Method for manufacturing microstructure, microstructure, microstructure transfer body, and protein adsorption repressor

Abstract

To provide a method for manufacturing a microstructure having a microneedle structure, the microstructure, a microstructure transfer body, and a protein adsorption repressor.SOLUTION: This method for manufacturing the microstructure comprises: a step of scanning with a first effective pulse number along a first locus by a laser spot on a base material surface to form a first minute microneedle groove structure which is periodically formed in self-organization with a first depth along the first locus; and a step of scanning with a second effective pulse number different from the first effective pulse number along a second locus by a laser spot to form a second munite microneedle groove structure which is periodically formed in self-organization with a second depth along the second locus. The first effective pulse number P1 satisfies a following expression (1) below, and the second effective pulse number P2 satisfies a following expression (1'): 20<P1<2000,,,(1); 20<P2<2000,,,(1').SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a method for producing a microstructure, a microstructure, a microstructure transfer body, and a protein adsorption inhibitor. [Background technology]

[0002] A method for manufacturing a water-repellent surface structure is known in which a periodic structure is self-organized on the surface of a substrate by irradiating the substrate with a laser and scanning the irradiated areas while overlapping them, thereby compounding the surface of the periodic structure with a roughness of 100 nm or less (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6130004 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the periodic structure described in Patent Document 1 has submicron dimensions, such as a pitch of about 900 nm and a depth of 250 nm, and even if the surface of the periodic structure is compounded with roughness of 100 nm or less, the effect of inhibiting protein adhesion was low.

[0005] An object of the present invention is to provide a method for producing a microstructure having a fine needle-like groove structure, a microstructure, a microstructure transfer body, and a protein adsorption inhibitor. [Means for solving the problem]

[0006] The method for producing a microstructure according to the present invention is a method for producing a microstructure by processing a surface of a substrate with a short pulse laser having a laser spot diameter D and a repetition frequency F, comprising the steps of: On the substrate surface, by scanning along the first trajectory with a laser spot for the first effective number of pulses, a fine first needle-shaped groove structure that is self-organized and periodically formed is formed at the first depth along the first trajectory. On the substrate surface, by scanning along the second trajectory with a laser spot for a second effective number of pulses different from the first effective number of pulses, a fine second needle-shaped groove structure that is self-organized and periodically formed is formed at a second depth different from the first depth along the second trajectory, and the method has a step. The first effective number of pulses P1 satisfies the following formula (1): The second effective number of pulses P2 satisfies the following formula (1'): 20 < P1 < 2000 (1) 20 < P2 < 2000 (1') The polarization direction of the laser spot scanning along the first trajectory is parallel to the traveling direction of the first trajectory.

[0007] In the method for manufacturing a microstructure according to the present invention, when W1 ≥ D and W2 ≥ D, The first effective number of pulses P1 satisfies the following formula (2): P1 = F·D·S1 / V1 (2) The second effective number of pulses P2 satisfies the following formula (3): P2 = F·D·S2 / V2 (3) When W1 < D and W2 < D, The first effective number of pulses P1 satisfies the following formula (2'): P1 = F·D 2 ·S1 / (V1·W1) (2') The second effective number of pulses P2 satisfies the following formula (3'): P2 = F·D 2 ·S2 / (V2·W2) (3') Here, S1 is the number of scanning times along the first trajectory, V1 is the scanning speed of the laser spot along the first trajectory, S2 is the number of scanning times along the second trajectory, V2 is the scanning speed of the laser spot along the first trajectory, W1 is the scanning position interval of the laser spot along the first trajectory, and W2 is the scanning position interval of the laser spot along the second trajectory. It is preferred.

[0008] In the method for manufacturing a microstructure according to the present invention, the polarization direction of the laser spot that scans along the second locus is preferably parallel to the traveling direction of the second locus.

[0009] In the method for manufacturing a microstructure according to the present invention, the first locus and the second locus are preferably parallel or perpendicular to each other.

[0010] In the method for manufacturing a microstructure according to the present invention, when the first locus and the second locus are perpendicular, it is preferable that in a region where a scan performed by the laser spot along the first locus with a first effective pulse number overlaps with a scan performed by the laser spot along the second locus with a second effective pulse number, a fine third needle-shaped groove structure is formed periodically in a self-organized manner at a third depth different from the first depth and the second depth.

[0011] In the method for manufacturing a microstructure according to the present invention, it is preferable that a third locus other than the first locus and the second locus on the substrate surface is scanned with a laser spot along the third locus with a third effective pulse number P3, and that the third effective pulse number P3 satisfies the following equation (5). 20≦P3≦2000 (5)

[0012] The microstructure according to the present invention comprises: a substrate; and a first needle-shaped fine groove structure formed periodically in a self-organized manner along a first locus at a first depth on a surface of the substrate by scanning a laser spot of a short pulse laser having a spot diameter D and a repetition frequency F along a first locus at a first effective pulse number; The substrate surface has a fine second needle-shaped groove structure that is self-organized and periodically formed along a second trajectory at a second depth different from the first depth by scanning along the second trajectory with a laser spot of a short pulse laser at a second effective pulse number different from the first effective pulse number.

[0013] The microstructure transfer member according to the present invention is preferably formed by transferring from the microstructure described above as a master using a predetermined composition.

[0014] It is preferable that the protein adsorption inhibitor of the present invention is formed by using a specified composition and transferring from the microstructure described above as a master, and placing the microstructure transfer body in an area where protein adsorption is suppressed.

[0015] The microstructure transfer body of the present invention has first fine needle-like structures formed periodically at a first height and second fine needle-like structures formed periodically at a second height different from the first height, and it is preferable that the first height and the second height are 6 to 10 μm and the pitch at which the first needle-like structures and the second needle-like structures are formed is 3 to 5 μm. Effect of the Invention

[0016] The method for producing a microstructure, the microstructure, the microstructure transfer body, and the protein adsorption inhibitor according to the present invention make it possible to provide a microstructure having a fine needle-like groove structure, and the like. [Brief description of the drawings]

[0017] [Figure 1] 1 is a schematic diagram of a processing apparatus for carrying out a method for producing a microstructure according to the present invention; [Diagram 2] FIG. 1(a) is a diagram for explaining the principle of the method for manufacturing a microstructure according to the present invention, FIG. 1(b) is a diagram (1) showing the direction of the microstructure formed on the substrate and the laser characteristics, and FIG. 1(c) is a diagram (2) showing the direction of the microstructure formed on the substrate and the laser characteristics. [Diagram 3] (a) is an image showing an example of LIPSS, and (b) is an image showing an example of a needle-shaped groove structure. [Figure 4]FIG. 1(a) is an outline of an experiment to investigate the relationship between the effective pulse number and microstructures, and FIG. 1(b) is an outline of an experiment to investigate the relationship between the effective pulse number and microstructures. [Diagram 5] 4A and 4B are diagrams for explaining the relationship between a fine groove structure and a fine groove structure transferred body. [Figure 6] FIG. 1(a) is a diagram for explaining protein adhesion, and FIG. 1(b) is a diagram for explaining protein adhesion in a microstructure transfer body according to the present invention. [Figure 7] FIG. 2 is a diagram showing scanning of a laser spot in the first embodiment. [Figure 8] FIG. 4 is a diagram showing an in-plane distribution of the number of effective pulses in the first embodiment. [Figure 9] (a) is an image of the surface of the microstructure 100 manufactured as Example 1, (b) is a cross-sectional view of a portion of AA' in (a), (c) is a cross-sectional view of a portion of BB' in (a), (d) is a cross-sectional view of a portion of CC' in (a), (e) is a cross-sectional view of a portion of DD' in (a), and (f) is a cross-sectional view of a portion of EE' in (a). [Figure 10] 8(a) is an image of the surface of a microstructure transfer body 200 formed by transferring the microstructure 100 shown in FIG. 8(a) as a master, (b) is a cross-sectional view of a portion of FF' in (a), (c) is a cross-sectional view of a portion of GG' in (a), (d) is a cross-sectional view of a portion of HH' in (a), (e) is a cross-sectional view of a portion of II' in (a), and (f) is a cross-sectional view of a portion of JJ' in (a). [Figure 11] FIG. 11 is a diagram showing scanning of a laser spot in the second embodiment. [Figure 12] FIG. 13 is a diagram showing another example of an in-plane distribution of the number of effective pulses. [Figure 13] FIG. 1A is a diagram showing an example in which scanning with a laser spot is performed along a curved trajectory, and FIG. 1B is a diagram showing an example in which scanning with a laser spot is performed along a zigzag trajectory that combines multiple straight lines. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Various embodiments of the present disclosure will be described below with reference to the drawings. However, it should be noted that the technical scope of the present disclosure is not limited to these embodiments, but covers the inventions described in the claims and their equivalents.

[0019] 1 is a schematic diagram of a laser processing apparatus 1 for carrying out a method for manufacturing a microstructure according to the present invention. The laser processing apparatus 1 includes a short-pulse laser generator 2, a polarization modulation element 3, a dichroic mirror 4, an objective lens 5, and an observation optical system 6, and forms a microstructure on the surface of a substrate 10, which is a workpiece.

[0020] The short-pulse laser generator 2 emits an ultrashort pulsed laser beam 8 having an extremely narrow pulse width oscillated in femtosecond units. The laser beam 8 emitted from the short-pulse laser generator 2 is adjusted to a predetermined polarization direction 11 by a polarization modulation element 3, reflected by a dichroic mirror 4, and made incident on an objective lens 5. The laser beam 8 incident on the objective lens 5 is focused to form a laser spot having a diameter D (m) and irradiates the surface of a substrate 10. The focused laser spot is scanned along a predetermined scanning direction 12 on the surface of the substrate 10 by an optical mechanism (not shown) or the like. Hereinafter, the scanning direction 12 of the laser spot may also be referred to as a trajectory 12 of the laser spot.

[0021] The observation optical system 6 is an optical system for observing the surface of the base material 10 using reflected light 7 from the base material 10, and is provided in order to check the progress of the laser processing, etc. The observation optical system 6 is not necessarily provided since it is not directly related to the laser processing itself.

[0022] The polarization modulation element 3 is, for example, an optical element described in JP 2022-170578 A, and is composed of a wave plate and / or a liquid crystal element to rotate the polarization direction 11 of the laser light 8 parallel or perpendicular to the scanning direction 12. When changing the polarization direction 11 of the laser light 8 from parallel to perpendicular to the scanning direction 12 or from perpendicular to parallel during processing of the substrate 10, a polarization direction switching signal is sent from a control device (not shown) to the polarizing optical element 3 at a predetermined timing.

[0023] The substrate 10 may be a silicon wafer, but may also be made of other metal substrates or the like.

[0024] FIG. 2(a) is a diagram for explaining the principle of the method for manufacturing a microstructure according to the present invention, FIG. 2(b) is a diagram (1) showing the direction of the microstructure formed on the substrate and the laser characteristics, and FIG. 2(c) is a diagram (2) showing the direction of the microstructure formed on the substrate and the laser characteristics.

[0025] 2(a), during processing, laser light 8 having pulse energy near the processing threshold and a predetermined polarization direction 11 is irradiated from a short pulse laser generator 2 to a substrate 10 at a predetermined angle. Reflected lights 8-1 and 8-2 of the laser light 8 cause interference 40 with surface plasmons at predetermined periodic intervals, and processing of the microstructure progresses at points 41 and 42 on the surface of the substrate 10 where the interference is particularly emphasized. The pulse energy near the processing threshold refers to an energy level near the threshold at which the laser irradiation itself directly processes the substrate surface.

[0026] As shown in Fig. 2(b), when the scanning direction 12 of the laser 8 and the polarization direction 11 of the laser spot 20 are parallel, processing proceeds in a direction perpendicular to the scanning direction 12, as shown in cross section 43 of the microstructure. On the other hand, as shown in Fig. 2(c), when the scanning direction 12 of the laser 8 and the polarization direction 11 of the laser spot 20 are perpendicular, processing proceeds in a direction parallel to the scanning direction 12, as shown in cross section 44 of the microstructure.

[0027] When the scanning direction 12 of the laser 8 and the polarization direction 11 of the laser spot 20 are parallel (as in FIG. 2(b)), the scanning direction 12 of the laser light 8, which is the processing light, is parallel to the lattice vector of the microstructure. On the other hand, when the scanning direction 12 of the laser 8 and the polarization direction 11 of the laser spot 20 are perpendicular (as in FIG. 2(c)), the scanning direction 12 of the laser light 8, which is the processing light, is perpendicular to the lattice vector of the microstructure. When the scanning direction 12 of the laser light 8 is parallel to the lattice vector of the microstructure, the processing trace surface becomes flat in the lattice vector direction, and the laser light 8 and the surface plasmon interfere more strongly, resulting in a steeper microstructure. That is, the grooves are formed to be deeper in the cross section 43 of the microstructure than in the cross section 44 of the microstructure.

[0028] Based on the above-mentioned principle, by irradiating the surface of the substrate 10 with laser light 8, a microstructure called a LIPSS (Laser Induced Periodical Surface Structure) or a needle-like groove structure is formed in a self-organizing manner on the surface of the substrate 10.

[0029] FIG. 3(a) is an image showing an example of LIPSS, and FIG. 3(b) is an image showing an example of a needle-shaped groove structure.

[0030] FIG. 3(a) shows an example of a LIPSS formed when a laser spot 20 having a polarization direction 11 is scanned in a scanning direction 12 by a laser processing device 1. FIG. 3(b) shows an example of a needle-shaped groove structure formed when a laser spot 20 having a polarization direction 11 is scanned in a scanning direction 12 by a laser processing device 1. From FIG. 3(a) and FIG. 3(b), it can be seen that in a LIPSS, a groove portion is merely formed, whereas in a needle-shaped groove structure, multiple fine needle-shaped groove structures are formed deeply. As a result of the experiment, it was confirmed that whether the fine structure formed by scanning a laser beam becomes a LIPSS or a needle-shaped groove structure depends on the effective pulse number of a laser beam 8.

[0031] FIG. 4(a) is a diagram (1) showing an overview of an experiment for examining the relationship between the number of effective pulses and the microstructure, and FIG. 4(b) is a diagram (2) showing an overview of an experiment for examining the relationship between the number of effective pulses and the microstructure. FIG. 4(a) shows the case where the scanning position interval W of the laser spot 20 along the first locus 12 is equal to or greater than the diameter D (m) of the laser spot (W ≧ D), and FIG. 4(b) shows the case where the scanning position interval W of the laser spot 20 along the first locus 12 is less than the diameter D of the laser spot (W < D).

[0032] As shown in FIG. 4(a), a silicon wafer was used as the substrate 10, and laser processing was performed on the substrate 10 using a laser processing apparatus 1. The number of effective pulses P was varied, and the microstructure formed in the processing region 45 was observed. In the experiment, the repetition frequency of the short-pulse laser generator 2 was “F (Hz)”, the laser spot 20 of the irradiated laser light 8 had a diameter D (m), and the linearly polarized light (polarization direction 11) vibrated in the direction of the locus 12 of the laser spot 20. Also, the number of scans at the laser spot 20 was designated as “S” and the scanning speed was designated as “V (m / s)”. The number of effective pulses P in this case is represented by the following formula (2). Note that the number of scans indicates how many times the same position was traced and scanned. P = F·D·S / V ···(2)

[0033] The number of effective pulses P in the case of FIG. 4(b) is represented by the following formula (2´). P = F·D 2 ·S / (V·W) ···(2´)

[0034] In both cases of FIGS. 4(a) and (b), when the number of effective pulses P is 20 or less, a needle-shaped groove structure is not formed with a high probability, and LIPSS (see FIG. 3(a)) is formed. Note that when the number of effective pulses P = 0, the surface of the substrate 10 is not processed.

[0035] In both cases of Figures 4(a) and (b), it was confirmed that when the effective pulse number P is greater than 20 and less than 2000, a needle-shaped groove structure (see Figure 3(b)) is formed on the surface of the substrate 10. In other words, when the effective pulse number P reaches a certain level or more, the LIPSS state transitions to a state in which a needle-shaped groove structure is formed. Furthermore, in both cases of Figures 4(a) and (b), it was confirmed that when the effective pulse number P is 2000 or more, the number of pulses is too large and a needle-shaped groove structure (see Figure 3(b)) is not formed.

[0036] From the above, it was confirmed that when the effective pulse number P satisfies the following formula (1), a self-organized, periodic, and fine needle-like groove structure is formed on the surface of the base material 10. 20 <P<2000···(1)

[0037] Furthermore, it was confirmed that, in the trajectory 12 of the laser spot, when the number of effective pulses P was changed within a range satisfying the above formula (1), the depth of the needle-shaped groove structure was variable according to the number of effective pulses P. Specifically, the depth of the needle-shaped groove structure in the region where P=120 was approximately 6 μm, the depth of the needle-shaped groove structure in the region where P=240 was approximately 8 μm, and the depth of the needle-shaped groove structure in the region where P=360 was approximately 10 μm. Furthermore, in the scanning direction 12, the needle-shaped groove structure was formed periodically at a pitch of approximately 3 to 5 μm in all cases where P=120, 240, and 360. In other words, it was confirmed that the depth of the needle-shaped groove structure could be varied for each region by varying the number of effective pulses P.

[0038] Fig. 5 is a diagram for explaining the relationship between a fine groove structure and a fine groove structure transfer body. It is also possible to use a substrate 10 having a surface of a fine needle-like groove structure formed in a self-organized and periodic manner as an original plate to transfer the needle-like groove structure to a polymer material substrate (for example, a silicone resin such as PDMS (polydimethylsiloxane)). In Fig. 5, the fine structure 100 includes a first region 111 in which a first needle-like groove structure 101 having a first depth (d1) is formed, and a second region 112 in which a second needle-like groove structure 102 having a second depth (d2) different from the first depth is formed.

[0039] The transferred microstructure transfer body 200 has a plurality of types of needle-like structures with different heights, unlike the substrate 10, and is configured to include a first needle-like structure 201 with a first height (h1) which is a transferred portion of the first needle-like groove structure 101, and a second needle-like structure 202 with a second height (h2) different from the first height which is a transferred portion of the second needle-like groove structure 102. As described above, when the microstructure 100 includes needle-like groove structures having a depth of 6 to 10 μm and arranged periodically with a pitch of 3 to 5 μm, the microstructure transfer body 200 was formed to include needle-like structures having a height of 6 to 10 μm and arranged periodically with a pitch of 3 to 5 μm.

[0040] FIG. 6(a) is a diagram for explaining the adhesion of proteins to a normal substrate, and FIG. 5(b) is a diagram for explaining the adhesion of proteins to a microgroove structure transfer body according to the present invention.

[0041] 6(a) shows a state in which a protein 51 is attached to a hydrophobic substrate 50. Since the protein 51 is composed of hydrophilic groups 52 and hydrophobic groups 53, there is a possibility that the protein may attach to the hydrophobic groups 53 even if the substrate 50 is hydrophobic. Therefore, even if a microchannel or the like is composed only of a hydrophobic substrate 50, when a liquid containing a protein is handled, the protein may be adsorbed to the channel, causing blockage of the channel and variation in the protein concentration in the channel.

[0042] FIG. 6(b) shows the relationship between a protein 51 and a microstructure transfer body 200 obtained by transferring a microstructure 100 formed by the method for producing a microstructure according to the present invention.

[0043] 6(b), for example, when a microchannel or the like is formed using the microstructure transfer body 200, an air layer 220 or the like is formed in the gap between the needle-like structures 201 and 202 of different heights, and the contact area between the needle-like structures 201 and 202 of different heights and the protein 51 is extremely reduced, suppressing adhesion of the protein. Therefore, when a microchannel or the like is formed using the microstructure transfer body 200 according to the present invention, even when a liquid containing a protein is handled, the protein is not adsorbed to the channel, and blockage of the channel and variation in protein concentration in the channel do not occur.

[0044] In order to prevent protein adsorption, a method of chemically treating the substrate surface with a chemical solution or gas is known, but chemical treatment with a chemical solution or gas has problems such as sample contamination due to elution of the chemical solution and a decrease in the protein adsorption suppression effect over time. In addition, a microchannel is usually manufactured by bonding a substrate having a microchannel to a substrate that functions as a lid for the microchannel, but if a chemical treatment is performed before bonding, there is a problem that the adhesion of the substrates is significantly hindered. Therefore, there is a great advantage in being able to suppress protein adhesion using only the microstructure transfer body 200 according to the present invention without the above-mentioned chemical treatment.

[0045] In order to enhance the protein adhesion suppression effect, it is necessary that the microstructure transfer body 200 is configured to include a plurality of types of needle-like structures with different heights, as shown in Fig. 6(b). For this purpose, in a first region 111 on the surface of the base material 10 serving as the original, a first needle-like groove structure 101 having a first depth that is formed periodically in a self-organizing manner is formed by scanning with a first effective pulse number P1 (see formula (2) or (2')) by the laser spot 20, and in a second region 112 on the surface of the base material 10, a second needle-like groove structure 102 having a second depth that is formed periodically in a self-organizing manner is formed by scanning with a second effective pulse number P2 (see formula (3) or (3')) different from the first effective pulse number P1 by the laser spot 20, and the first effective pulse number P1 must satisfy the following formula (1), and the second effective pulse number P2 must satisfy the following formula (1'). 20 <P1<2000 (1) 20 <P2<2000 (1´)

[0046] 6, the microstructure transfer body 200 according to the present invention has been described, but the original microstructure 100 can also be called a protein adsorption inhibitor. Note that a microchannel or the like in which the microstructure transfer body according to the present invention is arranged only in the places where it is desired to inhibit protein adhesion can also be called a protein adsorption inhibitor. EXAMPLES

[0047] FIG. 7 is a diagram showing scanning of a laser spot in Example 1. In Example 1, a laser processing device 1 was used, and a silicon wafer was used as the substrate 10. A range 23 on the surface of the substrate 10 was scanned along a first trajectory 12 with an effective pulse number P1 (120) using a laser spot 20. Furthermore, a similar scan was performed on the surface of the substrate 10 from the top to the bottom in the figure, skipping one line at a total of four locations. In this scan, the direction of the first trajectory 12 of the laser spot 20 and the polarization direction 11 of the laser light are parallel to each other.

[0048] Next, scanning was performed in a range 24 on the surface of the substrate 10 using the laser spot 21 along the second locus 13 with an effective pulse number P2 (240). Furthermore, similar scanning was performed at a total of three locations on the surface of the substrate 10, skipping one line from the top to the bottom in the figure. In this scanning, the direction of the second locus 13 of the laser spot 20 and the polarization direction 11 of the laser light are parallel to each other.

[0049] Next, in the range 25 on the surface of the substrate 10, scanning was performed along the third trajectory 14 with the effective pulse number P1 (120) using the laser spot 22. Furthermore, similar scanning was performed on the surface of the substrate 10 from the right side to the left side in the figure, skipping every other line, at a total of three locations. In this scanning, the scanning direction of the laser spot 22 and the polarization direction 11' of the laser light are parallel. Note that the polarization direction 11' in the three regions 25 is rotated 90 degrees from the polarization direction 11 in the four regions 23 so that the scanning direction of the laser spot 22 and the polarization direction 11' of the laser light are parallel.

[0050] In Example 1, the laser frequency is 200 KHz, the spot diameter D of the laser spots 20, 21, and 22 is 12 μm, the number of scans along the first and third tracks is 1, the number of scans along the second track is 2, the scanning speed of the first to third tracks is 20 mm / s, and the pulse energy is 1 μJ. Note that in all of the ranges 23 to 25, W≧D.

[0051] Fig. 8 is a diagram showing an in-plane distribution 30 of the number of effective pulses in Example 1. As a result of performing the scan as shown in Fig. 6, an in-plane distribution 30 of the number of effective pulses as shown in Fig. 7 is generated on the surface of the substrate 10. The number of effective pulses in the region corresponding to range 23 and the region corresponding to range 25 is P1 (120), and the number of effective pulses in the region corresponding to range 24 is P2 (240).

[0052] In region 31 of range 23 that does not overlap with range 25, the number of effective pulses remains P1 = 120. In region 32 where range 23 and range 25 overlap, the number of effective pulses becomes P1 + P1 = 240. Furthermore, in region 33 where range 24 and range 25 overlap, the number of effective pulses becomes P1 + P2 = 360. As described above, by performing the scan shown in Fig. 6, an in-plane distribution 30 with three types of effective pulse numbers as shown in Fig. 7 is generated on the surface of substrate 10.

[0053] Fig. 9(a) is an image of the surface of the microstructure 100 manufactured as Example 1, Fig. 9(b) is a cross-sectional view of a portion of AA' in Fig. 9(a), Fig. 9(c) is a cross-sectional view of a portion of BB' in Fig. 9(a), Fig. 9(d) is a cross-sectional view of a portion of CC' in Fig. 9(a), Fig. 9(e) is a cross-sectional view of a portion of DD' in Fig. 9(a), and Fig. 9(f) is a cross-sectional view of a portion of EE' in Fig. 9(a). Fig. 9(a) is an SEM image of an area of ​​70 μm × 110 μm, Figs. 9(b) to 9(d) show cross-sectional shapes in an area of ​​50 μm out of 70 μm, and Figs. 9(e) to 9(f) show cross-sectional shapes in an area of ​​25 μm out of 110 μm.

[0054] In the cross section shown in Fig. 9(b), the shaded area indicates the area (P=360) where range 24 and range 25 in Fig. 7 overlap, and the unshaded area indicates the area of ​​range 24 (P=240). In the cross section shown in Fig. 9(c), the shaded area indicates the area (P=120) where the area between range 23 and range 24 in Fig. 7 and area 25 overlap, and the unshaded area indicates the area between range 23 and range 24. In the cross section shown in Fig. 9(d), the shaded area indicates the area (P=240) where range 23 and range 25 in Fig. 7 overlap, and the unshaded area indicates the area of ​​range 23 (P=120).

[0055] Fig. 9(b) shows a needle-shaped groove structure formed by superimposing a scan of a second locus with an effective pulse number P=240 and a scan of a third locus with an effective pulse number P=120, resulting in a total effective pulse number P=360, and a needle-shaped groove structure formed by scanning the second locus with an effective pulse number P=240. Fig. 9(c) shows a needle-shaped groove structure formed by scanning only the third locus, a portion of which has an effective pulse number P=120. Fig. 9(d) shows a needle-shaped groove structure formed by superimposing a scan of a first locus with an effective pulse number P=120 and a scan of a third locus with an effective pulse number P=120, resulting in a total effective pulse number P=240, and a needle-shaped groove structure formed by scanning the first locus with an effective pulse number P=120.

[0056] In the cross section shown in Fig. 9(e), the upper shaded area indicates the area where ranges 24 and 25 in Fig. 7 overlap, the lower shaded area indicates the area where ranges 23 and 25 overlap, and the unshaded area indicates range 25. In the cross section shown in Fig. 9(f), the upper shaded area indicates range 24 in Fig. 7, and the lower shaded area indicates range 23, which do not overlap with range 25.

[0057] Fig. 9(e) shows a needle-shaped groove structure formed by alternating between a first locus scan with an effective pulse number P=120, a second locus scan with an effective pulse number P=240, and a third locus scan with an effective pulse number P=120 superimposed on each other, resulting in a total effective pulse number P=240 and 360. Fig. 9(f) shows a needle-shaped groove structure formed by alternating between effective pulse numbers P=120 and 240, resulting from scanning of a first locus with an effective pulse number P=120 and a second locus with an effective pulse number P=240, without scanning the third locus with an effective pulse number P=120.

[0058] Fig. 10(a) is an image of the surface of a microstructure transfer body 200 formed by transferring the microstructure 100 shown in Fig. 9(a) as a master, Fig. 10(b) is a cross-sectional view of a portion of FF' in Fig. 10(a), Fig. 10(c) is a cross-sectional view of a portion of GG' in Fig. 10(a), Fig. 10(d) is a cross-sectional view of a portion of HH' in Fig. 10(a), Fig. 10(e) is a cross-sectional view of a portion of II' in Fig. 10(a), and Fig. 10(f) is a cross-sectional view of a portion of JJ' in Fig. 10(a). Fig. 10(a) is an SEM image of an area of ​​110 μm × 70 μm, Figs. 10(b) to 10(d) show cross-sectional shapes in a range of 50 μm in 110 μm, and Figs. 10(e) to 10(f) show cross-sectional shapes in a range of 25 μm in 70 μm.

[0059] The cross section shown in Fig. 10(b) shows a position (P=240) corresponding to Fig. 9(b), the cross section shown in Fig. 10(c) shows a position corresponding to Fig. 9(c), and the cross section shown in Fig. 10(d) shows a position corresponding to Fig. 9(d) (P=120), the cross section shown in Fig. 10(e) shows a position corresponding to Fig. 9(e), and the cross section shown in Fig. 10(f) shows a position (P=120) corresponding to Fig. 9(f). EXAMPLES

[0060] 11 is a diagram showing scanning of a laser spot in Example 2. In Example 2, a laser processing device 1 was used, and a silicon wafer was used as the substrate 10. A laser spot 20 was used to scan an area 61 on the surface of the substrate 10 along a first direction 12 with an effective pulse number P1 (120). Furthermore, a similar scan was performed at three locations on the surface of the substrate 10 from the top to the bottom in the figure. In this scan, the scanning direction of the laser spot 20 and the polarization direction 11 of the laser light are parallel to each other.

[0061] Next, in an area 62 on the surface of the substrate 10, scanning was performed along the first direction 12 with a laser spot 20 at an effective pulse number P2 (240). Furthermore, similar scanning was performed at three locations on the surface of the substrate 10 from the top to the bottom in the figure. In this scanning, the scanning direction of the laser spot 20 and the polarization direction 11 of the laser light were parallel to each other.

[0062] By scanning as shown in Figure 11, needle-shaped groove structures with a depth of approximately 6 μm and periodically arranged at a pitch of 3 to 5 μm were formed in region 61, and needle-shaped groove structures with a depth of approximately 8 μm and periodically arranged at a pitch of 3 to 5 μm were formed in region 62.

[0063] [Modifications] In order to form a microstructure transfer body having a high protein adsorption suppression effect, it is necessary to have a plurality of types of needle-like structures with different heights. For this purpose, it is necessary to perform scanning in the master with an in-plane distribution in which a plurality of regions having a predetermined range of effective pulse numbers and a plurality of types of effective pulse numbers are present on the substrate. The above-mentioned Example 1 and Example 2 are only examples, and as long as scanning can be performed with an in-plane distribution in which a plurality of regions having a predetermined range of effective pulse numbers and a plurality of types of effective pulse numbers are present on the substrate, various modified examples are possible, without being limited to the above. The modified examples are described below.

[0064] FIG. 12 is a diagram showing an example of another in-plane distribution of the effective pulse number. The in-plane distribution 30 of Example 1 shown in FIG. 8 corresponds to the case where, as shown in FIG. 7, scanning is performed with the effective pulse number P1 (120) in the region corresponding to the range 23 and the region corresponding to the range 25 of the substrate 10, and scanning is performed with the effective pulse number P2 (240) in the region corresponding to the range 24. In addition, in all scanning of the in-plane distribution in FIG. 7, the scanning direction of the laser spot and the polarization direction of the laser light are parallel. On the other hand, the in-plane distribution 70 of the effective pulse number shown in FIG. 12 corresponds to the case where, in FIG. 7, scanning is not performed in the region corresponding to the range 24, and scanning is performed with the effective pulse number P2 (240) instead of the effective pulse number P1 (120) in the region corresponding to the range 25. In addition, in all scanning of the in-plane distribution in FIG. 12, the scanning direction of the laser spot and the polarization direction of the laser light are parallel.

[0065] As a result, on the surface of the substrate 10, an in-plane distribution 70 is generated with four types of effective pulse numbers as shown in Fig. 12. In the region 31 in the figure where only horizontal scanning is performed, the effective pulse number is P1 = 120. In the region 71 in the figure where only vertical scanning is performed, the effective pulse number is P2 = 240. Furthermore, in the region 72 in the figure where the vertical and horizontal scanning overlap, the effective pulse number is P1 + P2 = 360. In the region 33 where no scanning is performed, P = 0.

[0066] In the scans that produce the in-plane distribution of the number of effective pulses shown in Figures 8 and 12, the scanning direction of the laser spot and the polarization direction of the laser light are parallel in both the horizontal and vertical scans. However, in one scan, the scanning direction of the laser spot and the polarization direction of the laser light may be parallel, and in the other scan, the scanning direction of the laser spot and the polarization direction of the laser light may be perpendicular.

[0067] 11, the effective pulse numbers are different in the regions 61 and 62 arranged in parallel, but the scanning direction is the same in all scans, and the scanning direction of the laser spot and the polarization direction of the laser light are parallel. However, the scanning direction of one scan may be different from that of the other scan, or the scanning direction of the laser spot and the polarization direction of the laser light may be parallel in one scan and perpendicular to each other in the other scan.

[0068] In the above-described examples, scanning with the laser spot 20 or 22 was performed along a fixed direction, such as the first directions 12 and 14 (see FIG. 7). However, scanning with the laser spot does not necessarily have to be performed along a fixed direction, and may be performed along, for example, a curved path, a zigzag path combining a plurality of straight lines, or the like.

[0069] FIG. 13(a) is a diagram showing an example in which scanning with a laser spot is performed along a curved trajectory. FIG. 13(a) shows an example in which a laser spot 20 with a diameter D scans along a curved trajectory 15 in a first processing area 81 with an effective pulse number P1=120, and a laser spot 20 with a diameter D scans along a curved trajectory 16 in a second processing area 82 with an effective pulse number P2=240. The trajectories 15 and 16 are arranged in parallel, but may not be parallel or may be perpendicular to each other. In the first processing area 81 and the second processing area 82, the scanning direction of the laser spot 20 and the polarization direction of the laser light may be parallel, perpendicular, or different from each other. In the first processing area 81 and the second processing area 82, the diameters of the laser spots may be different from each other.

[0070] FIG. 13(b) is a diagram showing an example in which scanning with a laser spot is performed along a zigzag trajectory combining a plurality of straight lines. FIG. 13(b) shows an example in which a laser spot 20 with a diameter D scans along a zigzag trajectory 17 in the third processing region 83 with an effective pulse number P1=120, and a laser spot 20 with a diameter D scans along a zigzag trajectory 18 in the fourth processing region 84 with an effective pulse number P2=240. The trajectories 17 and 18 are arranged in parallel, but may not be parallel or may be perpendicular to each other. In the third processing region 83 and the fourth processing region 84, the scanning direction of the laser spot 20 and the polarization direction of the laser light may be parallel, perpendicular, or different from each other. In the third processing region 83 and the fourth processing region 84, the diameters of the laser spots may be different from each other.

[0071] It should be understood by those skilled in the art that various changes, substitutions, and modifications can be made to the present invention without departing from the scope of the present invention. For example, the above-described embodiments and modifications may be appropriately combined within the scope of the present invention. [Explanation of symbols]

[0072] 1 Laser processing equipment 2. Short pulse laser generator 3. Polarization Modulation Element 4 Dichroic Mirror 4 5 Objective Lenses 8. Laser Light 10 Base material 11 Polarization direction 12 Scanning Direction 20 Laser Spot 100 Microstructure 200 Microstructure transfer body

Claims

1. A method for manufacturing a microstructure, comprising the steps of: processing a surface of a substrate with a short pulse laser having a laser spot diameter D and a repetition frequency F to manufacture the microstructure; scanning the surface of the substrate with the laser spot along a first trajectory at a first effective pulse number to form a first fine needle-shaped groove structure that is periodically formed in a self-organized manner along the first trajectory to a first depth; scanning the surface of the base material with the laser spot along a second trajectory at a second effective pulse number different from the first effective pulse number to form a fine second needle-shaped groove structure that is periodically formed in a self-organized manner along the second trajectory at a second depth different from the first depth, The first effective pulse number P1 satisfies the following formula (1): The second effective pulse number P2 satisfies the following formula (1'): 20<P1<2000 (1) 20<P2<2000 (1') The polarization direction of the laser spot scanning along the first trajectory is parallel to the traveling direction of the first trajectory. A method for producing a microstructure comprising the steps of:

2. If W1 ≧ D and W2 > D, The first effective pulse number P1 satisfies the following formula (2): P1=F・D・S1 / V1 (2) The second effective pulse number P2 satisfies the following formula (3): P2=F・D・S2 / V2 (3) If W1<D and W2<D, The first effective pulse number P1 satisfies the following formula (2'): P1=F・D ２ ・S1 / (V1・W1) (2´) The second effective pulse number P2 satisfies the following formula (3'): <h2 style=";text-align:left;direction:ltr">2252<h2 style=";text-align:left;direction:ltr"> ２ <h2 style=";text-align:left;direction:ltr">・S2 / (V2W2) (3´) Here, S1 is the number of scans along the first locus, V1 is the scanning speed of the laser spot along the first locus, S2 is the number of scans along the second locus, V2 is the scanning speed of the laser spot along the second locus, W1 is the scanning position interval of the laser spot along the first locus, and W2 is the scanning position interval of the laser spot along the second locus. The method for manufacturing a microstructure according to claim 1,

3. 2. The method for producing a microstructure according to claim 1, wherein a polarization direction of the laser spot that scans along the second trajectory is parallel to a traveling direction of the second trajectory.

4. The method for manufacturing a microstructure according to claim 3 , wherein the first trajectory and the second trajectory are parallel or perpendicular to each other.

5. 5. The method for manufacturing a microstructure as described in claim 4, wherein, when the first locus and the second locus are perpendicular to each other, in a region where a scan performed by the laser spot along the first locus with a first effective pulse number and a scan performed by the laser spot along the second locus with a second effective pulse number overlap, a fine third needle-shaped groove structure is formed periodically in a self-organized manner at a third depth different from the first depth and the second depth.

6. 2. The method for producing a microstructure according to claim 1, wherein a polarization direction of the laser spot that scans along the second trajectory is perpendicular to a traveling direction of the second trajectory.

7. The method for manufacturing a microstructure according to claim 6 , wherein the first trajectory and the second trajectory are parallel or perpendicular to each other.

8. The method further includes a step of scanning a third locus other than the first locus and the second locus on the surface of the substrate with the laser spot along the third locus at a third effective pulse number, The third effective pulse number P3 satisfies the following formula (5): 20≦P3≦2000 (5) A method for producing a microstructure according to any one of claims 1 to 7.

9. A substrate; a first needle-shaped groove structure is formed periodically in a self-organized manner along a first locus on a surface of the substrate by scanning the first locus with a laser spot of a short pulse laser having a spot diameter D and a repetition frequency F at a first effective pulse number; and a fine second needle-shaped groove structure that is periodically formed in a self-organized manner along a second trajectory at a second depth different from the first depth on the surface of the base material by scanning along the second trajectory with the laser spot of the short pulse laser at a second effective pulse number different from the first effective pulse number; A microstructure comprising:

10. 10. A microstructure transfer product formed by transferring from the microstructure according to claim 9 as a master using a predetermined composition.

11. A protein adsorption inhibitor characterized in that a microstructure transfer body formed by transferring from the microstructure described in claim 9 using a predetermined composition as a master is placed in an area where protein adsorption is inhibited.

12. a first fine needle-like structure periodically formed at a first height; and a second fine needle-like structure periodically formed at a second height different from the first height, the first height and the second height are 6 to 10 μm; The pitch at which the first needle-like structure and the second needle-like structure are formed is 3 to 5 μm. A microstructure transfer body characterized by:

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