JP2010207987A - Method of manufacturing micromachine device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a micromachine device having high reliability by a simple manufacturing process at a low cost. <P>SOLUTION: This method of manufacturing the micromachine device 1 includes: a process for forming a signal wire 15, a driving electrode 14 and a lower part electrode 13 on an insulation board 10; a process for forming insulation films 20 on the signal wire 15 and the driving electrode 14; a process for forming a sacrifice layer 18a made of an inorganic material on the insulation board 10; a process for forming a bridge supporting part 16a and a contact part 16c on the sacrifice layer 18a; a process for forming an insulation body connection joint 19 using an organic material for connecting the bridge supporting part 16a and the contact part 16c; and a process for removing the sacrifice layer 18a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a micromachine device such as packaging of micro-electromechanical components.

  As a micromachine device, as shown in FIG. 6, a micromachine device (microelectromechanical component) 101 in which a hollow structure MEMS element 106 as a micromachine with operation is mounted on a substrate 102 is known (for example, Patent Documents). 1 or 2) A micro-machine device (MEMS: Micro-Electro-Mechanical-Systems) 101 includes a substrate 102, a MEMS element 106, a signal line 105, and a drive electrode 103. A signal line 105 is formed of Au or the like immediately below the MEMS element 106.

  In the MEMS element 106, a bridge support portion 106a and a contact portion 106b are connected by an insulator joint 106c to prevent noise propagation, and are configured in a beam structure with both ends. The contact portion 106b has a gap of about several μm from the signal line 105. The bridge support portion 106a and the contact portion 106b are made of a conductive material such as aluminum or gold.

  The MEMS element 106 approaches the signal line 105 by applying a driving force such as an electrostatic force. When the driving force is unloaded, the MEMS element 106 returns to the position having the gap with the signal line 105 again due to its own spring characteristics. Thus, by changing the gap between the MEMS element 106 and the signal line 105, functions such as variable capacitance and switching are achieved.

  In the manufacturing process of such a micromachine device, first, as shown in FIG. 7A, a drive electrode 103 and a signal line 105 are formed on a substrate 102. Next, as shown in FIG. 7B, an insulating film 104 is formed on the drive electrode 103. Next, as shown in FIG. 7C, in order to provide a gap between the micromachine and the substrate, a sacrificial layer 108 is formed on the substrate 102 by using, for example, a polyimide organic film that is completely removed in a later step. Next, as shown in FIG. 7D, an insulating film 109 made of, for example, SiO 2 is formed around the signal line 105 on the sacrificial layer 108. Subsequently, as shown in FIG. 7E, a bridge support portion 106a is formed on the sacrificial layer 108 and the insulating film 109 using a conductive material such as aluminum or gold. Thereafter, as shown in FIG. 7F, a contact portion 106b is formed of a conductive material such as aluminum or gold in a portion located almost right above the signal line 105 in the substantially central portion of the bridge support portion 106a. Next, as shown in FIG. 7G, an insulating portion 106c made of an organic film of polyimide, for example, is formed at a connecting portion between the bridge support portion 106a and the contact portion 106b. Next, as shown in FIG. 7H, an insulating film 110 made of SiO 2 or the like is formed on the insulating portion 106c. Thereafter, as shown in FIG. 7I, the sacrificial layer 108 is removed by dry etching. Then, as shown in FIG. 7J, the inorganic insulating film 109 in the lower part of the contact portion 106b and the inorganic insulating film 110 in the upper part are removed by dry etching, and the micromachine device is completed.

JP2009-9785 U.S. Patent No. 70008812B1

  However, the above technique has the following problems. That is, in the manufacturing method of a structure in which a micromachine is configured by connecting with an insulating joint made of an organic material, if the same organic material is used for the sacrificial layer used when forming the hollow structure of the micromachine, the sacrificial layer can be removed. In the process, it is necessary to add a process for protecting the insulating joint from being etched and a process for removing the protective layer after removing the sacrificial layer, which complicates the manufacturing method.

  The present invention has been made in view of the above-described problems, and it is an object of the present invention to simplify a manufacturing process and provide a low-cost micromachine device.

  A method of manufacturing a micromachine device according to one aspect of the present invention includes a step of forming a signal line, a drive electrode, and a lower electrode on an insulating substrate, a step of forming an insulating film on the signal line and the drive electrode, A step of forming a sacrificial layer made of an inorganic material on an insulating substrate; a step of forming a bridge support portion and a contact portion on the sacrificial layer; and an organic material for connecting the bridge support portion and the contact portion. And a step of removing the sacrificial layer.

  According to the method of manufacturing a micromachine device according to the present invention, a highly reliable micromachine device can be manufactured at a low cost by a simple manufacturing process.

1 is a cross-sectional view schematically showing a micromachine device according to a first embodiment of the present invention. FIG. 2 is a plan view schematically showing the micromachine device. Sectional drawing which shows the manufacturing process of the micromachine apparatus typically. Sectional drawing which shows the manufacturing process of the micromachine apparatus typically. Sectional drawing which shows the manufacturing process of the micromachine apparatus typically. Sectional drawing which shows the manufacturing process of the micromachine apparatus typically. Sectional drawing which shows the manufacturing process of the micromachine apparatus typically. Sectional drawing which shows typically the micromachine apparatus concerning 2nd embodiment of this invention. Sectional drawing which shows the micromachine apparatus manufacturing process typically. Sectional drawing which shows the micromachine apparatus manufacturing process typically. Sectional drawing which shows the micromachine apparatus manufacturing process typically. Sectional drawing which shows the micromachine apparatus manufacturing process typically. Sectional drawing which shows the micromachine apparatus manufacturing process typically. Sectional drawing which shows the micromachine apparatus manufacturing process typically. Sectional drawing which shows the micromachine apparatus manufacturing process typically. Sectional drawing which shows the micromachine apparatus manufacturing process typically. Sectional drawing which shows an example of a microphone machine apparatus typically. Explanatory drawing which shows typically an example of the manufacturing process of a microphone machine apparatus. Explanatory drawing which shows typically an example of the manufacturing process of a microphone machine apparatus. Explanatory drawing which shows typically an example of the manufacturing process of a microphone machine apparatus. Explanatory drawing which shows typically an example of the manufacturing process of a microphone machine apparatus. Explanatory drawing which shows typically an example of the manufacturing process of a microphone machine apparatus. Explanatory drawing which shows typically an example of the manufacturing process of a microphone machine apparatus. Explanatory drawing which shows typically an example of the manufacturing process of a microphone machine apparatus. Explanatory drawing which shows typically an example of the manufacturing process of a microphone machine apparatus. Explanatory drawing which shows typically an example of the manufacturing process of a microphone machine apparatus. Explanatory drawing which shows typically an example of the manufacturing process of a microphone machine apparatus.

[First embodiment]
A micromachine device 1 according to a first embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In each figure, the configuration is schematically shown by appropriately enlarging, reducing, or omitting it. In the figure, X, Y, and Z indicate three directions orthogonal to each other.

  A micromachine device 1 illustrated in FIG. 1 is, for example, a microelectromechanical component (MEMS), and includes a base substrate 11 and an insulating layer 12 that constitute the substrate 10, a lower electrode 13 provided on the substrate 10, a drive electrode 14, and A signal line 15 and a MEMS element 16 as a micromachine formed across the signal line 15 on the substrate 10 are provided.

  The base substrate 11 is a silicon (Si) substrate, a glass substrate, or a sapphire substrate, and is formed in a predetermined plate shape.

  The insulating layer 12 is formed on the base substrate 11 and is made of, for example, a silicon oxide film (SiO 2). The base substrate 11 and the insulating layer 12 constitute the substrate 10.

  As shown in FIG. 2, the lower electrode 13 connected to the MEMS element 16, the signal line 15, and the drive electrode 14 are formed on the substrate 10.

  The lower electrode 13 is connected to the lower end of the MEMS element 16. The signal line 15 is made of Au (gold) or the like and extends in the Y direction directly below the MEMS element 16. The drive electrode 14 is formed of, for example, Au or Al, and is provided to reach both sides in the X direction of the signal line 15 immediately below the MEMS element 16, and has a function of driving the MEMS element 16.

  The MEMS element 16 is a movable mechanism portion of a micromachine, and is configured in a doubly supported beam shape straddling the signal line 15 as shown in FIG. The MEMS element 16 includes a contact portion 16c located at the center and a bridge support portion 16a that supports both sides of the contact portion 16c via an insulating connection joint 19 to form a beam shape. The support portion 16a and the contact portion 16c as a plurality of members are made of TiN, Al or the like having high spring characteristics.

  The contact portion 16 c is supported on the substrate 10 via a gap by being connected to the bridge support portion 16 a via the insulating connection joint 19. The contact portion 16c is spaced apart from the signal line 15 with a gap of about several μm. That is, the signal line 15 is arranged on the surface of the insulating layer 12 immediately below the contact portion 16c. The contact portion 16c is displaced so as to be in contact with and separated from the signal line 15 by the action of an electric field.

  The bridge support portions 16a arranged on both sides of the contact portion 16c are each configured in a cantilever shape. The lower end of the bridge support portion 16 a is connected to the lower electrode 13. The contact portion 16c is supported on the substrate 10 with a gap by the bridge support portion 16a. For example, as will be described later, a hollow structure can be ensured through a manufacturing process so that the MEMS element 16 is formed on the sacrificial layer 18a having a thickness of about several μm.

The insulating connection joint 19 is made of an organic material such as polyimide, epoxy, or benzocyclobutene, and functions to prevent noise propagation.

  For example, when a driving force such as an electrostatic force is applied from the driving electrode 14 as an action of an electric field, the MEMS element 16 is elastically deformed toward the signal line 15 and approaches. When the driving force is removed, the original position is restored again due to its own spring characteristics. That is, the MEMS element 16 is deformed so that the distance between the MEMS element 16 and the signal line 15 is changed according to the driving force when a driving force such as electrostatic force is applied and unloaded. Change the electrical characteristics of 1. Depending on how this is changed, it performs functions such as variable capacitance and switching.

Next, a method for manufacturing the micromachine device 1 according to the present invention will be described with reference to FIGS. 3A to 3E.

  First, as shown in FIG. 3A, the insulating layer 12 is formed on the base substrate 11, and the lower electrode 13, the drive electrode 14, and the signal line 15 are formed on the insulating layer 12. Later, an insulating film 20 is formed on the drive electrode 14 and the signal line 15.

  Next, as shown in FIG. 3B, a sacrificial layer 18a is formed with a thin film having a thickness of about several μm, for example, by PE-CVD using an inorganic film such as SiO 2, Si 3 N 4, amorphous silicon, or polysilicon. Then, as shown in FIG. 3C, the MEMS element 16 which is a movable beam using a metal material having high spring properties such as aluminum and TiN is formed on the sacrificial layer 18a as a thin film having a thickness of about several μm.

  Thereafter, as shown in FIG. 3D, an organic material such as polyimide, epoxy, or benzocyclobutene is applied by spin coating or the like, and exposure and development are performed. Insulation between the bridge support portion 16a and the contact portion 16c is performed. A connecting joint 19 is formed.

  Thereafter, as shown in FIG. 3E, the sacrifice layer 18a is removed by dry etching. As an etching material, HF mixed gas, XeF2 gas, CF4 gas, or the like is used.

During dry etching, the sacrificial layer 18a, which is an inorganic material, is selectively etched, and the MEMS element 16 using a metal material and the insulating connection joint 19 using an organic material can be prevented from being etched. .

  A plurality of through holes 16b are formed in the bridge support portion 16a. The through-hole 16b makes it possible to completely remove the sacrificial layer 18a below the bridge support portion in a short time during dry etching.

  As described above, the MEMS element 16 is formed in a predetermined both-end supported beam shape having a beam portion that is separated from the signal line 15.

  According to the present embodiment having such a configuration, the manufacturing process can be simplified by changing the materials of the MEMS element 16, the insulating connection joint 19, and the sacrificial layer 18a, and a low-cost micromachine device is provided. Can do.

[Second Embodiment]
4 and 5 show a second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same structure as 1st embodiment. In the second embodiment, the process of forming the hollow structure using the sacrificial layer is expanded to hermetically seal the MEMS element.

  As shown in FIG. 4, in the micromachine device 1, the MEMS element 16 is hermetically sealed by a sealing body constituted by a first sealing film 21 and a second sealing film 22.

  Hereinafter, the manufacturing method of the micromachine device of the second embodiment will be described with reference to FIG. In addition, since each thin film material, its thickness, formation method, etc. are the same as 1st embodiment, description is abbreviate | omitted.

  First, as shown in FIG. 5A, a lower electrode 13, a drive electrode 14, a signal line 15 and the like are formed on an insulating substrate 11. Next, the insulating film 20 is formed on the drive electrode 14 and the signal line 15. Then, a sacrificial layer 18a is formed as shown in FIG. 5B. Subsequently, as shown in FIG. 5C, a bridge support portion 16a and a contact portion 16c are formed on the sacrificial layer 18a. Next, as shown in FIG. 5D, an insulating connection joint 19 made of, for example, a polyimide organic film is formed between the bridge support portion 16a and the contact portion 16c.

  Next, as shown in FIG. 5E, the sacrificial layer 18b is formed on the MEMS element 16 by using an inorganic film such as SiO2, Si3N4, amorphous silicon, or polysilicon so as to cover the MEMS element. A thin film is formed, for example, by PE-CVD. At this time, the sacrificial layer 18a and the sacrificial layer 18b are preferably made of the same material, but are not particularly limited.

  Next, as shown in FIG. 5F, a first sealing film 21 is formed on the sacrificial layer 18b. The first sealing film 21 is applied by spin coating or the like with an organic material such as polyimide, epoxy, or benzocyclobutene in a normal pressure state, for example, under a pressure of 0.1 MPa (atmospheric pressure). Then, a film is formed to a predetermined thickness. The thickness of the first sealing film 21 is, for example, about 1 μm.

  At this time, the first sealing film 21 is an opening for introducing a sacrificial layer removal fluid when removing the sacrificial layers 18a and 18b around the MEMS element 16, and is closed after the sacrificial layer is removed. A plurality of opening-shaped portions 21a are formed.

  The first sealing film 21 is bonded to the upper surface of the surrounding insulating layer 12 at a position where the edge portion is separated from the MEMS element 16, and the central portion is located above the MEMS element 16 through the hollow portion 17. That is, the first sealing film 21 is separated from the MEMS element 16. The opening shape portions 21a are two-dimensionally arranged in the entire surrounding area including the upper part of the MEMS element 16, and are formed at intervals of, for example, 50 μm.

  Next, as shown in FIG. 5G, the sacrificial layers 18a and 18b are removed by dry etching. As an etching material, HF mixed gas, XeF2 gas, CF4 gas, or the like is used.

In dry etching, the sacrificial layers 18a and 18b, which are inorganic materials, are selectively etched, and the MEMS element 16 using a metal material, the insulating connection joint 19 using an organic material, and the first sealing film. 21 can be prevented from being etched.

  A plurality of through holes 16b are formed in the bridge support portion 16a. The first sealing film 21 has a plurality of opening-shaped portions 21a. Therefore, the sacrificial layers 18a and 18b can be completely removed in a short time during etching. As a result, the hollow portion 17 is formed inside the first sealing film 21.

  Next, as shown in FIG. 5H, a second sealing film 22 that closes the opening shape portion 21 a is formed on the first sealing film 21. For example, in a normal pressure state, an organic material such as polyimide is applied by a spin coat method under conditions of a pressure of 0.1 MPa (atmospheric pressure), patterned by exposure and development, cured, and filled in the opening shape portion 21a. The stop structure is completed.

  Further, for example, in order to improve the moisture resistance of the second sealing film 22, the second sealing film 22 is composed of a plurality of films so as to further cover low moisture-permeable SiN with a thickness of 0.5 to 1 μm. It is also possible to make it. Moreover, in order to improve the intensity | strength of the 2nd sealing film 22, it is also possible to comprise so that it may reinforce with an epoxy resin etc., for example.

  Also, for example, the pressure of the hollow portion 17 can be changed to an atmospheric pressure atmosphere by forming the second sealing film 22 by atmospheric pressure plasma CVD.

Further, when the hollow portion 17 is to be in a vacuum atmosphere, the second sealing film 22 is formed by putting it in a chamber having a high degree of vacuum in a plasma CVD apparatus or a sputtering apparatus.
Thus, the micromachine device 1 shown in FIG. 4 is completed.

  The manufacturing method of the micromachine device 1 according to the present embodiment has the following effects. That is, the insulating connection joint 19 is made of an organic material, and the sacrificial layers 18a and 18b are made of an inorganic material, so that it is not necessary to provide a protective layer for etching on the insulating connection joint 19 in the dry etching process of the sacrificial layers 18a and 18b. The insulating connection joint 19 can be left without being etched, the manufacturing process can be simplified, and the cost of the micromachine device can be reduced.

  In addition, this invention is not limited to the said embodiment, The material, shape, arrangement | positioning, size, structure, operation | movement, etc. of each component can be changed suitably and can be implemented. For example, the MEME element 16 may have a cantilever shape, and examples of the method for removing the sacrificial layer include wet etching with a chemical solution.

  The plurality of sacrificial layers 18a and 18b are not limited to the same material and can be applied.

  In addition, the present invention can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

DESCRIPTION OF SYMBOLS 1 ... Micromachine apparatus, 10 ... Substrate, 11 ... Base substrate, 12 ... Insulating layer,
13 ... Lower electrode, 14 ... Drive electrode, 15 ... Signal line, 16 ... MEMS element,
16a ... Bridge support part, 16b ... Through hole, 16c ... Contact part, 17 ... Hollow part,
18a, 18b ... Sacrificial layer, 19 ... Insulator connection joint, 20 ... Insulating film, 21 ... First sealing film,
21a ... opening shape part, 22 ... second sealing film.

Claims (3)

Forming a signal line, a drive electrode, and a lower electrode on an insulating substrate;
Forming an insulating film on the signal line and the drive electrode;
Forming a sacrificial layer made of an inorganic material on the insulating substrate;
Forming a bridge support and a contact on the sacrificial layer;
Forming an insulator connection joint using an organic material for connecting the bridge support portion and the contact portion;
Removing the sacrificial layer;
A method of manufacturing a micromachine device comprising: Forming a signal line, a drive electrode, and a lower electrode on an insulating substrate;
Forming an insulating film on the signal line and the drive electrode;
Forming a first sacrificial layer made of an inorganic material on the insulating substrate;
Forming a bridge support and a contact on the sacrificial layer;
Forming an insulator connection joint using an organic material for connecting the bridge support portion and the contact portion;
Forming a second sacrificial layer made of an inorganic material on the bridge support portion, the contact portion, and the insulator joint;
Providing an opening shape portion communicating with the second sacrificial layer on the second sacrificial layer, and forming a first sealing film using an organic material;
Removing the first sacrificial layer and the second sacrificial layer;
Forming a second sealing film for closing the opening-shaped portion on the first sealing film;
For manufacturing a micromachine device comprising: The organic material is at least one of polyimide, epoxy, or benzocyclobutene,
3. The method of manufacturing a micromachine device according to claim 1, wherein the inorganic material is selected from at least one of amorphous silicon, polysilicon, SiO2, or Si3N4.

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