Method and device for synchronously and compositely manufacturing diamond micro-grating based on micro-additive and micro-additive materials
Technical Field
The invention relates to a composite manufacturing method of a micro-additive and micro-additive material. In particular to a method and a device for synchronously and compositely manufacturing a diamond micro-grating based on micro-addition and reduction materials.
Background
The terahertz electromagnetic wave can realize extremely high data transmission rate and stability in the wireless communication process due to excellent broadband and transient properties, and thus becomes a key technology for future 6G communication research and development. With the continuous deepening of the research on terahertz scientific technology at home and abroad, the development of related terahertz devices puts higher requirements on materials. The CVD diamond material has good heat conduction performance, low dielectric constant, low microwave loss, excellent mechanical performance, relatively low preparation cost and the like, and has wide application prospect in the field of terahertz devices. A large number of high-aspect-ratio micro-grating structures are involved inside terahertz devices (such as terahertz MEMS filters, high-power terahertz sources and the like). Therefore, the preparation technology of the CVD diamond micro-grating structure with the high depth-to-width ratio becomes a key technology for realizing the application of the diamond in the field of terahertz devices.
Conventional microfabrication processes are difficult to apply directly due to the extremely high hardness and chemical stability of CVD diamond itself. At present, dry etching technologies such as RIE, DRIE, ICP and the like are applied to high aspect ratio micro-machining of diamond materials, and certain progress is made. However, the thermal effects of the above process are severe, very prone to contamination and damage to the diamond surface, and often involve the use of masks, resulting in a complex and costly process. How to develop a new method, overcome the deficiency of the prior art, develop the new micro-processing technology oriented to CVD diamond, prepare the micro-grating structure of high aspect ratio, it is a big difficult problem to wait for solving at present.
Ultrafast laser etching is a micro-machining method that has been rapidly developed in recent years. The method has the advantages of high machining precision and efficiency, small heat effect, no need of masks, simple process, low cost, no pollution to the environment and great potential in the high aspect ratio micro machining direction. However, ultrafast laser etching has some disadvantages for high aspect ratio CVD diamond microstructure processing. When the diamond material is processed by ultrafast laser, the high temperature near the focal spot often causes the phase change of the diamond material at the edge of the fine structure to form amorphous carbon and graphite phases, and simultaneously, the carbon phase removed by high-temperature gasification is recondensed on the surface of the diamond material to form an amorphous carbon phase, thereby reducing the surface quality of the diamond; in addition, the material near the focal spot is removed instantly, which causes the stress state of the surrounding material to change rapidly, thereby inducing the edge stress concentration of the fine structure, and the occurrence of cracks and chipping causes the surface quality reduction of the diamond fine structure.
Disclosure of Invention
The invention aims to provide a method and a device for synchronously and compositely manufacturing a diamond micro-grating based on micro-additive and micro-additive materials, which can obtain a diamond micro-grating structure with high quality and high depth-to-width ratio.
The technical scheme adopted by the invention is as follows: a method for synchronously and compositely manufacturing a diamond micro-grating based on micro-addition and subtraction materials comprises the steps of pretreating the surface of a diamond film sample to remove surface impurities; and carrying out low-temperature hot-wire CVD diamond deposition on the surface of the diamond film sample, and simultaneously carrying out graphical micro-processing on the surface of the CVD diamond film to obtain the diamond micro-grating.
The method is characterized in that the surface of the diamond film sample is pretreated by immersing the diamond film sample into a mixture of diamond micropowder and glycerol according to a mass ratio of 1: 1 for 5min, wherein the grain diameter of the diamond micro powder is 2-5 μm, then immersing the diamond micro powder in absolute ethyl alcohol for ultrasonic cleaning for 5min, and then drying.
The method is characterized in that low-temperature hot-wire CVD diamond deposition is carried out on the surface of a diamond film sample, and the adopted reaction gases are hydrogen, methane and hydrogen sulfide.
The low-temperature hot wire CVD diamond deposition adopts the following process parameters: the hydrogen flow is 800-1000 ml/min, the methane flow is 50-100 ml/min, the hydrogen sulfide flow is 0.1-0.4 ml/min, the reaction pressure is 10-15 Torr, the hot wire temperature is 2100-2200 ℃, and the substrate temperature is 100-250 ℃; the bias current is 1.0 to 4.0A.
The graphical micromachining is laser etching, wherein laser beams are repeatedly etched on the surface of the CVD diamond film according to a set scanning path at intervals of 1 hour until the diamond micro-grating with a set high aspect ratio is obtained.
The laser etching and the low-temperature hot wire CVD diamond deposition are synchronously carried out on the surface of the diamond film sample.
The laser etching adopts the following process parameters: the pulse width is 400 fs-6 ps, the output power is 0.5W-2W, the repetition frequency is 500 KHz-50 MHz, and the diameter of a light spot is 10 mu m.
The depth-to-width ratio of the diamond micro grating is 50-100.
A device for synchronously and compositely manufacturing a diamond micro-grating based on micro-additive and micro-additive materials comprises a low-temperature hot-wire CVD diamond deposition system for performing low-temperature hot-wire CVD diamond deposition on the surface of a diamond film sample and a laser etching system for performing graphical micro-processing on the surface of a CVD diamond film, wherein the low-temperature hot-wire CVD diamond deposition system comprises: the upper end is formed with the vacuum reaction chamber of optical window, be provided with the workstation that is used for laying the diamond film sample in the vacuum reaction chamber, vacuum reaction chamber outside be provided with be used for to the vacuum reaction chamber in input reaction gas's gas supply system, be provided with on the workstation and be used for arousing reaction gas and heating thereby the diamond film sample makes the heater strip that the CVD reacted takes place on diamond film sample surface adds the system.
The method and the device for manufacturing the diamond micro-grating based on the micro-additive and micro-subtractive synchronous compounding realize the space-time synchronous compounding of micro-additive processing and micro-subtractive processing and realize the continuous in-situ growth of diamond in a non-etching area. The invention can obtain the diamond micro-grating structure with high quality and high depth-to-width ratio, and has important significance for expanding the application of the diamond material in the fields of MEMS devices and terahertz devices. The invention has the following beneficial effects:
1. the method of the invention skillfully combines the laser etching and the CVD manufacturing processes in real time, breaks through the limitation of alternative material increasing and reducing in the existing material increasing and reducing composite manufacturing process, is rapid and efficient in graphical micromachining, avoids the repeated positioning of workpieces and has high precision.
2. According to the method, the laser etching process is carried out in the CVD reducing atmosphere, so that the influence of air on the laser etching quality is avoided, and the surface damage defect of the CVD diamond caused by laser etching is reduced.
3. The method realizes the defect repair of the CVD diamond in an etching area and the selective growth of the CVD diamond in a non-etching area by the CVD process synchronously carried out in the laser etching, and can obviously improve the depth-to-width ratio of the prepared graphical diamond film compared with the simple laser etching process.
4. The method can prepare the diamond micro-grating structure with high quality and high depth-to-width ratio, and has great significance for promoting the application and industrialization of diamond in the field of terahertz devices.
Drawings
FIG. 1 is a schematic structural diagram of the device for the method for synchronously and compositely manufacturing the diamond micro-grating based on the micro-additive and micro-additive materials;
FIG. 2 is a schematic view of the scanning path of example 1 of the present invention;
fig. 3 is a schematic view of the scanning path of example 2 of the present invention.
In the drawings
1: low temperature hot wire CVD diamond deposition system 1.1: vacuum reaction chamber
1.2: optical window 1.3: working table
1.4: diamond film sample 1.5: heating wire adding system
1.6: and (3) an air supply system 2: laser etching system
2.1: laser 2.2: beam expanding lens
2.3: dynamic focusing mirror 2.4: beam combining mirror
2.5: scanning galvanometer 2.6: control unit
Detailed Description
The method and the device for synchronously manufacturing the diamond micro-grating based on the micro-additive and micro-additive materials are described in detail below with reference to the embodiments and the accompanying drawings. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.
The invention relates to a device for synchronously and compositely manufacturing a diamond micro-grating based on micro-addition and reduction materials, which takes a diamond film as a processing object, synchronously implements two processes of ultrafast laser etching and low-temperature hot filament CVD, carries out high-efficiency graphical processing on the CVD diamond film through the ultrafast laser etching, simultaneously deposits diamond by using the low-temperature hot filament CVD process to repair the surface damage defect of the diamond caused by the ultrafast laser etching, and carries out rapid in-situ growth of the diamond in a non-etching area, thereby finally obtaining the diamond micro-grating structure with high quality and high depth-to-width ratio.
The invention relates to a method for synchronously and compositely manufacturing a diamond micro-grating based on micro-addition and micro-reduction materials, which comprises the following steps of pretreating the surface of a diamond film sample to remove surface impurities; and carrying out low-temperature hot-wire CVD diamond deposition on the surface of the diamond film sample, and simultaneously carrying out graphical micro-processing on the surface of the CVD diamond film to obtain the diamond micro-grating. Wherein:
(1) the method is characterized in that the surface of the diamond film sample is pretreated by immersing the diamond film sample into a mixture of diamond micropowder and glycerol according to a mass ratio of 1: 1 for 5min, wherein the grain diameter of the diamond micro powder is 2-5 μm, then immersing the diamond micro powder in absolute ethyl alcohol for ultrasonic cleaning for 5min, and then drying.
(2) The method is characterized in that low-temperature hot-wire CVD diamond deposition is carried out on the surface of a diamond film sample, and the adopted reaction gases are hydrogen, methane and hydrogen sulfide.
The hot wire low-temperature CVD diamond deposition adopts the following process parameters: the hydrogen flow is 800-1000 ml/min, the methane flow is 50-100 ml/min, the hydrogen sulfide flow is 0.1-0.4 ml/min, the reaction pressure is 10-15 Torr, the hot wire temperature is 2100-2200 ℃, and the substrate temperature is 100-250 ℃; the bias current is 1.0 to 4.0A.
(3) The graphical micromachining is laser etching, wherein laser beams are repeatedly etched on the surface of the CVD diamond film according to a set scanning path at intervals of 1 hour until the diamond micro-grating with a set high aspect ratio is obtained.
The laser etching adopts the following process parameters: the pulse width is 400 fs-6 ps, the output power is 0.5W-2W, the repetition frequency is 500 KHz-50 MHz, and the diameter of a light spot is 10 mu m. The depth-to-width ratio of the diamond micro grating is 50-100.
(4) The laser etching and the low-temperature hot wire CVD diamond deposition are synchronously carried out on the surface of the diamond film sample.
As shown in figure 1, the device for the method for synchronously and compositely manufacturing the diamond micro-grating based on the micro-additive and micro-additive materials comprises a low-temperature hot-wire CVD diamond deposition system 1 for performing low-temperature hot-wire CVD diamond deposition on the surface of a diamond film sample and a laser etching system 2 for performing patterned micro-machining on the surface of the CVD diamond film. Wherein:
the low temperature hot wire CVD diamond deposition system 1 comprises: the upper end is formed with optical window 1.2's vacuum reaction chamber 1.1, be provided with the workstation 1.3 that is used for laying diamond film sample 1.4 in the vacuum reaction chamber 1.1, vacuum reaction chamber 1.1 outside be provided with be used for to vacuum reaction chamber 1.1 in input reaction gas's air feed system 1.6, be provided with on the workstation 1.3 and be used for arousing reaction gas and heating thereby diamond film sample 1.4 makes the heating wire of diamond film sample 1.4 surface emergence CVD reaction adds system 1.5.
The laser etching system 2 comprises: laser instrument 2.1, beam expander 2.2, dynamic focus mirror 2.3, beam combiner 2.4 and the scanning mirror 2.5 that shakes that sets gradually, beam expander 2.2, dynamic focus mirror 2.3, beam combiner 2.4 and the scanning mirror 2.5 that shakes constitute optical path system, still be provided with and connect respectively laser instrument 2.1, dynamic focus mirror 2.3 and the scanning mirror 2.5's of shaking control unit 2.6, control unit 2.6 is used for controlling the pulse width, output power, the repetition frequency of laser instrument 2.1 output laser, and control dynamic focus mirror 2.3 revises laser facula focus error, control scanning mirror 2.5 output laser's scanning route, scanning mirror 2.5's output laser run through optical window 1.2 focus to diamond film sample 1.4 be used for carrying out the graphical micromachining to diamond film sample 1.4 surface after the CVD reaction takes place for the surface.
Examples are given below:
example 1:
pretreating the surface of a diamond film sample, and immersing the diamond film sample into a mixture of diamond micropowder and glycerol according to a mass ratio of 1: 1 for 5min, wherein the grain diameter of the diamond micro powder is 5 μm, then immersing the diamond micro powder in absolute ethyl alcohol for ultrasonic cleaning for 5min, and then drying.
Placing the pretreated diamond film sample in the device shown in figure 1, and carrying out low-temperature hot-wire CVD diamond deposition on the surface of the diamond film sample, wherein the adopted process parameters are as follows: the hydrogen flow is 800ml/min, the methane flow is 50ml/min, the hydrogen sulfide flow is 0.1ml/min, the reaction pressure is 10Torr, the hot wire temperature is 2100-2200 ℃, and the substrate temperature is 250 ℃; bias current 4.0A, deposition time 50 hours.
Carrying out laser etching graphical micromachining on the surface of a diamond film sample while depositing low-temperature hot-wire CVD diamond, repeatedly etching a laser beam on the surface of the CVD diamond film according to a scanning path shown in figure 2, wherein the interval time is 1 hour, and the laser etching adopts the following process parameters: pulse width 6ps, output power 2W, repetition frequency 50MHz, spot diameter 10 μm. Finally, the diamond micro-grating structure with the microstructure depth of 40 mu m, the width of 8 mu m and the depth-to-width ratio of 50 is obtained.
Example 2:
pretreating the surface of a diamond film sample, and immersing the diamond film sample into a mixture of diamond micropowder and glycerol according to a mass ratio of 1: 1 for 5min, wherein the grain diameter of the diamond micro powder is 5 μm, then immersing the diamond micro powder in absolute ethyl alcohol for ultrasonic cleaning for 5min, and then drying.
Placing the pretreated diamond film sample in the device shown in figure 1, and carrying out low-temperature hot-wire CVD diamond deposition on the surface of the diamond film sample, wherein the adopted process parameters are as follows: the hydrogen flow is 1000ml/min, the methane flow is 100ml/min, the hydrogen sulfide flow is 0.4ml/min, the reaction pressure is 15Torr, the hot wire temperature is 2100-2200 ℃, and the substrate temperature is 100 ℃; bias current 1.0A, deposition time 80 hours.
Carrying out laser etching graphical micromachining on the surface of a diamond film sample while depositing low-temperature hot-wire CVD diamond, repeatedly etching a laser beam on the surface of the CVD diamond film according to a scanning path as shown in figure 3, wherein the interval time is 100 hours, and the laser etching adopts the following process parameters: the pulse width is 400fs, the output power is 0.5W, the repetition frequency is 500KHz, and the spot diameter is 10 μm. Finally, the diamond micro-grating structure with the microstructure depth of 50 microns, the width of 5 microns and the depth-to-width ratio of 100 is obtained.