JP5172400B2 - Manufacturing method of fine structure - Google Patents

Description

The present invention relates to a method of manufacturing a fine structure formed on a substrate in a state where a fine structure including a movable part that constitutes a MEMS or the like is sealed.

  2. Description of the Related Art In recent years, development of a micromachine called MEMS (Micro Electro Mechanical System) based on a manufacturing technology of a semiconductor integrated circuit that forms and processes a thin film on a wafer such as a semiconductor substrate has been actively performed. For example, research and development of an RF-MEMS switch and a MEMS microphone having a movable structure are underway. In these MEMS, fine structures having a movable structure are collectively manufactured at a wafer level.

  In order for such a MEMS to maintain desired characteristics, a protective structure that prevents the entry of foreign matter from the outside around the movable structure and a hollow structure in which the movable structure does not contact the protective structure are required. In the production of this hollow structure, first, a sacrificial film is formed in a region to be a hollow structure, and a protective structure having an opening through which a part of the sacrificial film is exposed to the outside is formed on the sacrificial film. Next, by removing the sacrificial film through the opening of the protective structure, a hollow structure having a space in the region where the sacrificial film was formed can be obtained (see Patent Document 1).

  An example of a method for manufacturing the hollow structure described above will be briefly described with reference to the process diagrams of FIGS. 10 (a) to 10 (d). 10A to 10D schematically show cross sections. First, as shown in FIG. 10A, a recess region is formed on a semiconductor substrate 501, and silicon oxide is deposited by plasma CVD or the like to form an insulating film 503. Next, a sacrificial layer 504 that fills the recessed region is formed by applying an organic resin and performing predetermined annealing.

  Next, as shown in FIG. 10B, a plurality of metal structures 506 that are movable structures are formed on the sacrificial layer 504, and also serve as support portions that surround the periphery of these metal structures 506. The metal structure 507 is formed. The metal structures 506 are densely arranged at intervals of several μm, and the metal structures 507 are roughly arranged at intervals of several hundred μm.

  Next, an organic resin is applied so as to embed the metal structure 506 and the metal structure 507, heat treatment is performed under predetermined conditions, and processing is performed using a photolithography technique, as illustrated in FIG. The sacrificial layer 511 is formed in a state where the metal structure 507 is embedded and the upper portion of the metal structure 507 is open.

  Next, a ceiling 516 having an opening 516a is formed on the metal structure 507 and the sacrificial layer 511, and oxygen plasma or ozone is applied through the opening 516a, whereby the sacrificial layer 511 and the sacrificial layer are formed. 504 is ashed and removed. Accordingly, as shown in FIG. 10D, the ceiling 516 is supported by the metal structure 507, and is movable in a region (hollow structure) surrounded by the metal structure 507 and the ceiling 516. A state is obtained in which the movable part composed of the metal structure 506 is arranged.

JP 2006-196654 A K. Machida, et al., "Novel global planerization technology dielectrics using spin on glass film transfer and hot pressing", J. Vac. Sci. Technol. B, Vol. 16, No. 3, pp.1093-1097, 1998 .

  By the way, as described above, the sacrificial layer that is removed to form the hollow structure is made of an organic resin or the like because it can be easily removed. It is formed by coating such as spin coating. In order to obtain a sacrificial layer, the film is formed to a thickness of several μm to several tens of μm. In order to obtain such a thick film, it is generally used with a high viscosity. For this reason, the organic resin is difficult to enter between the minute gaps.

  For this reason, when forming the sacrificial layer 511 which is an organic resin, for example, as shown in FIG. 11A, when the bubbles 509a are formed between the metal structures 506 arranged closely with a small interval. Occurs. When the bubble 509a is formed in this way, as shown in FIG. 11B, the metal structure 506 may be deformed or destroyed due to expansion by the heat treatment to become the bubble 509b.

  Further, as shown in FIG. 11C, a gap 509c where the resin as the sacrificial layer 511 does not enter may be formed. When the gap 509c is formed in this way, when the ceiling 516 is formed, the material constituting the ceiling 516 enters the gap 509c, and the ceiling 516 is formed as shown in FIG. An abnormal structure 509d is formed between the structures 506. When the abnormal structure 509d is formed in this way, the movement of the metal structure 506 is inhibited.

  Further, since the interval between the plurality of metal structures 506 is narrow, for example, when the ratio of the height of the metal structure 506 to the interval is increased, the sacrificial layer 511 between them cannot be completely removed, and FIG. As shown in FIG. 5, the organic resin residue 509e may be formed. If the organic resin residue 509e is thus formed, the movement of the metal structure 506 is hindered as described above.

  As described above, when a hollow structure is formed using a sacrificial layer of an organic resin, if a plurality of structures arranged at fine intervals are arranged inside the hollow structure, the structure operates. There is a problem that it is not easy to form in a possible state.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to make it possible to easily form a structure having a fine interval in a hollow structure portion.

  The method for manufacturing a fine structure according to the present invention includes a first step in which a structure having a fine gap is formed on a substrate, and a first resin layer so as to embed the structure on the substrate. The second step in which the first resin layer is formed, the third step in which the first resin layer in the gap region is removed, and the second resin layer is formed on the first resin layer by transfer. A fourth step in which the ceiling structure is formed on the second resin layer, a fifth step in which the ceiling structure is formed on the second resin layer, and the ceiling structure is on the substrate by removing the first resin layer and the second resin layer. And at least a sixth step in which the structure is placed between the ceiling structure and the substrate. In the sixth step, when the first resin layer and the second resin layer are removed, a space is already formed in the gap portion of the structure.

  In the fine structure manufacturing method, in the first step, the support structure is formed together with the structure on the substrate, and in the second step, an opening is provided to expose the upper surface of the support structure. In the third step, the first resin layer is formed, and in the third step, the second resin layer is formed with an opening through which the upper surface of the support structure is exposed. In the fourth step, on the support structure. It is assumed that the ceiling structure is formed in a connected state, and in the fifth step, the ceiling structure is in a state of being supported by the support structure.

  In the first step, a frame-like support structure surrounding the structure is formed, and in the fourth step, the ceiling structure is formed with a plurality of through holes. Then, the first resin layer and the second resin layer are removed through the through hole. Further, the structure body and the support structure body may be formed from a metal formed by plating. In addition, the first resin layer is made of a resin having photosensitivity, and in the third step, the first resin layer in the gap region may be removed by photolithography. The second resin layer can be formed by the STP method.

  As described above, in the present invention, after the first resin layer is formed so as to embed the structure on the substrate, first, the first resin layer in the region of the gap is removed, and The second resin layer is formed on the first resin layer by transfer, and then the ceiling structure is formed on the second resin layer. Thereafter, the first resin layer and the second resin layer are formed. Was to be removed. Therefore, according to the present invention, when the first resin layer and the second resin layer are removed, since a space is already formed in the gap portion of the structure, the structure having a fine interval An excellent effect that the body can be easily formed in the hollow structure portion is obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Embodiment 1]
First, the manufacturing method of the fine structure according to the first embodiment of the present invention will be described with reference to FIGS. 1 (a) to 4 (q). FIG. 1A to FIG. 4Q are process diagrams for explaining the manufacturing method, and schematically show the state (cross section) of the microstructure in each process except for some drawings. ing. In addition, FIGS. 1A to 4Q show a partial region that is a minimum unit portion (element portion) of the fine structure, and a plurality of components having the same configuration are also shown in a region that is not illustrated. The microstructure is formed.

  First, as shown in FIG. 1A, for example, a recess 102 is formed on a substrate 101 made of single crystal silicon having a predetermined conductivity type. A resist pattern having an opening in a region that becomes the recess 102 is formed by a known photolithography technique, and the surface of the substrate 101 is etched by well-known wet etching using the resist pattern as a mask, so that the depth is about 3 μm. The recess 102 can be formed.

  Further, an insulating layer 103 made of, for example, a silicon oxide film is formed on the surface of the substrate 101 where the recess 102 is formed. For example, the insulating layer 103 can be formed by depositing silicon oxide with a thickness of about 1 μm by a known plasma CVD method. Note that the substrate 101 may include a semiconductor integrated circuit including a plurality of transistors, resistors, capacitors, wirings, and the like. For example, a contact hole for electrical connection with the wiring of the integrated circuit is insulated. It may be formed at a predetermined location of the layer 103.

  Next, as shown in FIG. 1B, the organic resin layer 104 is formed so that the recess 102 on the insulating layer 103 is filled. For example, an organic resin composed of positive photosensitive polyimide is applied to form a coating film, and an area other than the concave portion 102 of the coating film is irradiated (exposed) with ultraviolet light and developed. By removing the coating film in the region, a resin layer filling the recess 102 can be formed. Thereafter, the organic resin layer 104 is formed by heating and curing under a heating condition of 310 ° C./30 minutes.

  Next, as illustrated in FIG. 1C, the first seed layer 105 is formed on the organic resin layer 104 and the insulating layer 103. The first seed layer 105 may be formed by first depositing titanium by, for example, sputtering or vapor deposition, and depositing gold thereon. The thickness of titanium may be about 0.1 μm, and the thickness of gold may be about 0.1 μm.

  Next, as shown in FIG. 1D, on the first seed layer 105, a first metal pattern 107a that becomes a part of a support frame (support structure) for forming a hollow structure, a fine structure The second metal pattern 106a and the third metal pattern 110a serving as a support portion for supporting the fine structure are formed. The formation of these metal patterns will be briefly described. First, a photosensitive resist material is applied on the first seed layer 105 to form a photosensitive resist film, and exposure is performed using a mask having a desired pattern. By doing so, it is set as the state by which the resist pattern provided with the opening part in the desired location was formed. The film thickness of the photosensitive resist (resist pattern) may be about 15 μm.

  Next, a gold pattern is formed by plating (electrolytic plating) on the first seed layer 105 exposed at the opening of the resist pattern, and then the resist pattern is removed. To do. The plating film may be formed to a thickness of about 10 μm. As a result, a state in which the first metal pattern 107a, the second metal pattern 106a, and the third metal pattern 110a are formed on the first seed layer 105 is obtained.

  Next, the first seed layer 105 is etched away using the first metal pattern 103a, the second metal pattern 103b, and the third metal pattern 103c as a mask, and the first seed layer 105 becomes the first metal pattern 103a, the second metal pattern. 103b and the third metal pattern 103c are electrically separated from each other. For example, gold over the first seed layer 105 may be etched using aqua regia. Further, wet etching with an etching solution composed of iodine, ammonium iodide, water, and ethanol may be used. The titanium under the first seed layer 105 exposed by this etching may be wet-etched with a hydrogen fluoride aqueous solution.

  As described above, as shown in FIGS. 1 (f) and 1 (e), the support frame 107 for forming the hollow structure, the fine structure 106, and the support portion 110 for supporting the fine structure 106 are provided. It is assumed that it is formed. FIG. 1E is a plan view, and a cross section of the ff line is shown in FIG. The fine structure 106 is a so-called line and space pattern formed to have a width in a plan view of about 3 μm and a gap 108 having a size of about 3 μm. The fine structure 106 is formed with a height of about 10 μm. The fine structure 106 may be a line and space pattern having a height of 10 to 20 μm and a width and interval of about 3 to 5 μm. Note that the fine structure 106 is connected to the support portion 110 by a beam 109. Moreover, the support part 110 is formed in a rectangular frame shape in plan view, and includes an area of 500 μm × 800 μm inside and has a width of about 100 μm. The inner side surface of the support part 110 is separated from the support part 110 by about 50 to 100 μm, for example.

  Next, a photosensitive resin layer is formed on the insulating layer 103 so as to cover the microstructure 106, the support frame 107, the beam 109, the support portion 110, and the like that are formed separately. As the photosensitive resin layer, for example, a base resin such as polyamide, polyamic acid, polybenzoxazole (or a precursor thereof) added with a positive photosensitive agent may be used. The photosensitive resin layer can be formed by spin coating these materials. As a positive photosensitive resin based on polybenzoxazole, for example, “CRC8300” manufactured by Sumitomo Bakelite Co., Ltd. is available.

Next, the photosensitive resin layer in the upper part of the support frame 107 and the area of the fine structure 106 is removed, and the upper surface of the support frame 107 is exposed and the area of the fine structure 106 is exposed as shown in FIG. It is assumed that the sacrificial layer (first resin layer) 111 from which is removed is formed on the insulating layer 103. The photosensitive resin layer at least in the region of the gap 108 of the microstructure 106 may be removed. By patterning the photosensitive resin layer having photosensitivity by a known lithography technique, the region of the fine structure 106 can be removed and the upper surface of the support frame 107 can be exposed. When patterning the photosensitive resin layer, pre-baking at 120 ° C. is performed for about 1 minute as a pretreatment. In addition, after patterning, a heat treatment at about 310 ° C. is performed for about 30 minutes so that the resin film is thermally cured.

  Here, the sacrificial layer 111 may be formed, for example, in a gray portion shown in the plan view of FIG. In this manner, if the sacrificial layer 111 is formed by removing the region of the fine structure 106 by patterning, defects such as bubbles are formed between the fine structures 106 when the resin layer is formed by applying resin. However, it will be removed when the sacrificial layer 111 is formed. For this reason, the conventional problem in the subsequent process can be prevented from occurring. In the above-described patterning, the resin is removed by development before thermosetting, so that the resin between them can be more easily removed even if the interval between the fine structures 106 is narrow.

Next, by a known STP method (see Non-Patent Document 1), as shown in FIG. 2I, the region of the fine structure 106 is covered on the support frame 107 and the sacrificial layer 111. The photosensitive resin layer (second resin layer) 112 is formed. The formation of the photosensitive resin layer 112 by the STP method will be briefly described. First, a sheet film on which a photosensitive resin film made of a photosensitive organic resin material and having a thickness of about 5 μm is previously formed is prepared. Next, the photosensitive resin film forming surface of the sheet film is thermocompression bonded to the upper surfaces of the support frame 107 and the sacrificial layer 111. The thermocompression bonding may be performed by, for example, applying a load of 10 kgf to a circular range of 6 inches in diameter for about 1 minute in a processing chamber depressurized to about 20 Pa, at a temperature condition of 120 ° C. Next, the sheet film is peeled off from the photosensitive resin film, and heat treatment is performed on the photosensitive resin film at 100 ° C. for about 1 hour. As a result, a state in which the photosensitive resin layer 112 is stuck on the support frame 107 and the sacrificial layer 111 is obtained.

  In the STP method for forming a film in this manner, unlike the coating method, the resin does not flow into the region of the microstructure 106 where the sacrificial layer 111 is not formed, and a space is formed in the region of the microstructure 106. The photosensitive resin layer 112 can be formed while maintaining the state. Further, as described above, when the photosensitive resin layer 112 is bonded in a reduced pressure environment, the gas molecules sealed by the formed photosensitive resin layer 112 are few in the space in the microstructure 106, and this continues thereafter. Heating in other steps can also prevent the sealed space from expanding and causing problems.

  After the photosensitive resin layer 112 is transferred by the STP method as described above, the photosensitive resin layer 112 is patterned by a well-known photolithography technique, and as shown in FIG. It is assumed that the opening 113 is exposed. In addition, the photosensitive resin layer 112 in which the opening 113 is formed is heated and cured under a condition of 310 ° C./30 minutes.

  Next, as shown in FIG. 2 (k), the second seed layer 114 is formed on the photosensitive resin layer 112 including the support 110 in the opening 113. The second seed layer 114 is the same as the first seed layer 105. For example, the second seed layer 114 may be formed by first depositing titanium by sputtering or vapor deposition, and then depositing gold thereon. The thickness of titanium may be about 0.1 μm, and the thickness of gold may be about 0.1 μm.

  Next, as shown in FIG. 2 (l), a plurality of resist patterns 115 are formed on the second seed layer 114 in the region inside the support frame 107, and the regions other than the resist pattern 115 are formed in the second seed layer. The upper surface of the layer 114 is exposed. The resist pattern 115 may be formed by a known photolithography technique.

  Next, as illustrated in FIG. 3M, the ceiling structure 116 is formed on the exposed second seed layer 114. For example, the ceiling structure 116 made of a gold plating film may be formed by forming a gold film by electrolytic plating. Thereafter, for example, by removing the resist pattern 115 by ashing using oxygen plasma, the ceiling structure 116 having a plurality of openings 116a is formed as shown in FIG. Become.

  Subsequently, the second seed layer 114 is removed by etching using the ceiling structure 116 as a mask pattern. This etching is the same as in the case of the first seed layer 105 described above. For example, the gold in the upper layer may be etched using aqua regia. Further, wet etching with an etching solution composed of iodine, ammonium iodide, water, and ethanol may be used. The underlying titanium exposed by this etching may be wet etched with an aqueous hydrogen fluoride solution. By this etching, the opening 116a penetrates and the photosensitive resin layer 112 is exposed at the bottom.

  Next, active oxygen such as oxygen plasma or ozone is removed by applying an ashing treatment to the photosensitive resin layer 112, the sacrificial layer 111, and the organic resin layer 104 through the opening 116a. As shown in (o), a space (hollow structure) is formed below the ceiling structure 116 in the region surrounded by the support frame 107. In other words, the ceiling structure 116 disposed away from the insulating layer 103 is supported and formed on the support frame 107. In the above-described removal of the photosensitive resin layer 112 and the sacrificial layer 111, since the resin to be removed does not exist in the minute gap 108 in the microstructure 106, the gap that has been a problem in the conventional technique is present. Resin residue at 108 does not occur.

  Further, since the fine structure 106 is formed in a state in which there is no resin residue and the gap 108 exists normally, the operation of the fine structure 106 is not hindered at all. For example, as shown in the plan view of FIG. 3 (p), the fine structure 106 operates on the recess 102 in the direction of the arrow indicated in the drawing, but there is no resin residue in the gap 108. This movement will not be hindered. After forming the hollow structure in this way, a sealing film 118 may be formed on the ceiling structure 116 so as to close the opening 116a as shown in FIG. 4 (q). For example, the sealing film 118 may be formed by transferring an organic resin film by the STP method. Further, the sealing film may be formed by a deposition method such as a CVD method.

  In the above description, the opening 116a is formed in the ceiling structure 116, and the sacrificial layer 111 is removed through the opening 116a. However, the present invention is not limited to this. For example, if the ceiling structure 116 is supported not by the support frame 107 but by a partially formed support column, an opening exists on the side, and the sacrificial layer 111 is removed from here. Is possible.

[Embodiment 2]
Next, the manufacturing method of the microstructure in Embodiment 2 of this invention is demonstrated using Fig.5 (a)-FIG.5 (c). 5A to 5C are process diagrams for explaining the manufacturing method, and schematically show the state (cross section) of the microstructure in each process. 5A to 5C show a partial region that is a portion (element portion) of the minimum unit of the fine structure, and a plurality of the same configuration is provided in a region that is not illustrated. The microstructure is formed.

  First, as shown in FIG. 5A, an insulating layer 202 made of, for example, a silicon oxide film is formed on a substrate 201 made of, for example, single crystal silicon having a predetermined conductivity type. For example, the insulating layer 202 can be formed by depositing silicon oxide with a thickness of about 1 μm by a known plasma CVD method. Note that the substrate 201 may include a semiconductor integrated circuit including a plurality of transistors, resistors, capacitors, wirings, and the like. For example, a contact hole for electrical connection with the wiring of the integrated circuit is insulated. The layer 202 may be formed at a predetermined location.

  Next, a seed layer 203 is formed on the insulating layer 202, a predetermined resist pattern is formed by a known photolithography technique, and then the seed layer 203 exposed at the opening of the resist pattern is formed by an electrolytic plating method. The metal structure 204 and the metal structure 209 are formed by plating gold having a thickness of about 3 μm. Thereafter, as described above, the seed layer 203 is removed using the formed metal structure 204 and metal structure 209 as a mask. Here, a support frame is formed on the metal structure 204, and a support portion for supporting the fine structure is formed on the metal structure 209.

  Next, the resin layer 205 is formed on the insulating layer 202 so that the space between the metal structure 204 and the metal structure 209 is filled. For example, an organic resin having positive photosensitivity is applied, and a predetermined pattern image is exposed and developed so that openings are formed in the upper portions of the metal structure 204 and the metal structure 209. Thereafter, 310 ° C. The resin layer 205 can be formed by curing under the condition of / 30 minutes.

  As described above, on the insulating layer 202, the metal structure 204, the metal structure 209, and the resin layer 205 are formed so as to flatten them, and then, similarly to the first embodiment described above, First, the support frame 207, the fine structure 206, and the support portion 210 for supporting the fine structure 206 are formed together with the sacrificial layer, and the sacrificial layer of the fine structure 206 is removed. .

  Next, a resin film is formed on these by a STP method, and a ceiling structure 216 provided with an opening 216a is formed thereon. Thereafter, a sacrificial layer and an STP method are used. The formed resin layer is removed. As a result, the ceiling structure 216 is supported and formed on the support frame 207, and the fine structure 206 is formed on the support 110 in a space below the ceiling structure 216 in a region surrounded by the support frame 207. It comes to be formed in the state supported so that movement was possible. In the second embodiment, the microstructure 206 is formed on the insulating layer 202 by forming the support frame 207 and the support portion 210 on the metal structure 204 and the metal structure 209. As in the first embodiment described above, the fine structure 206 is movable.

[Embodiment 3]
Next, the manufacturing method of the fine structure in Embodiment 3 of this invention is demonstrated using Fig.6 (a)-FIG.7 (f). 6B to FIG. 6D and FIG. 7F are process diagrams for explaining the manufacturing method, and schematically show the state (cross section) of the microstructure in each process. Yes. Further, FIGS. 6A to 7F show a partial region which is a minimum unit portion (element portion) of the fine structure, and a plurality of components having the same configuration are provided in a region not shown. The microstructure is formed.

  In the third embodiment, as shown in the plan view of FIG. 6A, a case where a plurality of fine structures 306 and fine structures 316 are provided will be described. Other configurations are the same as those in the first embodiment.

  First, as described in the first embodiment, the recess 102 is formed on the substrate 101 made of single crystal silicon having a predetermined conductivity type, for example. Further, an insulating layer 103 made of, for example, a silicon oxide film is formed on the surface of the substrate 101 where the recess 102 is formed. Next, the organic resin layer 104 is formed.

  Next, the first seed layer 105 is formed on the organic resin layer 104 and the insulating layer 103, and the support frame 107 and the fine structure are formed by an electrolytic plating method using the first seed layer 105. 306, the microstructure 316, and the support 110 are formed. Next, a photosensitive resin layer is formed on the insulating layer 103 so as to cover the microstructure 306, the microstructure 316, the support frame 107, the support portion 110, and the like. Next, the photosensitive resin layer in the upper part of the support frame 107 and the regions of the microstructures 306 and 316 is removed, the upper surface of the support frame 107 is exposed, and the regions of the microstructures 306 and 316 are exposed. The sacrificial layer 111 from which is removed is formed on the insulating layer 103.

  Next, in the third embodiment, as shown in FIG. 6B, the regions of the fine structure 306 and the fine structure 316 are covered on the support frame 107 and the sacrificial layer 111 by the STP method. In this state, the insulating film 312 is formed. For example, a sheet film on which an SOG (Spin-On-Glass) film having a thickness of about 5 μm is previously formed is prepared. Next, the SOG film forming surface of the sheet film is thermocompression bonded to the upper surfaces of the support frame 107 and the sacrificial layer 111. By this thermocompression bonding, the SOG film is also in contact with the upper surfaces of the microstructure 306 and the microstructure 316. Thereafter, the sheet film is peeled off, and the SOG film formed on the support frame 107 and the sacrificial layer 111 is heated and cured under the condition of about 200 ° C. for about 30 minutes, so that the insulating film 312 is formed. .

  Next, as shown in FIG. 6C, a resist pattern 309 is formed on the insulating film 312 in a region extending over the microstructure 306 and the microstructure 316 by a known photolithography technique. . Next, the insulating film 312 is patterned by selective dry etching using the resist pattern 309 as a mask, and then the resist pattern 309 is removed. As a result, as shown in FIGS. 6D and 6E, a state in which the connecting portion 312a for connecting the microstructure 306 and the microstructure 316 is formed can be obtained.

  After the connection portion 312a is formed as described above, a photosensitive resin layer is first formed on the support frame 107, the sacrificial layer 111, and the connection portion 312a by the STP method, as in the first embodiment. In this state, an opening is formed on the support frame 107, and the second seed layer 114 is formed on the photosensitive resin layer including the support 110 in the opening. The ceiling structure 116 is formed on the second seed layer 114, and the second seed layer 114 is removed by etching using the ceiling structure 116 as a mask pattern so that the opening 116a penetrates.

  Next, active oxygen such as oxygen plasma or ozone is removed by applying an ashing treatment to the sacrificial layer 111 and the organic resin layer filling the recess 102 through the opening 116a. As shown in (f), it is assumed that a space (hollow structure) is formed under the ceiling structure 116 in a region surrounded by the support frame 107. In other words, the ceiling structure 116 disposed away from the insulating layer 103 is supported and formed on the support frame 107. In the above-described removal of the photosensitive resin layer 112 and the sacrificial layer 111, since the resin to be removed does not exist in the minute gap 108 in the microstructure 106, the gap that has been a problem in the conventional technique is present. Resin residue at 108 does not occur.

  Further, since the fine structure 106 is formed in a state in which there is no resin residue and the gap 108 exists normally, the operation of the fine structure 106 is not hindered at all. For example, as shown in the plan view of FIG. 3 (p), the fine structure 106 operates on the recess 102 in the direction of the arrow indicated in the drawing, but there is no resin residue in the gap 108. This movement will not be hindered.

  Further, the connecting portion 312a is not removed by the ashing process, and the fine structure 306 and the fine structure 316 are kept in a connected state. In this embodiment mode, the microstructure 306 and the microstructure 316 are connected by the connecting portion 312a made of an insulating material. Therefore, the microstructure 306 and the microstructure 316 that operate simultaneously are electrically separated. A state is obtained.

  As described above, according to the first to third embodiments, a fine structure having a fine gap can be stably hollow without being limited in its movement due to a sacrificial layer remaining in the gap. It becomes possible to form easily in the state accommodated in the inside.

  Further, the present invention can be applied not only to a fine structure that operates but also to a fixed structure having a fine gap, such as an inductor, as described above. For example, in the case of an inductor, if a sacrificial layer partially remains in the gap, a designed capacitance value cannot be obtained, which is a problem. On the other hand, by applying the manufacturing method of the present invention as described above, without causing problems such as the sacrificial layer remaining in the gap, in a state of being stably housed in the hollow structure, It can be formed easily.

  In the above description, the photosensitive resin layer having photosensitivity is used in order to remove the region of the gap of the fine structure of the resin layer serving as the sacrificial layer, but the present invention is not limited to this. For example, a resin layer is formed so as to embed the fine structure 106, a resist pattern having an opening in a gap portion of the fine structure is formed on the resin layer, and the resin layer is formed using the resist pattern as a mask. By selectively etching, the resin layer in the region of the gap of the fine structure may be removed. In this case, the resist pattern is removed after removing the resin layer in the gap portion of the fine structure.

  In the above description, a substrate made of a semiconductor such as silicon is used. However, the present invention is not limited to this, and a substrate such as quartz or glass may be used.

[Embodiment 4]
Next, a fourth embodiment will be described. First, as shown in the perspective view of FIG. 8A and the cross-sectional view of FIG. 8B, an opening 402 is formed in the substrate 401, and the substrate 401 is etched isotropically from the opening 402. Thus, the space 403 is formed inside the substrate 401, and the movable structure 404 is formed on the space 403.

  Next, as illustrated in FIG. 8C, the opening 402 is closed, and a sacrificial layer 405 having an opening in a predetermined region is formed on the substrate 401. For example, a sacrificial layer 405 may be formed by forming a photosensitive resin layer by the STP method and patterning the photosensitive resin layer by a known photolithography technique. According to the STP method, even on the substrate 401 having the opening 402, a photosensitive resin layer can be formed without allowing a resin material or the like to enter the opening 402 and the space 403.

  Next, as illustrated in FIG. 8D, a protective structure 406 including a plurality of openings 408 is formed on the sacrificial layer 405. Thereafter, the sacrificial layer 405 is removed through the opening 408 of the protective structure 406, so that the movable structure 404 is formed on the substrate 401 as shown in FIGS. 9 (e) and 9 (f). Moreover, the movable structure 404 is covered with the protective structure 406 to be protected.

It is process drawing for demonstrating the manufacturing method of the fine structure in Embodiment 1 of this invention. It is process drawing for demonstrating the manufacturing method of the fine structure in Embodiment 1 of this invention. It is process drawing for demonstrating the manufacturing method of the fine structure in Embodiment 1 of this invention. It is process drawing for demonstrating the manufacturing method of the fine structure in Embodiment 1 of this invention. It is process drawing for demonstrating the manufacturing method of the fine structure in Embodiment 2 of this invention. It is process drawing for demonstrating the manufacturing method of the fine structure in Embodiment 3 of this invention. It is process drawing for demonstrating the manufacturing method of the fine structure in Embodiment 3 of this invention. It is process drawing for demonstrating the manufacturing method of the fine structure in Embodiment 4 of this invention. It is process drawing for demonstrating the manufacturing method of the fine structure in Embodiment 4 of this invention. It is process drawing for demonstrating the manufacturing method of the existing fine structure. It is process drawing for demonstrating the problem in the manufacturing method of the existing fine structure.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 101 ... Substrate, 102 ... Recess, 103 ... Insulating layer, 104 ... Organic resin layer, 105 ... First seed layer, 106 ... Fine structure, 106a ... Second metal pattern, 107 ... Support frame, 107a ... First metal pattern , 108 ... gap, 109 ... beam, 110 ... support part, 110 a ... third metal pattern, 111 ... sacrificial layer, 112 ... photosensitive resin layer, 113 ... opening, 114 ... second seed layer, 115 ... resist pattern, 116: ceiling structure, 116a: opening, 118 ... sealing film.

Claims (6)

A first step in which a fine structure having a fine gap is formed on a substrate;
A second step in which a first resin layer is formed so as to embed the microstructure on the substrate;
A third step in which the first resin layer in a region of the gap is removed;
A fourth step of forming a second resin layer in a state where the region of the fine structure is covered by transfer onto the first resin layer;
A fifth step in which a ceiling structure is formed on the second resin layer;
The state in which the first resin layer and the second resin layer are removed and the ceiling structure is supported on the substrate so as to be spaced apart, and the fine structure is disposed between the ceiling structure and the substrate. A method for producing a fine structure, comprising at least a sixth step. In the manufacturing method of the fine structure according to claim 1,
In the first step, a support structure is formed on the substrate together with the microstructure.
In the second step, the first resin layer is formed with an opening through which the upper surface of the support structure is exposed,
In the third step, the second resin layer is formed with an opening through which the upper surface of the support structure is exposed,
In the fourth step, the ceiling structure is formed in a state of being connected on the support structure,
In the fifth step, the ceiling structure is in a state of being supported by the support structure. In the manufacturing method of the fine structure according to claim 2,
In the first step, the frame-shaped support structure surrounding the fine structure is formed,
In the fourth step, the ceiling structure is formed with a plurality of through holes,
In the fifth step, the first resin layer and the second resin layer are removed through the through hole. In the manufacturing method of the fine structure according to claim 2 or 3,
The fine structure and the support structure are formed from a metal formed by plating. In the manufacturing method of the microstructure according to any one of claims 1 to 4,
The first resin layer is made of a resin having photosensitivity,
In the third step, the first resin layer in a region of the gap is removed by a photolithography technique. In the manufacturing method of the fine structure according to any one of claims 1 to 5,
The method of manufacturing a microstructure, wherein the second resin layer is formed by an STP method.

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