second isolation layer (27) is fixedly connected in the isolation grooves (26).

2. A photoelectric sensor according to claim 1, characterized in that: A shielding layer (23) is provided on the upper surface of the substrate (1), and a first isolation layer (24) is fixedly connected to the lower surface of the substrate (1).

3. A photoelectric sensor according to claim 1, characterized in that: The PN junction component (25) comprises a first doping region (251), a second doping region (252), a P-type semiconductor (253), an N-type semiconductor (254), a first electrode (255) and a second electrode (256), wherein the first doping region (251) and the second doping region (252) are arranged in a substrate (1), the P-type semiconductor (253) is arranged in the first doping region (251), and the N-type semiconductor (254) is arranged in the second doping region (252).

4. A photoelectric sensor according to claim 2, characterized in that: A first through groove (241) is provided on the first isolation layer (24) at a position corresponding to the P-type semiconductor (253), and a second through groove (242) is provided on the first isolation layer (24) at a position corresponding to the N-type semiconductor (254).

5. A photoelectric sensor according to claim 4, characterized in that: A first electrode (255) is fixedly connected in the first through groove (241), and the first electrode (255) is fixedly connected to the P-type semiconductor (253); a second electrode (256) is fixedly connected in the second through groove (242), and the second electrode (256) is fixedly connected to the N-type semiconductor (254).

6. A method for preparing a photoelectric sensor, comprising step 1, processing an isolation groove; step 2, preparing a second isolation layer; step 3, processing a trapezoidal groove; step 4, preparing a shielding layer; step 5, preparing an N-type semiconductor; step 6, preparing a P-type semiconductor; step 7, preparing a first isolation layer; step 8, preparing an electrode; characterized in that: In the above step 1, a clean substrate (1) is taken, a photoresist is coated on the lower surface of the substrate (1), and after exposure and development, a regional pattern of the isolation groove (26) is obtained, and the lower surface of the substrate (1) is processed by a directional ion reactive etching technology, and then the photoresist on the substrate (1) is removed to obtain the isolation groove (26); In the above step 2, SiO2 is deposited on the upper and lower surfaces of the substrate (1) using a low-pressure chemical vapor deposition method, and the SiO2 is filled in the isolation groove (26) to form a second isolation layer (27); In the above step 3, Si3N4 is deposited on the upper and lower surfaces of the substrate (1) by using a low-pressure chemical vapor deposition method, and then a photoresist is coated on the upper surface of the substrate (1). After exposure and development, a regional pattern of a trapezoidal groove (21) is obtained, and a reactive ion etching technique is used to remove SiO2 and Si3N4 in the regional pattern, and then a reactive ion etching technique is used to process the upper surface of the substrate (1) to obtain a trapezoidal groove (21); In the above step 4, a reactive ion etching technique is used to remove SiO2 and Si3N4 on the upper and lower surfaces of the substrate (1), and an ion implantation technique is used to implant phosphorus ions on the upper surface of the substrate (1) to obtain a shielding layer (23); In the above step 5, a photoresist is coated on the lower surface of the substrate (1), and after exposure and development, a regional pattern of the second doping region (252) is obtained, and then phosphorus ions are implanted on the lower surface of the substrate (1) using an ion implantation technique to remove the photoresist on the substrate (1) to obtain an N-type semiconductor (254), wherein the width of the N-type semiconductor (254) is 10 μm and the thickness is 0.6 μm; In the above step 6, a photoresist is coated on the lower surface of the substrate (1), and after exposure and development, a regional pattern of the first doped region (251) is obtained, and boron ions are implanted on the lower surface of the substrate (1) using an ion implantation technique, and the photoresist on the substrate (1) is removed to obtain a P-type semiconductor (253), wherein the width of the P-type semiconductor (253) is 110 μm and the thickness is 0.6 μm; In the above step 7, Si3N4 is deposited on the lower surface of the substrate (1) by plasma enhanced chemical vapor deposition to obtain a first isolation layer (24); In the above step eight, a photoresist is coated on the lower surface of the substrate (1), and after exposure and development, a regional pattern of the first electrode (255) and the second electrode (256) is obtained, and a reactive ion etching technique is used to remove Si3N4 in the regional pattern. A physical vapor deposition technique is used to sputter metal aluminum on the lower surface of the substrate (1), and after stripping and removing the photoresist on the substrate (1), the first electrode (255) and the second electrode (256) are obtained.

7. The method for preparing a photoelectric sensor according to claim 6, characterized in that: In the step 1, the isolation groove (26) has a depth of 70 μm and a width of 5 μm.

8. The method for preparing a photoelectric sensor according to claim 6, characterized in that: In the step three, the depth of the trapezoidal groove (21) is 250 μm, the angle between the first plane (211) and the first inclined plane (212) of the trapezoidal groove (21) is 135°, and the angle between the first plane (211) and the second inclined plane (213) is 45°.

9. The method for preparing a photoelectric sensor according to claim 6, characterized in that: In the step 4, the thickness of the shielding layer (23) is 1 μm.

10. The method for preparing a photoelectric sensor according to claim 6, characterized in that: In the step seven, the thickness of the first isolation layer (24) is 100 nm.

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