JP4501307B2 - Method for forming a three-dimensional structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a three-dimensional structure forming method for forming a three-dimensional structure such as a micromachine on the surface of a plastic substrate, for example.
[0002]
[Prior art]
Conventionally, in various industrial fields, a micromachine having a structure generally called “MEMS (Micro Electro Mechanical Systems)” has been developed. The micromachine is manufactured by forming various three-dimensional structures on the surface of a silicon substrate, a glass substrate, or the like using a semiconductor process including a film formation process, an etching process, and the like. This micromachine has already been put into practical use as a component constituting various devices such as a pressure sensor and DMD (Digital micromirror device) mounted on an automobile.
[0003]
[Problems to be solved by the invention]
However, conventionally, there has been a problem that the application range related to the material of the substrate is limited when forming a micromachine for the following reasons.
[0004]
That is, when a semiconductor process is used, the processing temperature is as high as about 400 ° C. or higher. For this reason, when a silicon substrate or glass substrate having a relatively high melting point is used when forming a micromachine, there is no problem, but a plastic having a relatively low melting point (or softening point) (about 100 ° C. or less), etc. In the case of using such a resin substrate, the plastic substrate may be deformed or damaged due to high heat. Conventionally, a polyimide resin is known as a resin material having a relatively high heat resistance, but even this polyimide resin substrate cannot be said to have a sufficient resistance temperature (around 350 ° C.).
[0005]
In addition, as a micromachine configured by a resin material, for example, a piezoelectric actuator configured by a piezoelectric resin material such as PVDF (Poly vinylidene fluoride) has already been known. In the case of forming this type of micromachine, however, However, for the reason relating to the heat resistance of the substrate described above, a high melting point silicon substrate or the like was used instead of a low melting point plastic substrate.
[0006]
The present invention has been made in view of such problems, and an object of the present invention is to provide a three-dimensional structure capable of forming a three-dimensional structure on the surface of a low-melting-point substrate such as a plastic substrate without causing deformation or breakage. It is to provide a forming method.
[0007]
[Means for Solving the Problems]
The method for forming a three-dimensional structure of the present invention is a method for forming a three-dimensional structure on the surface of a processing object, and includes a first step of forming a first precursor film so as to cover the surface of the processing object. A second step of selectively forming a first thin film pattern by selectively forming a first opening in the first precursor film, and a third step of selectively forming a sacrificial film in the first opening. A fourth step of forming a second precursor film so as to cover at least the first thin film pattern and the sacrificial film, and a second opening in a portion corresponding to the first opening of the second precursor film And forming the second thin film pattern by selectively forming the first thin film pattern and the second thin film on the surface of the object to be processed by selectively removing the sacrificial film. And a sixth step of forming a three-dimensional structure including the pattern, And in the third step, film-forming ions are generated by evaporating the cathode using the energy of arc discharge, and a first precursor film and a second precursor film are formed by using the film-forming ions, In steps 2 and 4, plasma containing etching ions is generated, and the first opening and the second opening are formed by the etching ions in the plasma, respectively.
[0008]
In the method for forming a three-dimensional structure of the present invention, first, in the first step, a first precursor film is formed so as to cover the surface of the object to be processed. Subsequently, in the second step, the first thin film pattern is formed by selectively forming the first opening in the first precursor film. Subsequently, in the third step, a sacrificial film is selectively formed in the first opening. Subsequently, in the fourth step, a second precursor film is formed so as to cover at least the first thin film pattern and the sacrificial film. Subsequently, in the fifth step, the second thin film pattern is formed by selectively forming the second opening at a portion corresponding to the first opening in the second precursor film. Subsequently, in the sixth step, the sacrificial film is selectively removed, so that a three-dimensional structure including the first thin film pattern and the second thin film pattern is formed on the surface of the object to be processed. It is formed. When a three-dimensional structure is formed, film formation ions are generated by evaporating the cathode using the energy of arc discharge in the first step and the third step. The first precursor film and the second precursor film are formed, respectively, and in the second step and the fourth step, plasma containing etching ions is generated. The etching ions in the plasma cause the first opening and the second precursor film to be formed. Each opening is formed. Film formation temperature is lower than when using a conventional semiconductor process, and it becomes possible to use an object to be processed that has a lower heat resistance than metal or the like, so there is no deformation or breakage due to the influence of heat. A three-dimensional structure can be formed on the surface of the object to be processed.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0010]
[First Embodiment]
First, a method for forming a three-dimensional structure according to the first embodiment of the present invention will be described. FIG. 1 shows an example of the configuration of a manufacturing apparatus used in the method for forming a three-dimensional structure according to the present embodiment. This manufacturing apparatus is, for example, for forming a three-dimensional structure having various characteristic configurations on the surface of a plastic substrate.
[0011]
<1. Configuration of manufacturing equipment>
The manufacturing apparatus 10 includes, for example, a vacuum chamber 1 made of metal or the like, a plurality of (for example, three) processing sources 2, 3, and 4 disposed on the wall surface of the vacuum chamber 1, and an exhaust pipe 1 </ b> K. A plurality of (for example, three) introduction terminals 6 that are respectively arranged corresponding to the processing sources 2 to 4 and that have one end portion introduced into the interior of the vacuum chamber 1. (6A, 6B, 6C) and a bias power source 7 connected to the introduction terminal 6 via the wiring S and applying a bias voltage to the introduction terminal 6. One end of each of the introduction terminals 6A to 6C is connected to a plurality of (for example, three) substrate holders 8 (8A, 8B, 8C), and a substrate K to be processed is mounted on the substrate holder 8. ing. The substrate K can be moved between the substrate holders 8A to 8C at any time by a moving arm (not shown). FIG. 1 shows a case where the substrate K is mounted on the substrate holder 8A.
[0012]
The processing source 2 is constituted by, for example, a Kaufman ion source, and mainly performs etching processing on the substrate K and implants ions into a thin film formed on the surface of the substrate K by the processing source 4. . During the etching process, the processing source 2 generates a plasma containing etching ions in the vacuum chamber 1 using a gas (etching gas) that can generate ions (etching ions) required for the etching process, while the ion implantation process. Sometimes, a plasma containing implanted ions is generated inside the vacuum chamber 1 using a gas (operating gas) that can generate ions (implanted ions) required for the ion implantation process. As an etching gas, for example, nitrogen (N ₂ ), Oxygen (O ₂ ), Chlorine (Cl ₂ ) Or an inert gas such as argon (Ar). Examples of the working gas include nitrogen and hydrogen (H ₂ ), Methane (CH _Four ) And the like. The principle of ion implantation by the processing source 2 is generally called a PBII (Plasma-Based Ion-Implantation) system.
[0013]
The processing source 3 is constituted by, for example, a DC (Direct Current) sputter source, and mainly a film other than the film formed by the processing source 4 such as an electrode is formed on the surface of the substrate K or the like. To form.
[0014]
The processing source 4 is constituted by, for example, an FCVA (Filtered Cathodic Vacuum Arc) ion source, and mainly forms a thin film on the surface of the substrate K. The FCVA ion source is a general cathodic arc source provided with an electromagnetic filter for removing droplets generated by melting of the cathode. The processing source 4 has, for example, a cathode composed of high-density carbon rods as an ion source, and vaporizes the cathode using the energy of arc discharge generated by using a striker trigger electrode, whereby a vacuum chamber is obtained. Carbon ions (film-forming ions) are generated inside 1. Then, carbon ions are guided to the substrate K2 by the two duct coils mounted on the processing source 4, and the carbon ions are deposited on the surface of the substrate K to form a thin film. Unlike the processing source 2 (Kaufman type ion source) that requires an etching gas or an operating gas to generate etching ions or implanted ions, the processing source 4 generates film-forming ions without using an ion generating gas. Therefore, film-forming ions can be generated while maintaining a high vacuum state. As the cathode material, in addition to the above-mentioned carbon, for example, tungsten (W), tantalum (Ta), silicon (Si), nickel (Ni), chromium (Cr), aluminum (Al), titanium (Ti), copper (Cu), iron (Fe), etc. can also be used.
[0015]
The vacuum pump 5 includes, for example, a turbo molecular pump. Mainly, a gas (for example, air) filled in the vacuum chamber 1 is exhausted through the exhaust pipe 1K to obtain a desired vacuum state. The inside of the vacuum chamber 1 is depressurized until it becomes.
[0016]
The introduction terminal 6 (6A to 6C) is constituted by, for example, a general-purpose introduction terminal, and is movable in the direction of the arrow Y1 in the drawing according to the processing conditions of the processing sources 2 to 4, respectively. The introduction terminal 6 incorporates, for example, a refrigerant circulation pipe 6H. By circulating the refrigerant W through the pipe 6H, the substrate K mounted on the substrate holder 8 can be cooled. The introduction terminal 6 is made of a conductive material such as metal, and is supported by a support member 1B provided in the vacuum chamber 1. The support member 1B is made of, for example, an insulating material such as ceramic, and the vacuum chamber 1 and the introduction terminal 6 are electrically separated via the support member 1B.
[0017]
The bias power source 7 includes, for example, a high voltage vacuum tube circuit, and applies a pulse voltage to the substrate K mounted on the substrate holder 8. Of course, the bias power source 7 can apply a constant voltage to the substrate K in addition to the pulse voltage. The bias power source 7 applies a negative pulse voltage (−10 kV to −2 kV) to the substrate K as necessary, for example, during the etching process by the processing source 2, and particularly during the ion implantation process by the processing source 2. When the substrate K has insulating properties, a pulse voltage including a positive pulse voltage and a negative pulse voltage is applied to the substrate K. When a negative pulse voltage is applied to the substrate K by the bias power source 7, film-forming ions and implanted ions generated in the vacuum chamber 1 are attracted to the substrate K, while a positive pulse voltage is applied. The electrons are sometimes accelerated, and the substrate K is subjected to film formation processing, ion implantation processing, or electron beam processing. Note that conditions such as a pulse peak value (pulse wave height), a pulse rise time, a pulse interval, and a pulse width relating to the pulse voltage can be adjusted independently for each of the introduction terminals 6A to 6C.
[0018]
The substrate holder 8 (8 </ b> A to 8 </ b> C) holds the substrate K, and is made of a conductive material such as metal, for example, like the introduction terminal 6. The substrate K has, for example, a disk shape or a rectangular structure. Examples of the material of the substrate K include amorphous polyolefin (APO), alicyclic olefin, polymethyl methacrylate (PMMA), alicyclic acrylic, polycarbonate (PC), polyethylene terephthalate (PET). Polyethylene Terephthalate), acrylonitrile-butadiene-styrene copolymer (ABS), polyacetal (POM), polytetrafluoroethylene (PTFE), nylon 6, polyethylene and other insulating properties A plastic having
[0019]
In addition to the above-described series of components, the film forming process 10 includes, for example, a microcomputer for controlling the entire manufacturing apparatus 10, a gas cylinder for supplying various gases to the processing source 2, and the outside of the vacuum chamber 1. It is connected to the other end of the lead-in terminal 6 led out to, and includes a driving device for moving the lead-in terminal 6.
[0020]
<2. Method for Forming Three-dimensional Structure according to Embodiment>
Next, an example of a method for forming a three-dimensional structure according to the present embodiment will be described with reference to FIGS. In the following, for example, a characteristic beam structure (hereinafter referred to as “beam structure”) in which a part of the surface of the substrate K made of plastic is separated from the surface of the substrate K and the other part covers the surface of the substrate K. A case of forming a micromachine (three-dimensional structure) having “)” will be described.
[0021]
This three-dimensional structure is formed through, for example, a film forming process, an etching process, an ion implantation process, and the like sequentially using the manufacturing apparatus 10 shown in FIG. 2 to 10 illustrate a method for forming a three-dimensional structure according to the present embodiment. 2 to 10, FIG. 2 shows a first film forming step, FIGS. 3 and 4 show a first etching step, FIG. 5 shows a sacrificial film forming step, FIG. 6 shows a second film forming step, and FIG. FIG. 8 shows a second etching process, FIG. 9 shows an ion implantation process, and FIG. 10 shows a sacrificial film removal process. FIG. 11 shows the waveform (A) and current change (B) of the pulse voltage applied to the substrate K by the bias power source 7 during the ion implantation process. 2 to 10, (B) shows a planar configuration of the substrate K and the like in each step, and (A) shows a sectional configuration of the substrate K and the like along the line AA shown in (B). Yes. 2A to 10A, the configuration of the main part of the manufacturing apparatus 10 (the peripheral part of the substrate K) is shown together with the substrate K and the like.
[0022]
When the micromachine is formed on the surface of the substrate K made of plastic, the following preparation work is performed by an operator or the like. That is, first, after a substrate K (about 1 mm thick) made of, for example, APO, PMMA, PC or the like is cleaned, the substrate K is mounted on the substrate holder 8C (see FIG. 2). Subsequently, after the sealed state of the vacuum chamber 1 is confirmed, a series of processing conditions (processing sources 2 to 4, vacuum pump 5, introduction terminal 6, bias power source 7 and the like operating conditions, etc. are provided via an input device such as a keyboard. ) Is entered. Finally, the vacuum pump 5 is operated to reduce the pressure until the inside of the vacuum chamber 1 is in a desired vacuum state, the bias power supply 7 is operated, and a voltage is applied to the substrate holder 8. Further, the coolant W is circulated through the pipe 6H, and the substrate K held by the substrate holder 8C is cooled.
[0023]
<< 2-1. First film forming step (forming step of base film precursor film) >>
After the preparatory work is completed, first, as shown in FIG. 2, for example, the degree of background vacuum = about 2.3 × 10 by the processing source 4 (FCVA ion source). ^-Four A film forming process is performed on the surface of the substrate K under the condition of Pa, the operating voltage of the processing source 4 = about 25V. Thus, after carbon ions (film-forming ions) N1 having an energy of about 25 eV and generating an ion current of about 0.7 A are generated continuously and at a high density in the vacuum chamber 1, the carbon ions N1 Is selectively filtered in a magnetic field and guided to the substrate K, whereby a base precursor film 21P (first precursor film) made of, for example, ta-C (tetrahedral amorphous carbon) is formed on the surface of the substrate K. The This base precursor film 21P is a preparatory film that becomes a base film 21 (see FIG. 4) to be described later by patterning in a later step. Hereinafter, the preparatory film to be patterned in the subsequent process is referred to as a “precursor film”. When performing the first film forming process, for example, the base precursor film 21P has a thickness of about 100 nm.
[0024]
<< 2-2. First Etching Process (Under Film Formation Process) >>
Next, as shown in FIG. 3, a mask 22 (about 10 μm thick) made of, for example, PMMA and having a rectangular opening 22U is disposed on the base precursor film 21P. When the mask 22 is disposed, for example, the substrate K on which the base precursor film 21P is formed is once taken out from the vacuum chamber 1 into the atmosphere, and a PMMA layer is formed on the base precursor film 21P by, for example, spin coating. The mask 22 may be formed by patterning the PMMA layer using a photolithography process, or the mask 22 formed through the above-described series of procedures is prepared in the vacuum chamber 1 in advance. The mask 22 may be placed on the base precursor film 21P using the moving arm without taking out the substrate K and the like from the vacuum chamber 1.
[0025]
Next, as shown in FIG. 3, after moving the substrate K and the like to the substrate holder 8A using the moving arm, as shown in FIG. 4, the mask 22 is used and, for example, oxygen gas is used as an etching gas. In addition, the entire etching process is performed by the processing source 2. When performing the etching process, for example, as an etching condition, the amount of introduced etching gas = about 2.5 × 10 6 ^-7 m ^Three / S (about 15 sccm), ion beam acceleration voltage = about 200 V, ion beam acceleration current = about 10 mA, background vacuum (vacuum degree in the vacuum chamber 1 before ion emission) = about 2.3 × 10 ^-Four Pa, operating vacuum (vacuum in the vacuum chamber 1 after ion emission) = about 5.0 × 10 ^-2 Pa. Plasma containing oxygen ions (etching ions) N2 is generated inside the vacuum chamber 1, and the oxygen ions N2 in the plasma selectively collide with the underlying precursor film 21P through the openings 22U of the mask 22. Thereby, a portion of the base precursor film 21P corresponding to the opening 22U of the mask 22 is selectively removed. For example, the base film 21 (first thin film pattern) having a rectangular opening 21U (first opening). Is formed. In order to shorten the time required for the etching process, for example, during the etching process, the bias power source 7 applies a negative pulse peak value to the substrate K in the range of −10 kV to −2 kV, specifically −6 kV. , It is preferable to apply a negative pulse voltage under the conditions of pulse width = about 60 μsec and period = about 1 msec. This is because when a negative pulse voltage within the above range is applied to the substrate K, the oxygen ions N2 generated in the vacuum chamber 1 are efficiently guided to the substrate K, thereby increasing the etching rate.
[0026]
<< 2-3. Sacrificial film formation process >>
Next, after removing the mask 22, as shown in FIG. 5, a sacrificial film 23 is selectively disposed with a thickness of about 110 nm on the exposed surface of the substrate K in the opening 21U. This sacrificial film 23 functions as a support for supporting a coating precursor film 24P (see FIG. 6), which will be described later, formed in a later step (<< 2-4, second film forming process described later >>). It is. When the sacrificial film 23 is disposed, for example, one side surface (for example, the left side surface in the drawing) is adjacent to one side surface (for example, the left side surface in the drawing) of the base film 21 in the opening 21U. To do. As a constituent material of the sacrificial film 23, for example, a predetermined solvent is used so that the sacrificial film 23 can be removed by being dissolved in a later step (<2-7. Sacrificial film removing step described later>). A resin material (for example, PMMA) that is soluble in (for example, acetone) is used. For example, << 2-2. This is the same as the method of disposing the mask 22 in the “first etching step”.
[0027]
<< 2-4. Second film forming step (coating precursor film forming step) >>
Next, as shown in FIG. 6, after moving the substrate K or the like to the substrate holder 8C using the moving arm, << 2-1. Under the same conditions as in the first film forming step, the coating source film 24P (second precursor film) made of, for example, ta-C is formed with a thickness of about 100 nm so as to cover the whole by the processing source 4. . The coating precursor film 24P has a crank-like structure in which a part thereof rides on the sacrificial film 23.
[0028]
<< 2-5. Second Etching Process (Coating Film Forming Process) >>
Next, as shown in FIG. 7, a mask 25 (about 10 μm thick) made of PMMA, for example, is disposed on the coating precursor film 24P. When the mask 25 is formed, for example, a “U” -shaped opening 25U is provided at a position corresponding to the opening 21U. For example, << 2-2. This is the same as the method of disposing the mask 22 in the “first etching step”.
[0029]
Next, as shown in FIG. 7, the substrate K and the like are moved to the substrate holder 8 </ b> A using the moving arm, and then, using the mask 25 as shown in FIG. 8, << 2-2. Under the same conditions as in the first etching step, the processing source 2 performs an etching process on the entire surface. Thereby, a portion of the coating precursor film 24P corresponding to the opening 25U of the mask 25 is selectively removed, and the coating film 24 (second opening) having, for example, a “U” -shaped opening 24U (second opening). Thin film pattern) is formed. Even when the coating film 24 is formed, a negative pulse voltage may be applied to the substrate K during the etching process in order to shorten the time required for the etching process.
[0030]
<< 2-6. Ion implantation process >>
Next, after removing the mask 25, as shown in FIG. 9, the base film 21 and the coating film 24 are applied to the base film 21 and the coating film 24 by the processing source 2 (Kaufmann type ion source) using, for example, nitrogen gas as an operating gas. Ion implantation treatment is performed. When performing the ion implantation process, for example, acceleration voltage = about 200 V, operating gas introduction amount = about 2.5 × 10 ^-7 m ^Three / S (about 15 sccm), operating vacuum = about 5.0 × 10 ^-2 Pa, ion implantation amount = about 8.0 × 10 ¹⁶ In addition, the positive pulse peak value V1 = about +10 kV, the negative pulse peak value V2 = about −20 kV, the positive / negative pulse width B = about 60 μsec, and the period T = about A pulse voltage including a positive pulse voltage and a negative pulse voltage is applied under the condition of 1 ms (see FIG. 11A). In addition, the ion implantation process is performed under current conditions such that when the nitrogen ion current from the processing source 2 is about 1 mA, the peak value of the current due to the ion current and the secondary electrons at the bias electrode is about 0.05 A. Perform for 5 minutes (FIG. 11B). Plasma containing nitrogen ions (implanted ions) N3 is generated inside the vacuum chamber 1 by the processing source 2, and the nitrogen ions N3 are implanted into the base film 21 and the coating film 24. As a result, the base film 21 and the coating film 24 made of ta-C are modified, and their physical properties such as Young's modulus and yield point strength are improved.
[0031]
<< 2-7. Sacrificial film removal process >>
Finally, after the substrate K is once taken out from the vacuum chamber 1 into the atmosphere, the sacrificial film 23 is subjected to a wet etching process by immersing the substrate K or the like in a solvent such as acetone. As shown in FIG. 10, the sacrificial film 23 is exposed to a solvent through the opening 21U of the base film 21 and the opening 24U of the coating film 24, and the sacrificial film 23 is dissolved in the solvent and selectively removed. The surface of the substrate K is constituted by the base film 21 and the coating film 24, and a part (part 24T of the coating film 24) is separated from the surface of the substrate K, and the other part (part 24T of the coating film 24). The micromachine 100 having a beam structure in which the other portions and the base film 21) cover the surface of the substrate K is completed. The specific resistance of the micromachine 100 constituted by the base film 21 and the coating film 24 is about 3 × 10. ^-1 It was Ωcm.
[0032]
<3. Action and Effect According to First Embodiment>
As described above, in this embodiment, the processing source 4 (FCVA ion source), the base film 21 (opening 21U), and the coating film are used as film formation sources for forming the base precursor film 21P and the coating precursor film 24P. The sacrificial film 23 is made of a material (PMMA or the like) soluble in a predetermined solvent (acetone or the like) while using the processing source 2 (Kaufman type ion source) as an etching source for forming 24 (opening 24U). Is used as a support for the coating precursor film 24P. In such a case, the micromachine 100 having a beam structure is easily formed on the surface of the substrate K without causing problems such as deformation or breakage of the substrate K during processing for the following reasons. be able to.
[0033]
That is, when a conventional semiconductor process is used as a method of forming the micromachine 100, the processing temperature is relatively high (about 400 ° C. or higher), and therefore the material of the substrate K is resistant to the high temperature conditions. For example, the metal is limited to a metal having a relatively high melting point of about 400 ° C. or higher. In such a case, if a plastic having a relatively low melting point (or softening point) of about 100 ° C. or less is used as the material of the substrate K, the substrate K may be deformed or damaged due to high heat. Therefore, a conventional semiconductor process cannot be used as a forming method when forming the micromachine 100 on the surface of the substrate K made of plastic.
[0034]
On the other hand, in this embodiment, the film forming process and the etching process are performed by the processing source 4 (FCVA ion source) and the processing source 2 (Kaufmann type ion source) whose processing temperature is relatively low (about 150 ° C. or less). Since each is performed, the substrate K is not exposed to a high temperature environment higher than the melting point of the plastic as in the case of using a semiconductor process, and the temperature of the substrate K itself is also maintained at about 150 ° C. or less. For this reason, the material of the substrate K is not limited depending on the processing temperature, and even when plastic is used as the constituent material of the substrate K, a micromachine is formed on the surface of the substrate K without causing defects such as deformation and breakage. 100 can be formed.
[0035]
In addition, in the present embodiment, the sacrificial film 23 that can be selectively removed in the subsequent process is used as a support for the coating precursor film 24P. Therefore, the coating precursor film 24P is partially over the sacrificial film 23. Is formed. In such a case, after the formation of the coating precursor film 24P, the sacrificial film 23 is selectively removed, so that a portion (part 24T of the coating film 24) is formed on the substrate unlike the case where the sacrificial film 23 is not used. It is possible to easily form the micromachine 100 having a beam structure that is separated from the surface of K and has other parts (the part other than the part 24T of the non-peritoneum 24 and the base film 21) covering the surface of the substrate K. It becomes possible.
[0036]
Further, in the present embodiment, in order to improve the physical properties (Young's modulus, yield point strength, etc.) of the micromachine 100, the processing source 2 (Kaufman type) is used as an ion implantation source for modifying the underlayer 21 and the coating layer 24. Since the ion source is used, the processing temperature at the time of the ion implantation process is the same as that when the processing source 2 is used as the etching source, and other conventional ion implantation methods (for example, dynamic mixing method) are used. Lower than the processing temperature in the case (about 300 ° C. to 400 ° C.). For this reason, it is possible to improve the physical characteristics of the micromachine 100 using the ion implantation process while suppressing the occurrence of the problems related to the thermal deformation or the like of the substrate K described above.
[0037]
In the present embodiment, since a pulsed voltage including a positive pulse voltage and a negative pulse voltage is applied to the substrate K by the bias power supply 7 during the ion implantation process, the negative voltage remaining on the substrate K is applied. By neutralizing the charge with a positive charge at any time, even when an insulating plastic is used as the material of the substrate K, it is possible to prevent the charge from remaining inside the substrate K during processing (charge-up). Is done. For this reason, the stagnation phenomenon of the ion implantation process caused by the charge-up can be avoided, and ions can be implanted into the substrate K smoothly and uniformly.
[0038]
Further, in the present embodiment, a pulse voltage including a negative pulse voltage (−10 kV to −2 kV) is applied to the substrate K by the bias power source 7 during the etching process. Oxygen ions N2 are efficiently induced to the substrate K, and the etching rate increases. For this reason, an etching process can be performed in a short time.
[0039]
<4. Modified example according to first embodiment>
In the present embodiment, the substrate K made of plastic is used as the formation target of the micromachine 100. However, the present invention is not necessarily limited to this. For example, a film made of plastic or the like is used. May be. Even in such a case, the same effect as in the case of the above-described embodiment can be obtained.
[0040]
In this embodiment, the substrate K is made of plastic, but is not necessarily limited to this. For example, an insulating material other than plastic, or a conductive material such as a metal or a semiconductor is used. You may make it use what was comprised with material. Even in such a case, the micromachine 100 can be formed on the surface of the substrate K in a relatively low processing environment (about 150 ° C. or less). When using the substrate K made of a conductive material, for example, only a negative pulse voltage may be applied to the substrate K by the pulse power supply 7.
[0041]
In this embodiment, the film formation process is performed by the processing source 4 (FCVA ion source), and the etching process and the ion implantation process are performed by the processing source 2 (Kaufman type ion source). However, each processing source in the case of performing the film forming process, the etching process, and the ion implantation process can be freely selected.
[0042]
In this embodiment, the micromachine 100 has a two-layer structure including the base film 12 and the coating film 24. However, the present invention is not limited to this, and a three-layer structure or more may be used.
[0043]
In the present embodiment, the same material (ta-C) is used as the constituent material of each of the base film 12 and the coating film 24. However, the present invention is not limited to this. Different materials may be used.
[0044]
[Second Embodiment]
Next, a method for forming a three-dimensional structure according to the second embodiment of the present invention will be described.
[0045]
The method for forming a three-dimensional structure according to the present embodiment uses the micromachine 100 (see FIG. 10) formed in the first embodiment to produce various devices such as a light control device. is there.
[0046]
<Configuration of light control device>
First, the configuration of the light control device manufactured in this embodiment will be described with reference to FIGS. FIG. 12 shows an example of a cross-sectional configuration of a light control device manufactured using the micromachine 100, and FIG. 13 shows a plan configuration of a main part (coil or the like) of the light control device shown in FIG. Note that description of the details of the method of forming the micromachine 100 is omitted.
[0047]
As shown in FIG. 12, the light control device mainly includes a substrate K on which the micromachine 100 is disposed on one surface (upper surface in the drawing), and a coil 31 and a lead 32 on one surface (lower surface in the drawing). It is comprised including the film F arrange | positioned. The substrate K and the film F are bonded to each other through, for example, an ultraviolet curable adhesive in a state in which the arrangement position of the micromachine 100 and the arrangement position of the coil 31 correspond to each other. ing.
[0048]
The film F has a thickness of about 0.1 mm, for example, and is made of the same plastic as the constituent material of the substrate K. For example, the coil 31 has a spiral structure as shown in FIG. 13, and is made of a conductive material such as aluminum or copper. For example, one end of a lead 32 as an extraction electrode is connected to the inner terminal portion of the coil 31. The lead 32 is made of the same material as that of the coil 31, for example. The outer terminal end of the coil 31 and the other end of the lead 32 are connected to a power source 40 for driving the light control device via a wiring 50, respectively. The coil 31 is formed by, for example, forming an aluminum film or a copper film on the surface of the film F with an FCVA ion source, and then patterning the aluminum film or the copper film by various etching processes (for example, chemical etching). The
[0049]
<Operation of light control device>
Next, the operation of the light control device will be described with reference to FIGS. 14 and 15 illustrate the operation of the light control device. In this light control device, when a current flows through the coil 31 from the power supply 40, a force F acts in a direction perpendicular to the extending surface of the coil 31 by a magnetic field generated according to the current. The direction of the force F (upward or downward) is determined according to the direction of the current flowing through the coil 31. At this time, when a force F (FU) is applied in the upward direction in the figure, the coating film 24 constituting the micromachine 100 expands in accordance with the force FU, so that the portion 24T moves upward (see FIG. 14). On the other hand, when a force F (FD) is applied downward in the figure, the coating film 24 contracts in accordance with the force FD, so that the portion 24T moves downward (see FIG. 15). ). According to this light control device, for example, in the state where the portion 24T is irradiated with light, by changing the direction of the current flowing through the coil 31, the light transmission characteristics, refraction characteristics, reflection characteristics, etc. in the vicinity of the portion 24T can be freely set. It becomes possible to change to.
[0050]
<Effects of Second Embodiment>
In the present embodiment, since the light control device is manufactured using the micromachine 100 formed in the first embodiment, the micromachine 100 is operated in the same manner as in the case of the first embodiment. The processing temperature at the time of forming is relatively low (about 150 ° C. or less). For this reason, the light control device can be manufactured without causing problems such as deformation and breakage of the substrate K when the micromachine 100 is formed.
[0051]
<Modification according to the second embodiment>
In the present embodiment, the coil 31 and the like are disposed on the surface of the film F as a drive source for driving the micromachine 100 (part 24T), but the present invention is not necessarily limited thereto. FIGS. 16 and 17 show an example of the configuration of a light control device as a modification of the light control device manufactured in this embodiment. FIG. 16 shows a cross-sectional configuration of a light control device as a modification, and FIG. 17 shows a plan configuration of a main part (electrode plate or the like) of the light control device shown in FIG. In this light control device, for example, a rectangular electrode plate 61 is disposed on the surface of the film F, and the micromachine 100 (coating film 24) and the electrode plate 61 are connected to the power supply 40 via the wiring 50, respectively. Connected. That is, the micromachine 100 and the electrode plate 61 constitute a parallel capacitor. According to this light control device, unlike the above embodiment in which the micromachine 100 (part 24T) is driven using the force F generated according to the magnetic field, the light control device is generated between the micromachine 100 and the electrode plate 61. By using the force F generated according to static electricity, the micromachine (part 24T) can be driven as in the case of the above-described embodiment (see FIGS. 14 and 15). In the light control device as a modified example, the configuration other than the above is the same as that shown in FIGS.
[0052]
In this embodiment, the micromachine 100 having a beam structure is used as a component of the light control device. However, the present invention is not limited to this. FIG. 18 shows a configuration of a light control device as another modification example of the light control device manufactured in the present embodiment, and FIG. 18B shows a micromachine constituting the light control device as another modification example. 100 is a planar configuration, and (A) shows a cross-sectional configuration taken along the line AA of the micromachine 100 shown in (B). FIGS. 19 and 20 illustrate the configuration and operation of a light control device as another modification. In this light control device, for example, the micromachine 100 is configured so as to have a beam structure in which a part (portion 24Y) of the coating film 24 crosses the opening 24U. According to the light control device configured to include the micromachine 100 and the coil 31, the portion 24Y moves upward in response to the upward force FU, as in the case of the above-described embodiment (see FIGS. 14 and 15). On the other hand, the portion 24Y moves downward according to the downward force FD (see FIG. 20). In the light control device as another modified example, the configuration other than the above is the same as that shown in FIGS. 12 to 15.
[0053]
In the present embodiment, a large device may be configured by collecting a plurality of light control devices. FIG. 21 shows still another modification example produced in the present embodiment. In this light control device, for example, the light control devices (see FIG. 12) manufactured in the above embodiment are arranged in a matrix (for example, 5 rows × 4 columns). According to this light control device, various light controls can be performed by changing the driving state (the moving state of the portion 24T) for each micromachine 100, and in particular, it can be applied to a display or the like.
[0054]
In this embodiment, the case where the light control device is configured using the micromachine 100 has been described. However, the present invention is not necessarily limited to this, and various devices other than the light control device can be configured. It is. As the “other various devices”, for example, when the driving state of the portion 24T is periodically changed and the micromachine 100 is used as a vibration generation source, a sound wave control device constituting an ultrasonic speaker or a tweeter, a heat Examples thereof include a fluid control device disposed inside a pipe or the like.
[0055]
Note that the operations, effects, modifications, and the like other than those described above according to the present embodiment are the same as in the case of the first embodiment.
[0056]
While the present invention has been described with reference to some embodiments, the present invention is not limited to the above embodiments, and various modifications can be made. For example, the method of forming the three-dimensional structure and the configuration of the manufacturing apparatus described in the first embodiment, the configuration of the light control device described in the second embodiment, and the like are not necessarily the same in the above embodiments. The substrate is not limited to the one described, and the substrate K is used without using a FCVA ion source or a Kaufman ion source having a relatively low processing temperature (about 150 ° C. or lower) without causing deformation of the substrate K during processing. As long as it is possible to form the micromachine 100 (three-dimensional structure) on the surface, it can be freely changed.
[0057]
【The invention's effect】
As described above, according to the method for forming a three-dimensional structure according to any one of claims 1 to 8, film-forming ions are formed by evaporating the cathode using the energy of arc discharge. The first precursor film and the second precursor film are formed by the film-forming ions, respectively, and plasma containing etching ions is generated. The first opening and the second opening are formed by the etching ions in the plasma. A second precursor film is formed so as to cover each of the sacrificial films that can be selectively removed. In such a case, the processing temperature (about 150 ° C. or lower) when forming the first precursor film, the second precursor film, the first opening, and the second opening is a conventional semiconductor process. Therefore, the material of the object to be processed is not limited depending on the processing temperature. Therefore, even when an object to be processed having a relatively low melting point is used, a three-dimensional structure can be easily formed on the surface of the object to be processed without causing problems such as deformation and breakage.
[0058]
In particular, according to the method for forming a three-dimensional structure according to claim 2, in a state where a pulse voltage is applied to the object to be processed, a plasma containing implanted ions is generated, and the implanted ions in the plasma are converted into the first ions. Since the implantation is performed on the thin film pattern and the second thin film pattern, the physical characteristics of the three-dimensional structure are improved by using the ion implantation process while suppressing the occurrence of defects related to thermal deformation of the object to be processed. be able to.
[0059]
According to the method for forming a three-dimensional structure according to claim 4, since the object to be processed is made of plastic, the object to be processed made of plastic having a relatively low melting point is used. Even in such a case, it is possible to form a three-dimensional structure on the surface of the target object made of plastic without causing problems such as deformation or breakage of the target object during processing.
[0060]
In the method for forming a three-dimensional structure according to claim 5, since a pulse voltage including a positive pulse voltage and a negative pulse voltage is applied to the object to be processed, It is possible to prevent the charge from remaining inside (charge up). For this reason, the stagnation phenomenon of the ion implantation process resulting from the charge-up can be avoided, and ions can be smoothly and uniformly implanted into the object to be treated.
[0061]
According to the method for forming a three-dimensional structure according to claim 6, since the pulsed voltage including the negative pulse voltage is applied to the object to be processed, the etching ions efficiently reach the object to be processed. Induced and etch rate increases. For this reason, an etching process can be performed in a short time.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an example of a configuration of a manufacturing apparatus used in a method for forming a three-dimensional structure according to a first embodiment of the present invention.
FIG. 2 is a diagram for explaining a first film forming step.
FIG. 3 is a diagram for explaining a first etching step.
FIG. 4 is a diagram for explaining a process following FIG. 3;
FIG. 5 is a diagram for explaining a sacrificial film forming step;
FIG. 6 is a diagram for explaining a second film formation step.
FIG. 7 is a diagram for explaining a second etching step.
FIG. 8 is a diagram for explaining a step following FIG. 7;
FIG. 9 is a diagram for explaining an ion implantation process;
FIG. 10 is a diagram for explaining a sacrificial film removal step.
FIG. 11 is a diagram illustrating a waveform of a pulse voltage and a current change during an ion implantation process.
FIG. 12 is a cross-sectional view illustrating an example of a cross-sectional configuration of a light control device configured by using the method for forming a three-dimensional structure according to the second embodiment of the present invention.
13 is a plan view showing a planar configuration of a main part (coil) of the light control device shown in FIG. 12. FIG.
FIG. 14 is a diagram for explaining the operation of the light control device;
FIG. 15 is a diagram for explaining the operation of the light control device;
FIG. 16 is a cross-sectional view illustrating a cross-sectional configuration of a light control device as a modification of the light control device according to the second embodiment of the present invention.
17 is a plan view showing a planar configuration of a main part (electrode plate) of the light control device shown in FIG. 16. FIG.
FIG. 18 is a cross-sectional view illustrating a configuration of a main part (micromachine) of a light control device as another modification example of the light control device of the second embodiment of the present invention.
FIG. 19 is a diagram for explaining the operation of the light control device shown in FIG. 18;
20 is a diagram for explaining the operation of the light control device shown in FIG. 18;
FIG. 21 is a cross-sectional view illustrating a cross-sectional configuration of a light control device as still another modification example of the light control device according to the second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Vacuum chamber, 2, 3, 4 ... Processing source, 5 ... Vacuum pump, 6 (6A, 6B, 6C) ... Introduction terminal, 7 ... Bias power supply, 8 (8A, 8B, 8C) ... Substrate holder, 10 ... Manufacturing apparatus, 21 ... Undercoat film, 21P ... Underlying precursor film, 22, 25 ... Mask, 21U, 22U, 24U, 25U ... Opening, 23 ... Sacrificial film, 24 ... Coating film, 24P ... Coating precursor film, 31 ... Coil , 32, leads, 40, power supply, 50, wiring, 61, electrode plate, 100, micromachine, F, film, K, substrate, N1, deposition ions, N2, etching ions, N3, implanted ions.

Claims (8)

A three-dimensional structure forming method for forming a three-dimensional structure on a surface of an object to be processed,
A first step of forming a first precursor film so as to cover the surface of the object to be processed;
A second step of forming a first thin film pattern by selectively forming a first opening in the first precursor film;
A third step of selectively forming a sacrificial film in the first opening;
A fourth step of forming a second precursor film so as to cover at least the first thin film pattern and the sacrificial film;
A fifth step of forming a second thin film pattern by selectively forming a second opening in a portion of the second precursor film corresponding to the first opening;
By selectively removing the sacrificial film, the sixth three-dimensional structure including the first thin film pattern and the second thin film pattern is formed on the surface of the object to be processed. Process,
In the first step and the fourth step,
A film forming ion is generated by evaporating the cathode using the energy of arc discharge, and the first precursor film and the second precursor film are formed by the film forming ion,
In the second step and the fifth step,
A method for forming a three-dimensional structure, characterized in that plasma containing etching ions is generated, and the first opening and the second opening are respectively formed by etching ions in the plasma. further,
Between the fifth step and the sixth step, a plasma containing implanted ions is generated in a state where a pulse voltage is applied to the object to be processed, and the implanted ions in the plasma are converted into the first ions. The method of forming a three-dimensional structure according to claim 1, further comprising a seventh step of injecting the thin film pattern and the second thin film pattern. 2. The method for forming a three-dimensional structure according to claim 1, wherein an insulating material is used as the object to be processed. 4. The method for forming a three-dimensional structure according to claim 3, wherein the object to be processed is made of plastic. In the seventh step,
5. The method for forming a three-dimensional structure according to claim 4, wherein a pulse voltage including a positive pulse voltage and a negative pulse voltage is applied to the object to be processed. In the second step and the fifth step,
The method for forming a three-dimensional structure according to claim 1, wherein a pulse voltage including a negative pulse voltage is applied to the object to be processed. In the first step and the fourth step,
The method for forming a three-dimensional structure according to claim 1, wherein the first precursor film and the second precursor film are formed using a material containing carbon. In the third step, the sacrificial film is formed using a material soluble in a predetermined solvent,
The method for forming a three-dimensional structure according to claim 1, wherein, in the sixth step, the sacrificial film is removed by dissolution using the predetermined solvent.

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