JP2006297571A - Method for manufacturing micro metallic structure, and micro metallic structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a micro metallic structure with more excellent processing accuracy using a nano imprinting technology capable of transferring a micro structure or a thin sheet-like micro structure with sub μm or less. <P>SOLUTION: (1) A die with micro recessed and projected patterns formed is pressed to a processed membrane in a fluidized state on a first substrate 1, and (2) a processed membrane 3 in the fluidized state is hardened, and the die 2 is released from the hardened processed membrane 3, to obtain the processed membrane 3 having structure patterns with the recessed and projected patterns of the die transferred. (3) A face with the formed structure patterns is adhered, and the processed membrane is attached to a second substrate having conductivity. (4) The face of the processed membrane not with the formed structure patterns is removed, so that the structure patterns are opened and the second substrate 7 is exposed through the structure patterns. (5) Plating is applied using the exposed second substrate 7 as an electrode, and (6) deposited plating metal is separated from the second substrate and the processed membrane, to manufacture a micro metallic structure. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a micro mechanical structure such as a functional part for a semiconductor chip such as an LSI, a micro machine part such as various actuators or a probe head, and a micro part used for MEMS (Micro Electro Mechanical Systems). The present invention relates to a metal structure. And it is related with the manufacturing method of the fine metal structure.

  Conventionally, it is difficult to manufacture by machining, and a fine metal structure with high aspect ratio (ratio of height to width of structure) on a scale of several nm to several μm is manufactured with higher accuracy and lower cost. As a method, there is known a method using an injection molding method using a mold produced by a MEMS (Micro Electro Mechanical Systems) manufacturing technique such as a LIGA (Lithographie Galvanoformung Adformung) technique or a silicon dry etching technique.

  For example, according to the manufacturing method disclosed in Patent Document 1, a resin mold is formed by injection molding or reactive injection molding using a parent mold produced by using an X-ray lithography method and electroforming, and the resin The mold is polished to a predetermined thickness to produce a mold having a through hole pattern. Then, this mold is bonded to a conductive substrate with a conductive paste to form an electroforming mold, and electroplating is performed using the electroforming mold as an electrode, and then the conductive substrate and the conductive paste are removed.

  On the other hand, as a method for forming a fine pattern, a nanoimprint method, which has a resolution that is not limited by the limitations of conventional machining and optical lithography and is a lower cost method, has recently attracted attention.

  For example, according to the contents disclosed in Patent Document 2, as shown in FIG. 4, a substrate 101 on which a film to be processed 103 is formed and a mold 102 on which a fine uneven pattern of about 25 nm or less is formed are prepared. (See FIG. 4A). Here, the film to be processed 103 is a resist film made of a thermoplastic resin such as polymethyl methacrylate formed on the surface of the substrate 101. Then, after the film to be processed 103 is softened by heating to the glass transition point or higher, the mold 102 is pressed against the film to be processed 103 (see FIG. 4B). Then, after the film to be processed 103 is solidified by cooling to the glass transition point or lower, the mold 102 is peeled off from the solidified film 103 to be processed, and a reversal pattern of the fine uneven pattern of the mold 102 is covered. Transfer to the processed film 103 (see FIG. 4C).

  Further, according to the contents disclosed in Patent Document 3, as shown in FIG. 5, a substrate 101 on which a film to be processed 103 is formed, and a light transmissive material such as quartz or Pyrex (registered trademark). A mold 102 is prepared (see FIG. 5A). Here, the film 103 to be processed is made of a photocurable material such as a UV curable resin. Then, the mold 102 is pressed against the workpiece film 103 (see FIG. 5B). Then, the mold 102 is peeled off from the processed film 103 cured by irradiating light through the mold 102, and a reverse pattern of the fine uneven pattern of the mold 102 is transferred to the processed film 103 (see FIG. 5C). ).

  As described above, in the nanoimprint method, if a mold on which a desired pattern is formed can be prepared, a fine pattern can be replicated by an extremely simple process. And since it is a method of pressing the mold against the stationary film to be processed, a fine pattern can be accurately transferred even if the film to be processed is thin and has a large area. Can do. As a mold, a silicon or quartz mold manufactured by an electron beam exposure technique and an etching technique having a resolution of several nanometers to several tens of nanometers, a metal mold using these molds as a master, or a LIGA (Lithographie having a resolution of several μm). Metal molds produced by Galvanoformung Adformung) technology can be used.

  And as a conventional method for forming a fine metal pattern using a nanoimprint method, for example, according to the contents disclosed in Patent Document 4 and Patent Document 5, a substrate having a concavo-convex pattern formed on the surface resin layer by the nanoimprint method A metal material is vapor deposited. Next, metal wiring and electrodes are formed by a lift-off method that leaves only the metal material deposited on the substrate by removing the resin layer.

  Moreover, according to the content currently disclosed by patent document 6, a seed layer is formed in the insulating substrate in which the uneven | corrugated pattern was formed by the nanoimprint method. Thereafter, a metal material is deposited on the insulating substrate by sputtering, vapor deposition, plating, or the like. Then, the deposited metal material is removed by etching or polishing to form a metal wiring corresponding to the concave portion of the concave / convex pattern.

  On the other hand, the nanoimprint method using heat can be said to be a technique that improves the resolution of a conventionally known hot embossing method, that is, an embossing method using heat. For example, according to the method for manufacturing a fine metal structure using the hot embossing method disclosed in Patent Document 7, the processed film 203 made of resin formed on the conductive substrate 201 is formed on the conductive substrate 201 as shown in FIG. A mold 202 formed by X-ray lithography is hot embossed (see FIG. 6A). Next, the thin film 203 to be processed remaining on the conductive substrate 201 is removed by reactive ion etching to expose the portion of the conductive substrate 201 (see FIG. 6B). Then, after performing nickel electroforming using the exposed conductive substrate 202 as an electrode, the electroformed film is subjected to thickness adjustment by polishing, grinding, cutting, etc. and smoothing, thereby providing a metal component such as an ink jet head. 204 is manufactured (see FIG. 6C).

JP 2003-147570 A US Pat. No. 5,772,905 JP 2000-194142 A JP 2004-36358 A JP 2004-335774 A Japanese Patent Laying-Open No. 2005-5721 Japanese Patent Laid-Open No. 2001-146017

  However, in the method of manufacturing a fine metal structure using a mold manufactured by a MEMS (Micro Electro Mechanical Systems) manufacturing technique and using an injection molding method, there is a problem in the fluidity of the resin at the time of injection molding, and the sub-μm or less. There is a problem that it is difficult to manufacture a fine structure having a thin and wide area such as a plate shape with high accuracy.

  In addition, in the conventional manufacturing method of a fine metal structure using the nanoimprint method, various actuators and probes can be used even if there is a method of forming a fine thin film pattern that provides one function in the whole, such as metal wiring and electrodes. A method for producing a fine metal structure such as a head has not been disclosed.

  Furthermore, in the conventional method for producing a fine metal structure using the hot embossing method, the film to be processed is removed from the surface on which the structure pattern is formed when the residue of the film to be processed is removed to expose the conductive substrate. Since etching has to be performed, the sidewall of the structure pattern is also etched at this time, resulting in a problem that processing accuracy deteriorates. In particular, when the side wall of the structure pattern has a taper, there is a problem that this problem becomes significant.

  Accordingly, an object of the present invention is to manufacture a fine metal structure with better processing accuracy by utilizing nanoimprint technology capable of transferring a fine structure of sub-μm or less or a thin plate-like fine structure. .

In order to achieve such an object, the first aspect of the present invention provides:
1) Press a mold on which a fine uneven pattern is formed on a work film in a fluid state on the first substrate,
2) Curing the film to be processed in the fluidized state, peeling the mold from the cured film to be processed, and transferring the uneven pattern of the mold to obtain a film to be processed having a structure pattern.
3) Affixing the surface on which the structure pattern is formed, and attaching the film to be processed to a second substrate having conductivity,
4) Opening the structure pattern by removing the surface of the film to be processed on which the structure pattern is not formed to expose the second substrate through the structure pattern;
5) Plating using the exposed second substrate as an electrode,
6) separating the deposited plated metal from the second substrate and the film to be processed;
A method for producing a fine metal structure, comprising producing a fine metal structure.

  The film to be processed is made using a thermoplastic resin and cured by cooling. Alternatively, it is made using a thermosetting resin and cured by heating. Alternatively, the film to be processed is made using an active energy curable resin such as a UV curable resin or an electron beam curable resin, and cured by irradiating with an active energy such as UV light or an electron beam.

  The mold is peeled to obtain a film to be processed having the structure pattern, the first substrate is separated from the film to be processed, and then the surface on which the structure pattern is formed is pasted. A film is attached to the second substrate. Alternatively, the processed film having the structure pattern is obtained by peeling the mold, the surface on which the structure pattern is formed is pasted, and the processed film is attached to the second substrate together with the first substrate. After the attachment, the first substrate is separated from the film to be processed.

  In order to achieve the above object, a second aspect of the present invention is a fine metal structure produced by using such a method for producing a fine metal structure.

  According to the present invention, a fine metal structure can be manufactured by utilizing a nanoimprint technology capable of transferring a fine structure of sub-μm or less or a thin plate-like fine structure. In addition, the side wall of the structure pattern is not affected when the conductive substrate is exposed, and the fine metal structure can be manufactured with better processing accuracy.

The best mode of the present invention will be described below with reference to the drawings.
1A to 1I show a manufacturing process of a fine metal structure according to the present invention.

  First, when a fine metal structure is manufactured, a film to be processed 3 is formed on a first substrate 1 and a mold 2 is disposed opposite to the first substrate 1 (see FIG. 1A).

  As the first substrate 1, a substrate having a certain strength such as a silicon substrate, a sapphire substrate, or a quartz substrate can be used. In the illustrated example, a silicon substrate having a diameter of 4 inches is used. As the work film 3 formed thereon, a polymer resin material such as a thermoplastic resin, a thermosetting resin, or an active energy curable resin is used. In the illustrated example, polymethyl methacrylate having a thickness of 100 μm, which is a thermoplastic resin, is used.

  On the other hand, the mold 2 can be manufactured by a MEMS (Micro Electro Mechanical Systems) manufacturing technique such as a LIGA (Lithographie Galvanoformung Adformung) technique or a silicon dry etching technique. In the illustrated example, a silicon mold 2 having a diameter of, for example, 4 inches manufactured by a silicon dry etching technique is used. For example, at least one electrostatic actuator pattern having a height of 50 μm and a width of 5 μm is provided. And it is preferable to perform the process for improving the peelability of the to-be-processed film 3 on the surface of the type | mold 2. In the illustrated example, the surface of the mold 2 is covered with a fluorine-based mold release agent (“OPTOOL DSX” manufactured by Daikin Industries, Ltd.).

  Next, the film to be processed 3 is heated to the glass transition point or higher and softened, and the mold 2 is pressed against the film to be processed 3 that is softened and in a fluid state (see FIG. 1B). The mold 2 is formed with a fine uneven pattern. In the example of illustration, it heats to about 130 degreeC and pushes in with the pressure of 30 Mpa.

  Then, the processed film 3 in a fluidized state is cured by cooling it to a glass transition point or lower, and the mold 2 is peeled off from the cured processed film 3 so that the uneven pattern of the mold 2 is transferred to the structure. A processed film 3 having a body pattern is obtained (see FIG. 1C). In the illustrated example, the cooling is performed until the temperature reaches about 80 ° C.

  After that, the first substrate 1 is removed by polishing or etching, and the first substrate 1 is separated from the film to be processed 3 (see FIG. 1D). When the first substrate 1 is separated from the film 3 to be processed, the first substrate 1 is not removed but silicon dioxide or the like formed between the first substrate 1 and the film 3 to be processed is used. Only the sacrificial layer (not shown) can be removed by etching, and the working efficiency can be improved.

  Next, the surface of the mold 2 having the concavo-convex pattern transferred thereon is attached by adhesion such as adhesive or conductive paste or ultrasonic welding, and the film 3 to be processed is applied to the second substrate 7 having conductivity. Attach (see FIG. 1E). As the second substrate 7, in addition to a conductive substrate, a substrate on which a conductive film is formed can be used.

  In order to facilitate separation of the fine metal structure from the second substrate 7, a conductive substrate made of a metal material constituting the fine metal structure and a material having etching selectivity, or a fine metal structure is constituted. It is preferable to use a substrate on the surface of which a conductive film made of a metal material to be etched and a material having etching selectivity is formed. In the illustrated example, as the second substrate 7, a silicon substrate is used in which a conductive film 8 having a thickness of 0.1 μm is formed on the surface by vapor deposition.

  Then, the structure pattern is opened by removing the surface of the film 3 on which the structure pattern is not formed by polishing or etching until the uneven pattern of the mold 2 formed on the film 3 is opened. Then, the second substrate 7 is exposed through the structure pattern (see FIG. 1F).

  Thereafter, electrolytic plating is performed using the conductive film 8 exposed by opening the structure pattern formed on the film 3 to be processed as an electrode, and plating is performed on the pattern recesses of the film 3 on which the structure pattern is formed. Metal 4 is deposited (see FIG. 1G). As the plating metal 4, various plating metals can be used. In the illustrated example, a nickel sulfamate bath is used to deposit a nickel film. When depositing the plating metal 4 in the recesses of the film to be processed 3, the recesses of the film to be processed 3 may be protruded and deposited. And the thickness of the plating metal 4 can be made uniform by removing the plating metal deposited until the concave portion of the film to be processed 3 protrudes to a desired thickness by polishing or etching.

  Next, the film 3 to be processed is selectively removed by an organic solvent or plasma ashing, the second substrate 7 is selectively removed by etching or polishing, and the deposited plating metal 4 is covered with the second substrate 7. Separated from the processed film 3 (see FIG. 1H).

  Then, the conductive film 8 is selectively removed by etching having a low etching property with respect to the metal material constituting the fine metal structure 6 and a high etching selectivity with respect to the conductive film 8. A fine metal structure 6 is formed (see FIG. 1I). In the illustrated example, the fine metal structure 6 is obtained by selectively removing the conductive film 8 using a copper plating stripper. The conductive film 8 may be used as a sacrificial layer for separating the fine metal structure 6 from the second substrate 7. Then, instead of removing the second substrate 7, only the conductive film 8 can be removed by etching to improve workability.

  In the illustrated example described above, the film 3 to be processed formed on the first substrate 1 is made of polymethyl methacrylate, which is a thermoplastic resin, and is cured by cooling. However, instead, it is made using a thermosetting resin such as phenol, epoxy, melamine, unsaturated polyester, etc. Similarly, the mold 2 is pressed to form a structure pattern, and then cured by heating, Or, use an active energy curable resin such as UV curable resin or electron beam curable resin, and press the mold 2 in the same way to form a structure pattern, and then irradiate active energy such as UV light or electron beam. The film to be processed 3 on which the structure pattern is formed may be obtained by separating the mold 2 from the cured film 3 to be processed.

  On the other hand, in the illustrated example described above, the mold 2 is peeled to obtain the film to be processed 3 on which the structure pattern is formed, and the first substrate 1 is separated from the film to be processed 3 to form the structure pattern. The processed film 3 was attached to the second substrate 7 by pasting the surface. However, after the mold 2 is peeled to obtain the film to be processed 3 on which the structure pattern is formed, the surface on which the structure pattern is formed is pasted as shown in FIG. After being attached to the conductive second substrate 7 together with the first substrate 1, as shown in FIG. 2B, the first substrate 1 is removed by polishing or etching. Alternatively, the first substrate 1 is separated from the processed film 3 by removing a sacrificial layer (not shown) such as silicon dioxide formed between the processed film 3 and the first substrate 1 by etching. You may do it.

  Further, after the mold 2 is peeled to obtain the film 3 to be processed on which the structure pattern is formed, the surface on which the concave / convex pattern of the mold 2 is transferred is bonded to an adhesive or conductive material as shown in FIG. As shown in FIG. 3 (B), the film 3 to be processed is attached to the second substrate 7 having conductivity together with the first substrate 1 by adhering with an adhesive paste or ultrasonic welding. In addition, the first substrate 1 and the film to be processed 3 may be simultaneously removed by polishing or etching.

(A) thru | or (I) is a manufacturing-process figure of the fine metal structure by this invention. It is a change partial process drawing of another manufacturing process. It is a change partial process figure of another manufacturing process. It is a manufacturing-process figure of the fine pattern using the conventional nanoimprint method. It is a manufacturing process figure of another conventional fine pattern. It is a manufacturing-process figure of the fine metal structure using the conventional hot embossing method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st board | substrate 2 type | mold 3 Processed film 4 Plating metal 6 Fine metal structure 7 2nd board | substrate 8 Film | membrane with electroconductivity

Claims (7)

1) Press a mold on which a fine uneven pattern is formed on a work film in a fluid state on the first substrate,
2) Curing the film to be processed in the fluidized state, peeling the mold from the cured film to be processed, and transferring the uneven pattern of the mold to obtain a film to be processed having a structure pattern.
3) Affixing the surface on which the structure pattern is formed, and attaching the film to be processed to a second substrate having conductivity,
4) Opening the structure pattern by removing the surface of the film to be processed on which the structure pattern is not formed to expose the second substrate through the structure pattern;
5) Plating using the exposed second substrate as an electrode,
6) separating the deposited plated metal from the second substrate and the film to be processed;
A method for producing a fine metal structure, comprising producing a fine metal structure.   The method for producing a fine metal structure according to claim 1, wherein the film to be processed is made by using a thermoplastic resin and is cured by cooling.   The method for producing a fine metal structure according to claim 1, wherein the film to be processed is made by using a thermosetting resin and is cured by heating.   The method for producing a fine metal structure according to claim 1, wherein the film to be processed is made using an active energy curable resin and cured by irradiating with active energy.   The mold is peeled to obtain a film to be processed having the structure pattern, the first substrate is separated from the film to be processed, and the surface on which the structure pattern is formed is attached. The method for manufacturing a fine metal structure according to claim 1, wherein the fine metal structure is attached to the second substrate.   The mold is peeled to obtain a film to be processed having the structure pattern, the surface on which the structure pattern is formed is attached, and the film to be processed is attached to the second substrate together with the first substrate. 5. The method for manufacturing a fine metal structure according to claim 1, wherein the first substrate is separated from the film to be processed.   A fine metal structure produced by the method for producing a fine metal structure according to any one of claims 1 to 6.

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