JP2011022440A - Mems-based exposure module and related technique - Google Patents

Abstract

The present invention has been made in view of these backgrounds, and provides a technique for forming a microstructure on a fiber-like elongated substrate.
An exposure module for transferring a pattern to a fiber-like elongated member by a photolithography technique, a translucent substrate provided with a cylindrical cavity having an inlet and an outlet, and the cylindrical cavity An exposure module having a light-shielding pattern provided on the wall surface is provided. Preferably, the module is formed in the vicinity of an inlet and an outlet of the cylindrical cavity, and supports a member to be exposed so as to be slidable with or without a lubricant, and the member supporting portion. And an exposure part having a larger cylinder diameter than the member support part, and the light shielding pattern is provided on a cave wall surface of the exposure part.
[Selection] Figure 5

Description

  The present invention relates to a technique for forming a microstructure on a fibrous substrate, and more particularly to a mask for photolithography.

  In a semiconductor manufacturing process or a MEMS manufacturing process, a planar substrate has traditionally been used as a substrate. On the other hand, for example, when a cylindrical or spherical substrate is used, the surface area per unit volume increases, so that the functions can be mounted with high density, and a device having the same function can be made smaller than before. In addition, it is possible to implement a higher function than the conventional one with the same size. Furthermore, if a micro functional structure can be formed on an ultrafine substrate such as an optical fiber, it will be possible to create a large area and flexible sheet having various functions by weaving it. For this reason, great expectations are placed on the realization of fibrous microdevices, which are considered to bring about significant development in many technical fields such as medical treatment, wireless communication, robots, and smart environments. Thus, efforts have been made to form a micro functional structure on an elongated substrate.

  One type of such technology is called soft lithography (see Non-Patent Document 1). FIG. 1 shows an outline of the soft lithography process. First, a photomask (101) formed of a flexible material is prepared, and is brought into close contact with the curved substrate (103) coated with the photoresist (102), and exposed (104) from above the mask. When the mask is peeled off, a pattern (105) composed of an exposed portion and an unexposed portion can be obtained. Since this technique uses a flexible mask, a pattern can be transferred to a curved surface using a photolithography technique. In addition, FIG. 1 extracts and uses a part of FIG. 7 of a nonpatent literature 1. FIG.

  However, since soft lithography requires a process of bringing a photomask into close contact with a substrate and peeling it, it is not suitable for pattern transfer onto a substrate having a small diameter. In particular, when the diameter is 4 mm or less, the problem of peeling off the photoresist together particularly in the peeling process becomes serious. In addition, although it is flexible, being bent at each transfer step considerably shortens the life of the mask. In particular, as the diameter of the base material becomes smaller, the photomask must be bent more greatly, so that the bending load is more intense and the deterioration is accelerated. For this reason, soft lithography is not suitable for lithography on a substrate having a small diameter. What is more problematic is that this technique is not at all suitable for a continuous process because of the photomask mounting and peeling process. Therefore, it is very difficult to apply the soft lithography technique as a lithography means for thin and long fibers.

  Non-Patent Document 2 describes a technique for manufacturing a microcoil using an optical molding method. The photomolding method is a technique for obtaining a desired three-dimensional structure by curing a liquid photocurable resin with an ultraviolet laser in accordance with three-dimensional CAD data (see FIG. 2). The photo-molding method can produce a three-dimensional structure such as a microcoil, but cannot form a circuit pattern on a substrate. Also, in the photomolding method, it is very difficult to form a long structure due to restrictions on manufacturing equipment, and it takes time to cure the resin. Absent. Furthermore, the cost is very high.

  Non-Patent Document 3 describes a technique for directly cutting a microcoil from a substrate with strong synchrotron light. An overview of this technique is shown in FIG. As shown in the figure, (a) a PTFE resin layer 304 is formed around the rotating shaft 302, and (b) the PTFE resin layer 304 is rotated and irradiated with synchrotron light through a mask 306 to be cut off. Do. When the cutting is finished, a microcoil as shown in FIG.

  A technique is described in which a micro-coil is directly cut from the substrate by irradiating with strong synchrotron light through a mask while rotating the cylindrical substrate (see FIG. 3). However, it is possible to obtain synchrotron light that is strong enough to cut the substrate at a realistic speed in only a limited number of facilities, and it is likely that this method will be put into practical use on a commercial basis. Absent.

  In addition, Patent Documents 1 to 3 describe a technique capable of transferring a pattern by uniformly exposing the surface of a spherical substrate. However, this technique is an exposure method for a spherical substrate, and is not suitable for forming a micro functional structure on a long substrate.

J. G. Kim, N. Takama, B. J. Kim, H. Fujita, Optical-softlithographic technology for patterning on curved surfaces, Journal of Micromechanics and Microengineering, 19 (2009) 055017 C. Sun, N. Fang, D. M. Wu, X. Zhang, Projection micro-stereolithography using digital microy-mirror dynamic mask, Sensors and Actuators A 121 (2005) 113-120 T. Katoh, N. Nishi, M. Fukagawa, H. Ueno, S. Sugiyama, Direct writing for three-dimensional microfabrication using synthcrotron radiation etching, MEMS 2000

Japanese Patent Laid-Open No. 11-195580 Japanese Patent Laid-Open No. 11-121368 Japanese Patent Application Laid-Open No. 11-11609

  The present invention has been made in view of these backgrounds, and an object thereof is to provide a technique for forming a microstructure on a fiber-like elongated substrate.

  The scope of the present invention includes a novel exposure module for transferring a pattern to a fiber-like elongated member by photolithography. This exposure module has a light-transmitting substrate provided with a cylindrical cavity having an inlet and an outlet, and a light shielding pattern provided on the wall surface of the cylindrical cavity.

  The cylindrical cavity can be, for example, a cylindrical cavity. Exposure can be performed by inserting a fiber-like member coated with a photoresist into the cavity and irradiating light from the outside of the module. The exposed fiber part is pulled out of the module, and the next step is to expose each part of the long fiber material in sequence by repeating the step of exposing the fiber part to be exposed next in the module. It becomes possible to do. That is, a substantially continuous lithographic means for long fiber materials is provided.

  And since this exposure module is not bent at the time of use unlike the flexible mask used by soft lithography, deterioration is very slow and it can be used for a long time.

  The exposure module preferably has a structure for supporting and guiding a member to be exposed. In one example, there is provided a member support portion that is formed in the vicinity of the inlet and outlet of the cylindrical cavity of the module and slidably supports a member to be exposed with or without a lubricant. The light shielding pattern is provided on a wall surface in a portion deeper than the member support portion. Of course, it is preferable that the lubricating liquid does not adversely affect the exposure process.

  The member support portion not only supports the module during exposure but also functions to position a member to be exposed with respect to the light shielding pattern at a predetermined location. Therefore, it is preferable that the shape of the member supporting portion is substantially equal to the outer shape of the member to be exposed so that the member to be exposed can be firmly supported without wobbling. However, in order to prevent the member or the module from being damaged by friction when sliding the member to perform the lateral alignment, the member support portion can support the member exposed through the lubricating liquid. It may be configured.

  According to this configuration, since the distance from the light shielding pattern is automatically determined only by passing the member through the exposure module, the vertical positioning can be easily performed with high accuracy.

  For lateral positioning, it is preferable to provide some marks that can be used for positioning, such as an annular mark, in the exposure module.

  In the exposure module, it is preferable that the inner diameter of the portion where the light shielding pattern is formed is slightly larger than the inner diameter of the member support portion. In this way, since the member does not contact the light shielding pattern, it is possible to prevent the light shielding pattern from being broken by friction when the member is slid. However, in order to prevent light scattering at the time of exposure, it is desirable that the space between the inner wall surface of the module cavity and the member to be exposed be filled with a liquid having the same or at least very close refractive index as the base material of the module. Alternatively, so-called immersion lithography is known in which refraction of light is actively utilized to fill a high refractive index liquid to improve the aperture ratio of the stepper, and the liquid used in this technique can be used. . These liquids can also function as the aforementioned lubricating liquid.

The present invention also includes within its scope several methods for manufacturing the aforementioned exposure module. The exposure module can be manufactured by being divided into a plurality of parts divided by a plane passing through the central axis of the cylindrical cavity. An example of a method for manufacturing the part is as follows.
Forming a groove on the translucent substrate, the groove surface forming part of the cylindrical surface;
Forming a film of an antiadhesive substance on the groove surface, forming a metal film on the antiadhesive substance film, and further forming an adhesive substance film on the metal film;
A step of laminating a translucent resin on the film of the adhesive substance;
-Curing the resin and peeling the resin together with the metal film from the translucent substrate;
A photoresist is applied on the metal film so that the ridge formed corresponding to the groove of the translucent substrate is covered with the peeled resin, and the metal film is patterned by photoetching. Forming the step,
-The anti-adhesive substance is removed from the translucent substrate from which the resin has been peeled off, and a second metal film is formed so as to cover the groove surface, and further on the second metal film. Forming a layer of photoresist;
A step of superimposing the resin on which the pattern has been formed on the translucent base so that the ridges are again accommodated in the grooves;
Transferring the pattern on the resin to the second metal film by performing photo-etching using the pattern on the resin as a mask;
including.

Another example of a method of manufacturing the aforementioned part is
Forming a groove on the translucent substrate, the groove surface forming part of the cylindrical surface;
A step of laminating a translucent resin on the groove and peeling off after curing;
A step of forming a metal film on the peeled resin so as to cover the ridge formed corresponding to the groove of the translucent substrate, and forming the metal film in a pattern;
A step of forming a second metal film on the translucent substrate from which the resin has been peeled so as to cover the groove surface, and further forming a photoresist layer on the second metal film;
A step of superimposing the resin on which the pattern has been formed on the translucent base so that the ridges are again accommodated in the grooves;
Transferring the pattern on the resin to the second metal film by performing photo-etching using the pattern on the resin as a mask;
including.

  Other objects, configurations, and operational effects related to the present invention, including the advantages of these manufacturing methods, will be described in detail later using exemplary embodiments.

Diagram for explaining the outline of the conventional soft lithography process The figure for demonstrating manufacture of the microcoil using the stereolithography method which is a prior art A diagram for explaining the manufacture of microcoils using synchrotron light, which is a prior art It is a figure for demonstrating the outline | summary of the MEMS exposure module introduced as an Example. It is a figure for demonstrating the outline | summary of the MEMS exposure module introduced as an Example. It is a figure for demonstrating the outline | summary of the MEMS exposure module introduced as an Example. It is sectional drawing which cut | disconnected the MEMS exposure module 400 by the central axis of the longitudinal direction. FIG. 6 is a diagram for explaining a process of a first example of a method for manufacturing a part 402 or 404 of the MEMS exposure module 400. 3 is an optical micrograph of a base body 601 in which a semicircular groove 602 is formed. It is the optical microscope photograph which image | photographed the components 600 from the direction of the code | symbol 618 of FIG.6 (e). It is the optical microscope photograph which image | photographed the components 600 from the direction of the code | symbol 620 of FIG.6 (e). It is a figure for demonstrating the process of the 2nd example of the method of manufacturing the parts 402 and 404 of the MEMS exposure module 400. FIG. It is a figure for demonstrating the process of the 2nd example of the method of manufacturing the parts 402 and 404 of the MEMS exposure module 400. FIG. It is a figure for demonstrating the process of the 3rd example of the method of manufacturing the parts 402 and 404 of the MEMS exposure module 400. FIG. It is a figure which shows the circuit pattern example 1100 of the micro thermometer which can be formed in a fiber-like base | substrate. It is a figure for demonstrating the process of forming the micro thermometer circuit pattern 1100 in a fiber-like base | substrate using the MEMS exposure module 400. FIG. FIG. 6 is a diagram for explaining a microinductor that can be manufactured using a MEMS exposure module 400; 13B is a diagram for explaining an example of a process for manufacturing the microinductor 1320 of FIG. 13B using the MEMS exposure module 400. FIG.

  Hereinafter, various aspects of the present invention will be described in detail with reference to the drawings through the description of preferred embodiments in order to contribute to a deeper understanding of the present invention.

  Preferred embodiments of the present invention can provide a low cost, high resolution lithography technique for very thin fibrous substrates that can be up to 1 mm in diameter. This lithography technique utilizes what is referred to herein as a “MEMS exposure module”. The reason for calling it a “MEMS” exposure module is that this exposure module can be manufactured using MEMS technology. FIG. 4A shows a radial cross-sectional view of a MEMS exposure module 400 introduced as an example. The MEMS exposure module 400 is manufactured by being divided into an upper half portion 402 and a lower half portion 404, and these are joined. A cylindrical hole (cavity) 406 is formed in the central portion of the module 400. The fiber member 420 to be exposed is inserted into this cavity. FIG. 4B illustrates a state where the fiber member 420 is inserted into the cavity 406. A mask pattern 408 to be transferred by exposure is provided on the inner surface of the cavity 406. The MEMS exposure module 400 generally has a rectangular parallelepiped appearance, and the direction of the center line of the cavity 406 coincides with the longitudinal axis of the module 400. (Note that this is merely an exemplary shape and does not limit the shape of embodiments of the present invention.)

  The joint surfaces of the portions 402 and 404 are located on a plane passing through the center line of the cavity 406. Thus, the semi-cylindrical grooves formed in these portions each form exactly half of the cavity 406. In the present embodiment, it is divided into two parts, but if necessary for manufacturing, it may be divided into more parts. However, if the shape of the cavity 406 is cylindrical, it can be sufficiently fulfilled for the purpose of ensuring ease of manufacture if it is divided into two parts. These parts are joined using MEMS or other existing packaging technology. Grooves are formed in the substrate of each portion using a micromachining process or a precision machining process according to the size of the fiber to be lithographically processed. FIG. 4C is a cross-sectional view depicting the lower half 404 of the module 400 depicted in FIG. 4A, but it can be seen that a semi-cylindrical groove 414 having a semi-circular cross-section is formed. This groove is combined with a corresponding groove in portion 402 to form the cylindrical cavity 406 depicted in FIG. 4A. The groove 414 can be easily formed using an existing dry etching or wet etching technique.

Since the module 400 must pass light for exposure, the module 400 needs to be formed of a highly light-transmitting substance. It is also desirable that the material be highly workable. An example of a material that meets these requirements is quartz and glass. Of course, it is not limited to these substances. Since the pattern 408 is used as a mask during exposure, it needs to be formed of a metal or other light shielding material. An example of a suitable mask material is Cr / Cr ₂ O ₃ because of its good suitability for MEMS manufacturing processes.

  FIG. 5 shows a cross-sectional view of the MEMS exposure module 400 cut along the central axis in the longitudinal direction. The upper half 402 of the module 400 depicted in FIG. 4A is divided into a portion 402a where the mask pattern 408 is provided and another portion 402b. Similarly, the lower half 404 (see FIG. 4A) of the module 400 is also divided into a portion 404a where the mask pattern 408 is provided and another portion 404b.

  Portions 402b and 404b are formed near the inlet and outlet of the module 400, ie, near the inlet and outlet of the cavity 406 indicated by reference numeral 406 in FIG. 4A, and serve to support the fiber 420 passing through the cavity 406. For this reason, it is desirable that the inner diameter of the hole defined by the portions 402 b and 404 b is formed so as to substantially match the outer diameter of the fiber 420. On the other hand, the area where the mask pattern 408 is provided, that is, the inner diameter of the hole defined by the portions 402 a and 404 a is slightly larger than the outer diameter of the fiber 420. This is for preventing the fiber 420 and the mask pattern 408 from coming into contact with each other during the feeding of the fiber 420 and damaging the mask pattern 408.

  In the lithography process for the long fiber member 420 using the exposure module 400, the portion to be exposed is positioned and set in the module 400, the exposure is performed, and the portion after the exposure is completed by feeding the fiber 420. This is performed by a stepwise process in which a portion to be extracted and then exposed is set in the module 400 and exposed again. In FIG. 5, a portion where the pattern is transferred after the exposure is indicated by reference numeral 42. Therefore, this lithography process can be expressed as “continuous” or “sequential”.

  In order for the pattern exposed at each position of the fiber 420 to be formed with the same resolution, the distance between the photoresist layer 424 formed around the core material 422 of the fiber 420 and the mask pattern 408 is different from each other. It must be the same in the exposure stage. In this regard, if the inner diameter of the hole defined by the portions 402b and 404b is formed to substantially match the outer diameter of the fiber 420, the hole not only supports the fiber 420 but also the photoresist layer. Since it also has a function of keeping the distance between 424 and the mask pattern 408 constant, it is very advantageous. That is, the hole defined by the portions 402 b and 404 b has a function of positioning the fiber 420 in the radial direction in addition to the function of supporting the fiber 420.

  As described above, the inner diameter of the hole defined by the portions 402a and 404a is preferably slightly larger than the outer diameter of the fiber 420 in order to prevent contact damage of the mask pattern 408. Since the MEMS process can be processed with very high accuracy, it is possible to precisely control the exposure gap to be several μm or less. However, even if the gap is very small, if the mask pattern 408 and the photoresist layer 424 are separated from each other, light refraction or scattering may occur at the time of exposure. This is a disadvantage. Therefore, during the exposure, it is preferable to fill the gap between the mask pattern 408 and the photoresist layer 424 with a liquid having a refractive index as close as possible to the members of the portions 402a and 404a. Of course, if possible, the refractive index of the liquid is preferably exactly equal to the refractive index of the portions 402a and 404a. By doing so, it becomes possible to suppress the influence of light refraction and scattering caused by the separation of the mask pattern 408 and the photoresist layer 424 to the maximum.

  Alternatively, light refraction may be actively used to fill the gap with a high refractive index liquid. So-called immersion lithography, which improves the aperture ratio of a stepper by filling a liquid having a high refractive index, is known, and the same principle can be applied to embodiments of the present invention.

  In addition, these liquids can also serve as a lubricating liquid to reduce friction during fiber feeding in the portion of the hole defined by portions 402b and 404b. Accordingly, the inner diameter of the hole defined by the portions 402b and 404b preferably matches the outer diameter as much as possible for supporting the fiber 420, but there is a very small gap between which the lubricating liquid can be interposed. It is better to have

  The material of the portions 402a and 404a needs to be formed of a light-transmitting material that transmits the light 500 as conceptually shown in FIG. 5, but the portions 402b and 404b are not necessarily transparent. However, in order not to irradiate the resist layer 424 with extra light, it is preferable to use a material that does not transmit light. When the portions 402b and 404b are formed of the same material as the portions 402a and 404a, the cylindrical surfaces of the portions 402b and 404b are preferably coated with a light shielding material.

Next, some examples of a method for manufacturing the MEMS exposure module 400 will be described. As described above, the MEMS exposure module 400 is manufactured in two parts 402 and 404, which are later joined. Described below is a method for manufacturing these portions 402 or 404.
[Production Method Example 1]

  FIG. 6 shows steps of a first example of a method for manufacturing the portions 402 and 404 of the MEMS exposure module 400.

  FIG. 6A shows a step of forming a semi-cylindrical groove 602 in a rectangular base 601. The base 601 is a base for the parts 402 and 404 of the MEMS exposure module 400 described above, and is thus made of a translucent material such as quartz or glass. The groove 602 corresponds to half of the cavity 406 depicted in FIG. 4A and the like. The semicircular groove 602 can be easily formed using a known technique such as tri-etching or wet etching. FIG. 7 shows an optical micrograph of the substrate 601 on which the semicircular groove 602 is formed.

Subsequently, as shown in FIG. 6B, a metal layer 604 is formed on the surface of the substrate 601 by a technique such as electroplating, and a photoresist layer 606 is formed thereon by a technique such as spray coating. These layers can be formed using techniques well known in the semiconductor manufacturing process. The metal layer 604 and the resist layer 606 are not necessarily required to cover the front surface of the surface of the base body 601, but are preferably formed so as to cover at least the groove surface of the semicircular groove 602. Since the metal layer 604 is formed as a mask that blocks light later, it is necessary to prevent light from passing therethrough. For example, it can be a Cr / Cr ₂ O ₃ layer.

  Subsequently, as shown in FIG. 6C, the photoresist layer 606 is irradiated with light 610 through a photomask 608 to perform exposure. When this is developed, a photoresist pattern 606a remains on the metal layer 604, as shown in FIG. Further, by performing an appropriate etching process, unnecessary portions and remaining resist of the metal layer are removed, and necessary portions of the metal layer 604 remain on the inner surface of the semicircular groove 602, thereby forming a metal pattern 604a. (See FIG. 6 (e)). The parts 600 are completed by these processes. The component 600 can be a portion 402 or 404 of the MEMS exposure module 400.

  FIG. 8 a is an optical micrograph of the component 600. This photograph was taken from the direction of arrow 618 in FIG. The semicircular groove is indicated by an arrow 602, and a portion indicated by a black reference numeral 602a is a groove wall portion, and is a metal mask pattern in which a portion indicated by a reference numeral 604a is formed. It should be noted that the same reference numerals are used for the same components in FIGS. 6 and 8a. It will be understood from the photograph that a clean mask pattern can be formed by the method of FIG.

  The rectangular pattern indicated by reference numeral 622 and the lattice pattern indicated by reference numeral 624 are marks used for alignment when the two components 600 are bonded to finish an exposure module as shown in FIG. 4A. Such a pattern can be easily formed by a single exposure process. The marks 622 and 624 can be used not only for joining the two parts 600 but also for lateral positioning when feeding the fiber. Such alignment patterns are convenient for manufacturing microcoils and similar structures. However, it is difficult to form such patterns and other alignment marks with accuracy using conventional software. It is difficult by a lithography process.

  FIG. 8 b is an optical micrograph of the component 600 taken from the direction of the arrow 620 in FIG. As is apparent from the photograph, the semicircular groove 602 and the metal mask pattern 604a therein are shown. Also, a thin linear structure is shown in the groove wall portion 602a, and it can be seen that a metal mask pattern is also formed in this portion. These mask patterns are intended to form a coil pattern on the fiber substrate 420 by exposure. Even when the image is taken from the direction of the arrow 620, it can be seen that the base 601 is transparent because the groove structure is shown. That is, the base 601 is formed of a material that can transmit light for exposure in the photolithography process.

The weak point of the manufacturing method in FIG. 6 is that the resolution of lithography is lowered due to the influence of light refraction and scattering during exposure because there is a distance between the mask 608 and the bottom of the semicircular groove 602. 6 is preferably used when the groove is relatively shallow, for example, when the diameter is 100 μm or less (that is, when the maximum depth is 50 μm or less). When the groove is deeper, it is preferable to use the following manufacturing method.
[Production Method Example 2]

  FIG. 9 shows the steps of a second example of the method for manufacturing the portions 402 and 404 of the MEMS exposure module 400.

The process shown in FIG. 9A is a process of preparing a rectangular base 601 and forming a semi-cylindrical groove 602 thereon, which is the same as the process of FIG. In addition, the same code | symbol is attached | subjected to the same element as FIG. The process of FIG. 9B is different from the process of FIG. 6B, and the film 902 formed on the surface of the substrate 601 is a film of an anti-adhesive substance such as DTS. A metal thin film 904 is formed on the anti-adhesive material film 902 using a thin film forming technique. Since this film will be used later as a photomask, it should not be a material that allows light to pass through. One of the most preferred coating materials is Cr / Cr ₂ O ₃ .

  Subsequently, an adhesive substance is applied on the metal layer 904, and a PDMS layer is formed thereon (FIG. 9C). PDMS is cured in accordance with the shape of the semicircular groove 602. That is, the process of FIG. 9C is a molding process in which the PDMS is molded using the substrate 601 as a mold. After the PDMS is cured, when the PDMS molding 906 is peeled from the substrate 601, an anti-adhesive material film 902 exists between the substrate 601 and the metal layer 904, and the metal layer 904 and the PDMS molding 906 are present. Since the adhesive substance is applied, the metal layer 904 is peeled off from the substrate 601 while being attached to the PDMS molded product 906 (FIG. 9D). A semi-cylindrical ridge 907 corresponding to the semicircular groove 602 is formed on the PDMS molded product 906. The PDMS molding 906 is produced as a photomask for the substrate 601 in a subsequent process.

  In the step of FIG. 9E, first, a photoresist layer 908 is formed on the metal layer 904 of the PDMS molded product 906 using a technique such as spin coating or spray coating, and a photomask 910 is prepared. Exposure is performed by irradiating light 912 through 908 through a photomask 910. When this is developed and unnecessary resist and metal are removed by etching, the metal layer 904 is processed into a pattern 904a corresponding to the pattern of the photomask 910 as shown in FIG.

On the other hand, in the step of FIG. 9G, the surface of the substrate 601 from which the PDMS molded product 906 has been peeled is cleaned, in particular, the anti-adhesive material film 902 is removed cleanly, and the metal layer 914 is formed again. The metal layer 914 is preferably formed so as to cover at least the semicircular groove 602. The metal layer 914 can also be formed of Cr / Cr ₂ O ₃ or the like. Further, a photoresist layer 916 is formed on the metal layer 914 by using a technique such as spin coating or spray coating.

  In the step of FIG. 9 (h), a PDMS molded product 906 on which a mask pattern 904a is formed is overlaid on a substrate 601 on which a metal and photoresist film is formed. Since the ridge 907 of the PDMS molded product 906 is originally formed using the semicircular groove 602 of the base 601 as a mold, the PDMS molded product 906 and the base 601 can be fitted with almost no gap. Further, in the process of FIG. 9I, the photoresist layer 916 is exposed by irradiating light 918 from the side opposite to the contact surface, using the PDMS molded product 906 (the pattern 904a) as a mask. Note that PDMS is transparent and therefore allows light to pass through. By this exposure, the pattern of the mask 904a can be transferred to the resist layer 916.

  After the exposure is completed, the PDMS molded product 906 is removed, and unnecessary resist and metal are removed by development and etching. As shown in FIG. 9J, a metal derived from the metal layer 914 on the inner surface of the groove 602 is obtained. A pattern 914a can be obtained. In FIG. 9 (j), the completed part is represented by reference numeral 900, which is a part corresponding to the part 600 of FIG. 6 and can be the part 402 or 404 of the MEMS exposure module 400. .

  The advantage of the manufacturing method of FIG. 9 is that the distance between the mask and the transfer layer (photoresist) can be significantly shortened.

  In the manufacturing method of FIG. 6, the distance between the groove 602 and the mask 608 is open as illustrated in FIG. Because the mask 608 is planar, it is impossible to position the mask 608 at the bottom of the groove, and at best only place the mask directly above the groove opening. For this reason, there is no choice but to leave a certain distance between the depth of the groove and the mask. As a result, it is inevitable that light reaching the photoresist from the edge of the mask is slightly refracted, so that the transferred pattern is blurred and it is difficult to perform highly accurate transfer.

  However, in the manufacturing method of FIG. 9, since the mask (904a) and the photoresist layer (916) are in contact with or very close to each other as depicted in FIGS. It becomes possible to perform high-precision drawing without causing a problem.

  In the process of FIG. 9 (c), PDMS is initially poured into the groove 602 in a liquid state, so that whatever the shape of the groove 602 is, it can be adapted to a shape that closely matches the shape and can be cured. . Accordingly, the shapes of the mask (904a) and the photoresist layer (916) match very well, and the contact property is very good. This feature is very advantageous in performing high-precision drawing. Note that the material that can be used in the embodiment of the present invention is not limited to PDMS. Similarly to PDMS, a material that is cured from a liquid phase and has translucency can be used instead of PDMS. it can.

  A further advantage of the manufacturing method of FIG. 9 is that the most accurate mask can be formed near the top of the ridge-shaped mask 904a. This results in that drawing with the highest resolution can be performed near the bottom of the groove 602.

  Since the portion 907 corresponding to the groove 602 protrudes as illustrated in FIG. 9E, the portion of the resist layer 908 that is closest to the master mask 910 is the top of the ridge 907. Therefore, the top of the ridge 907 is least affected by refraction or scattering of light that has passed through the master mask 910. Furthermore, since the tangent plane is close to perpendicular to the light 912 at the top of the ridge 907, drawing with higher resolution is possible at that point. For these reasons, the most accurate pattern is formed in the mask 904a.

  In the steps of FIGS. 9 (h) and 9 (i) in which the PDMS molded product 906 is used to expose the resist layer 916 of the substrate 601, the most accurate pattern is near the top of the ridge 907, and Because the tangent plane is nearly perpendicular to 918, drawing with the highest resolution is possible at the bottom of the groove 602.

  As depicted in FIG. 5, when the fiber 420 is exposed, light is emitted perpendicular to the interface between the components 402 and 404. For this reason, the tangent plane is perpendicular to the light in the fiber 420, and the best places for drawing conditions are the upper and lower portions of the fiber 420 in FIG. 5, that is, the portions farthest from the joint surfaces of the components 402 and 404, That is, it is near the bottom of the semicircular groove 602 in FIGS. Therefore, it is preferable that a functional pattern that requires the most accuracy can be drawn in this vicinity. For example, the invention of the manufacturing method embodied in FIG. 9 makes it possible to form a mask pattern with the highest accuracy at the bottom of the semicircular groove, so that an appropriate pattern can be drawn on the fiber material. Very profitable.

  Even with the above manufacturing method, the mask pattern is formed obliquely with respect to the exposure light in the vicinity of the root of the ridge of the PDMS mask, that is, in the vicinity of the opening of the groove of the exposure module. Compared to the top of the ridge (the deep part of the groove), the resolution decreases. Therefore, it is preferable to form a pattern of a functional portion (for example, a simple wiring) that does not require accuracy, rather than the top of the ridge (the deep portion of the groove).

The manufacturing method of FIG. 9 can be applied regardless of the depth of the groove 602. In particular, in the manufacturing method of FIG. 6, an adverse effect depending on the distance between the mask 608 and the bottom of the groove 602 starts to be noticeable. The advantage is particularly great when the thickness is 100 μm or more (that is, when the maximum depth is 50 μm or more).
[Production Method Example 3]

  FIG. 10 shows the steps of a third example of the method for manufacturing the portions 402 and 404 of the MEMS exposure module 400. A difference from the manufacturing method of FIG. 9 is that a metal film is directly formed on a PDMS molded product, and a mask pattern is formed by soft lithography using a flexible stencil mask.

  The process shown in FIG. 10A is a process of preparing a rectangular base 601 and forming a semi-cylindrical groove 602 thereon, which is the same as the process of FIGS. 6A and 9A. . The same elements as those in FIG. 6 are denoted by the same reference numerals. However, after this, unlike the manufacturing method of FIG. 9, the PDMS layer 1002 is formed directly on the substrate 601. The PDMS layer 1002 is peeled from the substrate 601 after being cured. An anti-adhesive substance may be applied in advance between them so that peeling is easy.

  On the other hand, a flexible stencil mask 1004 as shown in FIG. 10C is prepared. A pattern 1006 is formed on the stencil mask 1004 in advance. The stencil mask can be made using existing MEMS technology and other patterning technologies. The stencil mask must be made with sufficient accuracy.

  In the step of FIG. 10D, a metal layer 1008 and a photoresist layer 1010 are formed on the PDMS molded product 1002. As a method for forming the metal layer 1008 on the PDMS molded product 1002, a sputtering method such as PVD or a chemical method such as electroless plating can be used. Then, the prepared stencil mask 1004 is placed on the photoresist layer 1010 and exposed by irradiating light 1012. Thereafter, a metal pattern 1008a derived from the metal layer 1008 can be formed by performing development and etching treatment.

  Since the PDMS mask completed in FIG. 10 (e) is the same as the PDMS mask in FIG. 9 (f), it is possible to perform drawing on the fiber material by the steps of FIGS. 9 (g) to 9 (j). It is.

  The manufacturing method of FIG. 10 requires a step of covering the PDMS 1002 with the stencil mask 1004. Therefore, the ridge portion 1003 of the stencil mask 1004 is desirably large to some extent. Therefore, the present invention can be preferably applied when the diameter of the groove 602 exceeds 200 μm, that is, when the depth of the groove is deeper than 100 μm and the height of the ridge portion 1003 exceeds 100 μm correspondingly.

In the case where the groove 602 is large, it may be considered that the stencil mask 1004 is directly installed in the groove, but in reality, the operation is difficult. Rather, it is much easier to manufacture the PDMS 1002 using the groove 602 as a mold and cover the ridge 1003 with the stencil mask 1004. Therefore, even when the groove 602 is large, the usefulness of making a PDMS molded product is still not lost.
[Parts joining]

  For example, after the respective portions 402 and 404 of the MEMS exposure module 400 are formed by the above-described manufacturing method, these are joined to complete the MEMS exposure module 400. A known MEMS manufacturing / packaging technique can be used for bonding. For alignment of the components 402 and 404, as described above, it is possible to use the alignment marks 622, 624 and the like that are formed together when the mask pattern is formed. These alignment marks can also be used for axial alignment during fiber feeding.

  Each of the above-described manufacturing methods is compatible with the existing MEMS manufacturing process, and the manufacturing and processing costs are low. In addition, it is advantageous in terms of ease of manufacturing and cost that a hard workable material such as glass or quartz can be used.

In the lithography process for the long fiber member 420 using the exposure module 400, the portion to be exposed is positioned, set in the module 400, exposed, the fiber 420 is fed, and the portion after the exposure is finished. A stepwise continuous process is performed in which a part to be exposed next is set in the module 400 and exposed again after being pulled out of the module 400. Since the fiber member 420 is supported by the head portions 402b and 404b and the radial position is determined, the radial positioning is completed only by passing the fiber member 420 through the module 420. Although the axial positioning is still necessary, the positioning operation is very easy. As far as the inventor is aware, this is the first time that a technique has been provided that allows alignment and exposure to a fiber-like substrate so easily in a single module. .
[Application Example 1 ... Micro Thermometer]

  Thermometers are the most commonly used physical sensors and are used in a variety of applications. It has also been desired to form a micro thermometer on a fibrous substrate. For example, it is considered to incorporate a micro thermometer formed on a fiber into a medical instrument that also uses the fiber. It is also considered that a sheet having a temperature detection function is made by incorporating a large number of micro thermometers formed in a fiber shape. Such a sheet is considered to be applicable to artificial skin and the like, and is highly expected in the medical and robot fields. According to the present invention, such a fiber-shaped micro thermometer can be easily manufactured at low cost.

  FIG. 11 shows an example of a circuit pattern of a micro thermometer that can be formed on a fiber substrate. The micro thermometer circuit pattern 1100 includes a platinum pattern portion 1102 and a tungsten pattern portion 1104, and the temperature can be measured by measuring the resistance value of the platinum pattern portion 1102 via the tungsten pattern portion 1104.

  A process for forming a micro thermometer circuit pattern 1100 on a fibrous substrate using the MEMS exposure module 400 will be described with reference to FIG.

  FIG. 12A shows a process of preparing the fibrous substrate 1202. As the fibrous substrate 1202, for example, a commercially available optical fiber can be used. In the step of FIG. 12B, a photoresist is applied to the outer periphery of the fiber 1202 by an appropriate technique such as spray coating. This is inserted into FIG. 4A and FIG. 5, and exposure is performed by aligning the positions. When the exposed fiber portion is pulled out from the module 400 and developed, a pattern made of a photoresist is formed on the surface of the fiber 1202 as shown in FIG. In the step of FIG. 12D, a metal film 1206 made of Pt is formed to a thickness of about 200 nm. The thin film of Pt can be formed by a sputtering method such as electroplating. Then, when an unnecessary part is removed by an appropriate etching process, the Pt pattern part 1102 of FIG. 11 is obtained (FIG. 12E). In FIG. 12, the completed Pt pattern portion is denoted by reference numeral 1206a. Returning to the step of FIG. 12D again (step 1208), this time, a tungsten film is formed, and unnecessary portions are removed by an appropriate etching process. As a result, the W pattern portion 1104 of FIG. 11 is also completed (FIG. 12E).

The zigzag structure of the platinum pattern 1102 has an advantage that it has high resistance to thermal mismatch and can measure temperature stably.
Further, a W (tank stainless) circuit is formed. FIG. 6 shows a circuit pattern formed on the fiber. Since the portion of Pt is deformed by temperature, the change in electric resistance is measured by a device connected to W. This thermometer structure is characterized by having high alignment accuracy because the (1) and (2) structures are at the top.
[Application Example 2 ... Micro Inductor]

Efforts to manufacture microinductors using MEMS technology have been made so far, but their application fields are extremely limited because of high manufacturing costs, difficult processing, fragile, low Q factor, etc. It had been. The most desirable form of microinductor is a solenoid as depicted in FIG. 13A. Non-patent document 3 mentioned above is a technique for irradiating a strong synchrotron light and directly cutting a microcoil from a substrate, but such a method is very costly and is used only in a very limited facility. It is not possible. Non-Patent Document 4 below describes a method of manufacturing a microcoil by an existing MEMS process, but it is necessary to perform deep etching and to perform alignment many times. However, there are drawbacks in that it takes cost and time, and the resulting coil is also fragile.
JW Kim, MH Jung, NK Park, EJ Yun, Microfabrication of solenoid-type RF SMD chip inductors with an Al2O3 core, Current Applied Physics, 8 (2008) 631-636.

  However, according to the manufacturing method described above, the microcoil can also be manufactured at low cost and with high accuracy. The pattern can be baked with only one exposure.

  FIG. 13A shows a microinductor 1300 in which a metal pattern 1304 is spirally formed around a ferromagnetic core 1302. It will be readily apparent to those skilled in the art from the foregoing description that a microsolenoid as in FIG. 13A can be manufactured using a MEMS exposure module 400 with an appropriate mask pattern. The microinductor 1320 in FIG. 13B is an example in which the core 1321 is formed of glass and the ferromagnetic material is formed as a thin film 1322 around the glass core 1321. The metal coil pattern 1324 is formed on the ferromagnetic thin film 1322. FIG. 13C shows an enlarged view of the layer structure of FIG. 13B. According to the simulation, the performance as an inductor does not change so much even if the core is not made of 100% magnetic material as shown in FIG. 13B. The microinductor 1320 in FIG. 13B uses a glass fiber instead of an expensive magnetic material for the core, so that the material cost can be greatly reduced.

  An example of a process for manufacturing the microinductor 1320 of FIG. 13B using the MEMS exposure module 400 will be described with reference to FIG.

  FIG. 14A shows a step of preparing the glass fiber 1321. 14B, a magnetic thin film 1322 is formed around the glass fiber 1321 using a technique such as electroplating. It should be noted that the same reference numerals are used for the same elements in FIGS. 14 and 13B. In the step of FIG. 14C, a photoresist layer 1330 is formed on the magnetic thin film 1322 using a technique such as spray coating.

  On the other hand, a MEMS exposure module 400 on which a coil pattern is formed is prepared separately. It is desirable that the mask pattern be formed so that all of the coil pattern can be transferred by one exposure. In order to form a continuous coil pattern, the module is preferably formed with a structure such as a mark that can be used for alignment. The fiber 1321 coated with a resist in the step of FIG. 14C is inserted into the prepared exposure module to perform exposure. When the exposed portion is pulled out from the module and developed, a resist pattern appears (FIG. 14D). On this pattern, a thin film 1324 ′ of a metal such as Au or Cu is formed by a technique such as sputtering or electroplating (FIG. 14E). Thereafter, by performing an appropriate etching process, a metal coil pattern 1324 can be obtained, and the microinductor 1320 is completed.

  Various other microdevices and microstructures can be created in the same process. For example, an electrode having a comb-shaped structure can be easily manufactured, which is an electrode structure that is very often used in the sensing field and the communication field.

  As described above, various aspects of the present invention have been described using examples. However, these examples and descriptions are not intended to limit the scope of the present invention, and are intended to contribute to an understanding of the present invention. Note that it was provided. The scope of the present invention is not limited to the configurations and manufacturing methods explicitly described in the specification, and includes combinations of various aspects of the present invention disclosed in the present specification. Among the present inventions, the configuration to be patented is specified in the appended claims, but the inventor has disclosed the present specification even if the present invention is not specified in the claims. I would like to remind you that you may claim the structure disclosed in the future in the future.

400 MEMS exposure module 402 Upper half portion of MEMS exposure module 404 Lower half portion 406 of MEMS exposure module Cylindrical cavity 408 Mask pattern 420 Fiber member 424 Photoresist layer 600 Component 601 Substrate 602 Semicircular groove 604 Metal layer 606 Photoresist Layer 608 Photomask 622, 624 Mark 902 Anti-adhesive substance film 904 Metal thin film 906 PDMS molding 907 Ridge 908 Photoresist layer 910 Photomask 914 Metal layer 916 Photoresist layer 1002 PDMS molding 1003 Ridge 1004 Stencil mask 1006 pattern 1008 metal layer 1010 photoresist layer 1100 micro thermometer circuit pattern 1102 platinum pattern portion 1104 tungsten pattern portion 1202 fiber 1206 gold Film 1300 microinductor 1302 Core 1304 metal pattern 1320 microinductor 1321 glass fiber 1322 magnetic thin film 1324 coil pattern 1330 photoresist layer

Claims (11)

An exposure module for transferring a pattern to a fiber-like elongated member by a photolithography technique,
An exposure module comprising: a translucent substrate provided with a cylindrical cavity having an inlet and an outlet; and a light shielding pattern provided on a wall surface of the cylindrical cavity.   Formed in the vicinity of the inlet and outlet of the cylindrical cavity, and a member supporting portion that slidably supports a member to be exposed with or without a lubricating liquid, and provided in a portion deeper than the member supporting portion, The exposure module according to claim 1, further comprising an exposure portion having a cylinder diameter larger than that of the member support portion, wherein the light shielding pattern is provided on a cave wall surface of the exposure portion.   The exposure module according to claim 2, wherein a cavity wall surface of the cavity in the member support portion is covered with a light shielding material.   4. The exposure module according to claim 2, wherein the member support portion is formed of a light-transmitting material different from a material of the exposure portion.   The exposure module according to claim 1, wherein the exposure module is manufactured by being divided into a plurality of parts divided by a plane passing through a central axis of the cylindrical cavity. A method for manufacturing at least one of the plurality of parts constituting the exposure module according to claim 5,
Forming a groove on the translucent substrate, the groove surface forming part of the cylindrical surface;
Forming a metal film on the groove surface, and further applying a photoresist on the metal film;
Irradiating the photoresist with light through a mask and developing it to transfer a pattern to the photoresist; and
A step of removing unnecessary photoresist and metal film by etching;
A method comprising: A method for manufacturing at least one of the plurality of parts constituting the exposure module according to claim 5,
Forming a groove on the translucent substrate, the groove surface forming part of the cylindrical surface;
Forming a film of an antiadhesive substance on the groove surface, forming a metal film on the antiadhesive substance film, and further forming an adhesive substance film on the metal film;
Laminating a translucent resin on the film of the adhesive substance;
Curing the resin and peeling the resin from the translucent substrate together with the metal film;
For the peeled resin, a photoresist is applied from above the metal film so that the ridge formed corresponding to the groove of the translucent substrate is covered, and the metal film is formed into a pattern by photoetching. Forming, and
The anti-adhesive substance is removed from the light-transmitting substrate from which the resin has been peeled off, and a second metal film is formed so as to cover the groove surface. Further, a photo film is formed on the second metal film. Forming a layer of resist;
Overlaying the resin on which the pattern has been formed on the translucent substrate so that the ridges fit again in the grooves;
Transferring the pattern on the resin to the second metal film by performing photo-etching using the pattern on the resin as a mask;
A method comprising: A method for manufacturing at least one of the plurality of parts constituting the exposure module according to claim 5,
Forming a groove on the translucent substrate, the groove surface forming part of the cylindrical surface;
Laminating a translucent resin on the groove, and peeling after curing;
For the peeled resin, forming a metal film so as to cover the ridge formed corresponding to the groove of the translucent substrate, and forming the metal film in a pattern;
Forming a second metal film on the translucent substrate from which the resin has been peeled so as to cover the groove surface, and further forming a photoresist layer on the second metal film;
Overlaying the resin on which the pattern has been formed on the translucent substrate so that the ridges fit again in the grooves;
Transferring the pattern on the resin to the second metal film by performing photo-etching using the pattern on the resin as a mask;
A method comprising:   The method according to claim 8, wherein the step of forming the pattern on the metal film on the resin is performed using soft lithography.   The method according to claim 8, wherein the step of forming the pattern on the metal film on the resin is performed using stencil lithography.   A method for manufacturing a fiber having a fine structure, wherein the fine structure is formed based on a photolithography method using the exposure module according to claim 1 as a mask.