JP7226344B2 - Manufacturing method of substrate for surface-enhanced Raman spectroscopy - Google Patents

Description

The present invention relates to a method for manufacturing a substrate for Surface Enhanced Raman Spectroscopy (hereinbelow simply referred to as SERS).

Conventionally, there has been proposed a substrate for the SERS method in which nano-order irregularities are formed on the surface of the substrate. For example, in Non-Patent Document 1, a silicon substrate is irradiated with a laser beam to form a base portion that is the base of the uneven portion, and then the base portion is coated with Ag (silver), which is a difficult-to-oxidize metal, to activate it. It has been proposed to form a substrate for the SERS process by forming layers.

When specifying the substance of the analysis object using such a substrate for SERS method, first, the object to be analyzed is attached to the portion of the substrate for SERS method where the concave and convex portions are formed. Then, in this state, the object to be analyzed is irradiated with a laser beam. Here, the presence of the analyte in a strong electric field in or near the microstructures (i.e., gaps) generated by the laser beam-induced plasmon resonance enhances the inherently weak SERS spectrum. Therefore, the analyte is identified by acquiring an enhanced SERS spectrum.

Jing Yang, Jiabao Li, Zheren Du, Qihuang Gong, Jinghua Teng, Minghui Hong, Laser Hybrid Micro/nano-structuring of Si Surfaces in Air and its Applications for SERS Detection, Scientific Reports volume 4, Article number:6657, 2014

By the way, at present, there is a demand for a substrate for the SERS method that can further improve the sensitivity.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a substrate for the SERS method, which can improve the sensitivity.

In claims 1 and 3 for achieving the above object, the workpiece (10) is provided with an uneven portion (20) formed on one surface (10a) side, and the uneven portion is a base portion ( 22a) and an active layer (22b) formed on the surface of the base portion, wherein the base portion includes a material containing an easily oxidizable metal as a main component, and the active layer is composed of an easily oxidizable metal. A method for manufacturing a substrate for SERS method composed of a material mainly composed of a difficult-to-oxidize metal that is difficult to oxidize, comprising preparing a workpiece having one surface, and forming a base portion on the one surface. forming an active layer on the surface of the base portion; By forming a base portion by scattering and depositing a part of the workpiece with a laser beam and preparing the workpiece , the easily oxidizable metal is the main component and a second metal layer (12) composed of a material containing a hard-to-oxidize metal as a main component are laminated and arranged, and the unevenness is formed. In forming the part, the base part and the active layer are formed in the same step by irradiating the workpiece with a laser beam to scatter the first metal layer and the second metal layer.
In claim 3, forming the base portion irradiates the workpiece with a pulsed laser as a laser beam.

According to this, it is possible to manufacture a substrate for the SERS method in which the base portion includes a material containing an easily oxidizable metal as a main component. Therefore, it is possible to manufacture a substrate for the SERS method that can improve the sensitivity.

It should be noted that the reference numerals in parentheses attached to each component etc. indicate an example of the correspondence relationship between the component etc. and specific components etc. described in the embodiments described later.

1 is a cross-sectional view of a substrate for SERS method in the first embodiment; FIG. 2 is an enlarged view of region II in FIG. 1; FIG. 3 is an enlarged view of region III in FIG. 2; FIG. It is a figure which shows the SERS spectrum at the time of analyzing an analysis object using the board|substrate for SERS methods in 1st Embodiment. 1. It is sectional drawing of the manufacturing process of the board|substrate for SERS method shown in FIG. FIG. 5B is a cross-sectional view of the manufacturing process of the substrate for the SERS method following FIG. 5A; FIG. 5C is a plan view corresponding to FIG. 5B; FIG. 4 is a cross-sectional view of a substrate for SERS method in a second embodiment; FIG. 8 is a plan view of the substrate for the SERS method shown in FIG. 7; It is sectional drawing of the manufacturing process of the board|substrate for SERS method in 3rd Embodiment. FIG. 9B is a cross-sectional view of the manufacturing process of the substrate for the SERS method following FIG. 9A; It is sectional drawing of the manufacturing process of the board|substrate for SERS method in the modification of 3rd Embodiment. 10B is a cross-sectional view of the manufacturing process of the substrate for the SERS method following FIG. 10A; FIG. It is a perspective view of the board|substrate for SERS method in 4th Embodiment. It is a sectional view of a fixture in a 5th embodiment.

An embodiment of the present invention will be described below with reference to the drawings. In addition, in each of the following embodiments, portions that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
A first embodiment will be described with reference to the drawings. As shown in FIG. 1, the substrate 1 for the SERS method of the present embodiment includes a substrate 10 having one surface 10a, and is configured by forming an uneven portion 20 having nano-sized unevenness on the one surface 10a. . In addition, in this embodiment, the board|substrate 10 corresponds to a to-be-processed object.

In the present embodiment, as shown in FIG. 2, the uneven portion 20 includes first micro-order unevenness 21 and nano-order second unevenness 22 (that is, nano-order unevenness) formed on the surface of and around the first unevenness 21 . unevenness). As will be described later, the first unevenness 21 is composed of laser irradiation traces formed by irradiating a laser beam. As will be described later, the second unevenness 22 includes substrate particles that are scattered by laser beam irradiation and subsequently deposited.

More specifically, as shown in FIG. 3, the second unevenness 22 has a base portion 22a forming the convex portion of the second unevenness 22 and an active layer 22b disposed on the surface of the base portion 22a. It is In FIG. 3, the active layer 22b is formed only on the tip of the surface of the base portion 22a, but it may be formed on the entire surface of the base portion 22a. It may be formed only on the side surface. Also, FIG. 3 is a schematic diagram based on a scanning electron microscope (that is, SEM) photograph of the concavo-convex portion 20 formed by the manufacturing method described below.

All of the uneven portions 20 of the present embodiment are configured to contain a metal material. Specifically, the base portion 22a is configured to contain an easily oxidizable metal, and the active layer 22b is configured to contain a difficult-to-oxidize metal that is more difficult to oxidize than the base portion 22a. In this embodiment, the base portion 22a is mainly composed of at least one easily oxidizable metal such as Ni (nickel), Cu (copper), Al (aluminum), Fe (iron), or the like. ing. The active layer 22b is mainly composed of at least one metal, such as Au (gold), Ag (silver), or Pt (platinum), which is more difficult to oxidize than the base portion 22a. In this embodiment, the entire substrate 10 is also made of an easily oxidizable metal.

The above is the configuration of the substrate 1 for the SERS method in this embodiment. Such a SERS method substrate 1 is used to identify an analyte in which a sample is dissolved in a liquid. Specifically, when the object to be analyzed is attached to the concave-convex portion 20 of the substrate 1 for the SERS method and is irradiated with a laser beam, the microstructure (i.e., the gap) generated by the plasmon resonance induced by the laser beam is detected in or in the gap. The presence of the analyte in a strong nearby electric field enhances the inherently weak SERS spectrum. Therefore, the analyte is identified by acquiring an enhanced SERS spectrum. For example, as shown in FIG. 4, when the analyte is a solution of 4,4-bipyridine dissolved in ultrapure water, it has a peak corresponding to 4,4-bipyridine. A SERS spectrum is obtained. Although not shown here, the substrate 1 for the SERS method is held by a predetermined fixture, and the object to be analyzed is applied to the concave and convex portions 20, and then irradiated with a laser beam.

Further, the substrate 1 for the SERS method of this embodiment is manufactured by a manufacturing method described later. Then, when the inventors examined the SERS method substrate 1 of the present embodiment, the SERS method substrate 1 of the present embodiment did not have a clear theory, but as shown in FIG. It was confirmed that the distance between the base portions 22a of the two unevennesses 22 is about 10 to 20 nm, and the width of the base portions 22a is about 10 to 20 nm. Here, the interval between the base portions 22a is the interval between the adjacent base portions 22a on the leading end side in the projecting direction, and the width of the base portions 22a is the thickness of the root portion of the base portions 22a.

On the other hand, when the base portion 22a is made of silicon by irradiating a silicon substrate with a laser beam as in the conventional art, the distance between the base portions is about 10 to 20 nm, which is about the same as in the present embodiment. is known to be about 100 to 150 nm. Therefore, in the SERS method substrate 1 of the present embodiment, it is possible to form the gaps between the base portions 22a more densely than in the conventional SERS method substrate. Therefore, when the object of analysis is attached to the concave-convex portion 20, the area in which the object of analysis can be placed increases, and the sensitivity can be improved.

The above is the configuration of the substrate 1 for the SERS method in this embodiment. Next, a method for manufacturing the substrate 1 for the SERS method will be described.

First, as shown in FIG. 5A, a substrate 10 is prepared. In this embodiment, a substrate 10 entirely composed of an easily oxidizable metal is prepared.

Next, as shown in FIG. 5B, by irradiating a laser beam L onto the uneven portion forming region 20a of the substrate 10, the substrate particles 100 are scattered and deposited to form the first uneven portion 21 and the second uneven portion. 22 forming a base portion 22a.

Specifically, in this embodiment, the substrate 10 is irradiated with a pulse laser as the laser beam L. As shown in FIG. In this case, for example, Nd:YAG (neodymium: yttrium aluminum garnet) or the like is prepared as a laser light source. When Nd:YAG is used as the laser light source, the laser beam L has a wavelength of 1064 nm, which is the fundamental wavelength, or 533 nm or 355 nm, which is its harmonic. Further, when Nd:YAG is used as the laser light source, the laser beam L has an irradiation spot diameter of 5 to 300 μm, an energy density of 1 to 100 J/cm ² , and a pulse width (that is, irradiation time per spot) of 10 to 1000 ns. These conditions are only examples, and various conditions can be adopted depending on the application. For example, the pulse width may be femtoseconds or picoseconds.

Then, as shown in FIG. 6, when irradiating the substrate 10 with the laser beam L, each region in the concavo-convex portion forming region 20a is sequentially irradiated along the arrow A in the drawing. The laser beam L is irradiated while the laser light source and the substrate 10 are relatively moved. In this case, in this embodiment, since a pulsed laser as the laser beam L is irradiated, the laser beam L is irradiated so that the irradiation spots S of the laser beam L overlap.

It should be noted that the laser light source and the substrate 10 do not have to move relative to each other as long as each region in the concavo-convex portion forming region 20a is irradiated in order. For example, the laser beam L may be irradiated using a so-called galvanometer scanner in which a mirror is arranged on the laser light source side and the laser beam L is scanned by rotating the mirror.

Then, by irradiating the substrate 10 with the laser beam L, the substrate particles 100 are scattered and deposited from the one surface 10a side of the substrate 10, thereby forming the base portion 22a of the first unevenness 21 and the second unevenness 22. In this case, since the first irregularities 21 are formed by irradiating the laser beam L, they are micro-order irregularities. Moreover, since the base portion 22a of the second unevenness 22 is formed by accumulating the scattered substrate particles 100, it has nano-order unevenness. Specifically, the base portion 22a of the second unevenness 22 is formed by laminating a plurality of substrate particles 100 .

Here, when the one surface 10a side of the substrate 10 is composed only of a hard-to-oxidize metal such as Au or Ag, and the substrate particles 100 scattered by irradiation with the laser beam L are only particles of a hard-to-oxidize metal such as Au or Ag. According to the studies of the present inventors, it was confirmed that the nano-order second unevenness 22 is difficult to form. It is presumed that this is because when the hard-to-oxidize metal scatters and deposits, it does not oxidize, so the energy retained during deposition increases, and rearrangement makes it difficult to form nano-order unevenness.

Therefore, in this embodiment, the substrate 10 is made of an easily oxidizable metal. In other words, the portion that is scattered by the laser beam L is composed of the easily oxidizable metal. Therefore, when the laser beam L irradiates and scatters, the retained energy is reduced by oxidation, and rearrangement during deposition is suppressed. Thereby, the base portion 22a of the second unevenness 22 is formed as described above.

After that, although not shown, the active layer 22b made of a hard-to-oxidize metal such as Au or Ag is formed on the surface of the base portion 22a by sputtering. As a result, as shown in FIG. 3, a second unevenness 22 having an active layer 22b mainly composed of a hard-to-oxidize metal is formed on the surface of the base portion 22a. A substrate 1 is constructed.

In the present embodiment described above, since the base portions 22a of the second unevenness 22 are made of an easily oxidizable metal, the interval between the base portions 22a of the second unevenness 22 can be set to about 10 to 20 nm. For this reason, in the SERS method substrate 1 of the present embodiment, the gaps between the base portions 22a are densely formed as compared with the conventional SERS substrate in which the base portion is made of silicon. be able to. Therefore, when the object of analysis is attached to the concave-convex portion 20, the area in which the object of analysis can be placed increases, and the sensitivity can be improved.

Moreover, in the present embodiment, the active layer 22b is formed by the sputtering method, so that the active layer 22b can be easily formed.

Furthermore, in this embodiment, when the laser beam L is applied, a pulsed laser is applied. For this reason, for example, compared to the case of irradiating a CW (Continuous Wave) laser as the laser beam L, it is possible to suppress the temperature in the vicinity of the region irradiated with the laser beam L from becoming too high, and the base portion 22a is preferably Can be configured.

(Second embodiment)
A second embodiment will be described. In this embodiment, grooves are formed in the substrate 10 in contrast to the first embodiment. Others are the same as those of the first embodiment, so description thereof is omitted here.

In the present embodiment, as shown in FIGS. 7 and 8 , the SERS substrate 1 has a frame-shaped groove 30 formed in the substrate 10 so as to surround the uneven portion 20 . In this embodiment, the groove portion 30 corresponds to the stepped portion. Note that FIG. 7 corresponds to a cross section along line VII-VII in FIG.

Such a groove 30 is formed by, for example, irradiating the region where the groove 30 is to be formed with the laser beam L for forming the uneven portion 20 a plurality of times to make the groove 30 deeper than the recesses in the first unevenness 21 of the uneven portion 20. It consists of Moreover, such a groove portion 30 is formed by etching or the like, for example.

According to this, it is possible to obtain the same effect as the above-described first embodiment while suppressing the spread of the analysis target in the planar direction by the groove 30 when the analysis target is adhered to the uneven part 20. .

(Third embodiment)
A third embodiment will be described. In this embodiment, the manufacturing method of the uneven portion 20 is changed from that of the first embodiment. Others are the same as those of the first embodiment, so description thereof is omitted here.

In this embodiment, as shown in FIG. 9A, when the substrate 10 is prepared, a first metal layer 11 made of an easily oxidizable metal and a second metal layer 12 made of a difficult-to-oxidize metal are formed on the one surface 10a side. is prepared. In this embodiment, the second metal layer 12 is laminated on the first metal layer 11 is prepared. However, the first metal layer 11 may be laminated on the second metal layer 12 .

Then, as shown in FIG. 9B, the laser beam L is irradiated to scatter the first particles 110 from the first metal layer 11 and to scatter the second particles 120 from the second metal layer 12 . In this embodiment, when one irradiation spot S is irradiated with the laser beam L, the first particles 110 are scattered from the first metal layer 11 and the second particles 120 are scattered from the second metal layer 12. The energy density, etc. are adjusted accordingly.

In this case, the uneven structure is not formed in the portion where the second particles 120 are deposited before the first particles 110 are deposited, as described above, because the energy retained is large. However, the portion where the first particles 110 are deposited constitutes the base portion 22a of the second unevenness 22, and the deposition of the second particles 120 on the base portion 22a constitutes the active layer 22b. That is, in the present embodiment, by irradiating the substrate 10 with the laser beam L, the base portion 22a and the active layer 22b are formed in the same step.

In the present embodiment, since the first particles 110 and the second particles 120 are scattered at the same time, the second particles 120 may be included inside the base portion 22a, but there is no particular problem.

In the present embodiment described above, the substrate 10 having the first metal layer 11 and the second metal layer 12 laminated is prepared, and the substrate 10 is irradiated with the laser beam L to form the uneven portion 20. . Therefore, it is not necessary to form the active layer 22b by a separate process such as sputtering, and the manufacturing process can be simplified.

(Modified example of the third embodiment)
A modification of the third embodiment will be described. In the third embodiment, the laser beam L may be applied as follows. That is, when the laser beam L is first applied, only the second particles 120 are scattered from the second metal layer 12 as shown in FIG. 10A. Then, as shown in FIG. 10B, when the laser beam L is irradiated next, the laser beam is arranged so as to have a portion that overlaps with the portion irradiated with the laser beam L first (that is, the irradiation spot S overlaps). By irradiating the beam L, the first particles 110 are scattered from the first metal layer 11 in the overlapped portion, and the second particles 120 are scattered from the second metal layer 12 in the non-overlapping portion. Even in this case, since the base portion 22a and the active layer 22b are formed by one irradiation of the laser beam L, the manufacturing process can be simplified.

(Fourth embodiment)
A fourth embodiment will be described. In this embodiment, a plurality of uneven portions 20 are formed on a substrate 10 in contrast to the first embodiment. Others are the same as those of the first embodiment, so description thereof is omitted here.

In this embodiment, as shown in FIG. 11, the substrate 1 for the SERS method has a structure in which a plurality of uneven portions 20 are formed on the substrate 10 . Each uneven portion 20 has a second uneven portion 22 having a base portion 22a and an active layer 22b, as in the first embodiment.

And in this embodiment, each uneven part 20 is formed so that the structure of the 2nd unevenness|corrugation 22 mutually differs. Specifically, each uneven portion 20 is different in height, interval, etc. of the second uneven portions 22 . Each uneven portion 20 is formed by appropriately changing the conditions for irradiating the substrate 10 with the laser beam L as described above.

Since the present embodiment described above has a plurality of concave-convex portions 20 , each concave-convex portion 20 can identify an object to be analyzed. Here, for example, when only one concave-convex portion 20 is formed on the substrate 10, it is necessary to prepare the substrate 10 for each object to be analyzed. Become. Therefore, by forming a plurality of concave-convex portions 20 on the substrate 10 as in the present embodiment, the substrate 10 can be effectively utilized, thereby improving economic efficiency.

In this embodiment, each uneven portion 20 has a different configuration of the second uneven portion 22 . Moreover, the sensitivity of the SERS method also changes depending on the relationship between the analyte and the shape of the second unevenness 22 . For this reason, by making the shape of each second unevenness 22 different and applying the analyte to the second unevenness 22 suitable for the analysis of the analyte, a plurality of analytes can be detected with higher sensitivity. can be detected by

(Fifth embodiment)
A fifth embodiment will be described. In contrast to the first embodiment, the present embodiment defines the configuration of the fixing jig when performing the SERS method. Others are the same as those of the first embodiment, so description thereof is omitted here.

As described above, the SERS substrate 1 is held by a fixture when the object to be analyzed is adhered to the concave-convex portion 20 of the SERS substrate 1 and irradiated with the laser beam L. In this embodiment, as shown in FIG. 11, the fixing jig 40 is configured to have a housing jig 50 and a pressing jig 60 .

The accommodation jig 50 is formed with an accommodation recess 51 in which the SERS substrate 1 is accommodated. The housing recess 51 is made larger than the outer shape of the substrate 1 for the SERS method. The pressing jig 60 has a frame shape with a hole portion 61 formed therein, and has a plurality of protrusions 62 on one surface 60 a facing the bottom surface of the housing recess portion 51 . In addition, the plurality of convex portions 62 are formed, for example, four pieces, and are arranged rotationally symmetrically about the hole portion 61 so as to be spaced apart from each other. Moreover, although not shown, a pair of fitting portions are formed in the housing jig 50 and the pressing jig 60 .

The pressing jig 60 is arranged in the housing recess 51 of the housing jig 50 in a state in which the SERS substrate 1 is housed in the housing recess 51, and is fixed to the housing jig 50 by a pair of fitting portions. be done. Specifically, the pressing jig 60 is fixed to the housing jig 50 so that the uneven portion 20 is exposed from the hole portion 61 and the SERS method substrate 1 is pressed and fixed by the convex portion 62 . . At this time, since the plurality of protrusions 62 are arranged at intervals, the protrusions 62 are not formed between the one surface 60a of the pressing jig 60 and the one surface 10a of the substrate 10 of the substrate 1 for the SERS method. A gap is formed in the part. In addition, since the housing recess 51 in the housing jig 50 is larger than the outer shape of the SERS substrate 1 , a gap is also formed between the housing recess 51 and the SERS substrate 1 .

The above is the basic configuration of the fixing jig 40 in this embodiment. When specifying the analysis target 70 , the analysis target 70 is arranged from the hole 61 to the concave-convex portion 20 . In this case, the analysis target 70 contains a liquid, and is arranged on the uneven portion 20 by being applied to the uneven portion 20 .

Here, when the analysis object 70 is applied to the uneven portion 20 , the analysis object 70 may wet and spread from the uneven portion 20 to the periphery of the uneven portion 20 . Further, as described above, a gap is formed between the one surface 60a of the pressing jig 60 and the one surface 10a of the substrate 10 of the SERS method substrate 1, and between the accommodation recess 51 and the SERS method substrate 1. There are also gaps. Therefore, when the wettability between the liquid (that is, the solution) contained in the analysis object 70 and the fixing jig 40 is high, the wetting and spreading of the analysis object 70 is promoted, and the analysis object is separated from the uneven portion 20 . There is concern that the object 70 will be lost.

Therefore, in the present embodiment, the portion of the fixing jig 40 that can be contacted by the analyte 70 has wettability with the liquid of the analyte 70 rather than the substrate 1 for the SERS method (hereinafter simply referred to as wettability). ) is configured to be small. In this embodiment, the accommodation jig 50 is configured such that the wall surface of the accommodation recess 51 that accommodates the SERS substrate 1 has lower wettability than the SERS substrate 1 . The pressing jig 60 is configured such that a surface 60 a facing the SERS substrate 1 has lower wettability than the SERS substrate 1 .

For example, in this embodiment, when water is used as the liquid in the object to be analyzed 70, the housing jig 50 and the pressing jig 60 are entirely made of polypropylene, polyethylene, polydimethylsiloxane, Teflon, or the like.

When the liquid in the analyte 70 is a polar organic solvent such as ethanol, acetonitrile, or ethyl acetate, the housing jig 50 and the pressing jig 60 are entirely made of Teflon or the like.

When the liquid in the analyte 70 is a non-polar organic solvent such as toluene or decane, the housing jig 50 and the pressing jig 60 are entirely made of nylon, polyvinyl alcohol, polyacrylamide, or the like.

In the present embodiment described above, the portion of the fixing jig 40 that can come into contact with the object to be analyzed 70 is configured to have lower wettability than the substrate 1 for the SERS method. Therefore, even if the analysis target 70 comes into contact with the fixing jig 40 , it is suppressed that the analysis target 70 spreads out, and it is possible to suppress the problem that the analysis target 70 disappears from the concave-convex portion 20 .

In the above description, an example in which the housing jig 50 and the pressing jig 60 as a whole are configured to have lower wettability than the substrate 1 for the SERS method has been described. However, the housing jig 50 and the pressing jig 60 need only be configured so that the wettability of the portion with which the object to be analyzed 70 can come into contact is low. For example, in the housing jig 50, a coating film that reduces wettability is formed on the wall surface of the housing recess 51 that houses the SERS substrate 1 so that the wettability of the wall surface of the housing recess 51 is lower than that of the SERS substrate 1. It may be configured as follows. The pressing jig 60 is configured such that a coating film that reduces wettability is formed on the surface 60a so that the surface 60a facing the substrate 1 for the SERS method has lower wettability than the substrate 1 for the SERS method. may be

Furthermore, at least a part of the housing jig 50 and the pressing jig 60 may be configured to have lower wettability than the substrate 1 for the SERS method. For example, only a part of the one surface 60a of the pressing jig 60 is configured to have lower wettability than the substrate 1 for the SERS method, and the housing jig 50 is configured to have higher wettability than the substrate 1 for the SERS method. may have been Even with such a fixing jig 40, it is possible to suppress the spread of the analysis target 70 in a portion where the wettability is low, and to obtain the same effect as described above.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and can be appropriately modified within the scope of the claims.

For example, in each of the above embodiments, an example in which the workpiece is the substrate 10 has been described, but the workpiece may be another member. For example, a physical quantity sensor that detects a physical quantity such as the flow rate of a measurement medium is mounted on the mounted member such that the sensing portion that measures the flow rate is exposed to the measurement medium. In this case, a portion of the portion exposed to the measurement medium may be the object to be processed, the uneven portion 20 may be formed on the portion, and the measurement medium may be the object to be analyzed.

Further, in each of the above-described embodiments, when the substrate 10 is irradiated with the laser beam L, the laser beam L does not irradiate the entire region in the concave-convex portion forming region 20a. good. For example, when irradiating the substrate 10 with the laser beam L, the irradiation spots S may not overlap each other. That is, the substrate 10 may be irradiated with the laser beam L in dots. Further, for example, the laser beam L may be irradiated along two orthogonal directions so that a plurality of rectangular regions to which the laser beam L is not irradiated are formed in the concave-convex portion forming region 20a. In this case, the concave-convex portion 20 may be composed only of the second concave-convex portion 22 formed in the region where the laser beam L is not irradiated.

In the first and second embodiments described above, the substrate 10 may not be entirely made of an easily oxidizable metal, and at least a portion that scatters when irradiated with the laser beam L is made of an easily oxidizable metal. It is good if there is For this reason, the substrate 10 may have, for example, a structure in which a metal layer made of an easily oxidizable metal is laminated on a silicon substrate. Similarly, in the above third embodiment, the substrate 10 may have a configuration in which a first metal layer 11 and a second metal layer 12 are laminated on a silicon substrate.

In the first and second embodiments described above, the active layer 22b may be formed by applying a solution containing Au or Ag nanoparticles to the base portion 22a instead of the sputtering method. According to this, it becomes easy to form the active layer 22b only on the base portion 22a, and the material can be reduced.

Further, in the above-described second embodiment, instead of forming the groove portion 30 as the stepped portion, a convex portion may be formed as the stepped portion.

10 substrate (workpiece)
10a One surface 20 Concavo-convex portion 22a Base portion 22b Active layer

Claims (5)

A workpiece (10) having an uneven portion (20) formed on one surface (10a) side,
The uneven portion has a base portion (22a) forming an uneven structure and an active layer (22b) formed on the surface of the base portion,
The base portion is composed of a material containing an easily oxidizable metal as a main component,
A method for producing a substrate for surface-enhanced Raman spectroscopy, wherein the active layer is made of a material mainly composed of a difficult-to-oxidize metal that is more difficult to oxidize than the easily-oxidizable metal,
providing the workpiece having the one surface;
forming the base portion on the one surface and forming the active layer on the surface of the base portion to form the uneven portion;
In forming the base portion, the base portion is formed by irradiating the work piece with a laser beam (L) to scatter and deposit a part of the work piece,
By preparing the workpiece , the first metal layer (11) made of a material containing the easily oxidizable metal as a main component and the difficult-to- preparing a second metal layer (12) composed of a material containing metal oxide as a main component and arranged in a laminated manner;
By forming the uneven portion, the first metal layer and the second metal layer are scattered by irradiating the workpiece with the laser beam to form the base portion and the active layer in the same process. A method for producing a substrate for forming surface-enhanced Raman spectroscopy. 2. The method of manufacturing a substrate for surface-enhanced Raman spectroscopy according to claim 1 , wherein forming the base portion includes irradiating the workpiece with a pulse laser as the laser beam. A workpiece (10) having an uneven portion (20) formed on one surface (10a) side,
The uneven portion has a base portion (22a) forming an uneven structure and an active layer (22b) formed on the surface of the base portion,
The base portion is composed of a material containing an easily oxidizable metal as a main component,
A method for producing a substrate for surface-enhanced Raman spectroscopy, wherein the active layer is made of a material mainly composed of a difficult-to-oxidize metal that is more difficult to oxidize than the easily-oxidizable metal,
providing the workpiece having the one surface;
forming the base portion on the one surface and forming the active layer on the surface of the base portion to form the uneven portion;
In forming the base portion, the base portion is formed by irradiating the work piece with a laser beam (L) to scatter and deposit a part of the work piece,
Preparing the workpiece includes preparing the workpiece in which at least a material containing the easily oxidizable metal as a main component is present in a portion that scatters when irradiated with the laser beam ,
The method of manufacturing a substrate for surface-enhanced Raman spectroscopy , wherein forming the base portion includes irradiating the workpiece with a pulse laser as the laser beam . 4. The method of manufacturing a substrate for surface-enhanced Raman spectroscopy according to claim 3 , wherein forming the active layer comprises forming the active layer by a sputtering method. 4. The method of manufacturing a substrate for surface-enhanced Raman spectroscopy according to claim 3 , wherein forming the active layer includes applying a solution containing particles of the hard-to-oxidize metal to the base portion to form the active layer.

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