Surface-enhanced raman scattering substrate

Abstract

A surface-enhanced Raman scattering substrate, including: a base layer; a nanopillar structure layer, which is formed on the base layer by means of nanoimprint lithography, and has a nanopillar array structure; and a thin film, which covers and is formed, by means of an oblique deposition evaporation process, on the top of the nanopillar array structure and at least one vertical side wall of the nanopillar array structure, wherein the thin film has a surface-enhanced Raman scattering effect and has an oblique angle.

Description

A substrate with surface-enhanced Raman scattering Technical Field

[0001] This invention relates to a surface-enhanced Raman scattering substrate, and more particularly to a surface-enhanced Raman spectroscopy (SERS) substrate suitable for detecting environmental substances or airborne substances. Background Technology

[0002] Traditional surface-enhanced Raman spectroscopy (SERS) is a detection technique proposed in the 1970s. It utilizes a rough silver electrode and the adsorption of single-molecule pyridine on the electrode surface. The Raman signal enhancement is not only due to the increased surface area caused by the rough structure, but also to the use of nanostructures made of precious metals (such as gold and silver), which can significantly enhance the Raman scattering signal. This has opened up research and detection applications of SERS spectroscopy in various fields. In addition, surface-enhanced Raman spectroscopy can further improve the discrimination of molecular vibrational recognition markers in chemical and biological systems. Recent studies have shown that the introduction of single-molecule Raman scattering further enhances the detection sensitivity of Raman spectroscopy, thus expanding the application range of sensors involving surface-enhanced Raman spectroscopy. Applications of surface-enhanced Raman spectroscopy are wide-ranging, including: biology (bacterial classification, protein research, and tumor cell identification); medicine (immunoassay and cell research); materials science (studies on carbon nanotubes, polymers, and self-assembled molecular layers); electrochemistry (detecting changes in the amount of a chemical substance during redox reactions); chemical pharmaceuticals, scientific forensics, biopharmaceutical development, and cosmetic testing; detection of heavy metal residues in food (e.g., lead, cadmium, arsenic, mercury); and environmental monitoring (e.g., water safety, water pollution monitoring, detection of residual toxic chemicals, and agricultural product inspection); and national security. Security, such as the detection of trace explosives and toxic gases; and medical testing and health monitoring, such as blood sugar and cholesterol detection.

[0003] As described in prior art patent TWI656336 "Surface Enhanced Raman Scattering Element", the SERS element 3 of this invention includes: a substrate 4; a microstructure 7 formed on the front side 4a of the substrate 4 and having a plurality of pillars 11; and a conductive layer 6 formed on the microstructure 7 and constituting an optical functional part 10 for generating surface enhanced Raman scattering. The conductive layer 6 has a base formed along the front side 4a of the substrate 4, and a plurality of protrusions protruding from the base at positions corresponding to each pillar 11. On the conductive layer 6, a plurality of gaps G with decreasing spacing in the direction of the protrusion of the pillars 11 are formed by the base and the protrusions.

[0004] Another prior art patent, TWI656336, "Surface Enhanced Raman Spectroscopy (SERS) Sensor and Method for Forming the Same," describes a SERS sensor that includes a nanostructured surface and a non-stoichiometric oxide layer. The nanostructured surface includes a first peak, a second peak, and a valley between the first and second peaks. The non-stoichiometric oxide layer includes a first portion on the first peak and a second portion on the second peak. The non-stoichiometric oxide layer is used on the peaks of the nanostructured surface to enhance or amplify substrate-analyte molecule interactions, such as plasma resonance. The SERS sensor includes a nanostructured surface and a non-stoichiometric oxide layer. The nanostructured surface includes a surface with multiple peaks separated by valleys. In the illustrated embodiment, the nanostructured surface is illustrated as having a first peak and a second peak separated by intermediate valleys between the peaks. Peak 4 contains local maxima, and the valley contains local minima. In the illustrated embodiment, the local maxima and local minima are physically isolated from each other or physically separated from each other by the local minima. In another practice, local maxima can be contained within functionally isolated local minima of structures / mechanisms that act as intermediate or intervening interference or diminution mechanisms, like functional valleys.

[0005] In prior art U.S. Patent US09057704, "SERS-sensor with nanostructured surface and methods of making and using," the surface-enhanced Raman scattering (SERS) sensor includes a substrate having a nanostructured surface. The nanostructured surface has an elongated ridge element in a quasi-periodic, anisotropic array, having a wave-order structural pattern, each ridge element having a wavy cross-section and being oriented substantially along a first direction. The sensor also includes a plurality of metallic elements disposed at least partially on top of the ridge elements.

[0006] Therefore, the inventors have strived to solve the conventional problems and improve the enhancement effect of surface-enhanced Raman scattering substrates or surface-enhanced Raman wafers. This invention discloses a surface-enhanced Raman scattering substrate, wherein a thin film is provided on a nanopillar structure layer. The thin film is formed on the top of the nanopillar array structure and at least one vertical sidewall of the nanopillar array structure by an oblique deposition evaporation process and has an inclined angle. The detection enhancement effect of the surface-enhanced Raman substrate can be greatly improved by using this thin film.

[0007] Summary of the Invention

[0008] One of the objectives of this invention is to disclose a surface-enhanced Raman scattering substrate, wherein a thin film is provided on a nanopillar structure layer. The thin film is formed on the top of the nanopillar array structure and at least one vertical sidewall of the nanopillar array structure by oblique deposition evaporation process. The purpose of using this thin film is to significantly improve the detection enhancement effect of the surface-enhanced Raman substrate.

[0009] According to the present invention, a surface-enhanced Raman scattering substrate comprises: a base layer; a nanopillar structure layer formed on the base layer by a nanoimprinting process having a nanopillar array structure; and a thin film formed on the top of the nanopillar array structure and at least one vertical sidewall of the nanopillar array structure by an oblique deposition evaporation process, wherein the thin film has surface-enhanced Raman scattering effect and has an oblique angle.

[0010] As described above, the substrate has a surface-enhanced Raman scattering substrate, wherein the substrate layer is made of glass, silicon, or plastic.

[0011] As described above, the surface-enhanced Raman scattering substrate, wherein the nanopillar structure layer system is any one of photoresist, thermoplastic polymer, light-transmitting polymer material, diallyl phthalate, or polymethyl methacrylate (PMMA).

[0012] As described above, a surface-enhanced Raman scattering substrate is provided, wherein the thickness of the thin film is 10 nm-50 nm.

[0013] As described above, the substrate has a surface-enhanced Raman scattering substrate, wherein the tilt angle of the thin film is between 10 degrees and 85 degrees.

[0014] As mentioned above, the substrate with surface-enhanced Raman scattering is made of silver, gold, titanium, or a metal that can reflect light.

[0015] As described above, a surface-enhanced Raman scattering substrate is provided, wherein the thin film at the top of the nanopillar array structure has a first thickness and the thin film on the vertical sidewalls of the nanopillar array structure has a second thickness.

[0016] As described above, in a surface-enhanced Raman scattering substrate, the greater the tilt angle of the thin film, the greater the second thickness of the thin film on the vertical sidewalls of the nanopillar array structure is than the first thickness of the thin film on the top of the nanopillar array structure.

[0017] As described above, the substrate with surface-enhanced Raman scattering has a first thickness of 10 nm to 50 nm for the thin film at the top of the nanopillar array structure.

[0018] As described above, the substrate has a surface-enhanced Raman scattering substrate, wherein the second thickness of the thin film on the vertical sidewalls of the nanopillar array structure is between 10 nm and 50 nm.

[0019] As described above, the substrate with surface-enhanced Raman scattering has a period length spacing of 200 nm, 250 nm, 300 nm, or 350 nm.

[0020] As described above, the substrate with surface-enhanced Raman scattering is wherein the thin film is formed on the top of the nanopillar array structure and at least one vertical sidewall of the nanopillar array structure by an oblique deposition evaporation process, wherein the deposition angle of the oblique deposition evaporation process is between 10 degrees and 90 degrees.

[0021] As described above, the substrate has a surface-enhanced Raman scattering substrate, wherein the thin film is further coated on the top of the nanopillar array structure and the vertical sidewalls of the nanopillar array structure by an oblique deposition evaporation process.

[0022] As described above, a surface-enhanced Raman scattering substrate is provided, wherein the thin film at the top of the nanopillar array structure has a first thickness and the thin films on the two vertical sidewalls of the nanopillar array structure have a second thickness. Attached Figure Description

[0023] Figure 1 is a flowchart illustrating the fabrication process of the nanopillar structure layer with surface-enhanced Raman scattering substrate of the present invention.

[0024] Figure 2 is a cross-sectional view of the substrate layer and nanopillar structure layer of the surface-enhanced Raman scattering substrate of the present invention.

[0025] Figure 3 is a side-view three-dimensional cross-sectional view of the nanopillar array structure with a surface-enhanced Raman scattering substrate of the present invention.

[0026] Figure 4 is a schematic diagram of the oblique deposition evaporation method for preparing a surface-enhanced Raman scattering substrate according to the present invention.

[0027] Figure 5 is a cross-sectional view of the surface-enhanced Raman scattering substrate (single-sided thin film) of the present invention.

[0028] Figure 6-1 is a conventional electron microscope (SEM) image of a substrate with surface-enhanced Raman scattering.

[0029] Figure 6-2 is an electron microscope (SEM) image of the nanopillar array structure with a surface-enhanced Raman scattering substrate of the present invention, showing a thin film on the side.

[0030] Figure 7 is a cross-sectional view of the surface-enhanced Raman scattering substrate (two-sided thin film) of the present invention.

[0031] Figure 8 is an electron microscope (SEM) image of the nanopillar array structure with a surface-enhanced Raman scattering substrate of the present invention, which has thin films on two sides.

[0032] Figure 9-1 is a cross-sectional view of the nanopillar array structure with a surface-enhanced Raman scattering substrate of the present invention, showing a thin film on the side.

[0033] Figure 9-2 is a cross-sectional view of the nanopillar array structure with surface-enhanced Raman scattering substrate of the present invention, showing the thin film on both sides.

[0034] Figure 9-3 is a cross-sectional view of the deposition angle of the oblique deposition evaporation process of the surface-enhanced Raman scattering substrate of the present invention.

[0035] Figure 10 is a cross-sectional view of the deposition sample A with a surface-enhanced Raman scattering substrate according to the present invention.

[0036] Figure 11 shows the SERS spectral measurement data of the deposited sample A with a surface-enhanced Raman scattering substrate of the present invention.

[0037] Figure 12 is a cross-sectional view of the deposition sample B of the surface-enhanced Raman scattering substrate of the present invention.

[0038] Figure 13 shows the SERS spectral measurement data of the deposited sample B with a surface-enhanced Raman scattering substrate of the present invention. Detailed Implementation

[0039] Certain terms are used in this specification and subsequent claims to refer to specific components. It will be understood by those skilled in the art that hardware manufacturers may use different names to refer to the same component. This specification and subsequent claims do not distinguish components by differences in name, but rather by differences in function. The term "comprising" as used throughout this specification and subsequent claims is an open-ended term and should be interpreted as "comprising but not limited to".

[0040] Figure 1 is a flowchart of the fabrication process of the surface-enhanced Raman scattering substrate of the present invention. The first embodiment of this invention is shown in Figure 1: The surface-enhanced Raman scattering substrate 100 of the present invention mainly consists of a substrate layer 10 and a nanopillar structure layer 20. The substrate 100 is a surface-enhanced Raman spectroscopy (SERS) substrate. The substrate 100 is a patterned substrate prepared by nanoimprint lithography (NIL) as shown in Figures 1-1 to 1-3. As shown in Figure 1-1, the substrate layer 10 is glass, and a nanopillar structure layer 20 is first coated on the substrate layer 10. The nanopillar structure layer 20 is made of photoresist and spin-coated onto the glass substrate layer 10. Continuing with the first embodiment, as shown in Figure 1-2, a hot-pressing step is performed on the spin-coated photoresist substrate layer 10. As shown in Figure 1-2, the surface-enhanced Raman scattering substrate 100 and the nanopillar structure mold (P) are heated simultaneously. After heating the DMS 60 to a temperature higher than the glass transition temperature Tg of the polymer or thermoplastic material, pressure is applied to the substrate 100 and the nanopillar structure mold (PDMS) 60 to press them together. Continuing with the first embodiment, as shown in Figures 1-3, after multiple cooling processes at different temperatures and times, the surface-enhanced Raman scattering substrate 100 and the nanopillar structure mold (PDMS) 60 are separated, leaving the nanopillar structure layer 20 formed on the base layer 10, as shown in Figure 2. After the above nanoimprinting process, the nanopillar structure layer 20 forms a nanopillar array structure 21 with a nanopillar diameter D. The base layer 10 can be further replaced with a silicon-based material or a plastic material. Continuing with the first embodiment, as shown in Figure 3, the nanopillar structure layer 20 has the appearance of a nanopillar array structure 21, with individual nanopillars on the base layer 10. The period length spacing of the nanopillar array structure 21 in the nanopillar structure layer 20 ranges from 300 nm. m, the period length spacing range of the above-mentioned nanopillar array structure 21 can be replaced with a spacing range of 250nm or 350nm, wherein the period length spacing range of the nanopillar array structure 21 in this embodiment is approximately 300nm on average, the nanopillar diameter is 200nm, and the height is approximately 400nm, wherein the nanopillar structure layer 20 is made of photoresist, and the material of the above-mentioned nanopillar array structure layer 20 can be replaced with any one of thermoplastic polymer, light-transmitting polymer material, poly(diallyl phthalate) or polymethyl methacrylate PMMA.

[0041] Continuing with the surface-enhanced Raman scattering substrate 100 in the embodiments of Figures 1 and 2 above, the thin film 30 prepared by the oblique deposition evaporation method shown in Figure 4, wherein the base layer 10 and a nanopillar array structure 21 are placed on a carrier substrate 50, wherein silver 40 is sputtered by the oblique deposition evaporation process. In addition to a single tilt angle, the oblique deposition evaporation process can perform staggered oblique deposition by controlling the deposition angle and the rotation angle of the carrier substrate, and change the deposition angle θ and the rotation angle Ф of the carrier substrate, as shown in Figure 4.

[0042] Continuing with the above embodiments, Figure 5 shows a cross-sectional view of the surface-enhanced Raman scattering substrate 100 of the present invention. The surface-enhanced Raman scattering substrate 100 is mainly composed of a base layer 10 and a nanopillar structure layer 20. It is formed by spraying silver 40 using an oblique deposition evaporation process to cover the top of the nanopillar array structure 21 and at least one vertical sidewall to form a thin film 30. The thin film 30 has a tilt angle E (as shown in Figure 9-3). In the first embodiment, the tilt angle E of the thin film is 50 degrees. The tilt angle of the thin film can be between 10 degrees and 85 degrees, and is controlled by the deposition angle θ and the substrate rotation angle Ф of the oblique deposition evaporation process. The material of the thin film 30 is silver, or it can be replaced by gold, titanium, or a metal that can reflect light. In the above embodiment, the thickness of the thin film 30 is 20 nm. The thickness of the thin film 30 can be between 10 nm and 50 nm, and is controlled by the oblique deposition evaporation process.

[0043] Figure 6-1 shows a SEM image of a substrate with a conventional non-oblique deposition vapor deposition process. In Figure 6-1, the diameter of the nanopillars in the conventional non-oblique deposition vapor deposition nanopillar array structure is 160 nm. Figure 6-2 shows a SEM image of a substrate with at least one sidewall having undergone an oblique deposition vapor deposition process. In the oblique deposition vapor deposition process, the diameter of the thin film deposited on the nanopillar array structure 21 is larger, and the diameter of the nanopillars in the nanopillar array structure 21 is approximately 200 nm. Compared with the conventional nanopillar array structure, it can be seen that the average range of the period length spacing of the nanopillar array structure 21 after the oblique deposition vapor deposition process is smaller, while the diameter of the nanopillar array structure 21 is larger.

[0044] Continuing with another embodiment of the present invention, as shown in Figure 7, the surface-enhanced Raman scattering substrate 100 of the present invention is cross-sectionally divided into a base layer 10 and a nanopillar structure layer 20. It is coated with silver 40 by an interleaved deposition oblique deposition evaporation process. As shown in Figure 7, a thin film 30 covers the top and two vertical sidewalls of the nanopillar array structure 21. Continuing with the above embodiment, Figure 8 shows the SEM image of the substrate with the top and two vertical sidewalls of the nanopillar array structure 21 after the oblique deposition evaporation process. The nanopillar array structure coated with the thin film by the oblique deposition evaporation process is approximately 200 nm.

[0045] Continuing with the above-described embodiments using the oblique deposition evaporation process, as shown in Figures 9-1 to 9-3, as shown in Figure 9-1, the thin film 30 is further coated with silver on the top of the nanopillar array structure 21 and the vertical sidewalls of the nanopillar array structure using an oblique deposition evaporation process. The thin film 30 on the top of the nanopillar array structure 21 has a first thickness H1, and the thin film on the vertical sidewalls of the nanopillar array structure has a second thickness H2. In this embodiment, the first thickness H1 of the thin film 30 on the top of the nanopillar array structure 21 is 25 nm, and the second thickness H2 of the thin film 30 on the vertical sidewalls of the nanopillar array structure is 46 nm. The first thickness H1 of the thin film 30 can be controlled between 10 nm and 50 nm, and the second thickness H2 of the thin film 30 can be controlled within 10 nm. Between -50nm, continuing from the above embodiments, as shown in Figures 9-3, the thin film 30 has a tilt angle E, where the tilt angle E is 50 degrees. The tilt angle E of the thin film 30 can be between 10 degrees and 85 degrees. In this embodiment, the deposition angle θ of the oblique deposition evaporation process is further controlled between 10 degrees and 90 degrees, and the rotation angle Ф of the substrate is between 0 degrees and 90 degrees. In addition, in this invention, the larger the tilt angle E of the thin film 30, the greater the second thickness H2 of the thin film 30 on the vertical sidewall of the nanopillar array structure is than the first thickness H1 (not shown) of the thin film 30 at the top of the nanopillar array structure. The tilt angle E and the combination of the first thickness H1 and the second thickness H2 can be adjusted by other embodiments. The above embodiments are only examples.

[0046] Figure 9-2 illustrates a second embodiment of the invention. The thin film 30 prepared by the oblique deposition method shown in the figure is formed by sputtering silver 40 using an oblique deposition evaporation process. This oblique deposition evaporation process can employ an alternating deposition and continuous rotation method to deposit the film, changing the deposition angle θ and the substrate rotation angle Ф. Furthermore, the deposition angle θ of this oblique deposition process is controlled between 10 degrees and 90 degrees, and the substrate rotation angle Ф is between 0 degrees and 180 degrees, as shown in Figure 9-2. The nanopillars... The thin film 30 on the array structure 21 is further coated on the top of the nanopillar array structure 21 and the two vertical sidewalls of the nanopillar array structure using an oblique deposition evaporation process. The thin film 30 on the top of the nanopillar array structure has a first thickness H1, and the thin films 30 on the two vertical sidewalls of the nanopillar array structure have a second thickness H2. In this embodiment, the first thickness H1 of the thin film 30 on the top of the nanopillar array structure is 23 nm, and the second thickness H2 of the thin films 30 on the two vertical sidewalls of the nanopillar array structure is 19 nm. The first thickness H1 of the aforementioned thin film 30 can be controlled between 10 nm and 50 nm, and the second thickness H2 of the aforementioned thin film 30 can be controlled between 10 nm and 50 nm. Furthermore, the thin film 30 of the nanopillar array structure in the above embodiment has an L1 deposition length of 96 nm on its two vertical sidewalls, wherein the L1 deposition length of the aforementioned thin film 30 can be controlled between 50 nm and 150 nm. In the second embodiment, the nanopillar array structure 21 has a nanopillar diameter D of approximately 200 nm, wherein the tilt angle of the aforementioned thin film 30 is 50 degrees, and the average thickness of the thin film 30 in the second embodiment is approximately 25 nm. The material of the aforementioned thin film 30 is silver, or it can be replaced with gold, titanium, or a light-reflecting metal. The material of the aforementioned nanopillar structure layer 20 is photoresist, and the material of the aforementioned nanopillar structure layer 20 can be replaced with thermoplastic polymers, light-transmitting polymers, diallyl phthalate (PPD), or polymethyl methacrylate (PMMA). The substrate layer 10 may be further replaced with a silicone-based material or a plastic material, wherein any of the following materials are used: methacrylate (methacrylate).

[0047] The following is a comparison of the actual test material measured using two deposition patterns on the surface-enhanced Raman scattering (SERS) substrate 100 of the present invention. As shown in Figure 10, sample A is a thin film 30 deposited by a single-sided oblique deposition process, and sample B is a thin film 30 deposited by a double-sided oblique deposition process. The surface-enhanced Raman scattering (SERS) signal of the two samples was measured. Rhodamine 6G (R6G) was used as the detection reagent. Rhodamine 6G (R6G) with a concentration of 10^(-5)M was prepared by diluting ethanol and deionized water. The ratio of R6G, ethanol and deionized water was 1:4.5:4.5. The solution was then titrated onto the surface-enhanced Raman scattering substrate 100. After waiting five minutes, the substrate was blotted dry with gauze before surface-enhanced Raman scattering measurements were performed. After removing the background signal, as shown in Figures 11 and 13, both samples exhibited Rhodamine at 607 cm⁻¹, 771 cm⁻¹, 1363 cm⁻¹, and 1510 cm⁻¹. The characteristic peak value of 6G (R6G) is shown in Figures 10 and 12. After the two sample numbers mentioned above are dropped into an aqueous solution of R6G, the test laser 80 is directed to a substrate with a nanopillar structure layer 20 for positive vector measurement. Figure 10 shows a cross-sectional view of sample A of the surface-enhanced Raman scattering substrate. The surface-enhanced Raman scattering substrate 100 of this invention mainly consists of a base layer 10, a nanopillar structure layer 20, a nanopillar array structure 21, and a thin film 30. In the above embodiment, an oblique deposition evaporation process is used on the nanopillar array structure 21, wherein the thin film 30 is formed as the top and one side film of the nanopillar array structure 21. The surface-enhanced Raman scattering substrate 100 can perform environmental substance measurement, wherein the test substance 70 is dropped onto the surface-enhanced Raman scattering substrate 100 and a laser 80 is used for measurement. 0. The scattered light of the test substance 70 was measured numerically. As shown in the SERS spectrum measurement data of sample A in the deposition state in Figure 11, it can be found that in sample A (single-sided thin film), the intensity of the 607 cm-1 peak measured in air showed a good enhancement effect at approximately 5800 counts, the intensity of the 771 cm-1 peak showed a good enhancement effect at approximately 3500 counts, the intensity of the 1363 cm-1 peak showed a good enhancement effect at approximately 6000 counts, the intensity of the 1510 cm-1 peak showed a good enhancement effect at approximately 5900 counts. The intensity of these peak segments all showed a good Raman spectral enhancement effect when measured in air.

[0048] Another embodiment is shown in Figure 12. When measuring at the air end, the measurement results of sample B using the bidirectional oblique deposition deposition process are compared. As shown in the cross-sectional view of sample B with surface-enhanced Raman scattering substrate in Figure 12, the surface-enhanced Raman scattering substrate 100 of the present invention is mainly composed of a base layer 10, a nanopillar structure layer 20, a nanopillar array structure 21, and a thin film 30. As in the above embodiment, the nanopillar array structure 21 is subjected to an oblique deposition deposition process. The thin film 30 is formed on the top and two sides of the nanopillar array structure 21. The surface-enhanced Raman scattering substrate 100 can be used to measure environmental substances. The test substance 70 is dropped onto the surface-enhanced Raman scattering substrate 100, and the scattered light of the test substance 70 is measured by a laser 80. The SERS spectrum measurement data of sample B with deposition state is shown in Figure 13. It can be observed that in sample B (double-sided thin film), the intensity of the 607 cm⁻¹ peak measured in air shows a good enhancement effect at approximately 13,000 counts, the intensity of the 772 cm⁻¹ peak shows a good enhancement effect at approximately 9,000 counts, the intensity of the 1363 cm⁻¹ peak shows a good enhancement effect at approximately 15,000 counts, the intensity of the 1511 cm⁻¹ peak shows a good enhancement effect at approximately 14,000 counts. The intensity of these peak segments shows a good enhancement effect when measured in air. Therefore, the double-sided thin film structure of the thin film 30 has a better enhancement effect than the conventional technology or the single-sided thin film structure when measured in air. Both of the above-described nanopillar structure layers of the present invention can be regarded as substrates for surface-enhanced Raman scattering.

[0049] After the detailed description of the various preferred embodiments of the present invention, those skilled in the art will clearly understand that various changes and modifications can be made without departing from the scope and spirit of the following claims, such as various embodiments of the substrate, etc., and are not limited to the implementation methods of the embodiments in the specification.

Claims

1. A surface-enhanced Raman scattering substrate, comprising: One basal layer; A nanopillar structure layer is formed on the substrate layer using a nanoimprint lithography process, resulting in an array structure of nanopillars; and A thin film is formed on the top of the nanopillar array structure and at least one vertical sidewall of the nanopillar array structure by oblique deposition evaporation process, wherein the thin film has surface-enhanced Raman scattering effect and has an oblique angle.

2. The surface-enhanced Raman scattering substrate according to claim 1, wherein the substrate layer is made of glass, silicon, or plastic.

3. The surface-enhanced Raman scattering substrate according to claim 1, wherein the nanopillar array structure is any one of photoresist, thermoplastic polymer, light-transmitting polymer material, diallyl phthalate, or polymethyl methacrylate (PMMA).

4. The surface-enhanced Raman scattering substrate according to claim 1, wherein the thickness of the thin film is 10 nm-50 nm.

5. The surface-enhanced Raman scattering substrate according to claim 1, wherein the tilt angle of the thin film is between 10 degrees and 85 degrees.

6. The surface-enhanced Raman scattering substrate according to claim 1, wherein the thin film is made of silver, gold, titanium or a metal that can reflect light.

7. The surface-enhanced Raman scattering substrate according to claim 1, wherein the thin film at the top of the nanopillar array structure has a first thickness and the thin film on the vertical sidewalls of the nanopillar array structure has a second thickness.

8. The surface-enhanced Raman scattering substrate according to claim 7, wherein the greater the tilt angle of the thin film, the greater the second thickness of the thin film on the vertical sidewall of the nanopillar array structure is than the first thickness of the thin film on the top of the nanopillar array structure.

9. The surface-enhanced Raman scattering substrate according to claim 7, wherein the first thickness of the top film of the nanopillar array structure is between 10 nm and 50 nm.

10. The surface-enhanced Raman scattering substrate according to claim 7, wherein the second thickness of the vertical sidewall film of the nanopillar array structure is between 10 nm and 50 nm.

11. The surface-enhanced Raman scattering substrate according to claim 1, wherein the period length spacing of the nanopillar array structure is in the range of 200 nm, 250 nm, 300 nm or 350 nm.

12. The surface-enhanced Raman scattering substrate according to claim 1, wherein the thin film is formed on the top of the nanopillar array structure and at least one vertical sidewall of the nanopillar array structure by an oblique deposition evaporation process, wherein the deposition angle of the oblique deposition evaporation process is further between 10 degrees and 90 degrees.

13. The surface-enhanced Raman scattering substrate according to claim 1, wherein the thin film is further coated on the top of the nanopillar array structure and the vertical sidewalls of the nanopillar array structure by an oblique deposition evaporation process.

14. The surface-enhanced Raman scattering substrate according to claim 1, wherein the thin film at the top of the nanopillar array structure has a first thickness and the thin films on the two sidewalls perpendicular to the nanopillar array structure have a second thickness.

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