A method for fabricating a superlens on the surface of an optical fiber probe

Abstract

This invention relates to the field of fiber optic probe technology, specifically a method for fabricating superlenses on the surface of fiber optic probes. The method comprises the following steps: S1: Preparing a thermally oxidized layer A; S2: Spin-coating an electron beam photoresist layer; S3: Etching to form M groups of nanowindows A; S4: Etching to form M groups of nanowindows B; S5: Etching to form M groups of nanopores; S6: Preparing M groups of thermally oxidized layers B; S7: Applying a photocurable slurry; S8: Filling the M groups of nanopores with the photocurable slurry; S9: Scraping away the photocurable slurry outside the M groups of nanopores; S10: Coating with a photocurable resin; S11: Curing the photocurable slurry within the M groups of nanopores to form M groups of nanoprotrusions; S12: Extracting M superlenses from the M groups of nanopores; S13: Separating the M fiber optic probes. This invention solves the problems of low fabrication efficiency, poor fabrication quality, and high fabrication cost of existing superlens fabrication methods, and is applicable to superlens fabrication.

Description

Technical Field

[0001] This invention relates to the field of fiber optic probe technology, specifically a method for fabricating a superlens on the surface of a fiber optic probe. Background Technology

[0002] Currently, the demand for miniaturization and integration of fiber optic sensors is driving the rapid development of micro-nano optics technology. Against this backdrop, researchers are exploring ways to endow fiber optic probes with special optical properties through rational optical design, functional materials, and micro-nano fabrication techniques. For example, by fabricating superlenses on the surface of fiber optic probes, it is possible to achieve focusing and phase modulation of light, thereby facilitating sensing technologies such as surface-enhanced Raman scattering (SERS), laser-induced ultrasound imaging, and bio-immunological responses. However, practice has shown that existing superlens fabrication methods generally suffer from low fabrication efficiency, poor fabrication quality, and high fabrication costs due to their inherent limitations. Therefore, it is necessary to invent a method for fabricating superlenses on the surface of fiber optic probes to address the problems of low fabrication efficiency, poor fabrication quality, and high fabrication costs associated with existing superlens fabrication methods. Summary of the Invention

[0003] To address the problems of low fabrication efficiency, poor fabrication quality, and high fabrication cost in existing superlens fabrication methods, this invention provides a method for fabricating a superlens on the surface of an optical fiber probe.

[0004] This invention is achieved using the following technical solution:

[0005] A method for fabricating a superlens on the surface of an optical fiber probe, comprising the following steps:

[0006] S1: Prepare a thermal oxide layer A on the upper surface of a silicon substrate;

[0007] S2: Spin-coat an electron beam photoresist layer onto the upper surface of thermally oxidized layer A;

[0008] S3: Using electron beam direct writing lithography and etching technology, M groups of nano-windows A are etched on the electron beam photoresist layer. Each group of nano-windows A includes N nano-windows A. The thermal oxide layer A is exposed through the M groups of nano-windows A, thereby forming M groups of exposed areas; M is a positive integer and M≥2; N is a positive integer and N≥2.

[0009] S4: Using plasma etching technology, M groups of exposed areas in the thermal oxide layer A are etched one-to-one to form M groups of nano-windows B. The silicon substrate is exposed through the M groups of nano-windows B, thereby forming the M groups of exposed areas.

[0010] S5: Using plasma etching technology, M groups of nano-recesses are formed by etching the M exposed areas of the silicon substrate one by one.

[0011] S6: Remove the electron beam photoresist layer and prepare the M-group thermal oxide layer B one-to-one on the hole walls of the M-group nano-recesses. Then, use a plasma deposition machine to simultaneously deposit a fluorocarbon layer on the upper surface of the thermal oxide layer A and the surface of the M-group thermal oxide layer B.

[0012] S7: Conductive glass is placed above the fluorocarbon layer and the M group of nano-recesses, and a photocurable slurry is applied between the fluorocarbon layer and the conductive glass, and between the M group of nano-recesses and the conductive glass. The photocurable slurry simultaneously covers the fluorocarbon layer and the M group of nano-recesses. Then, one end of the AC power supply is connected to the silicon substrate, and the other end of the AC power supply is connected to the conductive glass through a switch.

[0013] S8: Close the switch to connect the AC power supply, thereby allowing the photocurable slurry to fill the nanopores in group M under the action of the electric field.

[0014] S9: Remove the conductive glass, AC power supply, and switch, and use a scraper to remove the photocurable paste outside the nano-pores of group M;

[0015] S10: Bundle M fiber optic probes together and coat the lower surface of each fiber optic probe with a layer of photocurable resin. Then align the M layers of photocurable resin with the photocurable slurry in the M sets of nanopores one by one.

[0016] S11: Press M layers of photocurable resin one by one onto the photocurable slurry in M ​​groups of nano-holes, and simultaneously introduce light into M fiber optic probes. This causes the M layers of photocurable resin to cure under light irradiation to form M adhesive layers, and the photocurable slurry in the M groups of nano-holes to cure under light irradiation to form M groups of nano-protrusions. Each group of nano-protrusions together constitutes a superlens. The M superlenses are fixed to the lower surface of the M fiber optic probes one by one through the M adhesive layers.

[0017] S12: Apply a release force to make M superlenses detach from the M sets of nanopores;

[0018] S13: Separate the M fiber optic probes.

[0019] Compared with existing superlens fabrication methods, the superlens fabrication method for the surface of an optical fiber probe described in this invention achieves the fabrication of a superlens on the surface of an optical fiber probe by adopting a completely new fabrication principle and process. This not only effectively improves the fabrication efficiency and quality, but also effectively reduces the fabrication cost.

[0020] This invention effectively solves the problems of low preparation efficiency, poor preparation quality, and high preparation cost of existing superlens preparation methods, and is applicable to superlens preparation. Attached Figure Description

[0021] Figure 1This is a schematic diagram of step S1 in this invention.

[0022] Figure 2 This is a schematic diagram of step S2 in this invention.

[0023] Figure 3 This is a schematic diagram of step S3 in this invention.

[0024] Figure 4 This is a schematic diagram of step S4 in this invention.

[0025] Figure 5 This is a schematic diagram of step S5 in this invention.

[0026] Figure 6 This is a schematic diagram of step S6 in this invention.

[0027] Figure 7 This is a schematic diagram of step S7 in this invention.

[0028] Figure 8 This is a schematic diagram of step S8 in this invention.

[0029] Figure 9 This is a schematic diagram of step S9 in this invention.

[0030] Figure 10 This is a schematic diagram of step S10 in this invention.

[0031] Figure 11 This is a schematic diagram of step S11 in this invention.

[0032] Figure 12 This is a schematic diagram of step S12 in this invention.

[0033] Figure 13 This is a schematic diagram of step S13 in this invention.

[0034] In the figure: 1-Silicon substrate, 2-Thermal oxide layer A, 3-Electron beam photoresist layer, 4-Nano window A, 5-Nano window B, 6-Nano recess, 7-Thermal oxide layer B, 8-Fluorocarbon layer, 9-Conductive glass, 10-Photocurable slurry, 11-AC power supply, 12-Switch, 13-Scraper, 14-Fiber optic probe, 15-Photocurable resin, 16-Adhesive layer, 17-Nano protrusion. Detailed Implementation

[0035] A method for fabricating a superlens on the surface of an optical fiber probe, comprising the following steps:

[0036] S1: A thermal oxide layer A2 is prepared on the upper surface of silicon substrate 1;

[0037] S2: Spin-coat electron beam photoresist layer 3 on the upper surface of thermal oxide layer A2;

[0038] S3: Using electron beam direct writing lithography and etching technology, M groups of nano-windows A4 are etched on electron beam photoresist layer 3. Each group of nano-windows A4 includes N nano-windows A4. The thermal oxide layer A2 is exposed through the M groups of nano-windows A4, thus forming M groups of exposed areas; M is a positive integer and M≥2; N is a positive integer and N≥2.

[0039] S4: Using plasma etching technology, M groups of nano-windows B5 are formed in the M group of exposed areas of the thermal oxide layer A2, and the silicon substrate 1 is exposed through the M group of nano-windows B5, thereby forming the M group of exposed areas.

[0040] S5: Using plasma etching technology, M groups of nano-recesses 6 are formed by etching the M exposed areas of the silicon substrate 1 one by one.

[0041] S6: Remove the electron beam photoresist layer 3, and prepare the M group thermal oxide layer B7 one by one on the hole wall of the M group nano-recesses 6. Then, use a plasma deposition machine to simultaneously deposit a fluorocarbon layer 8 on the upper surface of the thermal oxide layer A2 and the surface of the M group thermal oxide layer B7.

[0042] S7: Conductive glass 9 is disposed above the fluorocarbon layer 8 and the M group of nano-recesses 6, and photocurable slurry 10 is applied between the fluorocarbon layer 8 and the conductive glass 9, and between the M group of nano-recesses 6 and the conductive glass 9. The photocurable slurry 10 simultaneously covers the fluorocarbon layer 8 and the M group of nano-recesses 6. Then, one end of the AC power supply 11 is connected to the silicon substrate 1, and the other end of the AC power supply 11 is connected to the conductive glass 9 through the switch 12.

[0043] S8: Close switch 12 to connect AC power supply 11, thereby allowing the photocurable slurry 10 to fill the M group of nano-pores 6 under the action of electric field.

[0044] S9: Remove the conductive glass 9, AC power supply 11, and switch 12, and use scraper 13 to scrape off the photocurable paste 10 outside the nano-pores 6 of group M;

[0045] S10: Bundle M fiber optic probes 14 together, and coat the lower surface of each fiber optic probe 14 with a layer of photocurable resin 15. Then align the M layers of photocurable resin 15 with the photocurable slurry 10 in the M groups of nano-holes 6 one by one.

[0046] S11: Press M layers of photocurable resin 15 one by one onto the photocurable slurry 10 in the M groups of nano-holes 6, and simultaneously introduce light into the M fiber optic probes 14. This causes the M layers of photocurable resin 15 to cure under light irradiation to form M adhesive layers 16, and causes the photocurable slurry 10 in the M groups of nano-holes 6 to cure under light irradiation to form M groups of nano-protrusions 17. Each group of nano-protrusions 17 together constitutes a superlens. The M superlenses are fixed to the lower surface of the M fiber optic probes 14 one by one through the M adhesive layers 16.

[0047] S12: Apply a release force to make the M superlenses dislodge from the M sets of nano-concave holes 6;

[0048] S13: Separate the M fiber optic probes 14.

[0049] In step S1, the thickness of the thermally oxidized layer A2 is 200nm~300nm.

[0050] In step S2, the electron beam photoresist layer 3 uses etch-resistant ZEP520A photoresist or HSQ photoresist, with a thickness of 200nm~500nm.

[0051] In steps S4 and S5, the plasma etching technology is either ICP plasma etching technology or RIE plasma etching technology, and the etching depth is 300nm~1000nm.

[0052] In step S6, the thickness of the thermally oxidized layer B7 is 50nm~100nm, and the thickness of the fluorocarbon layer 8 is 1nm~5nm.

[0053] In step S7, the light-curing slurry 10 is a UV-curing slurry, and the volume usage is 5μl~10μl.

[0054] In step S8, the voltage waveform of the AC power supply 11 is a square wave or a sine wave, the voltage amplitude is 50V~300V, and the voltage frequency is 10Hz~50Hz.

[0055] In step S9, the scraper 13 is a polytetrafluoroethylene scraper.

[0056] In step S10, the light-curing resin 15 is an ultraviolet light-curing resin, and the volume usage is 1μl~5μl.

[0057] In step S11, the light source is ultraviolet light with a wavelength of 365nm or 405nm and an irradiation power density of 10mW / cm². 2 ~20mW / cm 2 .

[0058] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A method for fabricating a superlens on the surface of an optical fiber probe, characterized in that: This method is implemented using the following steps: S1: Prepare a thermal oxide layer A (2) on the upper surface of a silicon substrate (1); S2: Spin-coat an electron beam photoresist layer (3) on the upper surface of the thermal oxide layer A (2); S3: Using electron beam direct writing lithography and etching technology, M groups of nano-windows A (4) are etched on the electron beam photoresist layer (3). Each group of nano-windows A (4) includes N nano-windows A (4). The thermal oxide layer A (2) is exposed through the M groups of nano-windows A (4), thereby forming M groups of exposed areas; M is a positive integer and M≥2; N is a positive integer and N≥2; S4: Using plasma etching technology, M groups of nano-windows B (5) are formed in the M groups of exposed areas of the thermal oxide layer A (2) in a one-to-one correspondence. The silicon substrate (1) is exposed through the M groups of nano-windows B (5), thereby forming the M groups of exposed areas. S5: Using plasma etching technology, M groups of nano-recesses (6) are formed by etching the M exposed areas of the silicon substrate (1) one by one. S6: Remove the electron beam photoresist layer (3) and prepare the M group thermal oxide layer B (7) one by one on the hole wall of the M group nano-holes (6). Then, use a plasma coating machine to simultaneously deposit a fluorocarbon layer (8) on the upper surface of the thermal oxide layer A (2) and the surface of the M group thermal oxide layer B (7). S7: Conductive glass (9) is placed above the fluorocarbon layer (8) and the M group of nano-holes (6), and a photocurable slurry (10) is applied between the fluorocarbon layer (8) and the conductive glass (9) and between the M group of nano-holes (6) and the conductive glass (9). The photocurable slurry (10) simultaneously covers the fluorocarbon layer (8) and the M group of nano-holes (6). Then, one end of the AC power supply (11) is connected to the silicon substrate (1), and the other end of the AC power supply (11) is connected to the conductive glass (9) through a switch (12). S8: Close the switch (12) to connect the AC power supply (11), thereby allowing the photocurable slurry (10) to fill the M group of nano-pores (6) under the action of the electric field; S9: Remove the conductive glass (9), AC power supply (11), switch (12), and use a scraper (13) to scrape off the photocurable slurry (10) outside the nano-pores (6) of group M. S10: Bundle M fiber optic probes (14) together and coat the lower surface of each fiber optic probe (14) with a layer of photocurable resin (15). Then align the M layers of photocurable resin (15) with the photocurable slurry (10) in the M groups of nano-holes (6). S11: Press M layers of photocurable resin (15) one by one onto the photocurable slurry (10) in the M groups of nano-holes (6), and simultaneously introduce light into M fiber optic probes (14). Thus, on the one hand, the M layers of photocurable resin (15) are cured under light irradiation to form M adhesive layers (16), and on the other hand, the photocurable slurry (10) in the M groups of nano-holes (6) is cured under light irradiation to form M groups of nano-protrusions (17). Each group of nano-protrusions (17) together constitutes a superlens. The M superlenses are fixed to the lower surface of the M fiber optic probes (14) one by one through the M adhesive layers (16). S12: Apply a release force to make M superlenses detach from the M sets of nano-concave holes (6); S13: Separate the M fiber optic probes (14).

2. The method for fabricating a superlens on the surface of an optical fiber probe according to claim 1, characterized in that: In step S1, the thickness of the thermal oxide layer A (2) is 200nm~300nm.

3. The method for fabricating a superlens on the surface of an optical fiber probe according to claim 1, characterized in that: In step S2, the electron beam photoresist layer (3) uses etch-resistant ZEP520A photoresist or HSQ photoresist with a thickness of 200nm~500nm.

4. The method for fabricating a superlens on the surface of an optical fiber probe according to claim 1, characterized in that: In steps S4 and S5, the plasma etching technology is either ICP plasma etching technology or RIE plasma etching technology, and the etching depth is 300nm~1000nm.

5. The method for fabricating a superlens on the surface of an optical fiber probe according to claim 1, characterized in that: In step S6, the thickness of the thermal oxidation layer B (7) is 50nm~100nm, and the thickness of the fluorocarbon layer (8) is 1nm~5nm.

6. The method for fabricating a superlens on the surface of an optical fiber probe according to claim 1, characterized in that: In step S7, the light-curing slurry (10) is a UV-curing slurry with a volume of 5 μl to 10 μl.

7. The method for fabricating a superlens on the surface of an optical fiber probe according to claim 1, characterized in that: In step S8, the voltage waveform of the AC power supply (11) is a square wave or a sine wave, the voltage amplitude is 50V~300V, and the voltage frequency is 10Hz~50Hz.

8. The method for fabricating a superlens on the surface of an optical fiber probe according to claim 1, characterized in that: In step S9, the scraper (13) is a polytetrafluoroethylene scraper.

9. The method for fabricating a superlens on the surface of an optical fiber probe according to claim 1, characterized in that: In step S10, the light-curing resin (15) is an ultraviolet light-curing resin, and the volume usage is 1μl~5μl.

10. The method for fabricating a superlens on the surface of an optical fiber probe according to claim 1, characterized in that: In step S11, the light source is ultraviolet light with a wavelength of 365nm or 405nm and an irradiation power density of 10mW / cm². 2 ~20mW / cm 2 .

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