JP5923912B2 - Method for manufacturing interference filter - Google Patents

Description

  The present invention relates to a method for manufacturing an interference filter.

  2. Description of the Related Art Conventionally, there is known an interference filter in which a reflective film is disposed on a surface of a pair of substrates facing each other via a predetermined gap (see, for example, Patent Document 1).

  The optical device (interference filter) described in Patent Document 1 includes a first base (substrate) including a first light reflecting portion (reflective film) and a second including a second light reflecting portion (reflective film). A configuration is adopted in which a base (substrate) is bonded by a bonding film. The bonding film includes a Si skeleton including a siloxane bond and a random atomic structure, and a leaving group bonded to the Si skeleton. Then, by applying energy to the bonding film and activating it, the substrates can be bonded to each other by the bonding portion. Here, examples of methods for applying energy to the bonding film include a method of irradiating energy rays such as ultraviolet rays and laser light, a method of heating the bonding film, and a method of exposing to plasma and ozone gas.

JP 2009-134027 A

By the way, as described in Patent Document 1, when energy is applied by irradiating the bonding film with energy rays such as ultraviolet rays and laser light, the reflective film is irradiated with the energy rays. The reflective film may be deteriorated or the reflective film may be deteriorated by the gas generated by the irradiation of energy rays (for example, oxidation of the reflective film due to generation of ozone gas). Further, even when energy is applied to the joint by heating, it is considered that the reflective film is deteriorated by heat or the like. Further, when the bonding film is subjected to O ₂ plasma treatment or exposed to ozone gas, the reflection film may be deteriorated due to oxidation.
As described above, when the reflective film deteriorates, the resolution of the wavelength variable interference filter decreases. For this reason, conventionally, a separate protective film is provided on the reflective film or energy is applied after the mask layer is formed to prevent the reflective film from being deteriorated. However, there is a problem that the manufacturing efficiency is lowered. It was.

  An object of the present invention is to provide a method of manufacturing an interference filter that does not cause a decrease in manufacturing efficiency and can prevent deterioration of a reflective film.

An interference filter manufacturing method according to an aspect of the present invention includes a first substrate on which a first reflective film is provided, and a second reflective film that faces the first reflective film with a gap having a predetermined size. An interference filter manufacturing method including a second substrate bonded to the first substrate, wherein the first reflective film and the first bonding film are formed on the first substrate. A second film forming step of forming the second reflective film and the second bonding film on the second substrate, and N ₂ plasma treatment or Ar for the first bonding film and the second bonding film. An activation step of activating the first bonding film and the second bonding film by performing plasma treatment, the first bonding film activated in the activation step, and activation in the activation step Bonding the first substrate and the second substrate by bonding the second bonding film formed And in the activation step, in the first substrate planar view of the first substrate viewed from the direction of plasma irradiation in the N ₂ plasma treatment or the Ar plasma treatment, Using the first metal mask that covers the overlapping region and opens the region overlapping with the first bonding film, the first bonding film is activated, and from the direction of plasma irradiation in the N ₂ plasma processing or Ar plasma processing In the second substrate plan view of the second substrate, the second bonding film is formed using a second metal mask that covers a region overlapping the second reflective film and opens a region overlapping the second bonding film. In the bonding step, after bonding the first bonding film and the second bonding film, the first bonding film and the second bonding are performed in an inert gas atmosphere or in a vacuum. Characterized in that an annealing process on.
The interference filter manufacturing method according to the present invention includes a first substrate on which a first reflective film is provided, and a second reflective film facing the first reflective film with a gap of a predetermined size, An interference filter manufacturing method including a second substrate bonded to the first substrate, wherein the first reflective film and the first bonding film are formed on the first substrate. A second film forming step of forming the second reflective film and the second bonding film on the second substrate, and N ₂ plasma treatment or Ar for the first bonding film and the second bonding film. An activation step of activating the first bonding film and the second bonding film by performing plasma treatment, the first bonding film activated in the activation step, and activation in the activation step By bonding the second bonding film formed, the first substrate and the second substrate are bonded. A bonding step for combining, in the activation step, the first reflective film in a first substrate plan view when the first substrate is viewed from a plasma irradiation direction in the N ₂ plasma treatment or the Ar plasma treatment The first bonding film is activated using a first metal mask that covers a region overlapping with the first bonding film and opens in a region overlapping with the first bonding film, and a plasma irradiation direction in the N ₂ plasma treatment or the Ar plasma treatment When the second substrate is viewed from the second substrate in plan view, the second bonding is performed using a second metal mask that covers a region overlapping with the second reflection film and opens a region overlapping with the second bonding film. It is characterized by activating the membrane.
The interference filter manufacturing method according to the present invention includes a first substrate on which a first reflective film is provided, and a second reflective film facing the first reflective film with a gap of a predetermined size, An interference filter manufacturing method including a second substrate bonded to the first substrate, wherein the first reflective film and the first bonding film are formed on the first substrate. A second film forming step of forming the second reflective film and the second bonding film on the second substrate, and N ₂ plasma treatment or Ar for the first bonding film and the second bonding film. An activation step of activating the first bonding film and the second bonding film by performing plasma treatment, the first bonding film activated in the activation step, and activation in the activation step By bonding the second bonding film formed, the first substrate and the second substrate are bonded. And a joining step for joining.
Here, the bonding of the first bonding film and the second bonding film in the present invention is a surface activation bonding, and the bonding surfaces are formed by activating the film surfaces of the first bonding film and the second bonding film. Then, bonding is performed by bonding unbonded hands. In order to perform such surface activation bonding, for example, a polymer film containing siloxane can be used as the first bonding film and the second bonding film. In the bonding film containing siloxane, when the surface is activated by applying activation energy, dangling bonds such as “Si—O—” can be formed, and the bonding bonds can be strongly bonded to each other. It becomes possible to make it join.

In the present invention, when the activation energy is applied to the first bonding film and the second bonding film in the bonding step, N ₂ plasma processing or Ar plasma processing is performed. Since N ₂ and Ar are inert gases and poor in reactivity, when the activation energy is applied to the first reflective film and the second reflective film, the first reflective film and the second reflective film are the surrounding N _2. It does not react with Ar. Accordingly, it is possible to prevent the first reflective film and the second reflective film from being deteriorated during the plasma treatment. Therefore, there is no deterioration in optical characteristics due to oxidation of the reflective film, and a high resolution interference filter can be manufactured. In addition, it is not necessary to form a protective film or mask layer to protect the first reflective film and the second reflective film during plasma processing, and plasma processing can be performed as it is, improving manufacturing efficiency. Can be made.

In the method for manufacturing an interference filter according to the aspect of the invention, in the bonding step, after the first bonding film and the second bonding film are bonded, the first bonding film and the first film are bonded in an inert gas atmosphere or in a vacuum. It is preferable to perform an ultraviolet irradiation treatment on the two-bonded film.
In this invention, after bonding a 1st joining film and a 2nd joining film, the joint strength of a 1st joining film and a 2nd joining film can further be raised by implementing an ultraviolet irradiation process. At this time, since the ultraviolet irradiation treatment is performed in an inert gas atmosphere or in a vacuum, the first reflective film and the second reflective film do not react with the surrounding gas and deteriorate.

In the method for manufacturing an interference filter according to the aspect of the invention, the joining step uses a light shielding mask that shields light incident on the first reflective film and the second reflective film, and uses the first reflective film and the second reflective film. The ultraviolet irradiation treatment is preferably performed in a state where light incident on the film is blocked.
In the present invention, in the above-described ultraviolet irradiation process, the light-shielding mask is used to prevent the ultraviolet rays from entering the first reflective film and the second reflective film. As a result, it is possible to prevent the first reflective film and the second reflective film from being deteriorated due to alteration or the like due to ultraviolet irradiation.

In the method for manufacturing an interference filter according to the aspect of the invention, in the bonding step, after the first bonding film and the second bonding film are bonded, the first bonding film and the first film are bonded in an inert gas atmosphere or in a vacuum. An annealing process is preferably performed on the two-bonded film.
In the present invention, the annealing of the first bonding film and the second bonding film can strengthen the bonding between the first bonding film and the second bonding film. In addition, annealing treatment may be performed after the ultraviolet irradiation treatment described above, and in this case, the bonding strength can be further increased.
And, in the present invention, since the annealing process is performed in an inert gas atmosphere or in a vacuum, the heat of the annealing process can avoid the inconvenience that the first reflecting film and the second reflecting film react with the surrounding gas, Deterioration of each reflective film can be prevented.

In the method for manufacturing an interference filter according to the aspect of the invention, in the activation step, the first reflection in the first substrate plan view of the first substrate viewed from the plasma irradiation direction in the N ₂ plasma treatment or the Ar plasma treatment. Using the first metal mask that covers the region overlapping the film and opens the region overlapping the first bonding film, the first bonding film is activated, and plasma irradiation in the N ₂ plasma treatment or Ar plasma treatment is performed. In the second substrate plan view of the second substrate viewed from the direction, the second metal mask is used to cover the region overlapping the second reflective film and open the region overlapping the second bonding film. It is preferable to activate the bonding film.

  In the present invention, in the activation process, plasma processing is performed using a first metal mask that covers a region overlapping the first reflective film and opens a region overlapping the first bonding film. Similarly, plasma processing is performed on the second substrate using a second metal mask that covers a region overlapping the second reflective film and opens a region overlapping the second bonding film. For this reason, when the first bonding film and the second bonding film are directly exposed to plasma, the activation treatment of the first bonding film and the second bonding film suitably proceeds. On the other hand, the first reflective film and the second reflective film are not directly exposed to the plasma, and the first reflective film and the second reflective film can be prevented from being deteriorated and deteriorated by the plasma.

1 is a block diagram showing a schematic configuration of a color measuring device including an interference filter according to an embodiment of the present invention. The top view which shows schematic structure of the interference filter of this embodiment. Sectional drawing which shows schematic structure of the interference filter of this embodiment. The figure which shows the 1st board | substrate formation process of this embodiment. The figure which shows the 2nd board | substrate formation process of this embodiment. The figure which shows the filter formation process of this embodiment. Sectional drawing which shows schematic structure of the optical filter device provided with the interference filter manufactured by the manufacturing method of the interference filter of this invention. Schematic which shows the gas detection apparatus provided with the interference filter manufactured by the manufacturing method of the interference filter of this invention. The block diagram which shows the structure of the control system of the gas detection apparatus of FIG. The figure which shows schematic structure of the food-analysis apparatus provided with the interference filter manufactured by the manufacturing method of the interference filter of this invention. The schematic diagram which shows schematic structure of the spectroscopic camera provided with the interference filter manufactured by the manufacturing method of the interference filter of this invention.

Hereinafter, an embodiment according to the present invention will be described with reference to the drawings.
[1. (Schematic configuration of the color measuring device)
FIG. 1 is a block diagram illustrating a schematic configuration of a colorimetric device 1 according to the present embodiment.
The colorimetric device 1 is an electronic apparatus including a wavelength variable interference filter (interference filter) manufactured by the interference filter manufacturing method of the invention. As shown in FIG. 1, the color measurement device 1 includes a light source device 2 that emits light to the inspection target A, a color measurement sensor 3, and a control device 4 that controls the overall operation of the color measurement device 1. The colorimetric device 1 reflects the light emitted from the light source device 2 by the inspection object A, receives the reflected inspection light by the colorimetric sensor 3, and outputs the light from the colorimetric sensor 3. This is an apparatus that analyzes and measures the chromaticity of the inspection target light, that is, the color of the inspection target A, based on the detection signal.

[2. Configuration of light source device]
The light source device 2 includes a light source 21 and a plurality of lenses 22 (only one is shown in FIG. 1), and emits white light to the inspection target A. The plurality of lenses 22 may include a collimator lens. In this case, the light source device 2 converts the white light emitted from the light source 21 into parallel light by the collimator lens and inspects from a projection lens (not shown). Inject toward the subject A. In the present embodiment, the colorimetric device 1 including the light source device 2 is illustrated. However, for example, when the inspection target A is a light emitting member such as a liquid crystal panel, the light source device 2 may not be provided.

[3. (Configuration of colorimetric sensor)
The colorimetric sensor 3 is an optical module including a wavelength variable interference filter 5 manufactured by the interference filter manufacturing method of the present invention. As shown in FIG. 1, the colorimetric sensor 3 includes a wavelength tunable interference filter 5, a detection unit 31 that receives light transmitted through the wavelength tunable interference filter 5, and a wavelength of light transmitted through the wavelength tunable interference filter 5. And a variable voltage control unit 32. Further, the colorimetric sensor 3 includes an incident optical lens (not shown) that guides the reflected light (inspection light) reflected by the inspection object A at a position facing the variable wavelength interference filter 5. In the colorimetric sensor 3, the wavelength variable interference filter 5 separates the light having a predetermined wavelength from the inspection target light incident from the incident optical lens, and the detected light is received by the detection unit 31.
The detection unit 31 includes a plurality of photoelectric exchange elements, and generates an electrical signal corresponding to the amount of received light. And the detection part 31 is connected to the control apparatus 4, and outputs the produced | generated electric signal to the control apparatus 4 as a light reception signal.

(3-1. Configuration of wavelength tunable interference filter)
FIG. 2 is a plan view showing a schematic configuration of the variable wavelength interference filter 5, and FIG. 3 is a cross-sectional view showing a schematic configuration of the variable wavelength interference filter 5.
The tunable interference filter 5 is manufactured by the interference filter manufacturing method of the present invention. An interference filter manufacturing method will be described later.
As shown in FIG. 2, the wavelength tunable interference filter 5 is a plate-like optical member having a planar square shape, for example. As shown in FIG. 3, the variable wavelength interference filter 5 includes a fixed substrate 51 that is a first substrate of the present invention and a movable substrate 52 that is a second substrate of the present invention. The fixed substrate 51 and the movable substrate 52 are each formed of, for example, various types of glass such as soda glass, crystalline glass, quartz glass, lead glass, potassium glass, borosilicate glass, and non-alkali glass, or crystal. . The fixed substrate 51 and the movable substrate 52 include a bonding film in which the first bonding portion 513 of the fixed substrate 51 and the second bonding portion 523 of the movable substrate are formed of, for example, a plasma polymerization film mainly containing siloxane. 53 (first bonding film 531 and second bonding film 532) are integrally formed by bonding.

The fixed substrate 51 is provided with a fixed reflective film 54 constituting the first reflective film of the present invention, and the movable substrate 52 is provided with a movable reflective film 55 constituting the second reflective film of the present invention. The fixed reflection film 54 and the movable reflection film 55 are disposed to face each other via the inter-reflection film gap G1. The variable wavelength interference filter 5 is provided with an electrostatic actuator 56 that is used to adjust the gap G1 between the reflection films. The electrostatic actuator 56 includes a fixed electrode 561 provided on the fixed substrate 51 and a movable electrode 562 provided on the movable substrate 52. The fixed electrode 561 and the movable electrode 562 are opposed to each other via an interelectrode gap G2 (G2> G1). Here, the electrodes 561 and 562 may be provided directly on the substrate surfaces of the fixed substrate 51 and the movable substrate 52, respectively, or may be provided via other film members.
Further, in the filter plan view as shown in FIG. 2 in which the wavelength variable interference filter 5 is viewed from the thickness direction of the fixed substrate 51 (movable substrate 52), the plane center point O of the fixed substrate 51 and the movable substrate 52 is fixed reflection. It coincides with the center point of the film 54 and the movable reflective film 55 and coincides with the center point of the movable part 521 described later.
In the following description, the wavelength tunable interference filter 5 was seen from a plan view seen from the thickness direction of the fixed substrate 51 or the movable substrate 52, that is, from the stacking direction of the fixed substrate 51, the bonding film 53, and the movable substrate 52. The plan view is referred to as a filter plan view.

(3-1-1. Configuration of Fixed Substrate)
The fixed substrate 51 is formed by processing a glass substrate having a thickness of, for example, 500 μm. Specifically, as shown in FIG. 3, the fixed substrate 51 is formed with an electrode placement groove 511 and a reflective film installation portion 512 by etching. The fixed substrate 51 is formed to have a thickness larger than that of the movable substrate 52, and the fixed substrate is caused by electrostatic attraction when a voltage is applied between the fixed electrode 561 and the movable electrode 562 or internal stress of the fixed electrode 561. There is no 51 deflection.
Further, a notch 514 is formed at the vertex C1 (see FIG. 2) of the fixed substrate 51, and a movable electrode pad 564P described later is exposed on the fixed substrate 51 side of the wavelength variable interference filter 5.

The electrode arrangement groove 511 is formed in an annular shape centering on the plane center point O of the fixed substrate 51 in the filter plan view. The reflection film installation portion 512 is formed to protrude from the center portion of the electrode arrangement groove 511 toward the movable substrate 52 in the plan view. Here, the groove bottom surface of the electrode arrangement groove 511 is an electrode installation surface 511A on which the fixed electrode 561 is arranged. In addition, the protruding front end surface of the reflection film installation portion 512 is a reflection film installation surface 512A.
In addition, the fixed substrate 51 is provided with electrode extraction grooves 511B (see FIG. 2) extending from the electrode arrangement grooves 511 toward the vertexes C1 and C2 of the outer peripheral edge of the fixed substrate 51.

A fixed electrode 561 is provided on the electrode installation surface 511 </ b> A of the electrode arrangement groove 511. The fixed electrode 561 is provided in a region of the electrode installation surface 511 </ b> A that faces a movable electrode 562 of the movable portion 521 described later. In addition, an insulating film for ensuring insulation between the fixed electrode 561 and the movable electrode 562 may be stacked over the fixed electrode 561.
The fixed substrate 51 is provided with a fixed extraction electrode 563 extending from the outer peripheral edge of the fixed electrode 561 in the direction of the vertex C2. The extended leading end portions of these fixed extraction electrodes 563 (portions located at the vertex C2 of the fixed substrate 51) constitute fixed electrode pads 563P connected to the voltage control unit 32.
In the present embodiment, a configuration in which one fixed electrode 561 is provided on the electrode installation surface 511A is shown. For example, a configuration in which two concentric circles centered on the plane center point O are provided (double electrode configuration). ) Etc.

As described above, the reflective film installation portion 512 is formed in a substantially cylindrical shape that is coaxial with the electrode arrangement groove 511 and has a smaller diameter than the electrode arrangement groove 511, and is formed on the movable substrate 52 of the reflection film installation portion 512. An opposing reflection film installation surface 512A is provided.
As shown in FIG. 3, a fixed reflection film 54 is installed in the reflection film installation portion 512. As the fixed reflective film 54, for example, a metal film such as Ag or an alloy film such as an Ag alloy can be used. For example, a dielectric multilayer film in which the high refractive layer is TiO ₂ and the low refractive layer is SiO ₂ may be used. Further, a reflective film in which a metal film (or alloy film) is laminated on a dielectric multilayer film, a reflective film in which a dielectric multilayer film is laminated on a metal film (or alloy film), a single refractive layer (TiO ₂ or SiO ₂₎ and a metal film (or alloy film) and the like may be used reflective film formed by laminating a.

  Further, an antireflection film may be formed at a position corresponding to the fixed reflection film 54 on the light incident surface of the fixed substrate 51 (the surface on which the fixed reflection film 54 is not provided). This antireflection film can be formed by alternately laminating low refractive index films and high refractive index films, and reduces the reflectance of visible light on the surface of the fixed substrate 51 and increases the transmittance.

  Of the surface of the fixed substrate 51 that faces the movable substrate 52, the surface on which the electrode placement groove 511, the reflective film installation portion 512, and the electrode extraction groove 511B are not formed by etching constitutes the first joint portion 513. The first bonding portion 513 is provided with a first bonding film 531. By bonding the first bonding film 531 to the second bonding film 532 provided on the movable substrate 52, as described above, The fixed substrate 51 and the movable substrate 52 are joined.

(3-1-2. Configuration of movable substrate)
The movable substrate 52 is formed by processing a glass substrate having a thickness of, for example, 200 μm.
Specifically, the movable substrate 52 holds a movable portion 521 which is coaxial with the movable portion 521 and is coaxial with the movable portion 521 in the filter plan view as shown in FIG. A holding part 522 and a substrate outer peripheral part 525 provided outside the holding part 522 are provided.
Further, as shown in FIG. 2, the movable substrate 52 has a notch 524 corresponding to the vertex C <b> 2, and the fixed electrode pad when the wavelength variable interference filter 5 is viewed from the movable substrate 52 side. 563P is exposed.

The movable part 521 is formed to have a thickness dimension larger than that of the holding part 522. For example, in this embodiment, the movable part 521 is formed to have the same dimension as the thickness dimension of the movable substrate 52. The movable portion 521 is formed to have a diameter larger than at least the diameter of the outer peripheral edge of the reflection film installation surface 512A in the filter plan view. The movable part 521 is provided with a movable electrode 562 and a movable reflective film 55.
Similar to the fixed substrate 51, an antireflection film may be formed on the surface of the movable portion 521 opposite to the fixed substrate 51. Such an antireflection film can be formed by alternately laminating a low refractive index film and a high refractive index film, reducing the reflectance of visible light on the surface of the movable substrate 52 and increasing the transmittance. Can be made.

The movable electrode 562 is opposed to the fixed electrode 561 via the interelectrode gap G2 (G2> G1), and is formed in an annular shape having the same shape as the fixed electrode 561. In addition, the movable substrate 52 includes a movable extraction electrode 564 that extends from the outer peripheral edge of the movable electrode 562 toward the vertex C <b> 1 of the movable substrate 52. The extended leading end of the movable extraction electrode 564 (the portion located at the vertex C1 of the movable substrate 52) constitutes a movable electrode pad 564P connected to the voltage control unit 32.
The movable reflective film 55 is provided at the center of the movable surface 521A of the movable part 521 so as to face the fixed reflective film 54 with the gap G1 between the reflective films. As the movable reflective film 55, a reflective film having the same configuration as that of the fixed reflective film 54 described above is used.
In the present embodiment, a configuration in which the gap G1 between the reflection films is smaller than the gap G2 between the electrodes is illustrated, but the present invention is not limited to this. That is, the inter-reflective film gap G1 and the inter-electrode gap G2 can be determined by the wavelength range of the light extracted by the wavelength variable interference filter 5. For example, the inter-reflective film gap G1 and the inter-electrode gap G2 have the same dimensions. Alternatively, a configuration in which the gap G1 between the reflection films is set larger than the gap G2 between the electrodes may be employed.

The holding part 522 is a diaphragm that surrounds the periphery of the movable part 521, and has a thickness dimension smaller than that of the movable part 521.
Such a holding part 522 is easier to bend than the movable part 521, and the movable part 521 can be displaced toward the fixed substrate 51 by a slight electrostatic attraction. At this time, since the movable portion 521 has a thickness dimension larger than that of the holding portion 522 and becomes rigid, even when the holding portion 522 is pulled toward the fixed substrate 51 by electrostatic attraction, the shape of the movable portion 521 changes. Absent. Therefore, the movable reflective film 55 provided on the movable portion 521 is not bent, and the fixed reflective film 54 and the movable reflective film 55 can be always maintained in a parallel state.
In this embodiment, the diaphragm-like holding part 522 is illustrated, but the present invention is not limited to this. For example, a configuration in which beam-like holding parts arranged at equiangular intervals around the plane center point O are provided. And so on.

  As described above, the substrate outer peripheral portion 525 is provided outside the holding portion 522 in the filter plan view. The surface of the substrate outer peripheral portion 525 that faces the fixed substrate 51 includes a second joint portion 523 that faces the first joint portion 513. The second bonding portion 523 is provided with the second bonding film 532. As described above, the second bonding film 532 is bonded to the first bonding film 531, so that the fixed substrate 51 and the movable substrate 52 are bonded. Are joined.

(3-2. Configuration of voltage control means)
The voltage control unit 32 is connected to the fixed electrode pad 563P and the movable electrode pad 564P. The voltage control unit 32 applies a voltage to the electrostatic actuator 56 by setting the fixed electrode pad 563P and the movable electrode pad 564P to predetermined potentials based on the control signal input from the control device 4. . As a result, an electrostatic attractive force is generated in the inter-electrode gap G2, and the holding portion 522 is bent, whereby the movable portion 521 is displaced toward the fixed substrate 51, and the inter-reflective film gap G1 can be set to a desired dimension. It becomes possible.

[4. Configuration of control device]
The control device 4 controls the overall operation of the color measurement device 1.
As the control device 4, for example, a general-purpose personal computer, a portable information terminal, other color measurement dedicated computer, or the like can be used.
As shown in FIG. 1, the control device 4 includes a light source control unit 41, a colorimetric sensor control unit 42, a colorimetric processing unit 43 that constitutes an analysis processing unit of the present invention, and the like.
The light source control unit 41 is connected to the light source device 2. Then, the light source control unit 41 outputs a predetermined control signal to the light source device 2 based on, for example, a user setting input, and causes the light source device 2 to emit white light with a predetermined brightness.
The colorimetric sensor control unit 42 is connected to the colorimetric sensor 3. The colorimetric sensor control unit 42 sets a wavelength of light received by the colorimetric sensor 3 based on, for example, a user's setting input, and outputs a control signal for detecting the amount of light received at this wavelength. Output to the colorimetric sensor 3. Thereby, the voltage control unit 32 of the colorimetric sensor 3 sets the voltage applied to the electrostatic actuator 56 so as to transmit only the wavelength of light desired by the user based on the control signal.
The colorimetric processing unit 43 analyzes the chromaticity of the inspection object A from the amount of received light detected by the detection unit 31.

[5. (Manufacturing method of wavelength tunable interference filter)
Next, a method for manufacturing the interference filter of the present invention (a method for manufacturing the wavelength tunable interference filter 5) will be described with reference to FIGS. 4, 5, and 6. FIG.
In order to manufacture the variable wavelength interference filter 5, the fixed substrate 51 and the movable substrate 52 are manufactured, and the manufactured fixed substrate 51 and the movable substrate 52 are bonded together.

(5-1. First substrate forming step)
In forming the fixed substrate 51, first, a synthetic quartz glass substrate (fixed substrate 51), which is a manufacturing material of the fixed substrate 51, is prepared, and both surfaces are mirror-polished until the surface roughness Ra of the substrate becomes 1 nm or less, and 500 μm. A fixed substrate 51 having a thickness of 5 mm is formed.

Thereafter, as shown in FIG. 4A, a first mask layer M1 (resist) is applied to both surfaces (all surfaces) of the fixed substrate 51, and the applied first mask layer M1 is exposed by a photolithography method. Development is performed to pattern the portions where the electrode placement groove 511, the electrode extraction groove 511B (not shown), and the reflection film installation portion 512 are to be formed.
Next, as shown in FIG. 4B, the fixed substrate 51 is etched to a depth of, for example, 0.5 μm. As the etching here, wet etching is performed using, for example, a hydrofluoric acid-based etching solution such as a hydrofluoric acid aqueous solution. As a result, the reflective film installation surface 512 </ b> A is formed on the fixed substrate 51.

  Thereafter, after removing the first mask layer M1, a second mask layer M2 (resist) for forming the electrode placement groove 511 is formed on the entire surface of the fixed substrate 51. And as shown in FIG.4 (C), the location which forms the electrode arrangement | positioning groove | channel 511 (and electrode extraction groove | channel 511B) is patterned. Here, an example is shown in which the first mask layer M1 is removed and a second mask layer M2 is newly formed. However, for example, the first mask layer M1 is not removed and the formation position of the reflective film installation part 512 is shown. Only the second mask layer M2 may be newly formed.

Then, the fixed substrate 51 is wet-etched to form an electrode arrangement groove 511 and an electrode extraction groove 511B (not shown). At this time, for example, the electrode installation surface 511A is positioned at a position where the depth dimension from the reflective film installation surface 512A is 1 μm (a position where the depth dimension from the upper surface of the fixed substrate 51 is 1.5 μm). Wet etching is performed. Thereafter, the second mask layer M2 is removed.
As a result, as shown in FIG. 4D, the substrate shape of the fixed substrate 51 on which the electrode arrangement groove 511, the electrode extraction groove 511B (not shown), and the reflection film installation portion 512 are formed is determined.

Next, the first film forming step of the present invention is performed.
In the first film formation step, first, an electrode material for forming the fixed electrode 561 is formed on the fixed substrate 51. As the fixed electrode 561 and the fixed extraction electrode 563, any electrode material may be used. In this embodiment, an ITO film having a thickness of 0.1 μm is formed using a sputtering method or the like. Thereafter, the electrode material is patterned to form a fixed electrode 561 and a fixed extraction electrode 563 (not shown) as shown in FIG. In this patterning, for example, a resist pattern is formed on the formed ITO at positions where the fixed electrode 561 and the fixed extraction electrode 563 are formed. And ITO is etched using the liquid mixture of nitric acid and hydrochloric acid, and a resist pattern is removed after an etching.
Further, when an insulating layer is formed on the fixed electrode 561, an insulating film (for example, having a thickness of about 100 nm is formed on the entire surface of the fixed substrate 51 facing the movable substrate 52 by, for example, plasma CVD after the fixed electrode 561 is formed. For example, TEOS or SiO ₂ ) is formed. Then, the insulating film on the fixed electrode pad 563P is removed by, for example, dry etching.

Next, as shown in FIG. 4F, a fixed reflective film 54 is provided on the reflective film installation surface 512A. Here, in this embodiment, an Ag alloy is used as the fixed reflective film 54. When a metal film such as an Ag alloy or an alloy film such as an Ag alloy is used as the fixed reflection film 54, the film of the fixed reflection film 54 is formed on the surface of the fixed substrate 51 where the electrode placement groove 511 and the reflection film installation portion 512 are formed. After the layer is formed, patterning is performed using a photolithography method or the like.
In the case where a dielectric multilayer film is formed as the fixed reflective film 54, it can be formed by, for example, a lift-off process. In this case, a resist (lift-off pattern) is formed on a portion other than the reflective film formation portion on the fixed substrate 51 by a photolithography method or the like. Thereafter, a material for forming the fixed reflective film 54 (for example, a dielectric multilayer film in which the high refractive layer is TiO ₂ and the low refractive layer is SiO ₂ ) is formed by sputtering or vapor deposition. Then, after forming the fixed reflective film 54, unnecessary portions of the film are removed by lift-off.
Further, when a fixed reflective film 54 in which a metal film or a metal alloy film is further laminated on a dielectric multilayer film is used, a metal film or a metal film or a metal film on a dielectric film (for example, a high refractive layer such as TiO ₂ or Ta ₂ O ₅ ) In the case of using the fixed reflective film 54 in which the metal alloy film is laminated, after forming the dielectric multilayer film (dielectric film) by the lift-off process as described above, the metal film or the metal alloy film is formed by the sputtering method or the vapor deposition method. And patterning using a photolithography method or the like.

Thereafter, as shown in FIG. 4G, a first bonding film 531 which is a plasma polymerized film containing polyorganosiloxane as a main component is formed on the first bonding portion 513 of the fixed substrate 51 by, for example, a plasma CVD method or the like. Form a film. In the film forming process of the first bonding film 531, for example, the first bonding film 531 is formed on the first bonding portion 513 of the fixed substrate 51 using a mask having an opening corresponding to the first bonding portion 513. . Here, the thickness of the first bonding film 531 may be, for example, 10 nm to 1000 nm. For example, in the present embodiment, the thickness is 50 nm.
Thereafter, the notch 514 is formed by using, for example, a sandblasting method or various cutting methods. Note that the notch 514 may be formed after the fixed substrate 51 and the movable substrate 52 are joined.
Thus, the fixed substrate 51 is formed.

(5-2. Second substrate forming step)
In forming the movable substrate 52, first, a synthetic quartz glass substrate (movable substrate 52), which is a manufacturing material of the movable substrate 52, is prepared, and both surfaces are mirror-polished until the surface roughness Ra of the substrate becomes 1 nm or less. A movable substrate 52 having a thickness of 5 mm is formed.
Then, a Cr film / Au film multilayer film E1 is formed on both surfaces (entire surface) of the movable substrate 52. Here, the film thickness dimensions of the Cr film and the Au film are not particularly limited, but in this embodiment, the Cr film is formed to 50 nm and the Au film is formed to 500 nm. Then, this laminated film E1 is patterned by a photolithography method or the like. Specifically, a third mask layer M3 (resist) is applied on the laminated film E1, and a mask pattern in which the formation position of the holding portion 522 is opened is formed using a photolithography method or the like. Thereafter, the Au film is etched with a mixed solution of iodine and potassium iodide, and the Cr film is etched with an aqueous cerium ammonium nitrate solution. As a result, as shown in FIG. 5A, the stacked film E <b> 1 and the third mask layer M <b> 3 in which only the formation position of the holding portion 522 is opened are formed on the movable substrate 52.

Next, the movable substrate 52 is etched to form a holding portion 522 having a thickness of 30 μm, for example, as shown in FIG. In the etching of the movable substrate 52, wet etching using a hydrofluoric acid-based etching solution is performed in the same manner as the etching of the fixed substrate 51 described above.
Moreover, since the movable part 521 and the board | substrate outer peripheral part 525 are the same thickness dimensions as the movable board | substrate 52, it is not necessary to process these.
Thereby, the substrate shape of the movable substrate 52 having the movable portion 521, the holding portion 522, and the substrate outer peripheral portion 525 is determined.
In this embodiment, the example in which the movable substrate 52 is etched using the Cr film / Au film laminated film E1 and the third mask layer M3 functioning as the movable electrode 562 and the movable extraction electrode 564 has been described. It is not limited. For example, only the third mask layer M3 may be formed on the movable substrate 52 and the movable substrate 52 may be etched.

Next, the second film forming step of the present invention is performed. In this second film forming step, first, after removing the third mask layer M3, as shown in FIG. 5C, the laminated film E1 is patterned to the shape of the movable electrode 562 and the movable extraction electrode 564. Four mask layers M4 are formed. Specifically, after the fourth mask layer M4 is formed on the entire surface of the movable substrate 52, the fourth mask layer M4 other than the positions where the movable electrode 562 and the movable extraction electrode 564 are formed is removed using a photolithography method or the like. .
Here, although the example in which the fourth mask layer M4 covering the formation positions of the movable electrode 562 and the movable extraction electrode 564 is newly formed after removing the third mask layer M3 is shown, for example, the third mask layer The third mask layer M3 may function as the fourth mask layer M4 by removing portions other than the positions where the movable electrode 562 and the movable extraction electrode 564 of the layer M3 are formed.
After that, the movable film 562 and the movable extraction electrode 564 are formed by etching the laminated film E1 other than the region covered with the fourth mask layer M4. In this etching, as described above, the Au film is etched with a mixed solution of iodine and potassium iodide, and the Cr film is etched with an aqueous cerium ammonium nitrate solution. As a result, as shown in FIG. 5D, the movable electrode 562 and the movable extraction electrode 564 (not shown) are formed on the movable substrate 52.

In this embodiment, the example in which the movable electrode 562 and the movable extraction electrode 564 are formed by etching the laminated film E1 used as a mask when the movable substrate 52 is etched has been shown. For example, FIG. After determining the shape of the movable substrate 52 shown in C), both the third mask layer M3 and the laminated film E1 may be removed to form a new electrode.
When ITO is used as a new electrode, for example, an ITO film having a thickness of, for example, 0.1 μm is formed on the surface of the movable substrate 52 facing the fixed substrate 51 after removing the third mask layer M3 and the laminated film E1. Form a film. In forming the ITO film, for example, a sputtering method or the like can be used. Thereafter, a resist is formed on the ITO film, the resist is patterned using a photolithography method or the like, and the ITO is etched using a mixed solution of nitric acid and hydrochloric acid. Thereafter, the resist is removed. Even with such a method, the movable electrode 562 and the movable extraction electrode 564 (not shown) can be formed on the movable substrate 52 as shown in FIG.

  Thereafter, as shown in FIG. 5E, a movable reflective film 55 is provided on the movable surface 521A. The movable reflective film 55 can be formed by the same method as the fixed reflective film 54. That is, when a metal film such as Ag or an alloy film such as an Ag alloy is used as the movable reflective film 55, after the film layer of the movable reflective film 55 is formed on the movable substrate 52, patterning is performed using a photolithography method or the like. To do. Further, when a dielectric multilayer film is formed as the movable reflective film 55, it can be formed by, for example, a lift-off process. Furthermore, when a reflective film in which a dielectric multilayer film (dielectric film) and a metal film (metal alloy film) are stacked is used as the movable reflective film 55, after forming the dielectric multilayer film by a lift-off process, the metal film ( A metal alloy film) is formed and patterned using a photolithography method or the like.

Thereafter, as shown in FIG. 5 (F), a second bonding film 532 which is a plasma polymerized film containing polyorganosiloxane as a main component is formed on the second bonding portion 523 of the movable substrate 52 by, for example, a plasma CVD method or the like. Form a film. In the film forming step of the second bonding film 532, for example, the second bonding film 532 is formed on the second bonding portion 523 of the movable substrate 52 using a mask having an opening corresponding to the second bonding portion 523. Here, the thickness of the second bonding film 532 may be, for example, 10 nm to 1000 nm, and for example, in this embodiment, it is formed to 50 nm.
Thereafter, the notch 524 is formed using, for example, a sandblasting method or various cutting methods. Note that the notch 524 may be formed after the fixed substrate 51 and the movable substrate 52 are joined.
Thus, the movable substrate 52 is manufactured.

(5-3. Filter formation process)
Next, a filter forming step of forming the wavelength variable interference filter 5 by bonding the substrates formed in the first substrate forming step and the second substrate forming step is performed.
In this filter forming step, first, an activation step is performed. In the activation step, as shown in FIG. 6A, the first bonding film 531 formed on the first bonding portion 513 of the fixed substrate 51 and the second bonding portion 523 formed on the movable substrate 52 are formed. In order to apply activation energy to the bonding film 532, N ₂ plasma treatment is performed. This N ₂ plasma treatment is performed for 30 seconds under the conditions of an N ₂ flow rate of 30 cc / min, a pressure of 4 Pa, and an RF power of 50 W.
At this time, plasma treatment is performed using the first metal mask M5 and the second metal mask M6 in order to avoid damages caused by direct exposure of the reflective films 54 and 55 to the plasma. Here, as shown in FIG. 6A, the first metal mask M5 has at least a first substrate plan view when the fixed substrate 51 is viewed from the substrate thickness direction (the fixed substrate 51 is viewed from the plasma irradiation direction). The region that overlaps with the fixed reflective film 54 is covered, and at least the region that overlaps with the first bonding film 531 is opened. The second mask M6 covers at least a region overlapping with the movable reflective film 55 in the second substrate plan view when the movable substrate 52 is viewed from the substrate thickness direction (the movable substrate 52 is viewed from the plasma irradiation direction), and at least the second bonding is performed. A region overlapping with the film 532 is opened. By using such metal masks M5 and M6, only the first bonding film 531 and the second bonding film 532 can be activated. Therefore, the fixed reflective film 54 and the movable reflective film 55 are not directly exposed to plasma with high activation energy, and deterioration due to alteration or the like is prevented.

Thereafter, as shown in FIG. 6B, the fixed substrate 51 and the movable substrate 52 are aligned, and the first bonding portion 513 and the second bonding portion 523 are interposed via the first bonding film 531 and the second bonding film 532. A joining step of superimposing the two is performed.
Then, for example, a load of 200 kgh is applied to the joining portion for 10 minutes to perform pressure joining. Thereby, the substrates 51 and 52 are bonded to each other.

Thereafter, as shown in FIG. 6C, ultraviolet irradiation treatment is performed to increase the bonding strength of the first bonding film 531 and the second bonding film 532. In this ultraviolet irradiation treatment, excimer UV (wavelength: 172 nm) is used as a UV light source, and the treatment is performed in an inert gas (N ₂ , Ar, etc.) atmosphere or in a vacuum for 3 minutes. At this time, in order to block the excimer UV irradiation to each of the reflection films 54 and 55, it is preferable to install a light shielding mask M7.
Further, instead of the ultraviolet irradiation treatment, for example, an annealing process may be performed in an oven at 100 degrees, for example, for 5 hours to increase the bonding strength of the first bonding film 531 and the second bonding film 532. When the annealing process is performed, it is performed in an inert gas (N ₂ , Ar, etc.) atmosphere or in a vacuum in order to prevent thermal oxidation of each of the reflective films 54 and 55.
Further, the annealing treatment as described above may be performed after the ultraviolet irradiation treatment. Even in this case, annealing is performed in an inert gas (N ₂ , Ar, etc.) atmosphere or in a vacuum. By performing both the ultraviolet irradiation process and the annealing process, the bonding of the first bonding film 531 and the second bonding film 532 can be further strengthened.

[6. (Effects of Embodiment)
In the present embodiment, the fixed reflective film 54 and the first bonding film 531 are formed on the fixed substrate 51 in the first substrate forming process of the variable wavelength interference filter manufacturing process. In the second substrate forming step, the movable reflective film 55 and the second bonding film 532 are formed on the movable substrate 52. In the bonding step, the first bonding film 531 and the second bonding film 532 are subjected to N ₂ plasma treatment to impart activation energy, and then the first bonding film 531 and the second bonding film 532 are applied. Are joined together.
In such a manufacturing method, activation energy is given to the first bonding film 531 and the second bonding film 532 by the N ₂ plasma treatment, so that the fixed reflection film 54 and the movable reflection film 55 are not deteriorated by oxidation or the like. Therefore, in the wavelength tunable interference filter 5 manufactured by such a manufacturing method, for example, a protective film or the like is not provided for each of the reflective films 54 and 55, and compared with a case where O ₂ plasma processing or the like is performed. The optical properties of the reflective film 54 and the movable reflective film 55 are good, and light having a target wavelength can be extracted with high resolution.
Furthermore, it is not necessary to provide a protective film or the like for the fixed reflective film 54 and the movable reflective film 55, so that manufacturing efficiency can be improved and manufacturing cost can be reduced.

Further, when performing the N ₂ plasma treatment, plasma is applied to the fixed substrate 51 using the first metal mask M5 that covers the region overlapping the fixed reflection film 54 and opens the region overlapping the first bonding film 531. Irradiate. In addition, the movable substrate 52 is irradiated with plasma using a second metal mask M6 that covers a region where the movable reflective film 55 is overlapped and has an opening where the region overlapping the second bonding film 532 is open. For this reason, it is possible to prevent the reflective films 54 and 55 from being directly exposed to plasma and being deteriorated (deteriorated).

In the bonding step, after the first bonding film 531 and the second bonding film 532 are bonded, an ultraviolet irradiation process is performed in an inert gas atmosphere or in a vacuum. By such ultraviolet irradiation treatment, the bonding strength of the first bonding film 531 and the second bonding film 532 can be further increased. Further, since the ultraviolet irradiation treatment is performed in an inert gas atmosphere or in a vacuum, even when the ultraviolet irradiation is performed, the first bonding film 531 and the second bonding film 532 do not react with the surrounding gas, and the reflection film There is no generation of gas or the like that degrades 54 and 55. Further, since the fixed reflection film 54 and the movable reflection film 55 do not react with the surrounding gas, the fixed reflection film 54 and the movable reflection film 55 are not deteriorated by a chemical reaction such as oxidation. Therefore, the first bonding film 531 and the second bonding film 532 can be bonded more firmly without reducing the optical characteristics (for example, resolution) of the wavelength variable interference filter 5.
Further, at this time, excimer UV irradiation to each of the reflective films 54 and 55 is blocked by using the light shielding mask M7. For this reason, it is possible to prevent the reflective films 54 and 55 from being deteriorated by the high activation energy of the excimer UV, and it is possible to more reliably prevent the optical characteristics of the wavelength variable interference filter 5 from being deteriorated.

  Further, in the bonding step, after the first bonding film 531 and the second bonding film 532 are bonded, an annealing process may be performed instead of the ultraviolet irradiation process or after the ultraviolet irradiation process. It is carried out in an inert gas atmosphere or in a vacuum. For this reason, the reflection films 54 and 55 do not react with the surrounding gas (for example, oxidation) due to the heat of the annealing treatment. Therefore, the first bonding film 531 and the second bonding film 532 can be bonded more firmly without degrading the optical characteristics of the wavelength variable interference filter 5.

[Modification]
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

For example, in the above-described embodiment, an electrostatic actuator 56 is provided as an interference filter manufactured by the method for manufacturing an interference filter of the present invention, and the wavelength can be changed by the electrostatic actuator 56 so that the wavelength of light to be extracted can be changed. Although the interference filter 5 was illustrated, it is not limited to this.
For example, an interference filter may be used in which the electrostatic actuator 56 and other means for changing the gap G1 between the reflection films are not provided, and light having a target wavelength to be extracted is fixed. In such an interference filter, the first substrate provided with the first reflective film, the second substrate provided with the second reflective film, the first bonding film provided on the first substrate, and the second substrate It is formed by bonding a second bonding film provided on the substrate. At this time, a strong bonding strength can be obtained by forming the first bonding film and the second bonding film by a plasma polymerization film containing siloxane and bonding them by a siloxane bond. In the bonding step, similarly to the above embodiment, the N ₂ plasma treatment is performed on the first bonding film and the second bonding film, thereby reducing damage to each reflection film and deteriorating optical characteristics. Can be prevented.

In the above embodiment, the example in which the N ₂ plasma treatment is performed on the first bonding film 531 and the second bonding film 532 in the bonding process has been described, but the present invention is not limited thereto. In the above embodiment, as the plasma treatment, N ₂ plasma treatment is performed in consideration of the availability of gas in addition to the influence on the reflection films 54 and 55. May be. Even in this case, as in the above-described embodiment, there is no generation of gas or the like that causes the chemical reaction of the bonding films 531 and 532 during the plasma processing, and deterioration of the reflection films 54 and 55 such as oxidation is prevented. Can do.

  In the above-described embodiment, the wavelength variable interference filter 5 is directly provided to the colorimetric sensor 3. However, the colorimetric sensor 3 is in the state of an optical filter device in which the wavelength variable interference filter 5 is housed in a housing. It is good also as a structure to provide.

FIG. 7 is a cross-sectional view showing a schematic configuration of the optical filter device as described above.
As shown in FIG. 7, the optical filter device 600 includes a housing 610 that houses the variable wavelength interference filter 5.
The housing 610 includes a bottom 611, a lid 612, an incident side glass window 613 (light guide portion), and an exit side glass window 614 (light guide portion).

  The bottom 611 is constituted by, for example, a single layer ceramic substrate. On the bottom portion 611, the movable substrate 52 of the wavelength variable interference filter 5 is installed. In addition, a light incident hole 611A is formed in the bottom 611 in a region facing the reflective film (the fixed reflective film 54 and the movable reflective film 55) of the wavelength variable interference filter 5. The light incident hole 611A is a window into which incident light (inspection target light) desired to be dispersed by the wavelength variable interference filter 5 is incident, and an incident side glass window 613 is joined thereto. In addition, as joining of the bottom part 611 and the incident side glass window 613, the glass frit joining using the glass frit which is a piece of glass which melt | dissolved the glass raw material at high temperature and rapidly cooled can be used, for example.

In addition, a number of terminal portions 616 corresponding to the electrode pads 563P and 564P of the wavelength variable interference filter 5 are provided on the upper surface of the bottom portion 611 (inside the housing 610). Further, the bottom portion 611 is formed with through holes 615 at positions where the respective terminal portions 616 are provided, and each terminal portion 616 has a bottom surface (outside of the housing 610) of the bottom portion 611 through the through holes 615. Is connected to a connection terminal 617 provided in the.
Further, a sealing portion 619 to be joined to the lid 612 is provided on the outer peripheral edge of the bottom portion 611.

As shown in FIG. 7, the lid 612 includes a sealing portion 620 joined to the sealing portion 619 of the bottom portion 611, a side wall portion 621 that continues from the sealing portion 620 and rises away from the bottom portion 611, and a side wall portion And a top surface portion 622 that covers the fixed substrate 51 side of the wavelength tunable interference filter 5. The lid 612 can be formed of an alloy such as Kovar or a metal, for example.
The lid 612 is joined to the bottom portion 611 by joining the sealing portion 620 and the sealing portion 619 of the bottom portion 611 by, for example, laser sealing. In addition, a light emission hole 612A is formed in the top surface portion 622 of the lid 612 in a region facing each of the reflective films 54 and 55 of the wavelength variable interference filter 5. The light exit hole 612A is a window through which the light separated and extracted by the wavelength variable interference filter 5 passes, and the exit side glass window 614 is joined by, for example, glass frit joining.

In such an optical filter device 600, since the wavelength tunable interference filter 5 is protected by the housing 610, the wavelength tunable interference filter 5 can be prevented from being damaged by an external factor. Therefore, when the wavelength variable interference filter 5 is installed in an optical module such as a colorimetric sensor or an electronic device or during maintenance, damage due to collision with other members can be prevented.
For example, when the wavelength tunable interference filter 5 manufactured in a factory is transported to an assembly line for assembling an optical module or an electronic device, the wavelength tunable interference filter 5 protected by the optical filter device 600 is transported safely. It becomes possible.
Further, since the optical filter device 600 is provided with the connection terminal 617 exposed on the outer peripheral surface of the housing 610, wiring can be easily performed even when the optical filter device 600 is incorporated in an optical module or an electronic apparatus. .

Although the colorimetric device 1 is illustrated as an example of an apparatus in which the interference filter manufactured by the manufacturing method of the present invention is incorporated, the interference filter can be incorporated in various other fields.
For example, it can be used as a light-based system for detecting the presence of a specific substance. As such a system, for example, an in-vehicle gas leak detector that detects a specific gas with high sensitivity by adopting a spectroscopic measurement method using a wavelength variable interference filter, a photoacoustic rare gas detector for a breath test, etc. A gas detection apparatus can be illustrated.
An example of such a gas detection device will be described below with reference to the drawings.

FIG. 8 is a schematic diagram illustrating an example of a gas detection apparatus including a wavelength variable interference filter.
FIG. 9 is a block diagram showing a configuration of a control system of the gas detection device of FIG.
As shown in FIG. 8, the gas detection device 100 includes a sensor chip 110, a flow path 120 including a suction port 120A, a suction flow path 120B, a discharge flow path 120C, and a discharge port 120D, a main body 130, It is configured with.
The main body unit 130 includes a sensor unit cover 131 having an opening to which the flow path 120 can be attached and detached, a discharge unit 133, a housing 134, an optical unit 135, a filter 136, a wavelength variable interference filter 5, a light receiving element 137 (detection unit), and the like. And a control unit 138 that processes the detected signal and controls the detection unit, a power supply unit 139 that supplies power, and the like. The optical unit 135 emits light, and a beam splitter 135B that reflects light incident from the light source 135A toward the sensor chip 110 and transmits light incident from the sensor chip toward the light receiving element 137. And lenses 135C, 135D, and 135E.
Further, as shown in FIG. 9, an operation panel 140, a display unit 141, a connection unit 142 for interface with the outside, and a power supply unit 139 are provided on the surface of the gas detection device 100. When the power supply unit 139 is a secondary battery, a connection unit 143 for charging may be provided.
Further, as shown in FIG. 9, the control unit 138 of the gas detection apparatus 100 controls a signal processing unit 144 configured by a CPU or the like, a light source driver circuit 145 for controlling the light source 135A, and the variable wavelength interference filter 5. Voltage control unit 146, a light receiving circuit 147 that receives a signal from the light receiving element 137, a sensor chip detection that reads a code of the sensor chip 110 and receives a signal from a sensor chip detector 148 that detects the presence or absence of the sensor chip 110 A circuit 149, a discharge driver circuit 150 for controlling the discharge means 133, and the like are provided.

Next, operation | movement of the above gas detection apparatuses 100 is demonstrated below.
A sensor chip detector 148 is provided inside the sensor unit cover 131 at the upper part of the main body unit 130, and the sensor chip detector 148 detects the presence or absence of the sensor chip 110. When the signal processing unit 144 detects the detection signal from the sensor chip detector 148, the signal processing unit 144 determines that the sensor chip 110 is attached, and displays a display signal for displaying on the display unit 141 that the detection operation can be performed. put out.

  For example, when the operation panel 140 is operated by the user and an instruction signal to start the detection process is output from the operation panel 140 to the signal processing unit 144, the signal processing unit 144 first sends the signal processing unit 144 to the light source driver circuit 145. A light source activation signal is output to activate the light source 135A. When the light source 135A is driven, laser light having a single wavelength and stable linear polarization is emitted from the light source 135A. The light source 135A includes a temperature sensor and a light amount sensor, and the information is output to the signal processing unit 144. When the signal processing unit 144 determines that the light source 135A is stably operating based on the temperature and light quantity input from the light source 135A, the signal processing unit 144 controls the discharge driver circuit 150 to operate the discharge unit 133. Thereby, the gas sample containing the target substance (gas molecule) to be detected is guided from the suction port 120A to the suction channel 120B, the sensor chip 110, the discharge channel 120C, and the discharge port 120D. The suction port 120A is provided with a dust removal filter 120A1 to remove relatively large dust, some water vapor, and the like.

The sensor chip 110 is a sensor that incorporates a plurality of metal nanostructures and uses localized surface plasmon resonance. In such a sensor chip 110, an enhanced electric field is formed between the metal nanostructures by laser light, and when gas molecules enter the enhanced electric field, Raman scattered light and Rayleigh scattered light including information on molecular vibrations are generated. Occur.
These Rayleigh scattered light and Raman scattered light enter the filter 136 through the optical unit 135, and the Rayleigh scattered light is separated by the filter 136, and the Raman scattered light enters the wavelength variable interference filter 5. Then, the signal processing unit 144 controls the voltage control unit 146 to adjust the voltage applied to the wavelength variable interference filter 5, and causes the wavelength variable interference filter 5 to split the Raman scattered light corresponding to the gas molecule to be detected. . Thereafter, when the dispersed light is received by the light receiving element 137, a light reception signal corresponding to the amount of received light is output to the signal processing unit 144 via the light receiving circuit 147.
The signal processing unit 144 compares the spectrum data of the Raman scattered light corresponding to the gas molecule to be detected obtained as described above and the data stored in the ROM, and determines whether or not the target gas molecule is the target gas molecule. To determine the substance. Further, the signal processing unit 144 displays the result information on the display unit 141 or outputs the result information from the connection unit 142 to the outside.

  8 and 9, the gas detection device 100 that performs gas detection from the Raman scattered light obtained by dispersing the Raman scattered light by the wavelength variable interference filter 5 is illustrated. You may use as a gas detection apparatus which specifies gas classification by detecting the light absorbency of. In this case, a gas sensor that allows gas to flow into the sensor and detects light absorbed by the gas in the incident light is used as the optical module of the present invention. A gas detection device that analyzes and discriminates the gas flowing into the sensor by such a gas sensor is an electronic apparatus of the present invention. Even in such a configuration, it is possible to detect a gas component using the wavelength variable interference filter.

In addition, the system for detecting the presence of a specific substance is not limited to the detection of the gas as described above, but a non-invasive measuring device for saccharides by near-infrared spectroscopy, and non-invasive information on food, living body, minerals, etc. A substance component analyzer such as a measuring device can be exemplified.
Hereinafter, a food analyzer will be described as an example of the substance component analyzer.

FIG. 10 is a diagram illustrating a schematic configuration of a food analyzer that is an example of an electronic apparatus using the wavelength tunable interference filter 5.
As shown in FIG. 10, the food analysis device 200 includes a detector 210 (optical module), a control unit 220, and a display unit 230. The detector 210 includes a light source 211 that emits light, an imaging lens 212 into which light from the measurement target is introduced, a wavelength variable interference filter 5 that splits the light introduced from the imaging lens 212, and the dispersed light. And an imaging unit 213 (detection unit) for detecting.
In addition, the control unit 220 controls the light source control unit 221 that controls the turning on / off of the light source 211 and the brightness control at the time of lighting, the voltage control unit 222 that controls the wavelength variable interference filter 5, and the imaging unit 213. , A detection control unit 223 that acquires a spectral image captured by the imaging unit 213, a signal processing unit 224, and a storage unit 225.

  In the food analyzer 200, when the system is driven, the light source 211 is controlled by the light source control unit 221, and light is irradiated from the light source 211 to the measurement object. Then, the light reflected by the measurement object enters the wavelength variable interference filter 5 through the imaging lens 212. The variable wavelength interference filter 5 is applied with a voltage capable of dispersing a desired wavelength under the control of the voltage control unit 222, and the dispersed light is imaged by an imaging unit 213 configured by, for example, a CCD camera or the like. The captured light is accumulated in the storage unit 225 as a spectral image. In addition, the signal processing unit 224 controls the voltage control unit 222 to change the voltage value applied to the wavelength tunable interference filter 5, and acquires a spectral image for each wavelength.

Then, the signal processing unit 224 performs arithmetic processing on the data of each pixel in each image accumulated in the storage unit 225, and obtains a spectrum at each pixel. In addition, the storage unit 225 stores, for example, information related to food components with respect to the spectrum, and the signal processing unit 224 analyzes the obtained spectrum data based on the information related to food stored in the storage unit 225. The food component contained in the detection target and the content thereof are obtained. Moreover, a food calorie, a freshness, etc. are computable from the obtained food component and content. Furthermore, by analyzing the spectral distribution in the image, it is possible to extract a portion of the food to be inspected that has reduced freshness, and to detect foreign substances contained in the food. Can also be implemented.
Then, the signal processing unit 224 performs processing for causing the display unit 230 to display information such as the components and contents of the food to be examined, the calories, and the freshness obtained as described above.

FIG. 10 shows an example of the food analysis apparatus 200, but it can also be used as a non-invasive measurement apparatus for other information as described above with a substantially similar configuration. For example, it can be used as a biological analyzer for analyzing biological components such as measurement and analysis of body fluid components such as blood. As such a bioanalytical device, for example, a device that detects ethyl alcohol as a device that measures a body fluid component such as blood, it can be used as a drunk driving prevention device that detects the drunk state of the driver. Further, it can also be used as an electronic endoscope system provided with such a biological analyzer.
Furthermore, it can also be used as a mineral analyzer for performing component analysis of minerals.

Furthermore, the variable wavelength interference filter, the optical module, and the electronic apparatus of the present invention can be applied to the following apparatuses.
For example, it is possible to transmit data using light of each wavelength by changing the intensity of light of each wavelength over time. In this case, light of a specific wavelength is transmitted by a wavelength variable interference filter provided in the optical module. The data transmitted by the light of the specific wavelength can be extracted by separating the light and receiving the light at the light receiving unit, and the electronic data having such a data extraction optical module can be used to extract the light data of each wavelength. By processing, optical communication can be performed.

Further, the electronic apparatus can be applied to a spectroscopic camera, a spectroscopic analyzer, or the like that captures a spectroscopic image by dispersing light with the variable wavelength interference filter of the present invention. An example of such a spectroscopic camera is an infrared camera incorporating a wavelength variable interference filter.
FIG. 11 is a schematic diagram showing a schematic configuration of the spectroscopic camera. As shown in FIG. 11, the spectroscopic camera 300 includes a camera body 310, an imaging lens unit 320, and an imaging unit 330 (detection unit).
The camera body 310 is a part that is gripped and operated by a user.
The imaging lens unit 320 is provided in the camera body 310 and guides incident image light to the imaging unit 330. Further, as shown in FIG. 11, the imaging lens unit 320 includes an objective lens 321, an imaging lens 322, and a variable wavelength interference filter 5 provided between these lenses.
The imaging unit 330 includes a light receiving element, and images the image light guided by the imaging lens unit 320.
In such a spectroscopic camera 300, a spectral image of light having a desired wavelength can be captured by transmitting light having a wavelength to be imaged by the variable wavelength interference filter 5.

Furthermore, the wavelength tunable interference filter of the present invention may be used as a bandpass filter. For example, only light in a narrow band centered on a predetermined wavelength out of light in a predetermined wavelength range emitted from the light emitting element can be wavelength-variable. It can also be used as an optical laser device that spectrally transmits through an interference filter.
In addition, the tunable interference filter of the present invention may be used as a biometric authentication device, and can be applied to authentication devices such as blood vessels, fingerprints, retinas, and irises using light in the near infrared region and visible region.

  Furthermore, an optical module and an electronic device can be used as a concentration detection device. In this case, the infrared energy (infrared light) emitted from the substance is spectrally analyzed by the variable wavelength interference filter, and the analyte concentration in the sample is measured.

  As described above, the variable wavelength interference filter, the optical module, and the electronic apparatus of the present invention can be applied to any device that splits predetermined light from incident light. Since the wavelength tunable interference filter according to the present invention can split a plurality of wavelengths with one device as described above, it is possible to accurately measure a spectrum of a plurality of wavelengths and detect a plurality of components. it can. Therefore, compared with the conventional apparatus which takes out a desired wavelength with a plurality of devices, it is possible to promote downsizing of the optical module and the electronic apparatus, and for example, it can be suitably used as a portable or in-vehicle optical device.

  In addition, the specific structure for carrying out the present invention can be appropriately changed to another structure or the like as long as the object of the present invention can be achieved.

  5 ... variable wavelength interference filter (interference filter), 51 ... fixed substrate (first substrate), 52 ... movable substrate (second substrate), 54 ... fixed reflection film (first reflection film), 55 ... movable reflection film (first film) Two reflecting films), 531... First bonding film, 532... Second bonding film, G1.

Claims (3)

A first substrate on which the first reflective film is provided; and a second substrate on which the second reflective film is provided to face the first reflective film with a gap having a predetermined size and is bonded to the first substrate A method for producing an interference filter comprising:
A first film forming step of forming the first reflective film and the first bonding film on the first substrate;
A second film forming step of forming the second reflective film and the second bonding film on the second substrate;
An activation step of activating the first bonding film and the second bonding film by performing N ₂ plasma processing or Ar plasma processing on the first bonding film and the second bonding film;
The first substrate and the second substrate are bonded by bonding the first bonding film activated in the activation step and the second bonding film activated in the activation step. Joining process;
With
In the activation step,
A region that covers the region that overlaps the first reflective film and that overlaps the first bonding film in a first substrate plan view when the first substrate is viewed from the direction of plasma irradiation in the N ₂ plasma treatment or the Ar plasma treatment Using the first metal mask that opens, the first bonding film is activated,
In the second substrate plan view of the second substrate viewed from the plasma irradiation direction in the N ₂ plasma treatment or the Ar plasma treatment, a region that covers the region overlapping the second reflective film and overlaps the second bonding film Using the second metal mask that opens, the second bonding film is activated ,
In the bonding step, after the first bonding film and the second bonding film are bonded, an annealing process is performed on the first bonding film and the second bonding film in an inert gas atmosphere or in a vacuum. A method for manufacturing an interference filter, characterized in that : In the manufacturing method of the interference filter according to claim 1,
In the bonding step, after the first bonding film and the second bonding film are bonded, an ultraviolet irradiation treatment is performed on the first bonding film and the second bonding film in an inert gas atmosphere or in a vacuum. A method for manufacturing an interference filter, characterized in that the method is implemented. In the manufacturing method of the interference filter according to claim 2,
In the bonding step, a light shielding mask that shields light incident on the first reflective film and the second reflective film is used, and light incident on the first reflective film and the second reflective film is shielded. An interference filter manufacturing method, wherein the ultraviolet irradiation treatment is performed in a state.

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