CN112643206A - Method for inducing super-regular nano-grating by femtosecond laser based on assistance of chromium film - Google Patents
Method for inducing super-regular nano-grating by femtosecond laser based on assistance of chromium film Download PDFInfo
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- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/352—Working by laser beam, e.g. welding, cutting or boring for surface treatment
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- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
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- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
- B23K26/064—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms
- B23K26/0648—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms comprising lenses
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- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/12—Working by laser beam, e.g. welding, cutting or boring in a special atmosphere, e.g. in an enclosure
- B23K26/1224—Working by laser beam, e.g. welding, cutting or boring in a special atmosphere, e.g. in an enclosure in vacuum
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Abstract
The invention provides a method for inducing a super-regular nano grating by femtosecond laser based on chromium film assistance, which comprises the following steps: s1, evaporating a chromium film with the thickness of 25-100 nm on the substrate by adopting a magnetron sputtering method; s2, building a femtosecond laser processing system; s3, fixing the chromium film on a three-dimensional vacuum translation table, integrally placing the chromium film in a vacuum unit, and adjusting the flux of the femtosecond laser pulse to 20.9-24.5 mJ/cm under the attenuation of a laser energy polarization adjusting unit2And vertically focusing on the chromium film through a focusing lens, and controlling a three-dimensional vacuum translation stage to drive the chromium film to be 0.3Moving at a speed of 2 mu m/s, and processing a deep sub-wavelength grating array with a grating period of 323-355 nm, a width of 60 mu m and a depth of 237nm on the chromium film. The method processes the ultra-regular and high-precision micro-nano structure on the surface of the chromium film by adjusting the processing parameters of the laser, the pressure of the processing environment and the processing area of the surface of the chromium film.
Description
Technical Field
The invention relates to the technical field of laser micro-nano processing, in particular to a processing method for inducing a super-regular deep sub-wavelength grating structure on the surface of a chromium film by femtosecond laser under a high vacuum condition.
Background
The surface micro-nano structure plays an important role in the research fields of microelectronics, micro-optics, micro-fluidics, photovoltaics and the like, such as integrated circuits, grating light splitting devices, super-hydrophilic/hydrophobic surfaces and solar cells. At present, the main micro-nano processing technologies include electron beam lithography, projection lithography, nano-imprinting and the like. However, the fabrication process of these methods can be roughly divided into two steps, one is to make a patterned resin template: constructing a structure by exposing a structured beam, an electron beam or directly imprinting a hard template onto a tailored resin, thereby obtaining a patterned resin template; secondly, structure transfer: the pattern of the resin template is transferred to the target object by dry and wet etching techniques such as plasma etching, wet etching with an acid/alkali solution, and the like. Despite the advantages of each of these techniques, the overall photoresist preparation and selection, and the choice of etchant, clearly increases the complexity of the process flow and the cost of fabrication.
The femtosecond laser has the capability of directly processing on almost all kinds of materials due to the characteristics of ultrahigh peak power and ultrashort time pulse width of the femtosecond laser. Compared with the traditional micro-nano processing method, the femtosecond laser one-step type maskless processing characteristic simplifies the processing flow and reduces the processing cost. In recent years, femtosecond laser induced surface periodic micro-nano structure is gradually developed into a high-efficiency and high-precision micro-nano processing technology. The femtosecond laser induced surface periodic micro-nano structure technology can efficiently prepare one-dimensional and two-dimensional periodic micro-nano structures breaking through diffraction limit on the surfaces of materials such as semiconductors, metals, media, biological tissues and the like through the interference form of incident femtosecond laser and surface plasma waves excited on the surfaces of the materials. However, although the femtosecond laser induced surface periodic micro-nano structure has been developed for decades, the periodic structure induced on the surface of the material still faces the problem of poor structural regularity. This disease has seriously hindered the practical and commercial development of this technology. Although few researchers have prepared regular one-dimensional periodic grating structures on the surface of silicon and easily-oxidized metal films (titanium, chromium, tungsten) by adjusting the processing parameters of the laser, the advantages of the technology are far from being realized by limited processing material selection and near-wavelength-scale grating structure fabrication. Therefore, a method for preparing a femtosecond laser induced surface periodic micro-nano structure which is ultra-regular, deep sub-wavelength (less than half of incident wavelength) and suitable for various materials is needed.
Disclosure of Invention
The invention aims to provide a method for inducing a super-regular nano grating by femtosecond laser based on chromium film assistance, which can process a micro-nano structure which is super-regular, deep sub-wavelength (less than half of incident wavelength) and suitable for various materials.
In order to achieve the purpose, the invention adopts the following specific technical scheme:
the invention provides a method for inducing a super-regular nano grating by femtosecond laser based on chromium film assistance, which comprises the following steps:
s1, evaporating a chromium film with the thickness of 25-100 nm on the substrate by adopting a magnetron sputtering method;
s2, building a femtosecond laser processing system; the femtosecond laser processing system comprises a femtosecond laser light source, a laser energy polarization adjusting unit, a focusing lens, a vacuum unit with adjustable processing environment pressure intensity, a three-dimensional vacuum translation table and a computer, wherein the laser energy polarization adjusting unit, the focusing lens, the vacuum unit with adjustable processing environment pressure intensity, the three-dimensional vacuum translation table and the computer are sequentially arranged along a laser emission light path;
s3, fixing the chromium film on a three-dimensional vacuum translation table, integrally placing the chromium film in a vacuum unit, controlling the pressure of the processing environment below 3.6Pa by the vacuum unit, and polarizing the laser energy of the femtosecond laser pulse emitted by the femtosecond laser sourceThe flux is adjusted to be 20.9-24.5 mJ/cm under the attenuation of the adjusting unit2And vertically focusing the chromium film on a focusing lens, and controlling a three-dimensional vacuum translation table by a computer to drive the chromium film to move at a speed of 0.3-2 μm/s, so as to process a row of deep sub-wavelength grating array with a grating period of 323-355 nm, a width of 60 μm and a depth of 237nm on the chromium film.
Preferably, the femtosecond laser light source adopts chirped amplified pulses of a titanium sapphire laser as a light source, and outputs horizontally polarized femtosecond laser; wherein the femtosecond laser has a central wavelength of 800nm, a repetition frequency of 1kHz, and a pulse width of 40 fs.
Preferably, the focusing lens has a focal length of 300mm and forms a spot on the order of hundreds of microns in diameter on the chromium film.
Preferably, the substrate is single crystal silicon, gallium arsenide, or sapphire.
Preferably, when the substrate is monocrystalline silicon with a crystal orientation of <100>, the grating period of the deep sub-wavelength grating array processed on the chromium film is 323-355 nm.
Preferably, when the substrate is monocrystalline silicon with the crystal orientation of <110>, the grating period of the deep sub-wavelength grating array processed on the chromium film is 344-348 nm.
Preferably, when the substrate is gallium arsenide, the grating period of the deep sub-wavelength grating array processed on the chromium film is 344.5-349.5 nm.
Preferably, when the substrate is sapphire, the grating period of the deep sub-wavelength grating array processed on the chromium film is 87.3-96.7 nm.
The invention can obtain the following technical effects:
1. the method comprises the steps of emitting laser by a femtosecond laser source, respectively adjusting processing parameters of the laser, the pressure of a processing environment and a processing area of the surface of the chromium film by laser energy and polarization adjusting unit, a focusing lens, a vacuum unit and a three-dimensional moving platform, and processing a super-regular and high-precision micro-nano structure on the surface of the chromium film.
2. The invention can replace different substrates, and the super-regular deep sub-wavelength micro-nano structure with different grating periods is processed on the surface of the chromium film.
Drawings
Fig. 1 is a schematic diagram of a femtosecond laser micro-nano processing system provided according to an embodiment of the invention;
FIG. 2 is a schematic flow chart of a method for inducing a super-structured nano-grating based on a femtosecond laser assisted by a chromium film according to an embodiment of the invention;
FIG. 3 is a schematic view of a 2.0X 10 display device according to an embodiment of the present invention～5Pa processing environment, thickness of 25nm<100>Scanning Electron Microscope (SEM) images of overlook and cross section of the micro-nano structure area on the surface of the silicon-based chromium film;
FIG. 4 is an SEM image of a micro-nano structure induced on the surface of a <100> silicon-based chromium film with a thickness of 25nm by femtosecond laser in different air pressure environments provided by an embodiment of the invention;
fig. 5 is a raman spectrum of a micro-nano structure region induced on the surface of a <100> silicon-based chromium film with a thickness of 25nm by femtosecond laser in different atmospheric pressure environments provided by an embodiment of the present invention;
fig. 6 shows that P is 2.0 × 10 according to an embodiment of the present invention～5Of different thickness in a Pa processing environment<100>SEM images of micro-nano structures induced on the surfaces of the silicon-based chromium film and the bulk chromium;
fig. 7 shows that P is 2.0 × 10 according to an embodiment of the present invention～5For thickness of 25nm in Pa processing environment<100>SEM (scanning electron microscope) images of micro-nano structure stitching conditions of areas scanned by two lasers on the surface of the silicon-based chromium film;
fig. 8 shows that P is 2.0 × 10 according to an embodiment of the present invention～5And (3) SEM images of micro-nano structures induced on the surfaces of chromium films evaporated on different substrates with the thickness of 25nm in a Pa processing environment.
Wherein the reference numerals include: 100-femtosecond laser light source, 110-laser emission light path, 200-laser energy polarization adjusting unit, 210-half wave plate, 220-Glan Taylor prism, 300-focusing lens, 400-vacuum unit, 500-vacuum three-dimensional moving translation stage and 600-computer.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention.
The embodiment of the invention provides a method for inducing a super-regular nano grating by femtosecond laser based on chrome film assistance, which is realized by depending on a micro-nano structure processing system.
Fig. 1 shows a structure of a micro-nano structure processing system provided by an embodiment of the invention.
As shown in fig. 1, a micro-nano structure processing system provided in an embodiment of the present invention includes: the laser system comprises a femtosecond laser light source 100, a laser energy polarization adjusting unit 200, a focusing lens 300, a vacuum unit 400, a vacuum three-dimensional moving translation stage 500 and a computer 600; the laser system comprises a femtosecond laser light source 100, a focusing lens 300, a vacuum unit 400, a vacuum three-dimensional moving translation table 500 and a computer 600, wherein the femtosecond laser light source 100 is used for emitting femtosecond laser to form a laser emission light path 110, the focusing lens 300, the vacuum unit 400, the vacuum three-dimensional moving translation table 500 and the computer 600 are sequentially arranged on the laser emission light path 110, the laser energy and polarization adjusting unit 200 is used for adjusting the energy and the polarization direction of the femtosecond laser, and the focusing lens 300 is used for focusing the femtosecond laser; the vacuum adjusting unit 400 is used for adjusting the environmental pressure during the laser processing of the chromium film; the three-dimensional vacuum translation stage 500 is placed in the vacuum unit 400, the chromium film is fixed on the three-dimensional vacuum translation stage 500, and the computer 600 establishes communication with the vacuum three-dimensional translation stage 500 to control the movement of the three-dimensional translation stage 500, so as to control the movement of the chromium film on the three-dimensional translation stage 500.
The working principle of the micro-nano structure processing system is as follows: the femtosecond laser source 100 emits femtosecond laser, vertically focuses the laser on the surface of the chromium film fixed on the three-dimensional vacuum translation stage 500 through the light transmission windows of the laser energy polarization adjusting unit 200, the focusing lens 300 and the vacuum unit 400 in sequence, and completes the micro-structuring of the surface of the chromium film by adjusting processing parameters.
It can be understood that the ultra-regular and high-precision processing of the surface of the chromium film can be realized by controlling the processing parameters. The control of the processing parameters comprises the environmental pressure adjusted by the vacuum unit 400, the laser energy and the laser polarization direction adjusted by the laser energy polarization adjusting unit 200, the defocusing distance of the chromium film adjusted by the vacuum three-dimensional moving platform 500 and the moving speed of the chromium film.
In this embodiment, the femtosecond laser source 100 uses chirped amplified pulses of a titanium sapphire laser as a light source, which outputs a horizontally polarized femtosecond pulsed laser with a center wavelength of 800nm, a repetition frequency of 1kHz, and a pulse width of 40fs, wherein the maximum single pulse energy of the system is about 7 mJ.
In the present embodiment, the laser energy polarization adjustment unit 200 includes a half wave plate 210 and a glan-taylor prism 220, the energy of the femtosecond laser can be continuously tuned by rotating the crystal axis direction of the half wave plate 210, and the linear polarization direction of the femtosecond laser can be adjusted by rotating the crystal axis direction of the glan-taylor prism 220.
In this embodiment, the focal length of the focusing lens 300 is 300mm, so that a spot with a diameter of one hundred micrometers is formed on the surface of the chromium film.
In this example, a chromium thin film was deposited by a magnetron sputtering method on the surface of <100> single crystal silicon in the crystal orientation and <110> single crystal silicon, gallium arsenide, or sapphire in the crystal orientation.
In this embodiment, the focal length of the focusing lens is 300mm, and a spot having a diameter of the order of hundreds of micrometers is formed on the chromium thin film.
In the present embodiment, the vacuum unit 400 includes necessary devices of a vacuum apparatus such as a vacuum chamber, a mechanical pump, and a molecular pump. The change of the environmental pressure during the chromium thin film processing can be achieved by adjusting the pressure in the vacuum chamber of the vacuum unit 400.
In this embodiment, the three-dimensional vacuum moving platform 500 is controlled by the computer 600, the moving speed of the three-dimensional vacuum moving platform 500 is adjusted to change the number of overlapping pulses irradiated on the surface of the chromium thin film, and the moving direction of the three-dimensional vacuum moving platform 500 is adjusted to change the area irradiated on the surface of the chromium thin film, so as to realize the super-regularity and high-precision processing of different areas of the surface of the chromium thin film.
In this embodiment, the processing power of the laser was 4mW, and the chromium thin film surface was placed 4mm in front of the focal plane of the focusing lens 300. The polarization direction of the laser light was kept in agreement with the moving direction of the chromium thin film, and the moving speed of the chromium thin film was kept at 2 μm/s. The environmental pressure of the chromium thin film can be adjusted by the vacuum unit 400 within a range of 10～6Pa～105Pa. Chromium films with different thicknesses are evaporated on the single-side polished crystal orientation by a magnetron sputtering method<100>Single crystal silicon of crystal orientation<110>Surfaces of single crystal silicon, gallium arsenide, and sapphire. The microstructured chromium film was characterized by scanning electron microscopy and raman spectroscopy.
The above details describe the structure of the micro-nano structure processing system provided by the embodiment of the present invention. Corresponding to the micro-nano structure processing system, the invention also provides a method for inducing the micro-nano structure on the chromium film by femtosecond laser by using the micro-nano structure processing system.
Fig. 2 shows a flow of a method for inducing a super-structured nano-grating based on a femtosecond laser assisted by a chromium film according to an embodiment of the invention.
As shown in fig. 2, the method for inducing the super-regular nano-grating based on the femtosecond laser assisted by the chromium film comprises the following steps:
s1, evaporating a chromium film with the thickness of 25-100 nm on the substrate by adopting a magnetron sputtering method.
The substrate may be <100> single crystal silicon, <110> single crystal silicon, gallium arsenide, or sapphire.
The chromium film is evaporated on the substrate by utilizing a magnetron sputtering method, and the chromium films with different thicknesses can be evaporated on the substrate by changing the process parameters.
S2, building a femtosecond laser processing system; the femtosecond laser processing system comprises a femtosecond laser light source, a laser energy polarization adjusting unit, a focusing lens, a vacuum unit with adjustable processing environment pressure intensity, a three-dimensional vacuum translation table and a computer, wherein the laser energy polarization adjusting unit, the focusing lens, the vacuum unit with adjustable processing environment pressure intensity, the three-dimensional vacuum translation table and the computer are sequentially arranged along a laser emission light path.
The device comprises a femtosecond laser light source, a focusing lens, a vacuum unit, a vacuum three-dimensional moving translation table and a computer, wherein the femtosecond laser light source is used for emitting femtosecond laser to form a laser emission light path; the vacuum adjusting unit is used for adjusting the environmental pressure during the laser processing of the chromium film; the three-dimensional vacuum translation stage is placed in the vacuum unit, the chromium film is fixed on the three-dimensional vacuum translation stage, and the computer is communicated with the vacuum three-dimensional translation stage and used for controlling the movement of the three-dimensional moving platform so as to control the movement of the chromium film on the three-dimensional moving platform
S3, fixing the chromium film on a three-dimensional vacuum translation table, integrally placing the chromium film in a vacuum unit, controlling the pressure of a processing environment to be below 3.6Pa through the vacuum unit, and adjusting the flux of femtosecond laser pulses emitted by a femtosecond laser light source to be 20.9-24.5 mJ/cm under the attenuation of a laser energy polarization adjusting unit2And vertically focusing the chromium film on a focusing lens, and controlling a three-dimensional vacuum translation table by a computer to drive the chromium film to move at a speed of 0.3-2 μm/s, so as to process a row of deep sub-wavelength grating array with a grating period of 323-355 nm, a width of 60 μm and a depth of 237nm on the chromium film.
The microstructured chromium film was characterized by scanning electron microscopy and raman spectroscopy.
FIG. 3 shows a graph of 2.0 × 10 according to an embodiment of the present invention～5Pa processing environment, 25nm thick<100>Top view and cross-sectional Scanning Electron Microscopy (SEM) images of the microstructure areas of the surface of the silicon-based chromium film.
As can be seen from fig. 3, the surface of the 25nm thick silicon-based chromium thin film was uniformly structured by the femtosecond laser under the processing parameters. The enlarged SEM top view shows that the surface of the silicon-based chromium film actually forms the super-regular one-dimensional periodic grating nick, and the nick period is 355 +/-4 nm. It is worth emphasizing that the induced grating period is less than half of the incident laser wavelength (800nm), i.e. the grating structure produced on the surface of the silicon-based chromium film by the processing method provided by the invention realizes the super-optical diffraction limit processing. It can be seen from the cross-sectional view that the score penetrates the chromium film and etches deep into the silicon substrate. It was found by measurement that the depth of the notch reached 237 ± 22nm, and a high aspect ratio notch of 2.7 was formed. It has also been found that the shape of the score is not a generally laser ablated sinusoidal shape but rather exhibits an hourglass shape that is wider at both ends and narrower in the middle.
FIG. 4 shows SEM images of the surface-induced microstructure of a <100> silicon-based chromium film with a thickness of 25nm by a femtosecond laser under different atmospheric pressure environments provided by the embodiment of the invention.
As shown in fig. 4, the processing environment pressure P is 2.0 × 10～5Pa、P＝2.3×10～3Pa、P＝3.7×10～1Pa, P-3.6 Pa and P-3.3X 101When Pa, the femtosecond laser induces SEM images of micro-nano structures on the surface of a silicon-based chromium film with the thickness of 25nm, and scales are all 1 micrometer. It was found that when the degree of vacuum of the processing environment remained relatively high (P ═ 2.3 × 10)～3Pa) and the grating structure described above (2.0X 10)～5Pa) and still maintains high regularity, and the profile of the grating is very sharp. The environmental pressure gradually increases along with the processing (P is 3.7 multiplied by 10)～1Pa, P ═ 3.6Pa), the regularity of the grating is still high, but the grating profile starts to become less sharp. However, when the pressure rises to P-3.3 × 101At Pa the grating structure starts to become less regular and it appears that a thick layer of something covers the grating structure.
Fig. 5 shows raman spectra of a micro-nano structure region induced on the surface of a <100> silicon-based chromium thin film with a thickness of 25nm by femtosecond laser under different atmospheric pressure environments provided by an embodiment of the invention.
As shown in fig. 5, the pressure in different atmospheres (P ═ 2.0 × 10) is shown respectively～5Pa、P＝2.3×10～3Pa、P＝3.7×10～1Pa, P-3.6 Pa and P-3.3X 101Pa), the femtosecond laser induces micro-particles on the surface of a 25nm silicon-based chromium filmRaman spectra of the structural regions. As can be seen from fig. 5, when the processing environment pressure is P ═ 2.0 × 10～5Pa and P2.3X 10～ 3At Pa, the Raman spectrum of the microstructure region is 540cm～1To 800cm～1The interval did not show any peak position and almost agreed with the raman spectrum of the silicon-based chromium film without laser treatment. However, when the pressure of the processing environment is gradually increased (P ═ 3.7 × 10)～ 1Pa, P-3.6 Pa and P-3.3X 101Pa), Raman spectrum of the microstructure area at 666cm～1The position begins to appear at a peak position, and the intensity of the peak position increases as the pressure of the processing environment increases. 666cm can be known by looking up the literature～1The appearance of the peak position suggests CrO2And (4) generation of an oxide. The experimental phenomenon in FIG. 4 can thus be explained, CrO following the increase in the pressure of the processing environment2The initial generation of oxide on the surface of the sample leads to the initial blurring of the grating profile, and finally a thick layer of CrO is formed on the surface of the chromium film2An oxide overlies the induced grating structure.
Fig. 6 shows that P is 2.0 × 10 according to an embodiment of the present invention～5Of different thickness in a Pa processing environment<100>SEM images of micro-nano structures induced on the surfaces of the silicon-based chromium film and the bulk chromium sample.
As shown in FIG. 6, SEM images of femtosecond laser-induced grating structures on 50nm, 100nm and 200nm silicon-based chromium films and bulk chromium films in a high vacuum environment are respectively shown, and scales of the SEM images are 2 μm. It can be observed from fig. 6 that the induced grating structure still maintains as high a regularity as the grating structure induced at the surface of the 25nm silicon-based chromium film when the chromium film thickness is increased to 50 nm. However, when the chromium film thickness is increased to 100nm, 200nm, and even when the chromium film becomes bulk chromium, the induced grating structure is found to be significantly less regular. And for the silicon-based chromium film sample, the period of the grating decreased as the thickness of the chromium film increased. But the grating period induced on the bulk chromium surface is significantly larger than the grating period on the surface of the silicon-based chromium film.
Fig. 7 shows that P is 2.0 × 10 according to an embodiment of the present invention～5For thickness of 25nm in Pa processing environment<100>SEM image of micro-nano structure stitching condition of two laser scanning areas on the surface of the silicon-based chromium film.
As shown in fig. 7, a graph of stitching effect when the overlapping rate of two laser scanning lines is 27% is shown. The C and D boxes represent the first and second laser scanning zones, respectively. As can be seen from the left inset of fig. 7, the grating structure in the overlapping region of the two scan lines remains intact without any breakage. Comparing the enlarged top view and cross-sectional SEM images of the overlapping region and the central region of the single scan line, both with a scale of 1 μm, it was found that the grating structure of the overlapping region was almost identical in period and depth to the structure of the single scan line. That is, at a suitable overlap ratio, the structure of the overlap region is hardly affected by the second laser scan. Therefore, the method for inducing the super-regular deep sub-wavelength grating structure by the femtosecond laser based on the chromium film can seamlessly sew the grating structure generated by multiple scanning. This shows that the processing method provided by the invention has the potential of manufacturing grating structures in a large area.
Fig. 8 shows that P is 2.0 × 10 according to an embodiment of the present invention～5And (3) SEM images of micro-nano structures induced on the surfaces of chromium films evaporated on different substrates with the thickness of 25nm in a Pa processing environment.
As shown in fig. 8, SEM images of femtosecond laser induced micro-nano grating structures on samples with <110> si, gaas and sapphire surface evaporated with 25nm chromium film in high vacuum processing environment are given. Fig. 8 shows that the processing method provided by the present invention can still induce a regular deep sub-wavelength grating structure on the surface of the chromium thin film under the condition of different substrates. A grating structure with the period of 346 +/-2 nm is induced on the surface of a <110> silicon substrate chromium film with the thickness of 25nm, and a grating structure with the period of 347 +/-2.5 nm is induced on the surface of a gallium arsenide substrate chromium film with the thickness of 25 nm. It is worth noting that on the surface of the chrome thin film of the sapphire substrate with the thickness of 25nm, a grating structure with the period of 92 +/-4.7 nm is induced, and the period of the grating structure is almost one tenth of the wavelength of incident light. The experimental phenomena show that the processing method provided by the invention has great potential in manufacturing the super-regular deep sub-wavelength grating structure.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
The above embodiments of the present invention should not be construed as limiting the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the protection scope of the claims of the present invention.
Claims (8)
1. A method for inducing a super-regular nano grating by femtosecond laser based on chromium film assistance is characterized by comprising the following steps:
s1, evaporating a chromium film with the thickness of 25-100 nm on the substrate by adopting a magnetron sputtering method;
s2, building a femtosecond laser processing system; the femtosecond laser processing system comprises a femtosecond laser light source, a laser energy polarization adjusting unit, a focusing lens, a vacuum unit with adjustable processing environment pressure intensity, a three-dimensional vacuum translation table and a computer, wherein the laser energy polarization adjusting unit, the focusing lens, the vacuum unit with adjustable processing environment pressure intensity, the three-dimensional vacuum translation table and the computer are sequentially arranged along a laser emission light path;
s3, fixing the chromium film on the substrateThe three-dimensional vacuum translation table is integrally placed in the vacuum unit, the pressure of a processing environment is controlled to be lower than 3.6Pa through the vacuum unit, and the femtosecond laser pulse emitted by the femtosecond laser light source adjusts the flux to be 20.9-24.5 mJ/cm under the attenuation of the laser energy polarization adjusting unit2And vertically focusing the chromium film through the focusing lens, controlling the three-dimensional vacuum translation stage through the computer to drive the chromium film to move at a speed of 0.3-2 μm/s, and processing a row of deep sub-wavelength grating array with a grating period of 323-355 nm, a width of 60 μm and a depth of 237nm on the chromium film.
2. The method for inducing the super-regular nano-grating based on the chrome film assisted femtosecond laser according to claim 1, wherein the femtosecond laser light source adopts chirped amplified pulses of a titanium sapphire laser as a light source, and outputs horizontally polarized femtosecond laser; wherein the femtosecond laser has a central wavelength of 800nm, a repetition frequency of 1kHz, and a pulse width of 40 fs.
3. The method for inducing the super-regular nano-grating based on the chrome film assisted femtosecond laser as in claim 1, wherein the focal length of the focusing lens is 300mm, and a light spot with the diameter of hundreds of microns is formed on the chrome film.
4. The method of claim 1, wherein the substrate is single crystal silicon, gallium arsenide, or sapphire.
5. The method for inducing the super-regular nano-grating based on the femtosecond laser assisted by the chromium film as in claim 4, wherein when the substrate is monocrystalline silicon with a crystal orientation of <100>, the grating period of the deep sub-wavelength grating array processed on the chromium film is 323-355 nm.
6. The method for inducing the super-regular nano-grating by the femtosecond laser based on the assistance of the chromium film according to the claim 4, wherein when the substrate is monocrystalline silicon with the crystal orientation of <110>, the grating period of the deep sub-wavelength grating array processed on the chromium film is 344-348 nm.
7. The method for inducing the super-regular nano-grating by the femtosecond laser based on the assistance of the chromium film according to the claim 4, wherein when the substrate is gallium arsenide, the grating period of the deep sub-wavelength grating array processed on the chromium film is 344.5-349.5 nm.
8. The method for inducing the super-regular nano-grating based on the chrome film assisted femtosecond laser as in claim 4, wherein when the substrate is sapphire, the grating period of the deep sub-wavelength grating array processed on the chrome film is 87.3-96.7 nm.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113917586A (en) * | 2021-10-18 | 2022-01-11 | 浙江大学 | Micro light splitting element and preparation method thereof |
| CN114425654A (en) * | 2021-12-29 | 2022-05-03 | 西湖大学 | System and method for preparing acoustic wave device interdigital transducer based on femtosecond laser processing mask |
| CN116551157A (en) * | 2023-04-19 | 2023-08-08 | 广东工业大学 | Graphene-based spiral micro-nano robot and processing method thereof |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1280303A (en) * | 1999-07-07 | 2001-01-17 | 三星电子株式会社 | Equipment and method for producing optic fibre grating |
| JP2002219587A (en) * | 2001-01-22 | 2002-08-06 | Vacuum Metallurgical Co Ltd | Producing method for metal micro projection and producing device therefor |
| US20050247923A1 (en) * | 2004-04-29 | 2005-11-10 | Korea Research Institute Of Standards And Science | Semiconductor nano-structure and method of forming the same |
| WO2012004903A1 (en) * | 2010-07-05 | 2012-01-12 | 株式会社日本製鋼所 | Laser annealing device and laser annealing method |
| US20140158937A1 (en) * | 2012-12-07 | 2014-06-12 | Samsung Electronics Co., Ltd. | Processes for synthesizing nanocrystals and nanocrystal compositions |
| CN105798454A (en) * | 2016-04-29 | 2016-07-27 | 西安交通大学 | Method for preparing micro-nano composite structure through nanosecond laser induced cracks |
| US20160377994A1 (en) * | 2012-02-03 | 2016-12-29 | Asml Netherlands B.V. | Substrate holder, lithographic apparatus, device manufacturing method, and method of manufacturing a substrate holder |
| CN108526699A (en) * | 2018-04-04 | 2018-09-14 | 中国科学院长春光学精密机械与物理研究所 | A kind of optical machining system of perovskite monocrystalline and application |
| CN108620728A (en) * | 2018-05-09 | 2018-10-09 | 广州大学 | Semiconductor silicon surface large area regular distribution nano-pore array structure preparation method |
-
2020
- 2020-12-29 CN CN202011608475.0A patent/CN112643206A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1280303A (en) * | 1999-07-07 | 2001-01-17 | 三星电子株式会社 | Equipment and method for producing optic fibre grating |
| JP2002219587A (en) * | 2001-01-22 | 2002-08-06 | Vacuum Metallurgical Co Ltd | Producing method for metal micro projection and producing device therefor |
| US20050247923A1 (en) * | 2004-04-29 | 2005-11-10 | Korea Research Institute Of Standards And Science | Semiconductor nano-structure and method of forming the same |
| WO2012004903A1 (en) * | 2010-07-05 | 2012-01-12 | 株式会社日本製鋼所 | Laser annealing device and laser annealing method |
| US20160377994A1 (en) * | 2012-02-03 | 2016-12-29 | Asml Netherlands B.V. | Substrate holder, lithographic apparatus, device manufacturing method, and method of manufacturing a substrate holder |
| US20140158937A1 (en) * | 2012-12-07 | 2014-06-12 | Samsung Electronics Co., Ltd. | Processes for synthesizing nanocrystals and nanocrystal compositions |
| CN105798454A (en) * | 2016-04-29 | 2016-07-27 | 西安交通大学 | Method for preparing micro-nano composite structure through nanosecond laser induced cracks |
| CN108526699A (en) * | 2018-04-04 | 2018-09-14 | 中国科学院长春光学精密机械与物理研究所 | A kind of optical machining system of perovskite monocrystalline and application |
| CN108620728A (en) * | 2018-05-09 | 2018-10-09 | 广州大学 | Semiconductor silicon surface large area regular distribution nano-pore array structure preparation method |
Non-Patent Citations (3)
| Title |
|---|
| 上海交通大学: "《机电词典》", 31 October 1991, 机械工业出版社 * |
| 刘琦等: "不同气压环境对飞秒激光在铬膜表面诱导周期性条纹结构的影响", 《光子学报》 * |
| 齐立涛: "《短脉冲激光微细加工技术》", 30 November 2012, 哈尔滨工程大学出版社 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113917586A (en) * | 2021-10-18 | 2022-01-11 | 浙江大学 | Micro light splitting element and preparation method thereof |
| CN114425654A (en) * | 2021-12-29 | 2022-05-03 | 西湖大学 | System and method for preparing acoustic wave device interdigital transducer based on femtosecond laser processing mask |
| CN116551157A (en) * | 2023-04-19 | 2023-08-08 | 广东工业大学 | Graphene-based spiral micro-nano robot and processing method thereof |
| CN116551157B (en) * | 2023-04-19 | 2023-11-03 | 广东工业大学 | Graphene-based spiral micro-nano robot and processing method thereof |
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