JP5157920B2 - Fabry-Perot interferometer and manufacturing method thereof - Google Patents

Description

  The present invention relates to a Fabry-Perot interferometer and a method for manufacturing the same.

  Conventionally, a Fabry-Perot interferometer using MEMS (MicroElectro Mechanical System) technology has been proposed for the purpose of downsizing the Fabry-Perot interferometer. In this Fabry-Perot interferometer, a pair of mirrors is constituted by an optical multilayer film in which a high refractive index layer such as silicon and germanium and a low refractive index layer such as a silicon oxide film and a silicon nitride film are alternately laminated. These mirrors are arranged to face each other via a gap (air gap). Then, by applying an electrostatic force between the two mirrors, the width of the gap can be changed, and thus the transmission wavelength can be changed.

  Among them, the Fabry-Perot interferometer shown in Patent Document 1 by the present applicant is a mirror in which an air layer having a refractive index smaller than that of the above material is interposed as a low refractive index layer between the above high refractive index layers ( By adopting an air mirror (hereinafter, referred to as an air mirror), the mirror's own high-reflective band is widened to realize a broadband spectral operation that has not been achieved in the past. An air mirror having an air layer has low mechanical strength and may cause warping of the high refractive index layer on the air layer. Therefore, a portion (reinforcing part) where the high refractive index layers are partially in contact with each other is provided. The air mirror is divided (subdivided) into a plurality of regions to ensure mechanical strength.

JP 2008-134388 A

  In the Fabry-Perot interferometer disclosed in Patent Document 1, when a voltage is applied to both mirrors (upper mirror and lower mirror), the entire high refractive index layer constituting the upper mirror becomes the same potential, and the lower mirror is configured. The entire high refractive index layer is at the same potential. In other words, among the high refractive index layers constituting the upper mirror, the entire high refractive index layer (third high refractive index layer) on the lower mirror side and the upper side among the high refractive index layers constituting the lower mirror. It has a structure in which electrostatic force acts on the entire high refractive index layer (second high refractive index layer) on the mirror side.

  By the way, as described above, each mirror is partially divided into a plurality of portions (reinforcing portions) where the high refractive index layers contact each other, but an air layer is interposed between the high refractive index layers. It has an air mirror. Since the two high refractive index layers are in contact with each other and the reinforcing portion has a highly rigid structure, when the above-described electrostatic force is applied, the reinforcing portion is displaced while substantially maintaining flatness.

  On the other hand, since the high refractive index layers of the air mirror are not in contact with each other, and the air layer is interposed, when the electrostatic force acts, the second high refractive index layer that faces the gap and directly receives the electrostatic force, A phenomenon occurs in which the displacement of the third high refractive index layer becomes larger than the displacement of the remaining high refractive index layers. In other words, the high refractive index layer on the side of the air mirror that is close to the counterpart mirror has a deformed shape that protrudes in the direction of the counterpart mirror.

  From the above, in the above configuration, the gap width variation in the opposing mirror region becomes large, and there is a possibility that the full width at half maximum (FWHM) of the transmission wavelength of the Fabry-Perot interferometer may be increased. The resolution may be reduced.

  In view of the above problems, an object of the present invention is to provide a Fabry-Perot interferometer having a wide spectral band and a small half-value width of a transmission wavelength and a method for manufacturing the same.

  In order to achieve the above object, the invention according to claim 1 is arranged on the first mirror via the substrate, the first mirror disposed on the substrate, and the support, and bridges the gap between the supports. A second mirror opposite to the first mirror, the part of which is a membrane, and the first mirror and the second mirror based on the voltage applied between the first mirror side electrode and the second mirror side electrode, The Fabry-Perot interferometer is configured such that the membrane is displaced by the electrostatic force generated between the two and the gap width changes. The first mirror is composed of a high refractive index lower layer disposed on the substrate as a high refractive index layer having a higher refractive index than air, and a high refractive index upper layer disposed on the high refractive index lower layer. An air mirror having an optical multilayer structure in which an air layer is interposed between a high-refractive index lower layer and a high-refractive index upper layer in the width direction of the gap, and a connecting portion that divides the air mirror into a plurality and connects the air mirrors. And a peripheral region sandwiching the mirror region in at least one direction perpendicular to the width direction. The second mirror is a high refractive index layer having a higher refractive index than air, and a high refractive index lower layer disposed on the support by bridging the gap, and a high refractive index disposed on the high refractive index lower layer. An air mirror having an optical multilayer structure in which an air layer is interposed between a high refractive index lower layer and a high refractive index upper layer in the width direction, and the air mirror is divided into a plurality of pieces and connected to each other in the width direction. A mirror region opposite to the mirror region on the first mirror side, and a peripheral region sandwiching the mirror region in at least one direction perpendicular to the width direction. A part of the area and a mirror area are included. At least one of the first mirror and the second mirror is provided with a wiring that is electrically insulated and separated from the corresponding high-refractive index lower layer and the high-refractive index upper layer. The wiring is electrically connected to the wiring without being electrically connected to the upper layer of the refractive index, and the wiring is not arranged in the air mirror but arranged in the connecting portion in the corresponding mirror region.

  In the present invention, the second mirror and the first mirror have an optical mirror having an optical multilayer structure as a mirror region. This air mirror has a large n ratio (refractive index of the high refractive index layer / refractive index of the low refractive index layer) between the high refractive index layer and the air layer as the low refractive index layer. As a result, it is a Fabry-Perot interferometer with a wide spectral band.

  Further, in the mirror region, the air mirror is divided (subdivided) into a plurality of parts by the connecting portion, so that it is a Fabry-Perot interferometer in which the mechanical strength of the air mirror is particularly secured.

  In addition, at least one of the first mirror and the second mirror is electrically connected to an electrode for applying a voltage. This wiring is electrically insulated and separated from the high refractive index lower layer and the high refractive index upper layer of the corresponding mirror, and in the corresponding mirror region, it is not arranged in the air mirror but in the connecting portion. That is, the wiring has the same potential as the electrode, and no potential is applied to the high refractive index layer. Therefore, in the mirror provided with wiring, electrostatic force does not act on the air mirror, and the high refractive index layer facing the opposite mirror in the air mirror (the portion of the high refractive index upper layer located on the air layer in the first mirror, In the second mirror, deformation of the high refractive index lower layer) is suppressed. Thereby, the dispersion | variation in the width | variety of the space | gap between a 1st mirror and a 2nd mirror is suppressed, and it is a Fabry-Perot interferometer with a small half value width (FWHM) of a transmission wavelength.

  The mirror region is an aggregate of air mirrors having an optical multilayer film structure, and is a part of the first mirror and the second mirror that functions as a mirror that actually reflects light.

  By the way, the second mirror is a mirror that is displaced at least by the electrostatic force, and in a state where the electrostatic force is applied, the membrane is bent toward the first mirror with the portion supported by the support as a fulcrum. It becomes. Therefore, in the structure in which the membrane composed of the high refractive index upper layer and the high refractive index lower layer has the mirror region including the air mirror and the peripheral region, the rigidity of the mirror region is lower than that of the peripheral region because the air mirror is included. Since the mirror region is more easily deformed, the variation in the width of the gap in the mirror region is increased.

  On the other hand, in the invention according to claim 2, the wiring is provided in the second mirror. As described above, when the wiring is provided in the second mirror, the thickness of the connecting portion that subdivides the air mirror includes the wiring and the insulating member that insulates and separates the wiring and the high refractive index layer, so that the thickness is substantially increased. Even if force is applied, the connecting portion is less likely to be distorted. Accordingly, since the membrane is displaced in a state where a plurality of air mirrors are connected by the connecting portion where the wiring is arranged, that is, in a state where the rigidity of the entire mirror region is increased, the mirror region when the electrostatic force acts is changed. The amount of deformation can be made smaller than in a configuration in which no wiring is provided at the connecting portion, and as a result, the variation in the width of the gap can be made smaller. That is, the half width (FWHM) of the transmission wavelength can be further reduced.

  Specifically, as described in claim 3, of the first mirror and the second mirror, the high refractive index upper layer of the mirror provided with the wiring is disposed on the high refractive index lower layer. In an air mirror of a mirror that includes a refractive index layer and a second high refractive index layer disposed on the first high refractive index layer and is provided with a wiring, the first high refractive index layer and the second high refractive index layer An air mirror is interposed between the high refractive index upper layer and the high refractive index lower layer, and the first high refractive index layer is in contact with the high refractive index lower layer and is adjacent to the mirror in which the wiring is provided. A recess having the surface of the first high-refractive-index layer as a wall is formed between the second high-refractive-index layer and the recess is sealed by the second high-refractive-index layer. The insulating member is filled, and the wiring is embedded in the insulating member. The air mirror of the first mirror and the second mirror The may be configured to through hole penetrating a portion of the high refractive index layer are provided, respectively.

  The Fabry-Perot interferometer having such a configuration is formed by the manufacturing method according to claim 9 described later. Since the effect of this invention is the same as the effect of the invention of Claim 9, the description is abbreviate | omitted.

  In addition, as described in claim 4, in the air mirror of the mirror provided with wiring among the first mirror and the second mirror, an air layer is interposed between the high refractive index upper layer and the high refractive index lower layer, In the connecting portion of the mirror provided with the wiring, a recess having a high refractive index lower layer as a bottom surface and a high refractive index upper layer surface as a side surface is formed between adjacent air mirrors, and the high refractive index upper layer bridges the recess. The recess sealed with the high refractive index upper layer is filled with an insulating member, and the wiring is embedded in the insulating member. The air mirror of the first mirror and the second mirror has a high refractive index upper layer. It is good also as a structure by which the through-hole which penetrates one part was each provided.

  The Fabry-Perot interferometer having such a configuration is formed by the manufacturing method according to claim 10 described later. Since the effect of this invention is the same as the effect of the invention of Claim 10, the description is abbreviate | omitted.

  According to a fifth aspect of the present invention, in the recess, the wiring is preferably arranged at a position closer to the mirror on the other side than the middle line of the recess in the width direction.

  According to this, since the distance between the wiring in the mirror region and the part having the same potential as the electrode in the mirror on the other side (wiring in the configuration in which the wiring is provided) is shortened, the second mirror is driven with a low voltage. Is possible.

  In particular, when the first mirror and the second mirror have a configuration in which the layout of the air mirror and the connecting portion in each mirror region coincide with each other as described in claim 6, the wiring approaches the counterpart mirror as described above. Therefore, the lines of electric force generated from the wiring are likely to go to the opposing connecting portion in the mirror region of the counterpart mirror. Therefore, in a configuration in which no wiring is provided in the other mirror and the entire high refractive index layer is at the same potential as the electrode, the electrostatic force acting between the wiring and the connecting portion in the other mirror is The electrostatic force acting between the air mirror of the counterpart mirror can be made larger. That is, deformation of the air mirror in the counterpart mirror can be suppressed.

  As described in claim 7, of the high refractive index upper layer constituting the air mirror, the portion located on the side surface of the air layer has a width in the direction perpendicular to the width direction of the air layer that is lower than the high refractive index lower layer in the width direction. It is preferable to have a configuration having an aspect that becomes wider as it gets closer.

  By providing an inclination in this way, stress concentration can be suppressed. Specifically, the stress applied by the weight of the portion parallel to the high refractive index lower layer among the high refractive index upper layers constituting the air mirror can be reduced. Therefore, the deformation of the high refractive index upper layer in the air mirror can be effectively suppressed.

  As described in claim 8, in the mirror region, each of the air mirrors divided by the connecting portion preferably has a hexagonal shape in the plane perpendicular to the width direction, and the connecting portion may have a honeycomb shape.

  Thus, when the connecting portion is formed in a honeycomb shape, the area occupied by the air mirror that actually functions as a mirror can be increased in the mirror region while realizing reinforcement by the connecting portion.

  Next, the invention according to claim 9 is a method of manufacturing the Fabry-Perot interferometer according to claim 3, wherein the first mirror is a part of the substrate or the second mirror is a part forming a gap. A step of laminating a high refractive index lower layer on one surface of the support before being removed, a step of selectively forming a sacrificial layer corresponding to the air layer of the air mirror on the surface of the high refractive index lower layer, A step of laminating the first high refractive index layer so as to cover the high refractive index lower layer and the sacrificial layer; a step of laminating the first insulating layer on the surface of the first high refractive index layer; and a surface of the first insulating layer. In addition, the step of selectively forming the wiring, the step of laminating the second insulating layer so as to cover the first insulating layer and the wiring, and the part adjacent to the wiring and the part located in the recess are left. Removing the first insulating layer and the second insulating layer, and after the removing step, removing the second high refractive index layer A step of layering, a step of forming a first high refractive index layer and a second high refractive index layer, removing the sacrificial layer through a through-hole provided in the upper layer of the high refractive index at the air mirror formation site, and forming an air layer; It is characterized by providing.

  According to the present invention, the high refractive index constituting the air mirror while leaving the first insulating layer and the second insulating layer in the recess sealed by the second high refractive index layer constituting the high refractive index upper layer as the insulating member. The first insulating layer and the second insulating layer interposed between the upper layer and the high refractive index lower layer can be removed by etching through a through hole to form an air layer. That is, while ensuring electrical insulation between the wiring and the high-refractive index layer (the high-refractive index upper layer and the high-refractive index lower layer), the thickness of the connecting portion (including the wiring and the insulating member) is set to the periphery of the membrane. It can be thicker than part of the region. That is, the Fabry-Perot interferometer according to claim 3 can be formed.

  The invention described in claim 10 is a method for manufacturing the Fabry-Perot interferometer described in claim 4, wherein the first mirror has a portion on one side of the substrate or the second mirror has a portion forming a gap. A step of laminating a high refractive index lower layer on one surface of the support before removal, a step of laminating a first insulating layer on the surface of the high refractive index lower layer, and selective wiring on the surface of the first insulating layer Forming the first insulating layer, the step of laminating the second insulating layer so as to cover the first insulating layer and the wiring, and the first insulating layer and the first insulating layer, leaving only the portion adjacent to the wiring and the portion located in the mirror region. (2) a step of removing the insulating layer, and a trench reaching the high refractive index lower layer is formed in a portion of the remaining first insulating layer and second insulating layer that constitutes the side surface of the recess in the portion located in the mirror region. The first insulating layer and the second insulating layer correspond to the air layer High refractive index on the lower layer of the high refractive index so as to divide the region into a portion corresponding to the insulating member including the wiring, and to fill the trench and cover the remaining first insulating layer and second insulating layer The step of laminating the upper layer, and the step of removing the first insulating layer and the second insulating layer corresponding to the air layer through the through hole provided in the high refractive index upper layer in the air mirror forming portion to form the air layer And a manufacturing method of a Fabry-Perot interferometer.

  According to the present invention, between the high refractive index upper layer and the high refractive index lower layer constituting the air mirror, leaving the first insulating layer and the second insulating layer in the recess sealed by the high refractive index upper layer as insulating members. About the 1st insulating layer and 2nd insulating layer which were interposed in, it can remove by an etching through a through-hole, and can be used as an air layer. That is, the thickness of the connecting portion (including the wiring and the insulating member) can be made thicker than a part of the peripheral region constituting the membrane while ensuring electrical insulation between the wiring and the high refractive index layer. . That is, the Fabry-Perot interferometer according to claim 4 can be formed.

  Further, although the number of steps for forming the trench is increased as compared with the manufacturing method according to claim 9, the step for forming the sacrificial layer is eliminated and the number of steps for forming the high refractive index upper layer is reduced from two to one. Therefore, the manufacturing process can be simplified.

  As described in claim 11, in the step of forming the air layer, it is preferable to remove a portion constituting the void in the support. According to this, the manufacturing process can be simplified.

It is sectional drawing which shows schematic structure of the conventional Fabry-Perot interferometer which has an air mirror. In the Fabry-Perot interferometer shown in FIG. 1, it is typical sectional drawing which shows a deformation | transformation of the air mirror at the time of applying a voltage. It is sectional drawing which shows schematic structure of the Fabry-Perot interferometer which concerns on 1st Embodiment. It is the top view seen from the 2nd mirror side. It is typical sectional drawing which shows the effect of a deformation | transformation suppression of an air mirror, (a) is the Fabry-Perot interferometer which concerns on this embodiment, (b) has shown the conventional Fabry-Perot interferometer as a comparative example. It is typical sectional drawing which shows the effect of the rigidity improvement of a mirror area | region, A solid line has shown the Fabry-Perot interferometer which concerns on this embodiment, and the broken line has shown the conventional Fabry-Perot interferometer as a comparative example. It is sectional drawing according to the process which shows the manufacturing method of a Fabry-Perot interferometer. It is sectional drawing according to the process which shows the manufacturing method of a Fabry-Perot interferometer. It is sectional drawing which shows schematic structure of the Fabry-Perot interferometer which concerns on 2nd Embodiment. It is sectional drawing which shows schematic structure of the Fabry-Perot interferometer which concerns on 3rd Embodiment. It is sectional drawing according to the process which shows the manufacturing method of a Fabry-Perot interferometer.

  First, before describing the embodiment of the present invention, the background of the inventor's creation of the present invention will be described. FIG. 1 is a cross-sectional view showing a schematic configuration of a conventional Fabry-Perot interferometer having an air mirror. FIG. 2 is a schematic cross-sectional view showing the deformation of the air mirror when a voltage is applied in the Fabry-Perot interferometer shown in FIG. The Fabry-Perot interferometer shown in FIG. 1 is disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2008-134388) by the present applicant, and will be briefly described below. Further, the width direction of the gap, in other words, the displacement direction of the second mirror when a voltage is applied or the stacking direction of the first mirror with respect to the substrate is simply referred to as the width direction.

  A Fabry-Perot interferometer 100 shown in FIG. 1 is formed using MEMS technology, and a semiconductor substrate made of, for example, silicon as the substrate 10, a first mirror 30 disposed on the substrate 10, and, for example, silicon A portion that is disposed on the first mirror 30 via the support 50 made of an oxide film and bridges a gap (hereinafter referred to as an air gap AG) between the supports 50 is the membrane MEM and faces the first mirror 30. And a second mirror 70. The membrane MEM is displaced by the electrostatic force generated between the first mirror 30 and the second mirror 70 based on the voltage applied between the electrode 34 on the first mirror 30 side and the electrode 74 on the second mirror 70 side. The width of the air gap AG in the width direction (hereinafter simply referred to as the width of the air gap AG) is changed. In other words, the width of the air gap AG is the facing distance between the membrane MEM of the second mirror 70 and the portion of the first mirror 30 facing the membrane MEM.

  The first mirror 30 is made of, for example, polysilicon, and a high refractive index lower layer 31 laminated on the entire surface of the substrate 10 with the insulating film 11 interposed therebetween. The first mirror 30 is made of, for example, polysilicon and is laminated on the high refractive index lower layer 31. And a high refractive index upper layer 32. In the width direction, an air mirror having an optical multilayer structure in which a portion where an air layer 33 as a low refractive index layer is interposed between the high refractive index lower layer 31 and the high refractive index upper layer 32 actually functions as a mirror. M1. The air mirror M1 is divided into a plurality of parts (divided) by a connecting part C1 in which a portion 32a of the high refractive index upper layer 32 is in contact with the high refractive index lower layer 31, and each air mirror M1 is connected by the connecting part C1. Has been. And the formation area of these air mirror M1 and connection part C1 is the mirror area | region P1 which is an aggregate | assembly of the air mirror M1. Further, in the peripheral region surrounding the mirror region P1, the high refractive index upper layer 32 is in contact with the high refractive index lower layer 31, and the electrode 34 is disposed on the high refractive index upper layer 32 at a portion outside the membrane MEM in the peripheral region. Is formed.

  On the other hand, the second mirror 70 is made of, for example, polysilicon, and a high refractive index lower layer 71 disposed on the support 50 by bridging the air gap AG, and is made of, for example, polysilicon and laminated on the high refractive index lower layer 71. The high refractive index upper layer 72 is formed. In the width direction, an air mirror having an optical multilayer structure in which a portion where an air layer 73 as a low refractive index layer is interposed between the high refractive index lower layer 71 and the high refractive index upper layer 72 actually functions as a mirror. It is M2. The air mirror M2 is divided (divided) into a plurality of parts by a connecting part C2 in which a portion 72a of the high refractive index upper layer 72 is in contact with the high refractive index lower layer 71. Each air mirror M2 is connected by the connecting part C2. Has been. The formation region of the air mirror M2 and the connecting portion C2 is a mirror region P2 that is an aggregate of the air mirrors M2, and the mirror region P2 faces the mirror region P1 of the first mirror 30. Further, in the peripheral region surrounding the mirror region P2, the high refractive index upper layer 72 is in contact with the high refractive index lower layer 71, and an electrode 74 is provided on the high refractive index upper layer 72 at a portion outside the membrane MEM in the peripheral region. Is formed. The above-described membrane MEM is configured by the mirror region P2 and a part of the peripheral region that bridges the air gap AG.

  As described above, in the Fabry-Perot interferometer 100 shown in FIG. 1, only the membrane MEM of the second mirror 70 out of the pair of mirrors 30 and 70 can be displaced by electrostatic force. Reference numeral 51 shown in FIG. 1 is an opening as a contact hole that penetrates the support 50 outside the membrane MEM and reaches the high refractive index upper layer 32, and the electrode 34 described above is formed in the opening 51. Has been. Reference numeral 75 denotes a through-hole that penetrates the high refractive index lower layer 71 and the high refractive index upper layer 72 in the membrane MEM and communicates the air gap AG with the outside.

  The present inventor has further studied the Fabry-Perot interferometer 100 as described above. As a result, when a voltage is applied between the electrodes 34 and 74 and an electrostatic force acts on the first mirror 30 and the second mirror 70, the air mirrors M1 and M2 are not fixed to other members as shown in FIG. It was revealed that the high refractive index upper layers 32 and 72 and the high refractive index lower layer 71 are deformed in a convex shape toward the other mirror. Further, the deformation amount in the width direction is larger in the high refractive index upper layer 32 and the high refractive index lower layer 71 which are opposed to each other through the air gap AG and directly subjected to electrostatic force than the high refractive index upper layer 72.

  The inventor considered that such a deformation phenomenon of the air mirrors M1 and M2 occurs due to the following reason. In the Fabry-Perot interferometer 100 described above, when a voltage is applied between the electrodes 34 and 74, the entire high refractive index layers 31 and 32 constituting the first mirror 30 have the same potential, and the high refractive index constituting the second mirror 70. The entire layers 71 and 72 are at the same potential. In other words, an electrostatic force acts on the entire high refractive index upper layer 32 and the entire high refractive index lower layer 71 opposed via the air gap AG.

  Further, as described above, the mirror regions P1 and P2 are configured by the air mirrors M1 and M2 and the connecting portions C1 and C2, respectively. The connecting portions C1 and C2 are reinforcing portions formed by bringing the high refractive index lower layers 31 and 71 into contact with the corresponding high refractive index upper layers 32 and 72, and have a structure having higher rigidity than the air mirrors M1 and M2. Therefore, even if the above-described electrostatic force is applied, the displacement is performed while the flatness is substantially maintained. On the other hand, the air mirrors M1 and M2 are not in contact with the high refractive index lower layers 31 and 71 and the corresponding high refractive index upper layers 32 and 72, and the air layers 33 and 73 are interposed therebetween. The high-refractive index upper layers 32 and 72 and the high-refractive index lower layer 71, particularly the high-refractive index upper layer 32 and the high-refractive index lower layer 71, which are not fixed to other members, are pulled in the direction of the counterpart mirror and deformed. Conceivable.

  When the air mirrors M1 and M2 are deformed in this way, the air mirrors M1 and M2 are convex, and thus the variation in the width of the air gap AG when an electrostatic force is applied increases, and the Fabry-Perot interferometer 100 as a whole is deformed. There is a possibility that the full width at half maximum (FWHM) of the transmission wavelength may be increased, that is, the resolution of the Fabry-Perot interferometer 100 may be reduced. The present invention is based on this finding, and hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 3 is a cross-sectional view illustrating a schematic configuration of the Fabry-Perot interferometer according to the first embodiment. FIG. 4 is a plan view seen from the second mirror side. 5A and 5B are schematic cross-sectional views showing the effect of suppressing deformation of the air mirror. FIG. 5A shows a Fabry-Perot interferometer according to this embodiment, and FIG. 5B shows a conventional Fabry-Perot interferometer as a comparative example. ing. FIG. 6 is a schematic cross-sectional view showing the effect of improving the rigidity of the mirror region. A solid line indicates a Fabry-Perot interferometer according to this embodiment, and a broken line indicates a conventional Fabry-Perot interferometer as a comparative example.

  In the following, the same elements as those shown in FIG. 1 are given the same reference numerals. Similarly to the above, the width direction of the air gap AG, in other words, the stacking direction of the first mirror with respect to the substrate is simply referred to as the width direction, and the direction perpendicular to the width direction is simply referred to as the vertical direction.

  As shown in FIGS. 3 and 4, the Fabry-Perot interferometer 100 according to the present embodiment has the same basic structure as the Fabry-Perot interferometer 100 shown in FIG. This part is different from the Fabry-Perot interferometer 100 shown in FIG.

  That is, the Fabry-Perot interferometer 100 according to the present embodiment is also disposed on the first mirror 30 via the substrate 10, the first mirror 30 disposed on the substrate 10, and the support 50. A portion that bridges the air gap AG is a membrane MEM, and includes a second mirror 70 that faces the first mirror 30. The membrane MEM is displaced by the electrostatic force generated between the first mirror 30 and the second mirror 70 based on the voltage applied between the electrode 34 on the first mirror 30 side and the electrode 74 on the second mirror 70 side. The width of the air gap AG in the width direction is changed.

  Also in this embodiment, a semiconductor substrate made of, for example, single crystal silicon is employed as the substrate 10, and the first mirror 30 is disposed on one surface of the substrate 10.

  The first mirror 30 is made of a material having a refractive index higher than that of air, for example, polysilicon or polygermanium, and a high refractive index lower layer 31 laminated on the entire surface of the substrate 10 with an insulating film 11 interposed therebetween, and the high refractive index. Similarly, the lower layer 31 is made of a high refractive index material such as polysilicon, and includes a high refractive index upper layer 32 laminated on the high refractive index lower layer 31.

  In the width direction, an air mirror having an optical multilayer structure in which a portion where an air layer 33 as a low refractive index layer is interposed between the high refractive index lower layer 31 and the high refractive index upper layer 32 actually functions as a mirror. M1. The air mirror M1 is divided into a plurality of parts (divided) by a connecting part C1 in which a portion 32a of the high refractive index upper layer 32 is in contact with the high refractive index lower layer 31, and each air mirror M1 is connected by the connecting part C1. Has been. And the formation area of these air mirror M1 and connection part C1 is the mirror area | region P1 which is an aggregate | assembly of the air mirror M1. Details of the arrangement of the air mirror M1 and the connecting portion C1 will be described later.

  Also, in at least one of the vertical directions, the high refractive index upper layer 32 is in contact with the high refractive index lower layer 31 in the peripheral region sandwiching the mirror region P1, and the second mirror 70 is opposed to the membrane MEM. An electrode 34 made of Au / Cr or the like is formed on the high refractive index upper layer 32 in the peripheral region excluding the part. In the present embodiment, the peripheral area surrounds the mirror area P1. The electrode 34 is in ohmic contact with a wiring (not shown) made of an impurity diffusion layer formed in the high refractive index upper layer 32. This wiring is not formed in the air mirror M1 in the above-described mirror region P1, but is formed only in the connecting portion C1. As described above, in the first mirror 30, although the wiring is formed in the high refractive index upper layer 32 by the diffusion of impurities, the entire high refractive index layers 31 and 32 are at the same potential as the electrode 34.

  On the high-refractive index upper layer 32 of the first mirror 30, a support 50 is locally disposed in a portion excluding a part of the peripheral region facing the mirror region P1 and the membrane MEM. The support 50 supports the second mirror 70 on the first mirror 30 and functions as a spacer for forming an air gap AG between the first mirror 30 and the second mirror 70. It is. In the present embodiment, the support body 50 is made of a silicon oxide film, and has a structure in which a central portion corresponding to the membrane MEM of the second mirror 70 is cut out. Further, an opening 51 for forming the electrode 34 is also formed at a portion outside the membrane MEM.

  On the other hand, the second mirror 70 is made of a material having a refractive index higher than that of air, such as polysilicon or polygermanium, and has a high refractive index lower layer 71 disposed on the support 50 by bridging the air gap AG, Similarly, the refractive index lower layer 71 is made of a high refractive index material such as polysilicon, and is composed of a high refractive index upper layer 72 laminated on the high refractive index lower layer 71. The high refractive index upper layer 72 includes a first high refractive index layer 76 on the high refractive index lower layer 71 side, and a second high refractive index layer 77 disposed on the first high refractive index layer 76. Yes.

  In the width direction, an air layer 73 as a low refractive index layer is interposed between the high refractive index lower layer 71 and the high refractive index upper layer 72 including the first and second high refractive index layers 76 and 77. The part is an air mirror M2 having an optical multilayer structure that actually functions as a mirror. Further, the air mirror M2 includes a connecting portion in which a portion 76a of the first high refractive index layer 76 is in contact with the high refractive index lower layer 71, and the second high refractive index layer 77 is located apart from the contact portion in the width direction. The air mirror M2 is divided (subdivided) into a plurality of parts by C2, and each air mirror M2 is connected by a connecting part C2. The formation region of the air mirror M2 and the connecting portion C2 is a mirror region P2 that is an aggregate of the air mirrors M2, and the mirror region P2 faces the mirror region P1 of the first mirror 30. Details of the arrangement of the air mirror M2 and the connecting portion C2 will be described later.

  In the mirror region P2, between the adjacent air mirrors M2, a recess having the surface of the first high refractive index layer 76 as a wall surface, more specifically, the surface of the portion 76b in contact with the side surface of the air layer 73 is defined as a side surface. A recess is formed. The second high refractive index layer 77 bridges the concave portion, and the insulating member made of a silicon oxide film or the like having a higher refractive index than air is contained in the concave portion sealed by the second high refractive index layer 77. 78 is filled, and a wiring 79 made of a metal material or the like is embedded in the insulating member 78.

  The wiring 79 is electrically connected to the electrode 74, and the above-described high refractive index layers 71 and 72 are electrically insulated and separated through an insulating member 78. Further, in the mirror region P2, it is not disposed on the air mirror M2, but is disposed only on the connecting portion C2, in other words, on one portion 76a of the first high refractive index layer 76 in the recess. That is, in the second mirror 70, only the wiring 79 is at the same potential as the electrode 74, and the high refractive index layers 71 and 72 are not at the same potential as the electrode 74 but are at a floating potential. Furthermore, in the recess, the wiring 79 is disposed closer to the first mirror 30 (high refractive index lower layer 71) than the middle line (intermediate position) of the recess in the width direction. In other words, in the insulating member 78 disposed in the recess, the thickness of the portion located between the wiring 79 and the first high refractive index layer 76 is between the wiring 79 and the second high refractive index layer 77. It is thinner than the thickness of the part located in.

  As described above, the connecting portion C2 is formed by laminating the high refractive index lower layer 71, the first high refractive index layer 76, the insulating member 78, the wiring 79, the insulating member 78, and the second high refractive index layer 77 in this order. Therefore, rigidity is ensured. Further, since the insulating member 78 has a higher refractive index than air and the metal material or the like constituting the wiring 79 absorbs light, the connecting portion C2 hardly functions as a mirror in the mirror region P2.

  Further, in at least one of the vertical directions, in a peripheral region sandwiching the mirror region P2 therebetween, a high refractive index upper layer 72 composed of the first and second high refractive index layers 76 and 77 is formed on the high refractive index lower layer 71. In particular, the part constituting the membrane MEM in the peripheral region is mainly constituted by these high refractive index layers 71 and 72.

  Here, the remaining portion of the wiring 79 that connects the electrode 74 and the portion of the wiring 79 provided along the connecting portion C2, that is, the wiring 79 arranged in the peripheral region, should ensure displaceable rigidity. The membrane MEM is disposed at a part of the site. Accordingly, the proportion of the area of the membrane MEM in the peripheral region occupied by the area where the wiring 79 (and the insulating member 78) is provided is smaller than the proportion occupied by the connecting portion C2 in the area of the mirror region P2. It has become. Further, in the mirror region P2, the wiring 79 is arranged in a honeycomb shape along the connecting portion C2, whereas in the region of the membrane MEM in the peripheral region, the wiring 79 is locally arranged in part. Therefore, in the membrane MEM that is displaced by electrostatic force, the high refractive index lower layer 71, the first high refractive index layer 76, the insulating member 78, the wiring 79, the insulating member 78, and the second high refractive index layer 77 are laminated in this order. The thickness of the connecting portion C2 in the width direction is thicker than a portion constituting most of the membrane MEM in the peripheral region. As described above, the wiring 79 (and the insulating member 78) located in the region of the membrane MEM in the peripheral region is not so much affected by the rigidity of the region of the membrane MEM in the peripheral region.

  In the peripheral region, an electrode 74 made of Au / Cr or the like is formed on the first high refractive index upper layer 76 outside the membrane MEM via a wiring 79. In the present embodiment, the peripheral area surrounds the mirror area P2. The membrane MEM described above is configured by the mirror region P2 and a part of the peripheral region that bridges the air gap AG.

  Next, the mirror areas P1 and P2 will be described in detail. In the present embodiment, the first mirror 30 and the second mirror 70 have the same layout of the air mirrors M1 and M2 and the connecting portions C1 and C2 in the respective mirror regions P1 and P2.

  The air layers 33 and 73 constituting the air mirrors M1 and M2 have a structure in which the upper surfaces are covered and the side surfaces are surrounded by the corresponding high refractive index upper layers 32 and 72. Of the high refractive index upper layers 32 and 72, the side wall portions 32b and 72b (including only 76b) surrounding the side surfaces of the air layers 33 and 73 have a high width in the vertical direction. It has an inclination that becomes wider as it approaches the refractive index lower layers 31 and 71. In detail, it inclines with respect to the corresponding high refractive index lower layers 31 and 71, and the angle is 45 degrees. Therefore, in the present embodiment, of the high refractive index upper layers 32 and 72, the portions of the air mirrors M1 and M2 corresponding to the portions covering the upper surfaces of the air layers 33 and 73 are portions that mainly function as mirrors.

  Further, as illustrated in FIG. 2 on the second mirror 70 side, in the mirror regions P1 and P2, the shape of the plane perpendicular to the width direction of the air mirrors M1 and M2 divided by the connecting portions C1 and C2, in other words, The upper surface shape of the air layers 33 and 73 is a hexagon. That is, the air layers 33 and 73 have a hexagonal frustum shape. The connecting portions C1 and C2 have a honeycomb shape, and in the mirror region P2, the wiring 79 is arranged in a honeycomb shape along the honeycomb-like connecting portion C2.

  In the Fabry-Perot interferometer 100 configured as described above, when a drive voltage is applied to the electrode 34 of the first mirror 30 and the electrode 74 of the second mirror 70, the first mirror 30 and the second mirror 70 are interposed between them. An electrostatic force (electrostatic attractive force) is generated, and the membrane MEM of the second mirror 70 is bent toward the first mirror 30 with the portion supported by the support 50 as a fulcrum. That is, the width of the air gap AG is different from the state before the drive voltage is applied. Then, it is possible to selectively transmit light having a predetermined wavelength corresponding to the width of the air gap AG.

  Reference numeral 35 shown in FIG. 3 is a through hole formed in the portion of the high refractive index upper layer 32 that covers the upper surface of the air layer 33 in the air mirror M 1 in the first mirror 30, and etching is performed through the through hole 35. Thus, the air layer 33 is formed. Reference numeral 80 shown in FIGS. 3 and 4 is a through hole formed in the portion of the high refractive index upper layer 72 that covers the upper surface of the air layer 73 in the air mirror M <b> 2 in the second mirror 70. The air layer 73 is formed by etching. The through holes 35 and 80 are formed in the air mirrors M1 and M2, respectively, and are not formed in the second high refractive index layer 77 that covers the concave portion in the second mirror 70.

  Next, the effect of the characteristic part of the Fabry-Perot interferometer 100 according to the present embodiment will be described. First, in the present embodiment, the first mirror 30 and the second mirror 70 have air mirrors M1 and M2 having an optical multilayer film structure as the mirror regions P1 and P2, respectively. The air mirrors M1 and M2 have an n ratio (the refractive index of the high refractive index layer / the refractive index of the low refractive index layer) of the high refractive index layers 31, 32, 71, 72 and the air layers 33, 73 as the low refractive index layers. ) Is large, it is a mirror with a wide band of high reflection. Thereby, the Fabry-Perot interferometer 100 according to the present embodiment is a Fabry-Perot interferometer having a wide spectral band.

  Further, in the mirror regions P1 and P2, the air mirrors M1 and M2 are divided (subdivided) into a plurality of parts by the connecting portions C1 and C2, respectively, so that the mechanical strength of the air mirrors M1 and M2 having the air layers 33 and 73 is obtained. Is secured.

  In addition, a wiring 79 is electrically connected to the electrode 74 in the second mirror 70. The wiring 79 is electrically insulated and separated from the high refractive index lower layer 71 and the high refractive index upper layer 72 (76, 77). In the mirror region P2, the wiring 79 is not disposed in the air mirror M2, but is disposed only in the connecting portion C2. Has been. That is, the wiring 79 has the same potential as the electrode 74, and the high refractive index layers 71 and 72 do not have the same potential as the electrode 74.

  Therefore, in the second mirror 70 provided with the wiring 79, the electrostatic force does not act on the air mirror M2 in a state where the drive voltage is applied, so that the air mirror M2 faces the first mirror 30 as shown in FIG. 5A. The convex deformation of the portion of the high refractive index lower layer 71 can be suppressed and displaced while maintaining the flatness substantially. On the other hand, in the conventional structure (without the wiring 79) shown as a comparative example in FIG. 5B, the electrostatic force also acts on the air mirror M2 with the driving voltage applied as described above. A portion of the high refractive index lower layer 71 facing the first mirror 30 is pulled toward the first mirror 30 and is deformed into a convex shape.

  Thus, according to the Fabry-Perot interferometer 100 according to the present embodiment, the variation in the width of the air gap AG between the mirror region P1 of the first mirror 30 and the mirror region P2 of the second mirror is suppressed, and as a result The half-width (FWHM) of the transmission wavelength can be made smaller than before.

  In the present embodiment, the high refractive index layers 71 and 72 of the second mirror 70 are set to a floating potential. Therefore, by fixing the high refractive index layers 71 and 72 at a predetermined potential, the high refractive index lower layer 71 positioned between the first mirror 30 and the electric lines of force generated from the wiring 79 when a driving voltage is applied. In addition, it is possible to avoid a state in which no electrostatic force is applied without terminating at the first high refractive index layer 76 and reaching the first mirror 30 side.

  Further, in order not to apply an electrostatic force to the air mirror M2, a structure in which the wiring 79 is arranged in a portion adjacent to the mirror region P2 in the peripheral region may be considered. However, in the deformed shape of the membrane MEM, the displacement of the peripheral region near the portion (fixed end) supported by the support body 50 is smaller than that of the central mirror region P2. The distance between the electrodes between the first mirror 70 and the second mirror 70 is increased. Since the electrostatic force is inversely proportional to the square of the distance between the electrodes, a high voltage is required during electrostatic driving. On the other hand, in the present embodiment, the wiring 79 to which a voltage is applied is disposed in the connecting portion C2 of the mirror region P2, and therefore, the electrode at the time of driving is compared with the configuration in which the wiring 79 is disposed only in the peripheral region. It is possible to reduce the distance, that is, the width of the air gap AG. Accordingly, it is possible to reduce the driving voltage while reducing the half width of the transmission wavelength.

  In the present embodiment, the wiring 79 is provided in the second mirror 70 having the membrane MEM, and in the mirror region P2, the wiring 79 is disposed not in the air mirror M2 but in the connecting portion C2. Thus, when the wiring 79 is provided on the second mirror 70 having the membrane MEM, the thickness of the connecting portion C2 that subdivides the air mirror M2 is smaller than that of the insulating member 78 and the wiring 79 compared to the configuration without the wiring 79. , Become substantially thicker. Further, as described above, the thickness of the connecting portion C2 is larger than the thickness of most of the portions of the membrane MEM in the peripheral region. Accordingly, the connecting portion C2 is less likely to be distorted even when an electrostatic force is applied. Further, in the mirror region P2, the wiring 79 is arranged in a honeycomb shape along the connecting portion C2, in other words, dispersed throughout the mirror region P2. Therefore, when the driving voltage is applied, the membrane 79 is disposed in a state where the plurality of air mirrors M2 are connected by the connecting portion C2 having increased rigidity, that is, the rigidity of the entire mirror region P2 is increased. The MEM will be displaced. As a result, as shown by the solid line in FIG. 6, the deformation amount ΔG1 of the mirror region P2 when the electrostatic force is applied is larger than the deformation amount ΔG2 of the mirror region P2 of the conventional structure as shown by the line in FIG. Can be small. Thereby, the variation in the width of the air gap AG, which is the facing distance between the mirror region P2 (air mirror M2) and the mirror region P1 (air mirror M1), can be further reduced. That is, the half-value width of the transmission wavelength can be further reduced.

  Further, in the present embodiment, in the mirror region P2, a recess having the wall surface of the surface of the first high refractive index layer 76 is formed between the adjacent air mirrors M2, and the wiring 79 connected to the electrode 74 is in the recess. Is arranged. In the recess, the wiring 79 is disposed at a position closer to the first mirror 30 (high refractive index lower layer 71) than the middle line (intermediate position) of the recess in the width direction. Specifically, in the insulating member 78 disposed in the recess, the thickness of the portion located between the wiring 79 and the first high refractive index layer 76 is between the wiring 79 and the second high refractive index layer 77. It is thinner than the thickness of the part located in. According to this, since the distance between the wiring 79 in the mirror region P2 and the high refractive index layers 31 and 32 having the same potential as the electrode 34 in the first mirror 30 is shortened, the second mirror 70 is driven with a low voltage. Is possible.

  In particular, in the present embodiment, the layout of the air mirrors M1 and M2 in the respective mirror regions P1 and P2 is the same in the first mirror 30 and the second mirror 70, and the insulating member 78 and the wiring are also connected to the connecting portions C1 and C2. Although there are 79, the layout is the same. Therefore, when the wiring 79 is arranged in the recess from the first mirror 30 as described above, the electric lines of force generated from the wiring 79 are not in the air mirror M1 but in the connecting portion C1 in the mirror region P1 of the first mirror 30. It becomes easier to face. Therefore, as shown in the present embodiment, in the first mirror 30, in the configuration in which the entire high refractive index layers 31 and 32 are at the same potential as the electrode 34, between the wiring 79 and the connecting portion C <b> 1 in the first mirror 30. Can be made larger than the electrostatic force acting between the wiring 79 and the air mirror M1 in the first mirror 30. Thereby, as shown to Fig.5 (a), (b), the convex-shaped deformation | transformation of the site | part of the high refractive index upper layer 32 in the air mirror M1 can be suppressed.

  Moreover, in this embodiment, the part located in the side surface of the air layers 33 and 73 among the high refractive index upper layers 32 and 72 constituting the air mirrors M1 and M2 is the width of the air layers 33 and 73 in the vertical direction. In the direction, the slope of the aspect becomes wider as it approaches the high refractive index lower layers 31 and 71. By providing an inclination in this way, stress concentration can be suppressed. Specifically, the stress applied by the weight of the high refractive index upper layers 32 and 72 covering the upper surfaces of the air layers 33 and 73 is reduced, and the warpage of the high refractive index upper layers 32 and 72 can be suppressed. The effect can be most obtained by setting the angle to 45 °.

  In particular, a sudden change in the neutral axis at the boundary between the mirror regions P1 and P2 and the peripheral region causes stress concentration at the change point and causes deformation. In the present embodiment, as described above, of the side wall portions 32b and 72b surrounding the side surfaces of the air layers 33 and 73, the side wall portion surrounding the side surfaces of the outer peripheral ends of the mirror regions P1 and P2 (the side wall portion 72b in the mirror region P2). Is also inclined, and has a structure in which a change in the amount of deviation of the neutral axis is small at the boundary between the mirror regions P1 and P2 and the peripheral region. Thereby, it becomes possible to suppress the curvature of the high refractive index upper layers 32 and 72.

  In the present embodiment, since the connecting portions C1 and C2 have a honeycomb shape, the air mirrors M1 and M2 are subdivided and reinforced by the connecting portions C1 and C2, and actually function as mirrors in the mirror regions P1 and P2. The area occupied by the air mirrors M1, M2 can be increased.

  Next, an example of a method for manufacturing the Fabry-Perot interferometer 100 will be described. The manufacturing method shown below is basically the same as the manufacturing method shown in Patent Document 1 by the present applicant. FIG. 7 is a cross-sectional view for each process showing the manufacturing method of the Fabry-Perot interferometer, which proceeds in the order of (a), (b), and (c). FIG. 8 is a cross-sectional view for each process showing the manufacturing method of the Fabry-Perot interferometer. The process proceeds to (a), (b), and (c) in this order following FIG.

  First, as shown in FIG. 7A, a semiconductor substrate made of single crystal silicon as a substrate 10 is prepared, and polysilicon is formed on the entire surface of the substrate 10 through an insulating film 11 made of a silicon oxide film or the like. A high refractive index lower layer 31 made of or the like is deposited. Next, a sacrificial layer 36 made of a material having a high etching selectivity with respect to the high refractive index layers 31 and 32 such as a silicon oxide film is deposited on the high refractive index lower layer 31. At this time, the thickness of the sacrificial layer 36 is equivalent to the thickness of the air layer 33 described above. Then, a mask made of resist or the like is formed on the surface of the sacrificial layer 36, and the sacrificial layer 36 is etched through the mask. In the present embodiment, isotropic wet etching is performed, and anisotropic etching (anisotropic dry etching) is performed as necessary, so that a hexagonal frustum that later becomes the air layer 33 by etching in the sacrificial layer 36. Leave only the shape part.

  Next, the mask is removed, and a high refractive index upper layer 32 made of polysilicon or the like is deposited on the high refractive index lower layer 31 so as to cover the sacrificial layer 36. At this time, since the sacrificial layer 36 has a hexagonal frustum shape, the portion of the high refractive index upper layer 32 disposed on the sacrificial layer 36 is inherited and becomes a hexagonal frustum shape. Then, a mask made of resist or the like is formed on the surface of the high-refractive index upper layer 32, and the high-refractive index upper layer 32 is etched (for example, anisotropic dry etching such as RIE) through the mask to form the sacrificial layer 36. The through-hole 35 is selectively formed in this part. Further, after removing the mask, a new mask is formed on the surface of the high refractive index upper layer 32, and impurities are ion-implanted into the high refractive index upper layer 32 through the mask. In this ion implantation, if there is an impurity in the region that becomes the air mirror M1, light is absorbed by the impurity. Therefore, in the mirror region P1, the impurity is selectively ion-implanted only in the region that becomes the connecting portion C1. . The above is the process shown in FIG. These steps are steps for forming the first mirror 30.

  Next, as shown in FIG. 7B, an insulating layer 50a such as a silicon oxide film is deposited over the entire surface of the upper layer 32 of the high refractive index film. The insulating layer 50a is a portion that will later be formed with the air gap AG to become the support 50. Therefore, the film thickness of the insulating layer 50a is set to the width of the air gap AG in a state where no driving voltage is applied. The constituent material of the insulating layer 50a is not particularly limited as long as it is an electrically insulating material, but preferably the same material as the sacrificial layer 36 is used. Depending on the thickness of the insulating layer 50a, the uneven shape of the high refractive index upper layer 32 remains on the surface of the insulating layer 50a, but the unevenness may remain.

  After the formation of the insulating layer 50a, a high refractive index lower layer 71 made of polysilicon or the like is deposited on the entire surface of the insulating layer 50a. Next, a sacrificial layer 81 made of a material having a high etching selectivity with respect to the high refractive index layers 71 and 72 (76, 77) such as a silicon oxide film is deposited on the high refractive index lower layer 71. At this time, the thickness of the sacrificial layer 81 is equivalent to the thickness of the air layer 73 described above. Then, a mask made of a resist or the like is formed on the surface of the sacrificial layer 81, and the sacrificial layer 81 is etched through the mask. In this embodiment, isotropic wet etching is performed, and anisotropic etching (anisotropic dry etching) is performed as necessary, so that a hexagonal frustum that later becomes the air layer 73 by etching in the sacrificial layer 81. Leave only the shape part.

  Next, the mask is removed, and a first high refractive index layer 76 made of polysilicon or the like is deposited on the high refractive index lower layer 71 so as to cover the sacrificial layer 81. At this time, since the sacrificial layer 81 has a hexagonal frustum shape, the portion of the first high refractive index layer 76 disposed on the sacrificial layer 81 is inherited, and the hexagonal frustum shape Become. The above is the process shown in FIG. These steps are steps for forming the support 50 and the second mirror 70.

  Next, as shown in FIG. 7C, a first insulating layer 78a made of a silicon oxide film or the like is deposited on the entire surface of the first high refractive index layer 76, and then the entire surface of the first insulating layer 78a. Then, a solid wiring layer (not shown) made of polysilicon or metal doped at a high concentration is deposited. Then, a mask made of resist or the like is formed on the surface of the wiring layer, and the wiring layer is etched through the mask. Thereby, the wiring 79 is formed.

  After the wiring 79 is formed, a second insulating layer 78b made of a silicon oxide film or the like is deposited on the first insulating layer 78a so as to cover the wiring 79. In the present embodiment, each of the first insulating layers 78a is formed so as to be thinner than the second insulating layer 78b in the recesses described above. The above is the process shown in FIG. These steps are steps for forming the second mirror 70.

  Next, a mask made of resist or the like is formed on the surface of the second insulating layer 78b, and the first insulating layer 78a and the second insulating layer 78b are etched (for example, isotropic wet etching) through the mask. . Thereby, in the first insulating layer 78a and the second insulating layer 78b, as shown in FIG. 8A, the portion adjacent to the wiring 79, that is, the portion located in the above-described recess and the peripheral region are described above. Only the part covering the part up to the electrode 74 is left. The above is the process shown in FIG. These steps are steps for forming the second mirror 70.

  Next, the mask is removed, and a second high refractive index layer 77 made of polysilicon or the like is formed on the first high refractive index layer 76 so as to cover the first insulating layer 78a, the wiring 79, and the second insulating layer 78b. To form a deposit. As a result, the connecting portion C2 becomes thicker than most of the peripheral region and has a highly rigid structure, and the wiring 79 is electrically insulated from the high refractive index layers 71, 76, and 77. Further, since the first insulating layer 78a, the wiring 79, and the second insulating layer 78b in the concave portion are sealed by the first high refractive index layer 76 and the second high refractive index layer 77, this allows Etching at the time of forming the air gap AG and the air layers 33 and 73 can prevent the first insulating layer 78a and the second insulating layer 78b in the recess from being etched. The second high refractive index layer 77 and the first high refractive index layer 76 become the high refractive index upper layer 72 of the second mirror 70. The above is the process shown in FIG. These steps are steps for forming the second mirror 70.

  In the present embodiment, the thicknesses of the high-refractive index lower layer 31, the high-refractive index upper layer 32, the high-refractive index lower layer 71, and the high-refractive index upper layer 72 are all substantially equal, and constitute the high-refractive index upper layer 72. Each thickness of the first high refractive index layer 76 and the second high refractive index layer 77 is half of the above thickness.

  Next, a mask made of resist or the like is formed on the surface of the second high refractive index layer 77, and etching (anisotropic dry etching such as RIE) is performed through the mask. As a result, as shown in FIG. 8C, a peripheral region corresponding to the membrane MEM, the through hole 80 penetrating the second high refractive index layer 77 and the first high refractive index layer 76 in the portion on each sacrificial layer 81. The second high refractive index layer 77, the first high refractive index layer 76, the through hole 75 that penetrates the high refractive index lower layer 71, and the second high refractive index layer 77, A through-hole 82 that penetrates the high-refractive index layer 76 and the high-refractive index lower layer 71 and an opening 83 that penetrates the second high-refractive index layer 77 are formed in portions corresponding to the regions where the electrodes 74 are formed.

  Next, after removing the mask, a mask having openings at portions corresponding to the through holes 75 and 82 is provided on the surface of the second high refractive index layer 77, and etching is performed through the mask (anisotropic dry etching). As a result, openings 51 and 84 as contact holes are formed, respectively.

  Next, after removing the mask, metal is deposited using a metal mask or the like to form an electrode 74 on the wiring 79 exposed in the opening 84 and on the high refractive index upper layer 32 exposed in the opening 51. An electrode 34 is formed on the substrate. Then, the electrodes 34 and 74 are ground and polished as necessary.

  Next, the sacrificial layer 81 is etched through the through hole 80, and a portion where the air gap AG is to be formed in the insulating layer 50 a is etched through the through hole 75. Further, the sacrificial layer 36 is etched through the through hole 35. By this etching, an air gap AG is formed, a support body 50 is also formed, and air layers 33 and 73 are also formed. Note that the electrodes 34 and 74 may not be removed by etching by covering the openings 82 and 83 with a mask as necessary. The above is the process shown in FIG.

  The Fabry-Perot interferometer 100 shown in FIGS. 3 and 4 can be obtained by the steps shown above.

(Second Embodiment)
Next, a second embodiment of the present invention will be described based on FIG. FIG. 9 is a cross-sectional view showing a schematic configuration of a Fabry-Perot interferometer according to the second embodiment, and corresponds to FIG. 3 shown in the first embodiment.

  Since the Fabry-Perot interferometer and its manufacturing method according to the second embodiment are in common with the Fabry-Perot interferometer and its manufacturing method shown in the first embodiment, a detailed description of the common parts will be omitted below. Focus on the differences. In addition, the same code | symbol shall be provided to the element same as the element shown in 1st Embodiment.

  In the first embodiment, the example in which the high-refractive index layers 71 and 72 and the wiring 79 that is insulated and separated is provided only in the second mirror 70 having the membrane MEM among the first mirror 30 and the second mirror 70 has been described. On the other hand, as shown in FIG. 9, the present embodiment is characterized in that the first mirror 30 is also provided with a wiring 40 that is insulated from the high refractive index layers 31 and 32.

  In the Fabry-Perot interferometer 100 shown in FIG. 9, the configuration excluding the first mirror 30 is the same as that of the first embodiment (see FIG. 3). The configuration of the first mirror 30 is basically the same as that of the second mirror 70.

  That is, in the first mirror 30, air as a low refractive index layer is disposed between the high refractive index lower layer 31 and the high refractive index upper layer 32 including the first and second high refractive index layers 37 and 38 in the width direction. The portion where the layer 33 is interposed is an air mirror M1 having an optical multilayer structure that actually functions as a mirror. Further, the air mirror M1 includes a connecting portion in which a portion 37a of the first high refractive index layer 37 is in contact with the high refractive index lower layer 31, and the second high refractive index layer 38 is located away from the contact portion in the width direction. The air mirror M1 is divided (subdivided) into a plurality by C1, and each air mirror M1 is connected by a connecting portion C1. And the formation area of these air mirror M1 and connection part C1 is the mirror area | region P1 which is an aggregate | assembly of the air mirror M1.

  Further, in the mirror region P1, a concave portion with the surface of the first high refractive index layer 37 as a wall surface between adjacent air mirrors M1, more specifically, the surface of a portion 37b in contact with the side surface of the air layer 33 with the partial position 37a as a bottom surface. A recess having a side surface is configured. The second high refractive index layer 38 bridges the recess, and the insulating member 39 made of a silicon oxide film or the like having a higher refractive index than air is contained in the recess sealed by the second high refractive index layer 38. The wiring 40 made of a metal material or the like is embedded in the insulating member 39.

  The wiring 40 is electrically connected to the electrode 34, and the high refractive index layers 31 and 32 are electrically insulated and separated through an insulating member 39. Further, in the mirror region P1, it is not disposed on the air mirror M1, but is disposed only on the connecting portion C1, in other words, on one portion 37a of the first high refractive index layer 37 in the recess. That is, in the first mirror 30, only the wiring 40 has the same potential as the electrode 34, and the high refractive index layers 31 and 32 are not electrically connected to the electrode 34. Further, in the recess, the wiring 40 is disposed at a position closer to the second mirror 70 (high refractive index upper layer 72) than the middle line (intermediate position) of the recess in the width direction. In other words, in the insulating member 39 disposed in the recess, the thickness of the portion located between the wiring 40 and the second high refractive index layer 38 is between the wiring 40 and the first high refractive index layer 37. It is thinner than the thickness of the part located in.

  As described above, the connecting portion C1 is formed by laminating the high refractive index lower layer 31, the first high refractive index layer 37, the insulating member 39, the wiring 40, the insulating member 39, and the second high refractive index layer 38 in this order. Therefore, rigidity is ensured. Further, since the insulating member 39 has a higher refractive index than air and the metal material or the like constituting the wiring 40 absorbs light, the connecting portion C1 hardly functions as a mirror in the mirror region P1.

  According to the Fabry-Perot interferometer 100 configured in this way, in addition to the effects shown in the first embodiment, the following effects can be further achieved.

  In the present embodiment, the wiring 40 is electrically connected to the electrode 34 of the first mirror 30. The wiring 40 is electrically insulated and separated from the high refractive index lower layer 31 and the high refractive index upper layer 32 (37, 38). In the mirror region P1, the wiring 40 is not arranged in the air mirror M1, but only in the connecting portion C1. Has been. That is, the wiring 40 has the same potential as the electrode 34, and the high refractive index layers 31 and 32 do not have the same potential as the electrode 34.

  Therefore, in the first mirror 30 provided with the wiring 40, electrostatic force does not act on the air mirror M1 in a state where the driving voltage is applied. Therefore, in the air mirror M1, the portion of the high refractive index upper layer 72 facing the second mirror 70 is Convex deformation can be suppressed. That is, variation in the width of the air gap AG can be more effectively suppressed, and as a result, the half-value width (FWHM) of the transmission wavelength can be further reduced.

  Further, in the mirror regions P1 and P2 facing each other, electrostatic force is generated only in the connecting portion C1 (wiring 40) of the first mirror 30 and the connecting portion C2 (wiring 79) of the second mirror 70. Thereby, the convex-shaped deformation | transformation in air mirror M1, M2 can be suppressed more effectively.

  In the present embodiment, the wiring 40 is also disposed closer to the second mirror 70 than the middle line (intermediate position) of the recess in the width direction even in the recess of the mirror region P1. With such an arrangement, the distance between the wiring 40 in the mirror region P1 and the wiring 79 in the mirror region P2 becomes short, so that the second mirror 70 can be driven with a lower voltage.

  The Fabry-Perot interferometer 100 described above can be obtained by applying the formation process of the second mirror 70 to the formation of the first mirror 30 in the manufacturing method shown in the first embodiment. Therefore, the description is omitted.

  In the present embodiment, the high refractive index layers 31, 32, 71 and 72 are not electrically connected to the corresponding electrodes 34 and 74. Therefore, a conductive material such as a metal material can be employed as a constituent material of the support 50 as long as the support 50 and the wiring 40 are electrically insulated and separated through an insulating layer or the like.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 10 is a sectional view showing a schematic configuration of the Fabry-Perot interferometer according to the third embodiment, and corresponds to FIG. 3 shown in the first embodiment. FIG.
Since the Fabry-Perot interferometer and the manufacturing method thereof according to the third embodiment are in common with the Fabry-Perot interferometer and the manufacturing method shown in each of the above-described embodiments, detailed descriptions of the common parts are omitted below. , Explain the different parts with emphasis. In addition, the same code | symbol shall be provided to the element same as the element shown to said each embodiment.

  In each of the above-described embodiments, for example, the high refractive index upper layer 72 of the second mirror 70 provided with the wiring 79 includes the first high refractive index layer 76 and the second high refractive index layer 77. In the example, the insulating member 78 and the wiring 79 are disposed in the concave portion constituted by the first high refractive index layer 76 between the matching air mirrors M <b> 2, and the concave portion is sealed by the second high refractive index layer 77.

  On the other hand, in this embodiment, as illustrated in FIG. 10, in the mirror region P2, between the adjacent air mirrors M2, in the concave portion having the high refractive index lower layer 71 as the bottom surface and the high refractive index upper layer 72 as the side surface. Further, the insulating member 78 and the wiring 79 are arranged, and the concave portion is sealed by the high refractive index upper layer 72. In other words, the feature is that the side surface of the recess is formed not only by a part of the film (layer) constituting the high refractive index upper layer 72 but also by the entire high refractive index upper layer 72.

  The Fabry-Perot interferometer 100 shown in FIG. 10 has substantially the same configuration as that shown in the first embodiment (see FIG. 3). As described above, a part of the configuration of the second mirror 70, in detail, is high. Only the configuration of the refractive index upper layer 72 is different.

  In the second mirror 70, in the width direction, an optical multilayer in which a portion where an air layer 73 as a low refractive index layer is interposed between the high refractive index lower layer 71 and the high refractive index upper layer 72 actually functions as a mirror. The air mirror M2 has a film structure. Further, in the connecting portion C2 between the adjacent air mirrors M2, a concave portion is formed with the upper surface of the high refractive index lower layer 71 as the bottom surface and the surface of the high refractive index upper layer 72 as the side surface.

  Although the side surface of the recess will be described later, a trench reaching the high refractive index lower layer 71 is provided in the insulating member 78 (the first insulating layer 78a and the second insulating layer 78b), and the high refractive index upper layer 72 is provided in the trench. The partition wall 72c is embedded. The partition wall 72c has a forward taper shape that is nearly vertical, that is, a shape that has a width that increases in the vertical direction as the distance from the high refractive index lower layer 71 increases in the width direction.

  Thus, also in this embodiment, the portion located on the side surface of the air layer 73 in the high-refractive-index upper layer 72 constituting the air mirror M2 has a small inclination compared to the first embodiment. Therefore, stress concentration can be suppressed. The side wall portion 72b surrounding the side surface of the outer peripheral end of the mirror region P2 has the same inclination as the first embodiment, that is, the inclination that the angle formed with the high refractive index lower layer 71 is larger than the inclination of the partition wall 72c. Thus, the change in the amount of deviation of the neutral axis is small at the boundary between the mirror region P2 and the peripheral region.

  The high refractive index upper layer 72 bridges the recess, and the recess sealed with the high refractive index upper layer 72 is filled with an insulating member 78 made of a silicon oxide film or the like. A wiring 79 made of a material or the like is embedded.

  That is, the connecting portion C2 is formed by sequentially laminating the high refractive index lower layer 71, the insulating member 78, the wiring 79, the insulating member 78, and the high refractive index upper layer 72 in the displacement direction, and no air layer is interposed therebetween. Thereby, rigidity is ensured. Further, since the insulating member 78 has a higher refractive index than air and the metal material or the like constituting the wiring 79 absorbs light, the connecting portion C2 hardly functions as a mirror in the mirror region P2. The air mirror M2 is divided into a plurality of parts (divided) by the connecting part C2, and the air mirrors M2 are connected by the connecting part C2. And the formation area of these air mirror M2 and the connection part C2 is the mirror area | region P2 which is an aggregate | assembly of the air mirror M2.

  The Fabry-Perot interferometer 100 configured as described above has the same or similar effects as those shown in the first embodiment.

  Next, an example of a method for manufacturing the Fabry-Perot interferometer 100 will be described. FIG. 11 is a cross-sectional view for each process showing the manufacturing method of the Fabry-Perot interferometer, which proceeds in the order of (a), (b), and (c). In addition, since it is the same as the manufacturing method shown in 1st Embodiment until the formation process of the high refractive index lower layer 71 by the side of the 2nd mirror 70, the description is abbreviate | omitted.

  As shown in FIG. 11A, high refractive index layers 71 and 72 such as a silicon oxide film and etching are selectively formed on the entire surface of the high refractive index lower layer 71 formed on the insulating layer 50a to be the support 50 later. A first insulating layer 78a made of a material having a high ratio is deposited and formed, and then a solid wiring layer (not shown) made of polysilicon or metal doped at a high concentration is formed on the entire surface of the first insulating layer 78a. To form a deposit. Then, a mask made of resist or the like is formed on the surface of the wiring layer, and the wiring layer is etched through the mask. Thereby, the wiring 79 is formed.

  After the wiring 79 is formed, a second insulating layer 78b made of a material having a high etching selectivity with respect to the high refractive index layers 71 and 72, such as a silicon oxide film, is deposited on the first insulating layer 78a so as to cover the wiring 79. Form. In the present embodiment, each of the first insulating layers 78a is formed so as to be thinner than the second insulating layer 78b in the recesses described above. The above is the process shown in FIG.

  Next, a mask made of resist or the like is formed on the surface of the second insulating layer 78b, and the first insulating layer 78a and the second insulating layer 78b are etched through the mask. In the present embodiment, isotropic wet etching is performed, and anisotropic etching (anisotropic dry etching) is performed as necessary, so that the first insulating layer 78a and the second insulating layer 78b are formed as shown in FIG. As shown in b), only the part located in the mirror region P2 and the part adjacent to the wiring 79 in the peripheral region are left.

  Next, after removing the mask, a mask made of resist or the like is formed on the entire surface of the high refractive index lower layer 71 so as to cover the first insulating layer 78a and the second insulating layer 78b, and the remaining is interposed through the mask. Of the first insulating layer 78a and the second insulating layer 78b thus formed, a portion constituting the side surface of the recess, in other words, a portion constituting the side wall portion 72b is etched (dry etching). By this etching, the high refractive index lower layer 71 is reached, and the first insulating layer 78a and the second insulating layer 78b in the mirror region P2 are replaced with a portion 81 corresponding to the air layer 73 and a portion corresponding to the insulating member 78 including the wiring 79. A trench 85 is formed to be divided into two.

  Since this trench 85 is a part that embeds the high refractive index upper layer 72 in a later step and constitutes the partition wall 72c, if the side far from the high refractive index layer 71 has a reverse taper shape, the trench 85 is clogged at the top. Cannot be completely embedded. Therefore, as described above, it is preferable to have a forward tapered shape with a wide upper side. Moreover, it is preferable to set it as the shape which has inclination (taper) also from a viewpoint of stress concentration. The above is the process shown in FIG.

  Next, the mask is removed, the trench 85 is buried, and the high refractive index upper layer made of polysilicon or the like is formed on the high refractive index lower layer 71 so as to cover the remaining first insulating layer 78a and second insulating layer 78b. 72 is deposited. Thereby, the partition wall 72c described above is formed. In addition, the connecting portion C2 is thicker than most of the peripheral region and has a highly rigid structure, and the wiring 79 is electrically insulated from the high refractive index layers 71 and 72. Further, since the first insulating layer 78a, the wiring 79, and the second insulating layer 78b in the recess are sealed by the high refractive index lower layer 71 and the high refractive index upper layer 72, the air gap AG or the like Etching at the time of forming the air layers 33 and 73 can prevent the first insulating layer 78a and the second insulating layer 78b in the recess from being etched.

  Next, a mask made of resist or the like is formed on the surface of the high refractive index upper layer 72, and etching (anisotropic dry etching such as RIE) is performed through the mask. Accordingly, the first insulating layer 78a and the second insulating layer 78b have a through hole 80 penetrating the high refractive index upper layer 72 in a portion 81 corresponding to the air layer 73 and a high refractive index upper layer 72 in a peripheral region corresponding to the membrane MEM. And the through-hole 75 which penetrates the high refractive index lower layer 71, the part corresponding to the formation region of the electrode 34, the through-hole 82 which penetrates the high refractive index upper layer 72 and the high refractive index lower layer 71, the part corresponding to the formation region of the electrode 74 Openings 83 penetrating the high refractive index layer 72 are respectively formed. The above is the process shown in FIG.

  In addition, since the following processes are the same as the process shown in 1st Embodiment, the description is abbreviate | omitted.

  As described above, in the manufacturing method of the Fabry-Perot interferometer 100 according to the present embodiment, the trenches 85 are formed and partitioned, so that the wiring 79 is connected to the high refractive index layer 71 from the first insulating layer 78a and the second insulating layer 78b. , 72 and a sacrificial layer 81 for forming an air layer 73 are obtained.

  Therefore, compared with the manufacturing method shown in the first embodiment, the number of steps for forming the trench 85 is increased, but the step for forming the sacrificial layer 81 is eliminated (also used as the step for forming the insulating member 78), and the high refractive index. The step of forming the upper layer 72 can be reduced from two steps to one step. Thereby, a manufacturing process can be simplified.

  In the present embodiment, as in the first embodiment, an example in which the wiring 79 is provided only on the second mirror 70 is shown. However, as described in the second embodiment, the above-described characteristic portions can be applied to both the mirrors 30 and 70 even in the configuration in which the wirings 40 and 79 are provided in the first mirror 30 and the second mirror 70, respectively. .

  In the present embodiment, of the high refractive index upper layer 72 constituting the air mirror M2, the inclined structure of the side wall portion 72b located at the outermost periphery of the mirror region P2 is formed by isotropic dry etching, and the partition wall 72c is formed. An example in which the trench 85 to be formed is formed by dry etching is shown. However, the first insulating layer 78a and the second insulating layer 78b may be dry-etched to realize the inclined structure of the side wall portion 72b and the trench 85 at the same time.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the first embodiment and the third embodiment, the wiring 79 is provided only in the second mirror 70, and in the second embodiment, the wirings 40 and 79 are provided in the first mirror 30 and the second mirror 70, respectively. . However, the wiring 40 may be provided only in the first mirror 30. However, since the second mirror 70 includes the membrane MEM, it is preferable that the wiring 79 is provided at least on the second mirror 70 side. By providing the wiring 79 in the second mirror 70, the rigidity of the connecting portion C2, and thus the entire mirror region P2, can be increased, so that the variation in the width of the air gap AG can be further reduced. That is, the half-value width of the transmission wavelength can be further reduced.

  In each of the embodiments described above, an example in which only the second mirror 70 has the membrane MEM has been described. However, a structure in which the first mirror 30 includes a membrane is formed in the substrate 10 by forming a gap that opens on one surface where the insulating film 11 is disposed, and the first mirror 30 bridges the gap. Also good. In this case, the wiring 40 may be provided only on the first mirror 30. In this case, even if the wiring 40 is provided only in the first mirror 30, the effects described above for the second mirror 70 can be expected from the first mirror 30. That is, it is possible to increase the rigidity of the coupling portion C1, and thus the entire mirror region P1, and to further reduce the variation in the width of the air gap AG. That is, the half-value width of the transmission wavelength can be further reduced.

  In the present embodiment, an example in which the connection portions C1 and C2 are arranged in a planar honeycomb shape is shown. However, the connecting portions C1 and C2 can be employed as long as the mechanical strength of the air mirrors M1 and M2 can be ensured by dividing the air mirrors M1 and M2 into a plurality of parts. For example, it is good also as a structure where the connection parts C1 and C2 are radially extended from one point.

  In the present embodiment, an example in which the insulating layer 50a is etched through the through hole 75 formed in the membrane MEM in the peripheral region of the second mirror 70 in order to form the air gap AG is shown. However, the through-hole 80 for forming the air layer 73 is a through-hole that penetrates the high refractive index lower layer 71 and reaches the insulating layer 50a, so that the air can be passed through the through-hole 80 without providing the through-hole 75. A gap AG may be formed.

DESCRIPTION OF SYMBOLS 10 ... Substrate 30 ... 1st mirror 31, 71 ... High refractive index lower layer 32, 72 ... High refractive index upper layer 33, 73 ... Air layer 34, 74 ... Electrode 39, 78 ... insulating members 40, 79 ... wiring 50 ... support 70 ... second mirrors 37, 76 ... first high refractive index layers 38, 77 ... second high refractive index layer 100 ... Fabry-Perot interferometer MEM ... Membrane P1, P2 ... Mirror region M1, M2 ... Air mirror C1, C2 ... Connection part AG ... Air gap

Claims (11)

A substrate,
A first mirror disposed on the substrate;
A second mirror disposed on the first mirror via a support, and a portion where the gap between the supports is bridged as a membrane and facing the first mirror;
The width of the gap is changed by an electrostatic force generated between the first mirror and the second mirror based on a voltage applied between the electrode on the first mirror side and the electrode on the second mirror side. A Fabry-Perot interferometer configured in
The first mirror includes a high refractive index lower layer disposed on the substrate as a high refractive index layer having a higher refractive index than air, and a high refractive index upper layer disposed on the high refractive index lower layer. An air mirror having an optical multilayer structure in which an air layer is interposed between the high refractive index lower layer and the high refractive index upper layer in the width direction of the gap, and the air mirror is divided into a plurality of air mirrors. A mirror region including a connecting portion to be connected, and a peripheral region sandwiching the mirror region in at least one direction perpendicular to the width direction,
The second mirror is a high refractive index layer having a refractive index higher than that of air, and is disposed on the high refractive index lower layer and the high refractive index lower layer disposed on the support by bridging the gap. An air mirror having an optical multilayer structure in which an air layer is interposed between the high refractive index lower layer and the high refractive index upper layer in the width direction, and the air mirror is divided into a plurality of parts. And a connecting region for connecting the air mirrors, a mirror region facing the mirror region on the first mirror side, and a peripheral region sandwiching the mirror region in at least one direction perpendicular to the width direction Have
The membrane is constituted by a part of the peripheral region and the mirror region,
At least one of the first mirror and the second mirror is provided with a wiring electrically insulated and separated from the corresponding high refractive index lower layer and the high refractive index upper layer,
The corresponding electrode is electrically connected to the wiring without being electrically connected to the high refractive index lower layer and the high refractive index upper layer,
The Fabry-Perot interferometer, wherein the wiring is not disposed on the air mirror in the corresponding mirror region, but is disposed on the connecting portion.   The Fabry-Perot interferometer according to claim 1, wherein the wiring is provided on the second mirror. Of the first mirror and the second mirror, a high refractive index upper layer of the mirror provided with the wiring is a first high refractive index layer disposed on the high refractive index lower layer, and the first high refractive index. A second high refractive index layer disposed on the layer,
In the air mirror of the mirror provided with the wiring, the air layer is interposed between the high refractive index upper layer and the high refractive index lower layer composed of the first high refractive index layer and the second high refractive index layer,
In the connecting portion of the mirror provided with the wiring, there is a recess having the wall surface of the surface of the first high refractive index layer between the adjacent air mirrors in contact with the first high refractive index layer. And the second high refractive index layer crosslinks the recess,
The concave portion sealed by the second high refractive index layer is filled with an insulating member, and the wiring is embedded in the insulating member,
3. The Fabry-Perot according to claim 1, wherein each of the air mirrors of the first mirror and the second mirror is provided with a through-hole penetrating a part of the high refractive index upper layer. Interferometer. Among the first mirror and the second mirror, in the mirror air mirror provided with the wiring, the air layer is interposed between the high refractive index upper layer and the high refractive index lower layer,
In the connecting portion of the mirror provided with the wiring, a recess having a bottom surface of the high refractive index lower layer and a side surface of the upper surface of the high refractive index upper layer is formed between the adjacent air mirrors, and the high refractive index. The upper layer bridges the recess,
An insulating member is filled in the concave portion sealed by the high refractive index upper layer, and the wiring is embedded in the insulating member,
3. The Fabry-Perot according to claim 1, wherein each of the air mirrors of the first mirror and the second mirror is provided with a through-hole penetrating a part of the high refractive index upper layer. Interferometer.   5. The Fabry-Perot interference according to claim 3, wherein in the recess, the wiring is disposed at a position closer to a mirror on the other side than a middle line of the recess in the width direction. Total.   6. The Fabry-Perot interferometer according to claim 5, wherein the first mirror and the second mirror have the same layout of air mirrors and connecting portions in the respective mirror regions.   Of the high refractive index upper layer constituting the air mirror, the portion located on the side surface of the air layer is wider as the width of the air layer in the direction perpendicular to the width direction approaches the high refractive index lower layer in the width direction. The Fabry-Perot interferometer according to any one of claims 3 to 6, characterized by having a slope of   Each of the air mirrors divided by the connecting portion in the mirror region has a hexagonal shape in a plane perpendicular to the width direction, and the connecting portion has a honeycomb shape. 8. A Fabry-Perot interferometer according to item 7. A method of manufacturing the Fabry-Perot interferometer according to claim 3, comprising:
Laminating the high refractive index lower layer on one surface of the substrate in the first mirror, or on one surface of the support before the portion constituting the gap is removed in the second mirror;
Selectively forming a sacrificial layer on the surface of the high refractive index lower layer corresponding to the air layer of the air mirror;
Laminating the first high refractive index layer so as to cover the high refractive index lower layer and the sacrificial layer;
Laminating a first insulating layer on the surface of the first high refractive index layer;
Selectively forming the wiring on the surface of the first insulating layer;
Laminating a second insulating layer so as to cover the first insulating layer and the wiring;
Removing the first insulating layer and the second insulating layer, leaving only the portion adjacent to the wiring and the portion located in the recess;
After the removing step, laminating the second high refractive index layer;
The sacrificial layer is removed through the through-hole provided in the upper layer of the high refractive index at the site where the air mirror is formed, and is formed of the first high refractive index layer and the second high refractive index layer to form the air layer. And a Fabry-Perot interferometer manufacturing method. A method of manufacturing the Fabry-Perot interferometer according to claim 4, comprising:
Laminating the high refractive index lower layer on one surface of the substrate in the first mirror, or on one surface of the support before the portion constituting the gap is removed in the second mirror;
Laminating a first insulating layer on the surface of the high refractive index lower layer;
Selectively forming the wiring on the surface of the first insulating layer;
Laminating a second insulating layer so as to cover the first insulating layer and the wiring;
Removing the first insulating layer and the second insulating layer, leaving only the portion adjacent to the wiring and the portion located in the mirror region;
Of the remaining first insulating layer and the second insulating layer, a trench reaching the lower layer of the high refractive index is formed in a portion constituting a side surface of the recess in a portion located in the mirror region, Partitioning the insulating layer and the second insulating layer into a portion corresponding to the air layer and a portion corresponding to the insulating member including the wiring;
Laminating the high refractive index upper layer on the high refractive index lower layer so as to fill the trench and cover the remaining first insulating layer and second insulating layer;
Removing the first insulating layer and the second insulating layer in a portion corresponding to the air layer through the through-hole provided in the high refractive index upper layer in the air mirror forming portion to form the air layer; And a manufacturing method of a Fabry-Perot interferometer.   11. The method for manufacturing a Fabry-Perot interferometer according to claim 9, wherein, in the step of forming the air layer, a portion of the support that constitutes the gap is also removed.

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