CN114289879B - Method for integrating multiple micro capacitors by single preparation of ultrafast laser - Google Patents
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Abstract
The invention relates to an integrated method for preparing a plurality of micro capacitors by ultrafast laser at a time, and belongs to the field of micro-nano manufacturing. The invention aims to solve the defects of low processing efficiency, inflexibility and unstable precision and performance in the prior art. According to the invention, local selective electronic dynamic regulation and control are carried out on the two-dimensional material through ultrafast laser, so that removal and ablation are generated, and finally, serial-parallel integrated preparation of various ultra-miniature capacitors can be realized by single exposure in the laser spot area; the method has extremely high preparation efficiency and simple process, and the miniature super capacitor prepared by the method has flexible and adjustable size, shape, performance and integration form. The method for preparing the integration of a plurality of capacitors by single exposure can promote the development of micro energy devices and even microelectronic industry, subvert the traditional photoetching processing method and realize the integration manufacture of ultrahigh-efficiency and high-performance devices.
Description
Technical Field
The invention relates to an integrated method for preparing a plurality of micro capacitors by ultrafast laser once, and belongs to the field of micro-nano manufacturing.
Background
In recent years, rapid development of microelectronic devices in the fields of aerospace, biomedical, automated manufacturing, flexible devices, portable devices, and the like, increasingly enhanced functions, processing speeds, and reliability thereof have shown urgent demands for microminiaturization of energy storage devices. Micro capacitors, also known as micro supercapacitors, have been widely studied and extensively discussed as typical energy storage devices.
The advent of two-dimensional materials has led to significant advances in human science in various ways. Two-dimensional material sheets such as graphene and metal phase molybdenum sulfide have excellent conductivity and abundant active edges, and the capacitance performance of the two-dimensional material sheets is greatly improved due to the fact that the specific surface area is improved due to further stacking. Therefore, micro capacitors using abundant two-dimensional material as active material are continuously developed.
The preparation of micro energy devices is the focus of human development, and various advanced manufacturing technologies are capable of solving the problems and challenges of micro energy devices in various aspects without any residual force. The methods for making individual miniature supercapacitors are currently diverse: including conventional laser scribing, photolithographic processing, focused ion beam etching, electrochemical processing, etc., but the problems are also quite obvious. The photoetching method needs to prepare a mask in advance, and the process flow is complex and is easy to introduce foreign impurities; the focused ion beam etching needs an extremely high vacuum environment, has high cost and is difficult to prepare and produce on a large scale; the methods such as electrochemical deposition are inefficient and have a high defective rate. More importantly, the micro super capacitor prepared by the method has relatively low efficiency, performance, miniaturization and integration degree, is difficult to be compatible with a plurality of advantages, and limits the development of the integrated manufacturing of the micro super capacitor to a certain degree.
Disclosure of Invention
The invention aims to provide a method for preparing a plurality of micro capacitors by ultrafast laser once for integration, which carries out spatial shaping on the ultrafast laser by realizing the single-pixel design of a target light field, shapes Gaussian light spots into the shapes of the light spots of a plurality of micro capacitors connected in series and parallel, carries out local electronic dynamic regulation and control on a two-dimensional material with electrochemical activity, generates removal, and thus realizes the preparation of the plurality of micro capacitors connected in series and parallel for integration by one-step single exposure.
In order to achieve the purpose, the invention provides the following technical scheme:
an integrated method for preparing a plurality of micro capacitors by ultrafast laser at a time comprises the following steps:
the method comprises the following steps: designing a series-parallel integrated pattern of a plurality of shapes or a single-shape miniature super capacitor, processing the image by a single-pixel method to enable the width of each line segment of the pattern to be a pixel point, and generating a plurality of capacitor pattern arrays which are connected with one another to form a target light field of a series-parallel integrated system;
step two: generating a phase diagram corresponding to a target light field through a computer Fourier transform iterative algorithm;
step three: constructing an ultrafast laser space shaping processing system;
step four: shaping the initial Gaussian distribution circular light spot of the ultrafast laser into a multi-capacitor integrated pattern light field by the corresponding phase diagram generated in the second step and the processing system built in the third step, and focusing the light field on the surface of the two-dimensional material film electrode material. By controlling the processing parameters of the ultrafast laser, specific position removal meeting requirements and design is obtained, and residual materials in one light spot form one-time processing of forming a plurality of super capacitors in integrated series-parallel connection;
step five: and D, dripping electrolyte solution on the two-dimensional material micro capacitor processed in the step four, standing for 12 hours, and fully immersing the micro capacitor to obtain the assembled micro super capacitor array.
Preferably, the self-programming program selected in the step two is based on a GS algorithm, and the design pattern is single-pixel precision so as to ensure the precision optimality of the processing result, so that the precision of material removal reaches 300nm;
further, the ultrafast laser light field shaping system in the third step comprises an ultrafast laser, a mechanical switch, an attenuation sheet group, an ultrafast laser space light shaper, an ultrafast reflector, a dichroic mirror, a white light illumination source, a CCD dynamic imaging unit, a focusing objective lens, a sample to be processed, a precise electric control translation stage, a computer and a convex lens; laser beams emitted by the titanium sapphire ultrafast laser enter the ultrafast laser field shaping device through the mechanical optical switch and the attenuation sheet group, and a target light field of the micro capacitor array is obtained through light field shaping, wherein the energy of the target light field is attenuated to an energy value meeting the preset use requirement; then the light is reflected by an ultrafast reflector, is focused to a sample to be processed on a precise electric control translation stage through a focusing objective lens, the illumination light emitted by the white light source positioned at the top passes through a dichroic mirror, the ultrafast reflector and the focusing objective lens to irradiate the sample to be processed, is reflected, returns through the focusing objective lens and the ultrafast reflector, is reflected by the dichroic mirror to reach a CCD dynamic imaging unit, a computer is connected with an ultrafast laser, controls the target pattern of the ultrafast laser field shaping, controls the opening and closing of a mechanical switch, and controls the precise electric control translation stage to move in the XYZ direction, wherein the movement meets the speed and the position of the preset use requirement, and is connected with the CCD dynamic imaging unit to monitor the surface of the processed sample.
Preferably, the ultrafast laser light field shaping system in the third step selects an ultrafast laser light field shaping device based on a phase type spatial light modulator;
preferably, the thickness of the two-dimensional material film selected in the fourth step is 1 μm;
and adopting the processing parameters of the fourth step to realize the local light field shaping of the ultrafast laser, further regulating and controlling the electronic distribution and the dynamic state of the material, and improving the manufacturing efficiency, wherein the processing parameters comprise the laser energy and the pulse number of the ultrafast laser and an objective lens required by processing.
The laser energy of the ultrafast laser is less than or equal to 100 muJ, the number of pulses is less than or equal to 1000/s, and the objective lens required by processing is 5-50 times. Preferably, the ultrafast laser energy adopted in the fourth step is 80 muJ, the number of pulses is 1000/s, and the objective lens is processed by 20 times; the target light field, the laser energy of 0-100 muJ, the number of pulses of 0-1000/s and the objective lens required by processing are changed by 5-50 times to obtain the micro-supercapacitor integrated system with different numbers, patterns and integrated forms, and the system still belongs to the protection range of the patent.
Preferably, in the fifth step, the electrolyte solution is 100 μ L of PVA/H with a concentration of 0.5mol/L 2 SO 4 A solid electrolyte solution.
Advantageous effects
1. The invention provides a method for integrating a plurality of micro capacitors by ultrafast laser once preparation. According to the method, a two-dimensional material is processed through ultrafast laser light field shaping, so that material removal and ablation at a specific position of any pattern are generated, and finally, the integrated preparation of various ultra-miniature capacitors can be realized by one-step method through single exposure in a laser spot area;
2. the method utilizes a Fourier transform iterative algorithm to cooperate with a single-pixel width pattern to calculate the phase diagram, the single-pixel width pattern necessarily and effectively controls the number of pixel points in the phase diagram, so that the modulated and shaped light field is clear and effective, the resolution of the processed pattern is improved unprecedentedly, the width of the removed material is as low as 300nm, and the high-precision and high-efficiency removal is realized;
3. the method also has the characteristics of high efficiency, flexibility, non-contact, no pollution and non-vacuum condition, and the ultrafast laser also has the advantages of extremely short pulse duration, extremely high pulse peak power, capability of avoiding heat effect and the like. More importantly, the local electronic dynamics of the material is regulated and controlled by changing the distribution of the ultrafast laser optical field. Therefore, according to the unique interaction mechanism of the ultrafast laser and the two-dimensional material and the programming of the customized integration pattern of the plurality of capacitors, a high-efficiency full-new method for simultaneously preparing the plurality of micro capacitors in series-parallel connection and integration by a single pulse one-step method can be realized.
4. The method has the advantages that mask and chemical doping treatment are not needed in the preparation, the area of light spots can be fully utilized, the shapes of capacitors can be flexibly regulated and controlled (namely, the micro super capacitor light fields with different shapes such as interdigital shapes, circular shapes and flat plates can be selected to appear in one light spot at the same time) and an integrated mode (namely, the micro super capacitors in one light spot can be integrally connected in a mode of combining series connection, parallel connection or series-parallel connection), and a corresponding micro super capacitor array integrated system (1000 micro capacitor integrated systems per second) can be prepared at ultrahigh efficiency;
5. the integration system of the multiple capacitors prepared by one-step single exposure can effectively realize the excellent effects that the voltage window of unit length is enlarged to every 2 volts/hundred micrometers, the area of the unit integration system is greatly reduced, and the area specific capacitance is obviously improved, thereby promoting the development of micro energy devices and even microelectronic industries, even subverting the traditional photoetching processing method and realizing the manufacture of ultra-high-efficiency high-performance micro-nano devices.
Drawings
FIG. 1 is a flowchart illustrating an integrated method for manufacturing a plurality of micro supercapacitors at a time according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of an integrated method for manufacturing a plurality of micro supercapacitors at a time according to an embodiment of the invention;
FIG. 3 is a schematic diagram illustrating the integration of various types of micro-capacitor arrays in accordance with an embodiment of the present invention;
FIG. 4 is a phase diagram and a corresponding single pixel target light field diagram according to an embodiment of the present invention, wherein A is the phase diagram; b, a target light field with single pixel width;
FIG. 5 is a diagram of an ultrafast laser processing system employed by an embodiment of the present invention;
FIG. 6 is a voltammetric curve of the integrated performance of a molybdenum disulfide micro-capacitor.
Wherein, fig. 5: 1-ultrafast laser; 2-grating; 3-an attenuation sheet; 4-an optical shutter; 5-a CCD imaging system; 6-a light source; 7-a dichroic mirror; 8-a mirror; 9-a focusing lens; 10-a substrate to be processed; 11-a six-dimensional translation stage; 12-a computer; 13-convex lens.
Detailed Description
The invention is further illustrated with reference to the following figures and examples.
Example 1
The main flow of this embodiment is shown in fig. 1.
The processing schematic diagram is shown in fig. 2, and one-time forming processing is realized by the ultrafast laser space shaping processing system loaded with the holographic phase diagram.
An integrated method for preparing a plurality of micro capacitors by ultrafast laser at a time takes a molybdenum disulfide film with the thickness of 1 micron as an example, and a silicon dioxide sheet with the thickness of 1mm as a substrate. The manufacturing steps are as follows:
(1.1) carrying out suction filtration on the molybdenum disulfide nanosheet dispersion liquid into a film with the thickness of 1 micron by adopting a vacuum suction filtration mode;
(1.2) transferring the film to a silicon dioxide sheet with the thickness of 1mm, and removing the filter membrane by using acetone to finally prepare a sample combining 1 micron molybdenum disulfide and 1mm silicon dioxide;
(1.3) designing four patterns (as shown in fig. 3) which are different in types and integrated with each other in advance, and carrying out single-pixel-point width processing on the patterns, namely, the width of each line in the patterns is one pixel.
(1.4) calculating and generating an integrated phase diagram of four micro-capacitance pattern arrays by a computer program according to a G-S algorithm, wherein the phase diagram is shown in FIG. 4A, and the corresponding modulation light field simulation is shown in FIG. 4B;
(1.5) inputting the generated phase diagram into a spatial light modulator in an ultrafast laser optical path processing system, shaping an original ultrafast laser optical field, focusing the shaped phase diagram on the surface of a sample through a 20-time objective lens, ablating a predetermined pattern of a molybdenum disulfide film, and processing four mutually-connected and mutually-different micro supercapacitors (the whole pattern area is 40 microns multiplied by 40 microns, the pattern area comprises 4 capacitors, each capacitor area is 20 microns multiplied by 20 microns, and the precision reaches 300 nanometers) at a time by adopting single pulse energy of 80 microns;
the ultrafast laser processing system on which this step relies is shown in fig. 5, which includes: 1-ultrafast laser; 2-grating; 3-an attenuation sheet; 4-an optical shutter; 5-a CCD imaging system; 6-a light source; 7-a dichroic mirror; 8-a mirror; 9-a focusing lens; 10-a substrate to be processed; 11-a six-dimensional translation stage; 12-a computer; 13-convex lens.
(1.6) the time of single processing is 0.001 second, and 1000 micro capacitance integration systems can be processed in 1 second by combining the movement of a translation stage of 40000 microns/second, which is matched with the repetition frequency of 1kHz of the ultrafast laser.
(1.7) placing the sample (1.5) in an air atmosphere, and adding dropwise a solid electrolyte solution (as long as the solid electrolyte solution has good ion migration ability, in this example, 100. Mu.L of PVA/H with a concentration of 0.5mol/L is selected 2 SO 4 Solid electrolyte solution) into an integrated micro supercapacitor array. The electrochemical performance volt-ampere characteristic curve is shown in figure 6, the quasi-rectangular shape is shown, the capacitance characteristic is good, the voltage window is 0.5V, and 8mF/cm can be obtained at the scanning speed of 10mV/s 2 Area to capacitance.
The above detailed description is intended to illustrate the objects, aspects and advantages of the present invention, and it should be understood that the above detailed description is only exemplary of the present invention and is not intended to limit the scope of the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (4)
1. An integrated method for preparing a plurality of micro capacitors by ultrafast laser at a time is characterized in that: modulating an original Gaussian light field of ultrafast laser into light fields of a plurality of capacitor pattern arrays connected with each other; exciting the two-dimensional material by single pulse once to remove the two-dimensional material, and forming an integrated system with a plurality of micro supercapacitors connected in series and parallel;
the modulation method comprises the following steps: the phase diagram is calculated by combining the single-pixel width pattern with a Fourier transform iterative algorithm, so that the number of pixel points in the phase diagram can be effectively controlled;
the method comprises the following steps: adjusting the integrated pattern of the micro capacitor into a single pixel pattern, and enabling the width of each line segment of the pattern to be one pixel point;
step two: respectively carrying out Fourier transformation on the single-pixel target light field pattern and the initial Gaussian spot and carrying out phase superposition, and carrying out Fourier inverse transformation on the superposed phase diagram and comparing the superposed phase diagram with the original target single-pixel pattern; if the requirement is met, outputting a phase diagram, if the requirement is not met, gradually iterating until the phase diagram meets the single-pixel target light field pattern;
step three: and calculating to obtain a phase diagram corresponding to the single-pixel width pattern.
2. The integrated method for preparing a plurality of micro capacitors by ultrafast laser once according to claim 1, wherein: the laser energy of the ultrafast laser is less than or equal to 100 muJ, and the number of pulses is less than or equal to 1000/s.
3. Apparatus for implementing the method of claim 1 or 2, characterized in that: the system comprises an ultrafast laser, a mechanical switch, an attenuation sheet group, an ultrafast laser space light shaper, an ultrafast reflector, a dichroic mirror, a white light illumination source, a CCD dynamic imaging unit, a focusing objective, a sample to be processed, a precise electric control translation stage, a computer and a convex lens; laser beams emitted by the laser enter the ultrafast laser light field shaping device through the mechanical optical switch and the attenuation sheet group, and a target light field of the micro capacitor array is obtained through light field shaping, wherein the energy of the target light field is attenuated to an energy value meeting the preset use requirement; then the light is reflected by an ultrafast reflector, is focused to a sample to be processed on a precise electric control translation stage through a focusing objective lens, the illumination light emitted by the white light source positioned at the top passes through a dichroic mirror, the ultrafast reflector and the focusing objective lens to irradiate the sample to be processed, is reflected, returns through the focusing objective lens and the ultrafast reflector, is reflected by the dichroic mirror to reach a CCD dynamic imaging unit, a computer is connected with an ultrafast laser, controls the target pattern of the ultrafast laser field shaping, controls the opening and closing of a mechanical switch, and controls the precise electric control translation stage to move in the XYZ direction, wherein the movement meets the speed and the position of the preset use requirement, and is connected with the CCD dynamic imaging unit to monitor the surface of the processed sample.
4. The apparatus of claim 3, wherein: the device adopts 5-50 times of focusing objective lens.
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