Method for manufacturing a periodic oxide stripe structure and applications thereof

Abstract

The application discloses a manufacturing method of a periodic oxidation stripe structure, which comprises the following steps: processing a stripe structure on a surface; and irradiating the surface by using a femtosecond laser, so that corresponding regions of the surface form periodically distributed oxide stripes under the action of the femtosecond laser and the induction of the stripe structure; and the direction of the stripe structure is consistent with the polarization direction of the incident femtosecond laser. The application also discloses an application of the above method. In the application, the oxidation stripe structure with extremely high collimation degree can be obtained by using a simple "artificial seed" for induction. Any additional processing process is not needed. The application is direct, simple, clear and controllable. Meanwhile, the energy density required for generating the oxidation stripe grating structure is lower than that of a long-pulse laser and a continuous laser, and is far lower than the ablation threshold of the surface, so that the ablation can be avoided, and therefore, the precise machining of a large-area subwavelength micro-nano stripe structure in a micro-nano range can be realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of femtosecond laser advanced micro-nano manufacturing, and particularly relates to a manufacturing method of a periodic oxidation stripe structure and application. BACKGROUND

[0002] Nanofabrication technology is one of the important strategic research directions that affect the future core competitiveness of a country, and is also one of the supporting technologies of new economic growth points. As an emerging comprehensive processing technology, it integrates modern optics, mechanics, electronics, computers, measurement and advanced materials technology, so that the precision of processing is improved from microns in the 1960s to 10 nm at present, and the performance and reliability of various products are greatly improved. At present, mature technologies widely used in micro-nano processing and manufacturing include electron beam exposure, focused ion beam etching, nano-imprinting, laser direct writing and chemical synthesis. However, these technologies, or rely on expensive and complex operation systems; or rely on special materials; or have low preparation efficiency and cannot be used for large-area processing; or have low controllability in the processing process. Therefore, it has important scientific significance and industrial application value to develop a surface micro-nano structure manufacturing method that can be quickly prepared, large-area processed, low-cost and controllable.

[0003] Since Birnbaum first observed the surface periodic stripe structure by using continuous laser irradiation on gallium arsenide semiconductor material in 1965, the phenomenon has attracted widespread attention. Especially with the popularity of high-energy femtosecond lasers, people have discovered a large number of new phenomena in the study of the interaction between femtosecond lasers and metals, semiconductors and dielectrics. In the past two decades, the research focus has been mainly on the formation mechanism of femtosecond laser-induced low spatial frequency periodic stripe structure, and three widely accepted models have been proposed: 1) femtosecond laser and surface scattered wave interference theory based on Sipe theory; 2) femtosecond laser and surface plasmon interference theory; 3) self-organization theory. According to the three models, people can basically explain most of the experimental phenomena. Therefore, in recent years, in order to expand the application of femtosecond laser-induced self-organization periodic stripes, people gradually turn their attention to how to improve the regularity.

[0004] Although the study of laser-induced self-organized stripe structures has been over half a century, this method has not been effectively promoted as a micro-nano processing technology. The fundamental reason is that the laser-induced self-organization process is uncontrollable, resulting in long-range disorder of the stripe structure with great randomness. In order to solve this problem, some solutions have been proposed. For example, using femtosecond laser-induced thermal chemical reaction to produce stripe structures accumulated by oxide particles with orientation along the polarization direction of the laser. This stripe structure formation process has a non-local feedback effect, which can improve the regularity of self-organized periodic structures to a certain extent. For another example, using the "strong ablation" effect of high-energy femtosecond laser to make the surface material rapidly vaporize. For another example, using metal materials (Ti, Cr, Mo) with high optical loss to reduce the decay length of surface plasmons to improve the coherence of surface electromagnetic waves.

[0005] The above methods can improve the regularity of self-organized stripe structures to a certain extent, but they all have a prerequisite, that is, they need to use small spot (spot diameter generally <10 wavelengths) point-by-point scanning. This is because when a large spot is used, there are a large number of random surface defects in the spot irradiation area, which will act as random "seeds" and cause the self-organized stripe structure to branch and disorder. Although using a small spot scanning can effectively reduce the number of random "seeds" in the steady-state exposure area and improve the regularity of the periodic stripe structure, it cannot ensure that a very collimated periodic stripe structure is obtained. This is because during the movement of the spot, new random "seed" structures will continue to appear at the center of the spot. These subsequent "random seeds" and previously formed stripes may have some positional error in space, resulting in the formation of curved periodic stripes. In addition, the existing small spot point-by-point scanning technology has the problems of low processing efficiency and can only realize relative regularity in two-dimensional plane, and the size of the nanostructure produced in the laser transmission direction is still irregular.

[0006] From the above analysis, we can know that the fundamental reason for the irregularity and disorder of the self-organized stripe structure is the "random seed" caused by the surface defects of the material. Therefore, inhibiting the formation of random seeds is the key to effectively improving the three-dimensional regularity of self-organized stripes and processing efficiency.

[0007] For example, the patent document with publication number CN 112008232 A discloses a method for preparing a periodic stripe structure on a glass surface coated with an ITO thin film. The method uses a femtosecond laser beam focused by a cylindrical lens to form a laser focal spot on the glass surface to induce the growth of periodic stripes. The method prepares a long strip-shaped periodic stripe structure with a width of the laser beam diameter on the glass surface by using a laser fluence density that is ten times lower than the glass ablation threshold. The method uses a layer of ITO thin film with a low ablation threshold on the glass surface to achieve the processing of periodic stripes on the glass surface. The laser fluence density used is as high as 400 mJ / cm 2 The processing is still based on the ablation mechanism, which requires the combination of sample X, Y and Z axis movement, repeated processing, and then the processing of periodic stripes, which is extremely low in processing efficiency. SUMMARY

[0008] The present application relates to a method for improving the regularity of laser-induced periodic oxidation stripes, specifically a method using "artificial seeds" to induce oxidation stripes along the direction of the seeds, and finally forming a highly regular periodic stripe structure. This method can significantly improve the regularity of oxidation stripes and lay the foundation for large-area processing of regular stripes. Moreover, this method can significantly reduce manufacturing costs and shorten the processing period when used in micro-nano manufacturing.

[0009] The present application uses "artificial seeds" to effectively suppress the generation of "random seeds" on a silicon thin film, and finally realizes the rapid and controllable preparation of highly regular nanostructures using a large spot.

[0010] A method for manufacturing a periodic oxidation stripe structure includes: processing a stripe structure on a surface; and irradiating the surface with a femtosecond laser, so that the surface forms a periodic distribution of oxide stripes under the action of the femtosecond laser and the induction of the stripe structure. The direction of the stripe structure is consistent with the polarization direction of the incident femtosecond laser.

[0011] The present application first prepares "artificial seeds" (i.e., stripe structures) on a specific surface, and then irradiates with a femtosecond laser. The threshold for generating oxidation stripes is effectively reduced on the seeds, and oxidation stripes are first generated at the seeds. Then, due to the influence of non-local feedback, the stripes will grow around the seeds in turn. The finally formed periodic oxidation stripes are strictly parallel to the "artificial seeds", and thus a highly regular stripe structure is obtained.

[0012] The above-mentioned manufacturing method of the present application can also be used as a method for improving the regularity of laser-induced periodic oxidation stripes.

[0013] The stripe structure of the present application can be prepared by using existing processes, such as one or more of the following: electron beam exposure, focused ion beam etching, nanoimprinting, laser direct writing, chemical synthesis, three-dimensional printing, etc. As a preferred embodiment, in the present application, the "artificial seed" stripe structure is obtained by using a highly focused continuous laser to etch. By moving the sample at a constant speed with a high-precision motorized translation stage, a straight seed can be obtained. In the present application, a continuous laser is first used to etch a straight groove, and then a femtosecond laser is used to irradiate a metal or semiconductor thin film. By adjusting the polarization direction of the incident light to be parallel to the direction of the groove, a periodic oxidation stripe with very high uniformity can be produced.

[0014] In the present application, the oxidation stripe formed by the femtosecond laser with polarization direction parallel to the seed direction on the surface of the seed (such as a silicon thin film) is strictly along the direction parallel to the seed. By preparing a seed long enough and using a large enough light spot, a large-area and fast preparation of subwavelength periodic stripes can be achieved. The present application can break through the optical diffraction limit in the traditional scanning laser direct writing process and quickly form a grating structure with a subwavelength period.

[0015] In terms of scale, a single beam of large spot laser exposure can be used to produce, or a large spot can be used in combination with a two-dimensional translation stage to produce a larger area of micro-nano stripe structure. During the preparation process, the scattered laser intensity can be used to realize real-time monitoring of the stripe formation process. As a preferred embodiment, the stripe structure is a groove structure, a protrusion structure, or a combination of the two.

[0016] As a further preferred embodiment, the stripe structure is a straight line stripe structure with a groove structure or a protrusion structure. During manufacturing, a continuous laser is first used to etch a highly collimated groove, and then a femtosecond laser with polarization direction parallel to the groove is used to act on the groove. This will first produce oxidation stripes on the groove, and then other oxidation stripes will grow completely parallel to the groove near the groove. The collimation degree of the oxidation stripe grating structure produced at this time will be very high.

[0017] As a preferred embodiment, the width of the stripe structure is 0.2-1 μm, and the depth is 3-20 nm. The stripe structure is further preferred to be a groove structure with a width of 200-500 nm and a depth of 3-10 nm. As a specific embodiment, it also includes a 532 nm continuous laser for producing a collimated groove. A highly focused 532 nm, 50 mW continuous laser acts on the thin film to produce a groove with a width of 300 nm and a depth of about 5 nm. As another preferred embodiment, it also includes a motorized translation stage for producing a collimated groove. The sample placed on the motorized translation stage can be moved by the precise movement of the translation stage when the focused 532 nm continuous laser acts on the thin film sample.

[0018] As a preferred embodiment, the surface is a thin film surface, and the thickness of the thin film is 100-500 nm. As a further preferred embodiment, the thin film is a silicon thin film, and the thickness of the thin film is 200-400 nm.

[0019] As a preferred embodiment, the surface contains a substance or material that can generate oxidation reaction to form oxide particles under the action of femtosecond laser. Alternatively, the thin film material used can undergo oxidation process under laser irradiation. Thus, the incident wave and the scattered wave of the oxide form interference, and the oxide stripes are periodically distributed. As a further preferred embodiment, the material is selected from one or more of silicon, titanium, tungsten, titanium nitride and other materials that can be oxidized. As a preferred embodiment, the surface is processed from the above-mentioned materials.

[0020] In the present application, the oxide stripes are formed, and the orientation is parallel to the polarization direction of the laser.

[0021] In the present application, the period of the oxide stripes is related to the wavelength of the incident laser, but is always slightly smaller than the wavelength of the laser. The period of the oxide stripes is closely related to the thickness of the thin film. As a preferred embodiment, the period of the oxide stripes depends on the wavelength of the incident laser or / and the thickness of the structure (e.g. the thin film) where the surface is located; the period of the oxide stripes can be adjusted by adjusting the wavelength of the incident laser or / and the thickness of the structure (e.g. the thin film) where the surface is located.

[0022] In the present application, the surface area with the oxide stripes depends on the laser action area. The area of the prepared grating can be controlled by controlling the size of the incident spot and the length of the seed. The above-mentioned femtosecond laser action can be combined with a controllable two-dimensional translation stage, and the oxide stripes of the grating can be quickly and large-area processed to prepare the grating structure.

[0023] A structure with periodic stripes is prepared by the method of any of the above technical solutions.

[0024] As a preferred embodiment, the structure with periodic stripes is a grating structure or a mask structure.

[0025] The grating structure or the mask structure generally includes a grating substrate or a mask substrate, and a grating stripe or a mask pattern arranged on the grating substrate or the mask substrate, which can be processed by the above-mentioned method for manufacturing the periodic oxide stripe structure. The present application provides a method for preparing a grating, which is prepared by the above-mentioned method for manufacturing the periodic oxide stripe structure. The method of the present application can achieve a wider range of fast processing and preparation.

[0026] The present application provides a grating structure, which is prepared by the method of any of the above technical solutions, and the grating structure is a grating structure with a subwavelength period.

[0027] The grating period can be controlled by controlling the wavelength of the incident laser or the thickness of the structure where the surface is located. The area of the prepared grating can be controlled by controlling the size of the incident light spot and the length of the seed.

[0028] As preferred, the present application can use a glass or sapphire with high flatness as the substrate, and use vacuum magnetron sputtering (or other existing methods) to coat a silicon thin film (or other materials that meet the requirements). The conditions of the thin film with high flatness are more conducive to the formation of neat oxidation stripes.

[0029] In order to facilitate processing, as preferred, the femtosecond laser is focused on the sample to achieve a high enough power density to cause oxidation of the silicon surface.

[0030] As preferred, the polarization mode of the light spot before the laser irradiates the thin film is determined, and the polarization is parallel to the seed direction.

[0031] In the present application, the oxidation stripe micro-nano structure is formed by continuously irradiating the seed with a focused femtosecond pulse laser, and the growth of the oxidation stripe parallel to the polarization direction is realized by using positive feedback oxidation effect.

[0032] As preferred, the laser used is a femtosecond pulse laser; the laser energy distribution can be a Gaussian spot or a flat-top spot, and the power density after focusing is much lower than the ablation threshold of the thin film. The laser energy is the oxidation threshold of the corresponding surface or thin film surface material in the presence of artificial seeds; for example, for a silicon film, the oxidation threshold is 0.023 J / cm 2 in the presence of artificial seeds. The energy density of the femtosecond pulse laser is 0.023-0.05 J / cm 2 .

[0033] In the present application, the femtosecond pulse laser has no limitation on the repetition frequency and central wavelength, and the laser is focused on the sample surface to induce oxidation reaction. A half-wave plate is used in cooperation with a polarizer (or an attenuator) to gradually increase the incident energy of the pulse laser.

[0034] In the above scheme, the sample is pre-prepared by using the "artificial seed" method, which has the advantage of significantly improving the neatness of the formed oxidation stripes. The seed stripe with a set shape is prepared, and the energy density of the femtosecond laser is adjusted so that it acts on the seed. The sample can be exposed at one time to realize the processing of high-regularity stripes in the whole light spot acting area. The transmitted light spot is monitored by a light spot analyzer to realize real-time monitoring of the whole processing process.

[0035] As a preference, the length of the "artificial seed" can be arbitrarily long. With the method of the present application, the entire seed area can be quickly scanned with a large laser spot, achieving processing of an arbitrarily large area. In the case of sufficient laser energy, the spot can also be expanded to achieve one-time processing in the maximum range.

[0036] The present application pre-prepares "artificial seeds" on a specific surface (such as a thin film material on a substrate) and then performs laser irradiation, causing the surface to form oxide (oxidizable material in the surface reacts with oxygen in the air) particles. The incident laser and the dipole scattering wave of the oxide particles interfere, forming periodic interference fringes on the surface. Where the interference is constructive, the oxidation reaction is further enhanced, and where the interference is destructive, almost no chemical reaction occurs. Therefore, the final thin film forms a periodic distribution of oxide fringes with extremely high collimation.

[0037] A mask structure prepared by the method of any of the above technical solutions.

[0038] In the present application, the oxide fringe grating structure formed after laser irradiation can also be used as a mask in the future. Different thin films can be plated on its surface to form grating structures of different thin films.

[0039] An apparatus for preparing a periodic oxide fringe structure, comprising:

[0040] A femtosecond laser emitter for providing the required femtosecond laser;

[0041] A light intensity adjusting element for adjusting the energy of the input laser;

[0042] A polarization adjusting optical element for adjusting the polarization of the incident laser to the required polarization state;

[0043] A spot analyzer for observing the required laser spot pattern.

[0044] A lens element for focusing the laser with adjusted light intensity and polarization direction onto the silicon thin film.

[0045] When the polarization direction of the incident laser has been determined and meets the processing needs, i.e., the polarization direction of the incident laser is consistent with the direction of the fringes to be processed, the above-mentioned polarization adjusting optical element can be omitted.

[0046] When the processing conditions (laser irradiation time, etc.) have been predetermined, the spot analyzer can also be omitted.

[0047] The light intensity adjusting element generally includes an optical half-wave plate and an optical polarizer, and of course can also be an attenuator capable of adjusting the energy size, for adjusting the laser intensity to obtain the required energy laser.

[0048] As preferred, an image collection industrial camera is further included for adjusting the spatial position of the laser spot acting on the silicon film and for observing the laser action process.

[0049] In the manufacturing process, the laser is emitted from a half-wave plate or other components that will change the laser mode, and then passes through a lens to focus the spot on the sample. During the laser irradiation process, the scattered light intensity gradually changes with the generation and growth of the oxidation stripes. When the transmitted light intensity no longer changes within a certain time range (depending on the laser repetition frequency), the laser irradiation can be stopped.

[0050] The present application first uses a vacuum sputtering device to deposit a 100-500 nm silicon film on a sapphire substrate. Then a femtosecond pulsed laser is used to irradiate the sample, causing the sample to oxidize and gradually grow into a periodic stripe. During the preparation process, a spot analyzer is used to detect the transmitted laser spot, achieving real-time monitoring of the formation process of the oxidation stripe grating structure.

[0051] In the present application, the advantage of using femtosecond laser to prepare the grating structure is that a very high collimation degree of the oxidation stripe structure can be obtained by simply inducing a "artificial seed". No additional processing is required. It is direct, simple, clear and controllable. At the same time, the energy density required to produce the oxidation stripe grating structure is lower than that of long pulse and continuous laser, far below the ablation threshold of the surface, which can avoid ablation, thus realizing precise machining of large-area subwavelength micro-nano stripe structure in the micro-nano range. In addition, the period of the oxidation stripe grating structure is proportional to the incident wavelength, and the grating period can be easily controlled by manipulating the incident laser wavelength, and the grating structure is in the subwavelength range, which greatly simplifies the process of high-precision micro-nano machining.

[0052] In the present application, the femtosecond laser is used to directly irradiate the subwavelength period micro-nano stripe structure, which is a completely new mechanism compared with laser direct writing processing, two-photon polymerization, interference lithography, or nano-imprinting. The outstanding advantage of this method is that it is more direct, simpler and more efficient. The stripe period is in the subwavelength range, which greatly reduces the processing time, difficulty and cost.

[0053] According to actual needs, an arbitrarily large-area high-regularity stripe can be further obtained by increasing the length of the seed and scanning the seed area with a large-spot laser.

[0054] In addition, in the present application, the energy of the femtosecond laser required due to the presence of the artificial seed is lower (lower than the oxidation threshold of the unprocessed seed stripe of the surface material), which can also suppress the influence of random seeds. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1A device for self-organizing periodic stripe grating structure by femtosecond laser induced oxidation stripe for the example.

[0056] Figure 2 A straight "artificial seed" with a width of 300 nm is made on the surface of a silicon film by focusing a 50 mW, 532 nm laser.

[0057] Figure 3 In (a), the "artificial seed" is under optical microscope dark field mode, and in (b), the groove depth of the "artificial seed" is plotted after scanning analysis by atomic force microscope (AFM).

[0058] Figure 4 A schematic diagram of the action of femtosecond laser with linear polarization parallel to the direction of the "artificial seed" on the seed.

[0059] Figure 5 In (a), the oxidation stripe grown on the "artificial seed" after the action of femtosecond laser is under optical microscope dark field mode, and in (b), the height of the oxidation stripe at the "artificial seed" is plotted after scanning analysis by atomic force microscope (AFM).

[0060] Figure 6 In (a), the scanning electron microscope picture of the oxidation stripe grating structure parallel to the polarization direction generated by the action of femtosecond laser on the 200 nm thick silicon film with "artificial seed"; in (b), the Fourier transform diagram of the oxidation stripe formed in (a); in (c), the scanning electron microscope picture of the oxidation stripe grating structure parallel to the polarization direction generated by the action of femtosecond laser on the 200 nm thick silicon film without "artificial seed"; in (d), the Fourier transform diagram of the oxidation stripe formed in (c); in (e) and (f), the diagrams of the corresponding silicon and oxygen components after EDX analysis of (a).

[0061] Figure 7 A scanning electron microscope picture of the 200 nm thick silicon film without "artificial seed" after the action of femtosecond laser. DETAILED DESCRIPTION

[0062] The application will be further described below in conjunction with the drawings:

[0063] As Figure 1 shown, a device for self-organizing periodic stripe grating structure by femtosecond laser induced oxidation stripe. It includes half-wave plate 4, polarizer 5, half-wave plate 6, focusing lens 7, industrial camera 8. Among them, the optical elements half-wave plate 4 and polarizer 5 are matched to continuously change the energy of the laser. The repetition frequency of femtosecond laser is not limited, and the repetition frequency in this example is 5000 Hz. Half-wave plate 6 is used to adjust the direction of linearly polarized laser. The laser 3 emitted by the femtosecond laser is focused on the silicon film 2 adhered to the substrate 1 through the lens 7.

[0064] In this example, the focal length of the lens 7 is 20 cm, the energy distribution of the femtosecond laser used can be a Gaussian spot, the central wavelength of the femtosecond laser is 1030 nm, the pulse width is 130 fs, and the spot diameter at the focal point is 120 microns. In this example, we use a magnetron sputtering coating device to prepare a 200-nanometer-thick silicon film on a 500-micron-thick sapphire substrate.

[0065] First, use the existing process to pre-process the "artificial seed" of the linear groove stripe structure on the surface of the 200-nanometer-thick silicon film; then use the femtosecond laser to irradiate the corresponding area of the "artificial seed".

[0066] When processing periodic stripes, when the low-energy laser is focused on the smooth surface of the silicon film, it is mainly reflected by the silicon film, so almost no scattered light can be detected by the lateral industrial camera 8. Rotate the half-wave plate 4 to gradually increase the incident laser energy until the oxidation threshold of silicon is reached, and a small amount of oxide particles appear on the surface of the silicon film. At this time, the scattered light can be observed in real time through the industrial camera 8. Keep the incident laser energy unchanged and detect the change of the scattered light spot captured by the industrial camera 8. When the scattered light spot basically no longer changes with the gradual increase of the number of irradiation pulses, stop the laser irradiation. Subsequently, the periodic changing stripes on the scale can be observed by using a scanning electron microscope.

[0067] As shown in Figure 2 , in this example, a straight "artificial seed" with a width of 300 nm is made on the surface of the silicon film by using a 50 mW, 532 nm laser. The processed "artificial seed" is analyzed by using an optical microscope, as shown in Figure 3 (a); and scanning analysis by using an atomic force microscope shows that the obtained "artificial seed" is a groove stripe structure with a depth of about 580 nm, as shown in Figure 3 (b).

[0068] Figure 4 A schematic diagram of the use of a linearly polarized femtosecond laser parallel to the direction of the "artificial seed" to act on the seed. In this embodiment, the laser threshold for forming regular stripes on a 200-nanometer-thick scale is 0.023 J / cm 2 (action time is 10-20 seconds). Therefore, the formation mechanism of such regular stripes is completely different from that of traditional laser ablation, because the ablation threshold of silicon is 0.2 J / cm 2 . At the same time, in order to further verify the influence of the "artificial seed" on the oxidation threshold, we use a femtosecond laser with an energy density of 0.023 J / cm 2 to irradiate the same silicon film, and the obtained electron microscope image is shown in Figure 7 , and Figure 7 can be seen that the energy density of 0.023 J / cm2 The femtosecond laser is insufficient to cause the thin film to have an oxidation reaction to generate the periodic oxidation stripe.

[0069] Meanwhile, the "artificial seed" after the laser action is detected by using an optical microscope, as shown in Fig. 2(a). Figure 5 Fig. 2(a) shows the oxidation stripe grown on the "artificial seed" after the femtosecond laser action. By using atomic force microscope (AFM) scanning analysis, the height of the oxidation stripe at the "artificial seed" is about 180 nm, and the width is about 0.6 μm.

[0070] Figure 6 Fig. 2(a) is a scanning electron microscope picture of the oxidation stripe grating structure parallel to the polarization direction generated by the method of the present application, in which the femtosecond laser acts on the 200 nm thick silicon film with "artificial seed" (the action time is 15 s); after the single-beam linearly polarized femtosecond laser irradiation, a regular grating structure with a period of 950 nm is formed on the 200 nm thick silicon film, and there is almost no interference phenomenon caused by random seed. Fig. 2(b) is a Fourier transform graph of the oxidation stripe formed in (a), from which it can be seen that the collimation degree of the stripe obtained by the present application is very high, and the dispersion value δθ in the LIPSS orientation angle (DLOA) is only 4.5°; Fig. 2(c) is a scanning electron microscope picture of the oxidation stripe grating structure parallel to the polarization direction generated by the femtosecond laser (the repetition frequency is 5000 Hz, the central wavelength of the femtosecond laser is 1030 nm, the laser energy density is 0.028 J / cm 2 2, and the action time is 15 s) acting on the 200 nm thick silicon film without "artificial seed"; from the graph, it can be seen that without the induction of "artificial seed", the regularity of the stripe is not as good as the periodic stripe structure obtained by the method of the present application due to the influence of random seed. Fig. 2(d) is a Fourier transform graph of the oxidation stripe formed in (c); from (b) and (d), it can be seen that compared with the processing technology without the induction of "artificial seed", the collimation degree of the periodic stripe processed by the method of the present application is higher; Figs. 2(e) and (f) are respectively the silicon and oxygen component graphs after the EDX analysis of (a), from which it can be seen that in the region irradiated by the femtosecond laser, silicon oxide particles are generated.

Claims

1. A method for manufacturing a periodic oxidation stripe structure, characterized by, The method comprises the following steps: a surface is processed to form a stripe structure; the surface is irradiated by a femtosecond laser, and under the action of the femtosecond laser and the induction of the stripe structure, a corresponding region of the surface forms periodically distributed oxide stripes; the direction of the stripe structure is consistent with the polarization direction of the incident femtosecond laser; the surface is a surface of a thin film, and the thin film is a silicon thin film with a thickness of 200-400 nm; the stripe structure is a groove structure with a width of 200-500 nm and a depth of 3-10 nm; The energy density of the femtosecond laser is 0.023-0.05 J / cm 2 ; a Gaussian light spot is used as the energy distribution of the femtosecond laser, the power density after focusing is lower than the ablation threshold of the thin film, the central wavelength of the femtosecond laser is 1030 nm, the pulse width is 130 fs, and the spot diameter at the focal point is 120 microns; the period of the periodically distributed oxide stripes is 950 nm.

2. A structure having periodic fringes, characterized in that, The method is prepared by the method in claim 1.

3. The structure having periodic fringes according to claim 2, wherein, The structure with the periodic stripes is a grating or a mask.

Images