wafer

Abstract

A wafer of the present application includes a substrate layer, a first mirror layer having a plurality of first mirror portions arranged two-dimensionally, and a second mirror layer having a plurality of second mirror portions arranged two-dimensionally. In an effective region, a plurality of Fabry-Perot interference filter portions are configured by forming gaps between the first mirror portions and the second mirror portions. In a dummy region along an outer edge of the substrate layer and surrounding the effective region, a plurality of dummy filter portions are configured by providing an intermediate layer between the first mirror portions and the second mirror portions. In each of the plurality of Fabry-Perot interference filter portions and the plurality of dummy filter portions, at least the second mirror portions are surrounded by first grooves.

Description

[0001] This application is a divisional application of the patent application with application number November 9, 2018 , application number 201880075333.7 , and invention title Wafer . TECHNICAL FIELD

[0002] The present disclosure relates to a wafer to obtain Fabry-Perot interference filters. BACKGROUND

[0003] As a conventional Fabry-Perot interference filter, there is known one having a substrate, and a fixed mirror and a movable mirror which are opposed to each other via a gap on the substrate (see, for example, Patent Literature 1).

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] [Patent Literature 1] Japanese Patent Application Laid-Open No. 2013-506154 SUMMARY

[0007] [PROBLEMS TO BE SOLVED BY THE INVENTION]

[0008] Since the Fabry-Perot interference filter as described above is a fine structure, it is difficult to improve both of the manufacturing efficiency and the yield when the Fabry-Perot interference filter is manufactured.

[0009] Therefore, an object of the present disclosure is to provide a wafer from which a plurality of Fabry-Perot interference filters can be obtained efficiently and with good yield.

[0010] [MEANS OF SOLVING THE PROBLEM]

[0011] The wafer of one aspect of the present disclosure has a substrate layer having a first surface and a second surface opposed to each other, a first mirror layer having a plurality of first mirror portions two-dimensionally arranged on the first surface, and a second mirror layer having a plurality of second mirror portions two-dimensionally arranged on the first mirror layer, and in an effective region, a plurality of Fabry-Perot interference filters are configured by forming a gap between the first mirror portions and the second mirror portions opposed to each other, and a distance between the first mirror portions and the second mirror portions opposed to each other is changed by an electrostatic force, in a dummy region along an outer edge of the substrate layer and surrounding the effective region, a plurality of dummy filter portions are configured by providing an intermediate layer between the first mirror portions and the second mirror portions opposed to each other, and of the plurality of Fabry-Perot interference filter portions and the plurality of dummy filter portions, at least the second mirror portions are surrounded by a first groove which is opened at opposite sides of the substrate layer.

[0012] In the wafer, a plurality of Fabry-Perot interference filter sections serving as a plurality of Fabry-Perot interference filters are provided in an effective region. On the other hand, in a dummy region along an outer edge of the substrate layer and surrounding the effective region, a plurality of dummy filter sections are provided, and in each of the dummy filter sections, an intermediate layer is provided between the first mirror section and the second mirror section facing each other. Thus, the strength of the entire wafer is sufficiently ensured. Therefore, for example, handling of the wafer when the plurality of Fabry-Perot interference filters are cut out from the wafer becomes easy. In the case where, in each of the dummy filter sections, a gap is formed between the first mirror section and the second mirror section facing each other, for example, when the dummy region of the wafer is held by a jig, there is a concern that the second mirror section is broken, pieces of the second mirror section adhere to the Fabry-Perot interference filter section, and the appearance, characteristics, or the like of the Fabry-Perot interference filter section are deteriorated. In the wafer, since the intermediate layer is provided between the first mirror section and the second mirror section facing each other in each of the dummy filter sections, such a situation is suppressed from occurring. In addition, at least the second mirror section of each of the Fabry-Perot interference filter sections is surrounded by the first groove. Thus, the yield when the plurality of Fabry-Perot interference filters are cut out from the wafer is improved. Further, at least the second mirror section of each of the dummy filter sections is surrounded by the first groove. Thus, stress in the dummy region is reduced, and warping of the wafer is suppressed. With the above, the wafer can efficiently and with good yield obtain the plurality of Fabry-Perot interference filters.

[0013] In the wafer of one aspect of the present disclosure, the first groove is continuous in the effective region and the dummy region, and can reach the outer edge of the substrate layer when viewed from a direction in which the first mirror section and the second mirror section face each other. Thus, the yield when the plurality of Fabry-Perot interference filters are cut out from the wafer can be further improved, and warping of the wafer can be more reliably suppressed.

[0014] The wafer of one aspect of the present disclosure further has a stress adjustment layer provided on the second surface, and in the stress adjustment layer, a second groove that is open on the opposite side of the substrate layer is formed, and the second groove can be formed in correspondence with the first groove. Thus, the yield when the plurality of Fabry-Perot interference filters are cut out from the wafer can be further improved, and warping of the wafer can be more reliably suppressed.

[0015] In the wafer of one aspect of the present disclosure, the plurality of Fabry-Perot interference filter sections and the plurality of dummy filter sections can be arranged to be each symmetrical with respect to a first straight line and a second straight line that pass through the center of the substrate layer and are orthogonal to each other when viewed from a direction in which the first mirror section and the second mirror section face each other. Thus, warping of the entire wafer can be more reliably suppressed.

[0016] In the wafer of one aspect of the present disclosure, a modification region can be formed in the substrate layer inside in correspondence with the first groove. Thus, a crack is caused to propagate in the thickness direction of the substrate layer from the modification region, and the plurality of Fabry-Perot interference filters can be easily and with good precision cut out from the wafer.

[0017] The wafer of one aspect of the present disclosure may further include an expansion tape attached to the second surface side of the substrate layer. This facilitates handling of the wafer even when a modified region is formed inside the substrate layer.

[0018] Alternatively, in one aspect of the wafer disclosed herein, a mirror removal portion is formed by removing at least a portion of the second mirror portion in a portion of the dummy region. Thus, for example, a gap is formed by etching between the first and second mirror portions that face each other in the portion corresponding to each Fabry-Perot interference filter portion. Therefore, when multiple through-holes are formed in the second mirror portion, the removal state of the second mirror portion can be monitored in the portion corresponding to the mirror removal portion, thereby ensuring that multiple through-holes are formed in the second mirror portion in the portion corresponding to each Fabry-Perot interference filter portion. Thus, the wafer becomes a wafer having multiple Fabry-Perot interference filter portions with gaps effectively formed between the first and second mirror portions that face each other.

[0019] In the wafer according to one aspect of the present disclosure, at least the first mirror portion may be surrounded by the first groove in the mirror removal portion. This reduces stress in the mirror removal portion, thereby suppressing wafer warping.

[0020] In one aspect of the present disclosure, a plurality of mirror-removed portions are provided in a dummy region along the outer edge of a substrate layer. A first groove is connected in the effective region and the dummy region, and when viewed from a direction in which the first dummy portion and the second dummy portion are opposite each other, the first groove also reaches the outer edge of the substrate layer. Thus, a plurality of dummy filter portions are arranged outside a plurality of Fabry-Perot interference filter portions, and a plurality of mirror-removed portions are arranged outside a plurality of dummy filter portions. Furthermore, the first groove also connects and reaches the outer edge of the substrate layer, thereby improving stress balance across the wafer and more reliably suppressing wafer warping.

[0021] [Effects of the Invention]

[0022] According to the present disclosure, a wafer can be provided that can produce a plurality of Fabry-Perot interference filters with good efficiency and high yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a top view of a Fabry-Perot interference filter cut from a wafer according to one embodiment.

[0024] Figure 2 for Figure 1 Bottom view of a Fabry-Perot interference filter is shown.

[0025] Figure 3 For the Figure 1 A cross-sectional view of a Fabry-Perot interference filter along line III-III is shown.

[0026] Figure 4 Cross-sectional view of a dummy filter cut from a wafer of an embodiment.

[0027] Figure 5 Plan view of a wafer of an embodiment.

[0028] Figure 6 Plan view of a wafer of an embodiment. Figure 5 Enlarged plan view of a portion of a wafer shown in

[0029] Figure 7 Cross-sectional views of a Fabry-Perot interference filter portion and a dummy filter portion of a wafer shown in Figure 5

[0030] Cross-sectional views of a method of manufacturing a wafer shown in Figure 8 Figure 5 Cross-sectional views of a method of manufacturing a wafer shown in

[0031] Figure 9 Figure 5 Cross-sectional views of a method of manufacturing a wafer shown in

[0032] Figure 10 Cross-sectional views of a method of manufacturing a wafer shown in Figure 5

[0033] Cross-sectional views of a method of manufacturing a wafer shown in Figure 11 Figure 5 Cross-sectional views of a method of manufacturing a wafer shown in

[0034] Figure 12 Figure 5 Cross-sectional views of a method of manufacturing a wafer shown in

[0035] Figure 13 Cross-sectional views of a method of manufacturing a wafer shown in Figure 5

[0036] Cross-sectional views of a method of cutting a Fabry-Perot interference filter from a wafer shown in Figure 14 Figure 5 Cross-sectional views of a method of cutting a Fabry-Perot interference filter from a wafer shown in

[0037] Figure 15 Figure 5 Cross-sectional views of a method of cutting a Fabry-Perot interference filter from a wafer shown in

[0038] Figure 16 Cross-sectional view of a light detection device provided with a Fabry-Perot interference filter. ​​​​​​

[0039] Figure 17 A top view of a wafer according to a modified example.

[0040] Figure 18 (a) and (b) are used to illustrate Figure 17 A cross-sectional view of a wafer manufacturing method is shown.

[0041] Figure 19 (a) and (b) are used to illustrate Figure 17 A cross-sectional view of a wafer manufacturing method is shown. DETAILED DESCRIPTION

[0042] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The same or corresponding parts in the various drawings are denoted by the same reference numerals, and repeated descriptions are omitted.

[0043] [Configuration of Fabry-Perot Interference Filter and Dummy Filter]

[0044] Before describing the structure of a wafer according to one embodiment, the structures of a Fabry-Perot interference filter and a dummy filter cut from the wafer will be described.

[0045] like Figure 1 、 Figure 2 and Figure 3 As shown, the Fabry-Perot interference filter 1 includes a substrate 11. The substrate 11 has a first surface 11a and a second surface 11b facing each other. An antireflection layer 21, a first stack 22, an intermediate layer 23, and a second stack 24 are stacked in this order on the first surface 11a. A gap (air gap) S is defined between the first stack 22 and the second stack 24 by the frame-shaped intermediate layer 23.

[0046] The shapes and positional relationships of the various parts when viewed from a direction perpendicular to the first surface 11a (top view) are as follows. The outer edge of the substrate 11 is, for example, a rectangular shape with a side length of several hundred μm to several mm. The outer edge of the substrate 11 and the outer edge of the second stack 24 are consistent with each other. The outer edge of the anti-reflection layer 21, the outer edge of the first stack 22, and the outer edge of the intermediate layer 23 are consistent with each other. The substrate 11 has an outer edge portion 11c located outside the outer edge of the intermediate layer 23 relative to the center of the gap S. The outer edge portion 11c is, for example, frame-shaped and surrounds the intermediate layer 23 when viewed from a direction perpendicular to the first surface 11a. The gap S is, for example, circular.

[0047] The Fabry-Perot interference filter 1 transmits light having a specific wavelength at a light-transmitting region 1a partitioned in the center thereof. The light-transmitting region 1a is, for example, a cylindrical region. The substrate 11 is composed of, for example, silicon, quartz, glass, or the like. In the case where the substrate 11 is composed of silicon, the antireflection layer 21 and the intermediate layer 23 are composed of, for example, silicon oxide. The thickness of the intermediate layer 23 is, for example, several tens of nm to several tens of μm.

[0048] A portion of the first laminated body 22 corresponding to the light-transmitting region 1a functions as a first mirror portion 31. The first mirror portion 31 is a fixed mirror. The first mirror portion 31 is disposed on the first surface 11a via the antireflection layer 21. The first laminated body 22 is composed of a plurality of polycrystal silicon layers 25 and a plurality of silicon nitride layers 26 alternately laminated one on another. In the Fabry-Perot interference filter 1, a polycrystal silicon layer 25a, a silicon nitride layer 26a, a polycrystal silicon layer 25b, a silicon nitride layer 26b, and a polycrystal silicon layer 25c are sequentially laminated on the antireflection layer 21. The optical thickness of each of the polycrystal silicon layers 25 and the silicon nitride layers 26 constituting the first mirror portion 31 is preferably an integral multiple of 1 / 4 of the center transmission wavelength. Further, the first mirror portion 31 can be disposed directly on the first surface 11a without passing through the antireflection layer 21.

[0049] A portion of the second laminated body 24 corresponding to the light-transmitting region 1a functions as a second mirror portion 32. The second mirror portion 32 is a movable mirror. The second mirror portion 32 opposes the first mirror portion 31 via a gap S on the side opposite to the first mirror portion 31 with respect to the substrate 11. The direction in which the first mirror portion 31 and the second mirror portion 32 oppose each other is parallel to the direction perpendicular to the first surface 11a. The second laminated body 24 is disposed on the first surface 11a via the antireflection layer 21, the first laminated body 22, and the intermediate layer 23. The second laminated body 24 is composed of a plurality of polycrystal silicon layers 27 and a plurality of silicon nitride layers 28 alternately laminated one on another. In the Fabry-Perot interference filter 1, a polycrystal silicon layer 27a, a silicon nitride layer 28a, a polycrystal silicon layer 27b, a silicon nitride layer 28b, and a polycrystal silicon layer 27c are sequentially laminated on the intermediate layer 23. The optical thickness of each of the polycrystal silicon layers 27 and the silicon nitride layers 28 constituting the second mirror portion 32 is preferably an integral multiple of 1 / 4 of the center transmission wavelength.

[0050] Further, in the first stack 22 and the second stack 24, a silicon oxide layer can be used instead of the silicon nitride layer. In addition, as the material of each layer constituting the first stack 22 and the second stack 24, titanium oxide, tantalum oxide, zirconium oxide, magnesium fluoride, aluminum oxide, calcium fluoride, silicon, germanium, zinc sulfide, or the like can be used. Here, the surface of the first mirror portion 31 on the side of the gap S (the surface of the polysilicon layer 25c) and the surface of the second mirror portion 32 on the side of the gap S (the surface of the polysilicon layer 27a) directly face each other via the gap S. However, an electrode layer, a protective layer, or the like (not constituting a mirror) can be formed on the surface of the first mirror portion 31 on the side of the gap S and the surface of the second mirror portion 32 on the side of the gap S. In this case, the first mirror portion 31 and the second mirror portion 32 face each other via the gap S with these layers interposed therebetween. In other words, in this case, the first mirror portion 31 and the second mirror portion 32 can face each other via the gap S.

[0051] A plurality of through holes 24b are formed in the portion of the second stack 24 corresponding to the gap S (the portion overlapping the gap S when viewed from the direction perpendicular to the first surface 11a). Each of the through holes 24b reaches the gap S from the surface 24a of the second stack 24 on the opposite side of the intermediate layer 23. The plurality of through holes 24b are formed to the extent that the function of the second mirror portion 32 is not substantially affected. The plurality of through holes 24b are used to remove a portion of the intermediate layer 23 by etching to form the gap S.

[0052] The second stack 24 further includes a cover portion 33 and a peripheral portion 34 in addition to the second mirror portion 32. The second mirror portion 32, the cover portion 33, and the peripheral portion 34 are integrally formed in a manner having a portion of the same stacked structure and being continuous with each other. The cover portion 33 surrounds the second mirror portion 32 when viewed from the direction perpendicular to the first surface 11a. The cover portion 33 covers the surface 23a of the intermediate layer 23 on the opposite side of the substrate 11, the side surface 23b (the outer side surface, i.e., the side surface on the opposite side of the side of the gap S) of the intermediate layer 23, the side surface 22a of the first stack 22, and the side surface 21a of the antireflection layer 21, to the first surface 11a. That is, the cover portion 33 covers the outer edge of the intermediate layer 23, the outer edge of the first stack 22, and the outer edge of the antireflection layer 21.

[0053] The peripheral portion 34 surrounds the covering portion 33 when viewed from a direction perpendicular to the first surface 11a. The peripheral portion 34 is located on the first surface 11a of the outer edge portion 11c. The outer edge of the peripheral portion 34 coincides with the outer edge of the substrate 11 when viewed from a direction perpendicular to the first surface 11a. The peripheral portion 34 is thinned along the outer edge of the outer edge portion 11c. That is, the portion of the peripheral portion 34 along the outer edge of the outer edge portion 11c is thinner than the other portions of the peripheral portion 34. In the Fabry-Perot interference filter 1, the peripheral portion 34 is thinned by removing a portion of the polysilicon layer 27 and the silicon nitride layer 28 that constitute the second layered body 24. The peripheral portion 34 has a non-thinned portion 34a that is continuous with the covering portion 33, and a thinned portion 34b that surrounds the non-thinned portion 34a. In the thinned portion 34b, the polysilicon layer 27 and the silicon nitride layer 28 other than the polysilicon layer 27a disposed directly on the first surface 11a are removed.

[0054] The height of the surface 34c of the non-thinned portion 34a on the side opposite to the substrate 11 from the first surface 11a is lower than the height of the surface 23a of the intermediate layer 23 from the first surface 11a. The height of the surface 34c of the non-thinned portion 34a from the first surface 11a is, for example, 100 nm to 5000 nm. The height of the surface 23a of the intermediate layer 23 from the first surface 11a is, for example, 500 nm to 20000 nm. The width of the thinned portion 34b (the distance between the outer edge of the non-thinned portion 34a when viewed from a direction perpendicular to the first surface 11a and the outer edge of the outer edge portion 11c) is 0.01 times or more the thickness of the substrate 11. The width of the thinned portion 34b is, for example, 5 μm to 400 μm. The thickness of the substrate 11 is, for example, 500 μm to 800 μm.

[0055] In the first mirror portion 31, the first electrode 12 is formed so as to surround the light-transmitting region 1a when viewed from a direction perpendicular to the first surface 11a. The first electrode 12 is formed by doping an impurity in the polysilicon layer 25c to lower the resistance. In the first mirror portion 31, the second electrode 13 is formed so as to include the light-transmitting region 1a when viewed from a direction perpendicular to the first surface 11a. The second electrode 13 is formed by doping an impurity in the polysilicon layer 25c to lower the resistance. The size of the second electrode 13 when viewed from a direction perpendicular to the first surface 11a is preferably the size including the entire light-transmitting region 1a, but can be substantially the same as the size of the light-transmitting region 1a.

[0056] In the second mirror portion 32, the third electrode 14 is formed. The third electrode 14 opposes the first electrode 12 and the second electrode 13 via the gap S. The third electrode 14 is formed by doping an impurity in the polysilicon layer 27a to lower the resistance.

[0057] A pair of terminals 15 is provided so as to face each other with the light-transmitting region la interposed therebetween. Each terminal 15 is disposed in the through-hole of the first laminate 22 to the surface 24a of the second laminate 24. Each terminal 15 is electrically connected to the first electrode 12 via the wiring 12a. Each terminal 15 is formed of, for example, a metal film of aluminum or an alloy thereof.

[0058] A pair of terminals 16 is provided so as to face each other with the light-transmitting region la interposed therebetween. Each terminal 16 is disposed in the through-hole of the first laminate 22 to the surface 24a of the second laminate 24. Each terminal 16 is electrically connected to the second electrode 13 via the wiring 13a and to the third electrode 14 via the wiring 14a. Each terminal 16 is formed of, for example, a metal film of aluminum or an alloy thereof. The direction in which the pair of terminals 15 faces each other is orthogonal to the direction in which the pair of terminals 16 faces each other (see FIG. 2). Figure 1 ).

[0059] On the surface 22b of the first laminate 22, a plurality of grooves 17 and 18 are provided. The groove 17 extends in a ring shape so as to surround the connecting portion of the wiring 13a to the terminal 16. The groove 17 electrically connects the first electrode 12 to the wiring 13a. The groove 18 extends in a ring shape along the inner edge of the first electrode 12. The groove 18 electrically insulates the first electrode 12 from the region (second electrode 13) inside the first electrode 12. The region inside each groove 17 and 18 can be an insulating material or a void.

[0060] On the surface 24a of the second laminate 24, a groove 19 is provided. The groove 19 extends in a ring shape so as to surround the terminal 15. The groove 19 electrically insulates the terminal 15 from the third electrode 14. The region inside the groove 19 can be an insulating material or a void.

[0061] On the second surface lib of the substrate 11, a reflection preventing layer 41, a third laminate 42, an intermediate layer 43, and a fourth laminate 44 are sequentially stacked. The reflection preventing layer 41 and the intermediate layer 43 each have the same configuration as the reflection preventing layer 21 and the intermediate layer 23. The third laminate 42 and the fourth laminate 44 each have a stacked configuration symmetrical to the first laminate 22 and the second laminate 24 with the substrate 11 as a reference. The reflection preventing layer 41, the third laminate 42, the intermediate layer 43, and the fourth laminate 44 have a function of suppressing warping of the substrate 11.

[0062] The third stacked body 42, the intermediate layer 43, and the fourth stacked body 44 are thinned along the outer edge of the outer edge portion 11c. That is, the portions of the third stacked body 42, the intermediate layer 43, and the fourth stacked body 44 along the outer edge of the outer edge portion 11c are thinned compared to the other portions of the third stacked body 42, the intermediate layer 43, and the fourth stacked body 44. In the Fabry-Perot interference filter 1, the portions of the third stacked body 42, the intermediate layer 43, and the fourth stacked body 44 that overlap the thinned portion 34b when viewed from the direction perpendicular to the first surface 11a are thinned by removing the entire third stacked body 42, the intermediate layer 43, and the fourth stacked body 44.

[0063] An opening 40a is provided in the third stacked body 42, the intermediate layer 43, and the fourth stacked body 44 in such a manner as to include the light-transmitting region la when viewed from the direction perpendicular to the first surface 11a. The opening 40a has a diameter substantially the same as the size of the light-transmitting region la. The opening 40a is open on the light-exit side. The bottom surface of the opening 40a reaches the antireflection layer 41.

[0064] On the surface of the fourth stacked body 44 on the light-exit side, a light-blocking layer 45 is formed. The light-blocking layer 45 is composed of, for example, aluminum or the like. On the surface of the light-blocking layer 45 and the inner surface of the opening 40a, a protective layer 46 is formed. The protective layer 46 covers the outer edges of the third stacked body 42, the intermediate layer 43, the fourth stacked body 44, and the light-blocking layer 45, and covers the antireflection layer 41 on the outer edge portion 11c. The protective layer 46 is composed of, for example, aluminum oxide. Furthermore, by setting the thickness of the protective layer 46 to 1 nm to 100 nm (preferably, about 30 nm), the optical effects caused by the protective layer 46 can be ignored.

[0065] In the Fabry-Perot interference filter 1 configured as described above, if a voltage is applied between the first electrode 12 and the third electrode 14 via the pair of terminals 15, 16, an electrostatic force corresponding to the voltage is generated between the first electrode 12 and the third electrode 14. By this electrostatic force, the second mirror portion 32 is drawn toward the first mirror portion 31 side that is fixed to the substrate 11, thereby adjusting the distance between the first mirror portion 31 and the second mirror portion 32. Thus, in the Fabry-Perot interference filter 1, the distance between the first mirror portion 31 and the second mirror portion 32 is changed by the electrostatic force.

[0066] The wavelength of the light that transmits through the Fabry-Perot interference filter 1 depends on the distance between the first mirror portion 31 and the second mirror portion 32 of the light-transmitting region la. Therefore, the wavelength of the light that transmits can be appropriately selected by adjusting the voltage applied between the first electrode 12 and the third electrode 14. At this time, the second electrode 13 and the third electrode 14 are at the same potential. Therefore, the second electrode 13 functions as a compensating electrode for maintaining the first mirror portion 31 and the second mirror portion 32 flat in the light-transmitting region la.

[0067] In the Fabry-Perot interference filter 1, for example, by changing the voltage applied to the Fabry-Perot interference filter 1 (i.e., changing the distance between the first mirror portion 31 and the second mirror portion 32 in the Fabry-Perot interference filter 1), and detecting light passing through the light-transmitting region 1a of the Fabry-Perot interference filter 1 using a photodetector, a spectroscopic spectrum can be obtained.

[0068] like Figure 4 As shown, the dummy filter 2 differs from the aforementioned Fabry-Perot interference filter 1 in that the plurality of through-holes 24b are not formed in the second stacked body 24, and the gap S is not formed in the intermediate layer 23. In the dummy filter 2, the intermediate layer 23 is provided between the first mirror portion 31 and the second mirror portion 32. That is, the second mirror portion 32 is not suspended above the gap S, but is disposed on the surface 23a of the intermediate layer 23.

[0069] [Wafer Structure]

[0070] Next, the structure of a wafer according to one embodiment will be described. Figure 5 and Figure 6 As shown, the wafer 100 includes a substrate layer 110. The substrate layer 110 is, for example, in the shape of a disk having a diameter of approximately 150 mm or 200 mm, and an orientation plane OF is formed on a portion thereof. The substrate layer 110 is made of, for example, silicon, quartz, or glass. Hereinafter, when viewed from the thickness direction of the substrate layer 110, an imaginary straight line passing through the center of the substrate layer 110 and parallel to the orientation plane OF is referred to as a first straight line 3, and when viewed from the thickness direction of the substrate layer 110, an imaginary straight line passing through the center of the substrate layer 110 and perpendicular to the orientation plane OF is referred to as a second straight line 4.

[0071] Wafer 100 is provided with an active region 101 and a dummy region 102. Dummy region 102 is a region along outer edge 110c of substrate layer 110 (i.e., outer edge 100a of wafer 100). Active region 101 is a region inside dummy region 102. When viewed in the thickness direction of substrate layer 110, dummy region 102 surrounds active region 101. Dummy region 102 is adjacent to active region 101.

[0072] In the effective region 101, a plurality of Fabry-Perot interference filter portions 1A are arranged two-dimensionally. The plurality of Fabry-Perot interference filter portions 1A are arranged in the entire effective region 101. In the dummy region 102, a plurality of dummy filter portions 2A are arranged two-dimensionally. The plurality of dummy filter portions 2A are arranged in the entire dummy region 102 except for one pair of regions 102a. One region 102a is a region along the orientation flat OF. The other region 102a is a region along a portion of the outer edge 110c of the substrate layer 110 on the opposite side of the orientation flat OF. In a boundary portion between the effective region 101 and the dummy region 102, the Fabry-Perot interference filter portion 1A and the dummy filter portion 2A are adjacent to each other. When viewed from the thickness direction of the substrate layer 110, the outer shape of the Fabry-Perot interference filter portion 1A is the same as the outer shape of the dummy filter portion 2A. The plurality of Fabry-Perot interference filter portions 1A and the plurality of dummy filter portions 2A are arranged to be symmetrical with respect to each of the first straight line 3 and the second straight line 4 which are orthogonal to each other. Further, the plurality of dummy filter portions 2A can be arranged in the entire dummy region 102. In addition, the plurality of dummy filter portions 2A can be arranged in the regions of the dummy region 102 except for any one of the regions 102a.

[0073] The plurality of Fabry-Perot interference filter portions 1A are predetermined portions of a plurality of Fabry-Perot interference filters 1 by cutting the wafer 100 along each line 5. The plurality of dummy filter portions 2A are predetermined portions of a plurality of dummy filters 2 by cutting the wafer 100 along each line 5. When viewed from the thickness direction of the substrate layer 110, the plurality of lines 5 extend in a direction parallel to the orientation flat OF, and the plurality of lines 5 extend in a direction perpendicular to the orientation flat OF. As an example, when each filter portion 1A, 2A is rectangular and each filter portion 1A, 2A is arranged in a two-dimensional matrix when viewed from the thickness direction of the substrate layer 110, the plurality of lines 5 are arranged in a lattice shape by passing through between adjacent filter portions 1A, 1A, between adjacent filter portions 1A, 2A, and between adjacent filter portions 2A, 2A.

[0074] Figure 7 (a) is a cross-sectional view of the Fabry-Perot interference filter portion 1A, Figure 7 (b) is a cross-sectional view of the dummy filter portion 2A. As Figure 7As shown in (a) and (b), substrate layer 110 is formed by cutting wafer 100 along lines 5 to form a predetermined layer of multiple substrates 11. Substrate layer 110 has a first surface 110a and a second surface 110b that face each other. Antireflection layer 210 is provided on first surface 110a of substrate layer 110. Antireflection layer 210 is formed by cutting wafer 100 along lines 5 to form a predetermined layer of multiple antireflection layers 21. Antireflection layer 410 is provided on second surface 110b of substrate layer 110. Antireflection layer 410 is formed by cutting wafer 100 along lines 5 to form a predetermined layer of multiple antireflection layers 41.

[0075] The device layer 200 is provided on the antireflection layer 210. The device layer 200 includes a first mirror layer 220, an intermediate layer 230, and a second mirror layer 240. The first mirror layer 220 includes a plurality of first mirror portions 31 and is a layer intended to form a plurality of first stacked bodies 22 by cutting the wafer 100 along the lines 5. The plurality of first mirror portions 31 are two-dimensionally arranged on the first surface 110a of the substrate layer 110 via the antireflection layer 210. The intermediate layer 230 is a layer intended to form a plurality of intermediate layers 23 by cutting the wafer 100 along the lines 5. The second mirror layer 240 includes a plurality of second mirror portions 32 and is a layer intended to form a plurality of second stacked bodies 24 by cutting the wafer 100 along the lines 5. The plurality of second mirror portions 32 are two-dimensionally arranged on the first mirror layer 220 via the intermediate layer 23.

[0076] A stress adjustment layer 400 is provided on the antireflection layer 410. Specifically, the stress adjustment layer 400 is provided on the second surface 110b of the substrate layer 110 via the antireflection layer 410. The stress adjustment layer 400 includes multiple layers 420, 430, and 440. Layer 420 is a layer intended to form the plurality of third stacks 42 by cutting the wafer 100 along each line 5. Layer 430 is a layer intended to form the plurality of intermediate layers 43 by cutting the wafer 100 along each line 5. Layer 440 is a layer intended to form the plurality of fourth stacks 44 by cutting the wafer 100 along each line 5.

[0077] A light shielding layer 450 and a protective layer 460 are provided on the stress adjustment layer 400. The light shielding layer 450 is a layer that is intended to be formed into a plurality of light shielding layers 45 by cutting the wafer 100 along the lines 5. The protective layer 460 is a layer that is intended to be formed into a plurality of protective layers 46 by cutting the wafer 100 along the lines 5.

[0078] like Figure 7As shown in FIG. 1 (a), in each Fabry-Perot interference filter section 1A, a gap S is formed between the first mirror section 31 and the second mirror section 32, which face each other. Specifically, in each Fabry-Perot interference filter section 1A, the intermediate layer 23 defines the gap S, and the second mirror section 32 is suspended above the gap S. Similar to the configuration of the aforementioned Fabry-Perot interference filter 1, each Fabry-Perot interference filter section 1A includes components related to the first electrode 12, the second electrode 13, the third electrode 14, the plurality of terminals 15 and 16, and the opening 40a. Therefore, even when the plurality of Fabry-Perot interference filter sections 1A are in the wafer 100 state, if a voltage is applied to each Fabry-Perot interference filter section 1A via the pair of terminals 15 and 16, the distance between the first mirror section 31 and the second mirror section 32, which face each other, changes due to electrostatic force.

[0079] like Figure 7 As shown in FIG. 2( b ), in each dummy filter section 2A, an intermediate layer 23 is provided between the first mirror section 31 and the second mirror section 32, which face each other. Specifically, in the dummy filter section 2A, the intermediate layer 23 does not define a gap S, and the second mirror section 32 is disposed on the surface 23a of the intermediate layer 23. Therefore, while each dummy filter section 2A includes the same components as the dummy filter 2 described above, including the first electrode 12, the second electrode 13, the third electrode 14, the plurality of terminals 15 and 16, and the opening 40a, the distance between the facing first mirror section 31 and the second mirror section 32 remains unchanged. Furthermore, it is also possible not to provide the first electrode 12, the second electrode 13, the third electrode 14, multiple terminals 15, 16 (metal films such as aluminum constituting each terminal 15, 16, through holes for configuring each terminal 15, 16, etc.) and the opening 40a in each dummy filter portion 2A.

[0080] like Figure 6 and Figure 7(a) shown, in the device layer 200, there is formed a first groove 290 which is opened on the side opposite to the substrate layer 110. The first groove 290 is formed along each line 5. The first groove 290 surrounds the first mirror portion 31, the intermediate layer 23, and the second mirror portion 32 in each Fabry-Perot interference filter portion 1A and each dummy filter portion 2A. In each Fabry-Perot interference filter portion 1A, the first mirror portion 31, the intermediate layer 23, and the second mirror portion 32 are surrounded by the first groove 290 which is annularly continuous. Similarly, in each dummy filter portion 2A, the first mirror portion 31, the intermediate layer 23, and the second mirror portion 32 are surrounded by the first groove 290 which is annularly continuous. If attention is paid to the adjacent filter portions 1A, 1A, the adjacent filter portions 1A, 2A, and the adjacent filter portions 2A, 2A, the first groove 290 corresponds to the regions on the peripheral portion 34 of one filter portion and the peripheral portion 34 of the other filter portion. The first groove 290 is connected in the effective region 101 and the dummy region 102, and reaches the outer edge 110c of the substrate layer 110 when viewed from the direction in which the first mirror portion 31 and the second mirror portion 32 face each other (hereinafter referred to as the "facing direction"). Further, the first groove 290 in each Fabry-Perot interference filter portion 1A and each dummy filter portion 2A need only surround at least the second mirror portion 32. In this case, the entire second mirror portion 32 in the facing direction need not be surrounded by the first groove 290, and at least a part of the second mirror portion 32 in the facing direction need only be surrounded by the first groove 290.

[0081] As Figure 7 (b) shown, in the stress adjustment layer 400, there is formed a second groove 470 which is opened on the side opposite to the substrate layer 110. The second groove 470 is formed along each line 5. That is, the second groove 470 is formed in a manner corresponding to the first groove 290. Here, the second groove 470 corresponding to the first groove 290 means that the second groove 470 overlaps the first groove 290 when viewed from the facing direction. Therefore, the second groove 470 is connected in the effective region 101 and the dummy region 102, and reaches the outer edge 110c of the substrate layer 110 when viewed from the facing direction.

[0082] [Method for manufacturing wafer]

[0083] Next, the method for manufacturing the wafer 100 will be described with reference to Figures 8-13 . Figures 8-13 (a) is a cross-sectional view of a portion corresponding to the Fabry-Perot interference filter portion 1A, and (b) is a cross-sectional view of a portion corresponding to the dummy filter portion 2A.

[0084] First, as Figure 8As shown, a reflection preventing layer 210 is formed on the first surface 110a of the substrate layer 110, and a reflection preventing layer 410 is formed on the second surface 110b of the substrate layer 110. Then, by alternately laminating a plurality of polysilicon layers and a plurality of silicon nitride layers on each of the reflection preventing layers 210, 410, a first mirror layer 220 is formed on the reflection preventing layer 210, and a layer 420 is formed on the reflection preventing layer 410.

[0085] When the first mirror layer 220 is formed, portions of the first mirror layer 220 along each line 5 are removed by etching so as to expose the surface of the reflection preventing layer 210. In addition, by impurity doping, specific portions of the polysilicon layers of the first mirror layer 220 are partially low-resistance, so that the first electrode 12, the second electrode 13, and the wiring lines 12a, 13a are formed in each portion corresponding to the substrate 11. Further, by etching, a trench 17, 18 is formed on the surface of the first mirror layer 220 in each portion corresponding to the substrate 11.

[0086] Then, as shown, Figure 9 on the first mirror layer 220, and on the surface of the exposed reflection preventing layer 210, an intermediate layer 230 is formed, and on the layer 420, a layer 430 is formed. In portions corresponding to each Fabry-Perot interference filter section 1A, the intermediate layer 230 includes a removal scheduled portion 50 corresponding to the gap S (refer to Figure 3 ). Then, by etching, portions of the intermediate layer 230 and the reflection preventing layer 210 along each line 5 are removed so as to expose the first surface 110a of the substrate layer 110. In addition, by this etching, in each portion corresponding to the substrate 11, a gap is formed in the intermediate layer 230 in portions corresponding to each terminal 15, 16 (refer to Figure 3 ).

[0087] Then, as shown, Figure 10 on each of the first surface 110a side and the second surface 110b side of the substrate layer 110, by alternately laminating a plurality of polysilicon layers and a plurality of silicon nitride layers, a second mirror layer 240 is formed on the intermediate layer 230 and the exposed first surface 110a of the substrate layer 110, and a layer 440 is formed on the layer 430.

[0088] When the second mirror layer 240 is formed, the side surface 230a of the intermediate layer 230, the side surface 220a of the first mirror layer 220, and the side surface 210a of the reflection preventing layer 210, which are opposite to each other along the line 5, are covered with the second mirror layer 240. In addition, by impurity doping, specific portions of the polysilicon layers of the second mirror layer 240 are partially low-resistance, so that the third electrode 14 and the wiring line 14a are formed in each portion corresponding to the substrate 11.

[0089] Then, as shown, Figure 11The surface of the polysilicon layer 27a (refer to FIG. 2) contained in the second mirror layer 240 is exposed in such a manner that the portion of the second mirror layer 240 along each line 5 is thinned by etching. In addition, by this etching, a void is formed in the portion of the second mirror layer 240 corresponding to each terminal 15, 16 (refer to FIG. 2) in each portion corresponding to the substrate 11. Then, in each portion corresponding to the substrate 11, the void forms each terminal 15, 16, connects each terminal 15 and the wiring 12a, and connects each terminal 16, the wiring 13a, and the wiring 14a. Figure 3 Figure 3

[0090] Hitherto, the antireflection layer 210 and the device layer 200 are formed on the first surface 110a of the substrate layer 110, and the first groove 290 is formed in the device layer 200. The first groove 290 is a region in which the device layer 200 is partially thinned along each line 5.

[0091] Figure 12 (a) In the portion corresponding to each Fabry-Perot interference filter portion 1A, a plurality of through-holes 24b are formed in the second stacked body 24 by etching to remove the surface 24a of the second stacked body 24 to the predetermined portion 50. At this time, as shown in Figure 12 (b) In the portion corresponding to each dummy filter portion 2A, the plurality of through-holes 24b are not formed in the second stacked body 24. Then, as shown in Figure 12

[0092] Hitherto, the antireflection layer 410, the stress adjustment layer 400, the light shielding layer 450, and the protective layer 460 are formed on the second surface 110b of the substrate layer 110, and the second groove 470 is formed in the stress adjustment layer 400. The second groove 470 is a region in which the stress adjustment layer 400 is partially thinned along each line 5.

[0093] Figure 13 ​​​​​(a) shown, in the portion corresponding to each Fabry-Perot interference filter section 1A, the plurality of predetermined portions 50 are simultaneously removed by etching (for example, vapor phase etching using hydrogen fluoride gas) through the plurality of through-holes 24b. Thereby, in the portion corresponding to each Fabry-Perot interference filter section 1A, a void S is formed in each portion corresponding to the substrate 11. At this time, as shown in Figure 13 (b) shown, since in the portion corresponding to each dummy filter section 2A, the plurality of through-holes 24b are not formed in the second layer stack 24, a void S is not formed in the intermediate layer 230.

[0094] From the above, in the effective region 101, as shown in Figure 7 (a) shown, by forming a void S between the first mirror section 31 and the second mirror section 32 that face each other, a plurality of Fabry-Perot interference filter sections 1A are constituted. On the other hand, in the dummy region 102, as shown in Figure 7 (b) shown, by providing the intermediate layer 23 between the first mirror section 31 and the second mirror section 32 that face each other, a plurality of dummy filter sections 2A are constituted.

[0095] [Method for manufacturing Fabry-Perot interference filter]

[0096] Next, a method for cutting out the Fabry-Perot interference filter 1 from the wafer 100 (method for manufacturing the Fabry-Perot interference filter 1) is described with reference to Figure 14 and Figure 15 Figure 14 and Figure 15 In (a), a cross-sectional view of the portion corresponding to the Fabry-Perot interference filter section 1A, and in (b), a cross-sectional view of the portion corresponding to the dummy filter section 2A.

[0097] First, as shown in Figure 14 , the expansion tape 60 is attached to the protective layer 460 (i.e., the second surface 110b side). Next, with the expansion tape 60 attached to the second surface 110b side, laser light L is irradiated from the opposite side of the expansion tape 60, the focal point of the laser light L is made to be inside the substrate layer 110, and the focal point of the laser light L is made to move relatively along each line 5. That is, the laser light L is made to be incident on the substrate layer 110 from the opposite side of the expansion tape 60, through the surface of the polysilicon layer exposed in the first groove 290.

[0098] ​Then, through irradiation with laser light L, modified regions 7 are formed within substrate layer 110 along each line 5. Modified regions 7 are regions whose density, refractive index, mechanical strength, and other physical properties differ from those of the surrounding areas. These regions serve as the starting points for cracks extending in the thickness direction of substrate layer 110. Examples of modified regions 7 include melt-processed regions (meaning at least one of a region that has been temporarily melted and then solidified, a region in a molten state, and a region in a state that has resolidified from melting), crack regions, dielectric breakdown regions, and regions with changed refractive indexes. There are also regions that are a mixture of these. Furthermore, modified regions 7 include regions where the density of modified regions 7 in the material of substrate layer 110 varies compared to that of unmodified regions, and regions where lattice defects are formed. When substrate layer 110 is made of single-crystal silicon, modified regions 7 can also be referred to as high dislocation density regions. Furthermore, the number of rows of modified regions 7 arranged in the thickness direction of substrate layer 110 relative to each line 5 is appropriately adjusted according to the thickness of substrate layer 110.

[0099] Then, if Figure 15 As shown, by expanding the expansion tape 60 attached to the second surface 110b, cracks are extended from the modified region 7 formed in the interior of the substrate layer 110 in the thickness direction of the substrate layer 110, thereby cutting the substrate layer 110 into a plurality of substrates 11 along the lines 5. At this time, the polysilicon layer of the second mirror layer 240 is cut along the lines 5 in the first groove 290, and the antireflection layer 410 and the protective layer 460 are cut along the lines 5 in the second groove 470. Thus, a plurality of Fabry-Perot interference filters 1 and a plurality of dummy filters 2 are obtained, each separated from the other on the expansion tape 60.

[0100] [Configuration of Photodetection Device]

[0101] Next, the structure of the light detection device 10 including the Fabry-Perot interference filter 1 will be described. Figure 16 As shown, the light detection device 10 includes a package 71. Package 71 is a CAN package having a base 72 and a lid 73. Lid 73 is integrally formed of sidewalls 74 and a top wall 75. Base 72 and lid 73 are formed of a metal material and are airtightly bonded to each other. In package 71 formed of metal, sidewall 74 is cylindrical with line 9 as the centerline. Base 72 and top wall 75 face each other in a direction parallel to line 9, respectively covering both ends of sidewall 74.

[0102] A wiring substrate 76 is fixed to the inner surface 72a of the base 72. As a substrate material of the wiring substrate 76, for example, silicon, ceramic, quartz, glass, plastic, or the like can be used. In the wiring substrate 76, a light detector (light detection section) 77 and a temperature detector (not shown) such as a thermistor are mounted. The light detector 77 is disposed on the line 9. More specifically, the light detector 77 is disposed so that the center line of the light receiving section thereof coincides with the line 9. The light detector 77 is, for example, an infrared sensor such as a quantum sensor using InGaAs or the like, a thermal sensor using a thermopile or a bolometer, or the like. When detecting light in each wavelength region of ultraviolet, visible light, and near infrared, for example, a silicon photodiode or the like can be used as the light detector 77. Further, one light receiving section can be provided in the light detector 77, or a plurality of light receiving sections can be provided in an array. Further, a plurality of light detectors 77 can be mounted to the wiring substrate 76. In order to be able to detect a temperature change of the Fabry-Perot interference filter 1, a temperature detector can be disposed, for example, in a position close to the Fabry-Perot interference filter 1.

[0103] On the wiring substrate 76, a plurality of spacers 78 are fixed. As a material of each spacer 78, for example, silicon, ceramic, quartz, glass, plastic, or the like can be used. The Fabry-Perot interference filter 1 is fixed to the plurality of spacers 78, for example, by an adhesive. The Fabry-Perot interference filter 1 is disposed on the line 9. More specifically, the Fabry-Perot interference filter 1 is disposed so that the center line of the light transmission region la coincides with the line 9. Further, the spacers 78 can be integrally formed with the wiring substrate 76. In addition, the Fabry-Perot interference filter 1 can be supported by one spacer 78, not by the plurality of spacers 78.

[0104] On the base 72, a plurality of lead pins 81 are fixed. More specifically, each lead pin 81 penetrates the base 72 in a state of maintaining electrical insulation and air tightness with the base 72. In each lead pin 81, each of an electrode pad provided in the wiring substrate 76, a terminal of the light detector 77, a terminal of the temperature detector, and a terminal of the Fabry-Perot interference filter 1 is electrically connected by a wire 82. Further, the light detector 77, the temperature detector, and the Fabry-Perot interference filter 1 can be electrically connected to each lead pin 81 via the wiring substrate 76. For example, each terminal and the electrode pad provided in the wiring substrate 76 can be electrically connected, and the electrode pad and each lead pin 81 can be connected by the wire 82. Thereby, an electrical signal or the like can be input and output to and from each of the light detector 77, the temperature detector, and the Fabry-Perot interference filter 1.

[0105] An opening 71a is formed in the package 71. More specifically, the opening 71a is formed in the top wall 75 of the cover 73 in such a manner that the center line thereof coincides with the line 9. The opening 71a has a circular shape when viewed from a direction parallel to the line 9. A light-transmitting member 83 is disposed so as to cover the opening 71a on the inner surface 75a of the top wall 75. The light-transmitting member 83 is in airtight contact with the inner surface 75a of the top wall 75. The light-transmitting member 83 has a light incident surface 83a and a light exit surface (inner surface) 83b which are opposed to each other in a direction parallel to the line 9, and a side surface 83c. The light incident surface 83a of the light-transmitting member 83 is substantially flush with the outer surface of the top wall 75 at the opening 71a. The side surface 83c of the light-transmitting member 83 is in contact with the inner surface 74a of the side wall 74 of the package 71. That is, the light-transmitting member 83 reaches the opening 71a and the inner surface 74a of the side wall 74. Such a light-transmitting member 83 is formed by disposing glass particles on the inner side of the cover 73 in a state where the opening 71a is on the lower side, and fusing the glass particles. That is, the light-transmitting member 83 is formed by fusing glass.

[0106] A band-pass filter 84 is fixed to the light exit surface 83b of the light-transmitting member 83 by an adhesive member 85. That is, the adhesive member 85 fixes the band-pass filter 84 to the inner surface 75a of the top wall 75 via the light-transmitting member 83 which is bonded to the inner surface 75a of the top wall 75. The band-pass filter 84 selectively transmits (that is, transmits only light in a specific wavelength range) light in a wavelength range to be measured by the light detecting device 10 (light which is light in a specific wavelength range and which is to be incident on the light-transmitting region la of the Fabry-Perot interference filter 1) among light which has transmitted through the light-transmitting member 83. The band-pass filter 84 has a quadrangular plate shape. More specifically, the band-pass filter 84 has a light incident surface 84a and a light exit surface 84b which are opposed to each other in a direction parallel to the line 9, and four side surfaces 84c. The band-pass filter 84 is a filter in which a dielectric multilayer film (for example, a multilayer film including a combination of a high-refractive material such as TiO2, Ta2O5, etc. and a low-refractive material such as SiO2, MgF2, etc.) is formed on the surface of a light-transmitting member formed in a quadrangular plate shape by a light-transmitting material (for example, silicon, glass, etc.).

[0107] The adhesive member 85 has a first portion 85a which is disposed on the entire region of the light incident surface 84a of the band-pass filter 84. That is, the first portion 85a is a portion of the adhesive member 85 which is disposed between the light exit surface 83b of the light-transmitting member 83 and the light incident surface 84a of the band-pass filter 84 which are opposed to each other. Further, the adhesive member 85 has a second portion 85b which protrudes outward from the outer edge of the band-pass filter 84 when viewed from a direction parallel to the line 9. The second portion 85b reaches the inner surface 74a of the side wall 74 and is in contact with the inner surface 74a of the side wall 74. In addition, the second portion 85b is in contact with the side surfaces 84c of the band-pass filter 84.

[0108] In the light detecting device 10 configured as above, if light is incident from the outside via the opening 71a, the light transmitting member 83, and the adhesive member 85 to the band pass filter 84, light in a specific wavelength range is selectively transmitted. If the light transmitted through the band pass filter 84 is incident to the light transmitting region la of the Fabry-Perot interference filter 1, light in a specific wavelength range is selectively transmitted. The light transmitted through the light transmitting region la of the Fabry-Perot interference filter 1 is incident to the light receiving portion of the photodetector 77, and is detected by the photodetector 77. That is, the photodetector 77 converts the light transmitted through the Fabry-Perot interference filter 1 into an electric signal and outputs it. For example, the photodetector 77 outputs an electric signal of a magnitude corresponding to the intensity of the light incident to the light receiving portion.

[0109] [Effects of the wafer]

[0110] The wafer 100 can efficiently and with high yield obtain a plurality of Fabry-Perot interference filters 1.

[0111] In the wafer 100, the plurality of Fabry-Perot interference filter portions 1A that become the plurality of Fabry-Perot interference filters 1 are provided in the effective region 101. On the other hand, in the dummy region 102 along the outer edge 110c of the substrate layer 110 and surrounding the effective region 101, a plurality of dummy filter portions 2A are provided, and in each dummy filter portion 2A, the intermediate layer 23 is provided between the first mirror portion 31 and the second mirror portion 32 that face each other. Thus, the strength of the entire wafer 100 is sufficiently ensured. Therefore, for example, the handling of the wafer 100 when cutting the plurality of Fabry-Perot interference filters 1 from the wafer 100 becomes easy. In addition, even if the plurality of Fabry-Perot interference filter portions 1A remain in the state of the wafer 100, since each Fabry-Perot interference filter portion 1A functions in the same manner as the Fabry-Perot interference filter 1, various characteristics of each Fabry-Perot interference filter portion 1A can be checked, but the handling of the wafer 100 when performing such checking also becomes easy. Assuming that in each dummy filter portion 2A, a gap S is formed between the first mirror portion 31 and the second mirror portion 32 that face each other, for example, when holding the dummy region 102 of the wafer 100 by a holder, there is a concern that the second mirror portion 32 is broken, pieces of the second mirror portion 32 adhere to the Fabry-Perot interference filter portion 1A, and the appearance, characteristics, and the like of the Fabry-Perot interference filter portion 1A are deteriorated. In the wafer 100, since the intermediate layer 23 is provided between the first mirror portion 31 and the second mirror portion 32 that face each other in each dummy filter portion 2A, such a situation is suppressed from occurring.

[0112] In addition, in the wafer 100, at least the second mirror portion 32 of each Fabry-Perot interference filter portion 1A is surrounded by the first groove 290. Thus, the yield at the time of cutting the plurality of Fabry-Perot interference filters 1 from the wafer 100 is improved. In the case where at least the second mirror portion 32 of each Fabry-Perot interference filter portion 1A is not surrounded by the first groove 290, there is a concern that the appearance, characteristics, and the like of the Fabry-Perot interference filter portion 1A deteriorate due to the peeling of the cut surface film of the device layer 200 and the generation of chippings at the time of cutting the plurality of Fabry-Perot interference filters 1 from the wafer 100.

[0113] In addition, in the wafer 100, at least the second mirror portion 32 of each dummy filter portion 2A is surrounded by the first groove 290. In the case where at least the second mirror portion 32 of each dummy filter portion 2A is not surrounded by the first groove 290, a gap is not formed between the first mirror portion 31 and the second mirror portion 32, and thus stress easily concentrates in each dummy filter portion 2A, and as a result, there is a concern that the wafer 100 warps. In the wafer 100, since at least the second mirror portion 32 of each dummy filter portion 2A is surrounded by the first groove 290, stress is reduced in the dummy region 102, and the warping of the wafer 100 is suppressed. In addition, in the case where at least the second mirror portion 32 of each dummy filter portion 2A is not surrounded by the first groove 290, at the time of cutting the plurality of dummy filters 2 from the wafer 100, the cut surface film of the device layer 200 peels, and chippings and the like easily occur, and as a result, there is a concern that these broken pieces adhere to the Fabry-Perot interference filter 1, and the appearance, characteristics, and the like of the Fabry-Perot interference filter 1 deteriorate. In the wafer 100, since at least the second mirror portion 32 of each dummy filter portion 2A is surrounded by the first groove 290, the occurrence of such a situation is suppressed.

[0114] In addition, in the wafer 100, the first groove 290 is connected in the effective region 101 and the dummy region 102, and reaches the outer edge 110c of the substrate layer 110 when viewed from the opposite direction. Thus, the yield at the time of cutting the plurality of Fabry-Perot interference filters 1 from the wafer 100 can be further improved, and the warping of the wafer 100 can be more reliably suppressed.

[0115] In addition, in the wafer 100, a stress adjustment layer 400 is provided on the second surface 110b of the substrate layer 110, and a second groove 470 is formed in the stress adjustment layer 400 in correspondence with the first groove 290. Thus, the yield of cutting the wafer 100 into a plurality of Fabry-Perot interference filters 1 can be further improved, and the warping of the wafer 100 can be more reliably suppressed. If the second groove 470 is not formed in the stress adjustment layer 400 in correspondence with the first groove 290, when the wafer 100 is cut into a plurality of Fabry-Perot interference filters 1 and a plurality of dummy filters 2, there is a risk that the film of the stress adjustment layer 400 will peel off at the cutting surface, and that debris will be generated, and the appearance, characteristics, and the like of the Fabry-Perot interference filter 1 will deteriorate. In the wafer 100, since the second groove 470 is formed in the stress adjustment layer 400 in correspondence with the first groove 290, such a situation can be suppressed.

[0116] In addition, in the wafer 100, the plurality of Fabry-Perot interference filter portions 1A and the plurality of dummy filter portions 2A are arranged to be symmetrical with respect to each of the first straight line 3 and the second straight line 4 that are orthogonal to each other. Thus, the warping of the entire wafer 100 can be more reliably suppressed.

[0117] Further, in the method of manufacturing the wafer 100, the plurality of Fabry-Perot interference filter portions 1A are maintained in the state of the wafer 100, and the voids S are formed in the respective Fabry-Perot interference filter portions 1A. Thus, compared to a case where the formation of the voids S is performed at each chip level, the efficiency is extremely high, and the voids S can be formed between the first mirror portion 31 and the second mirror portion 32. Further, in the effective region 101, the etching of the intermediate layer 230 and the like is simultaneously performed on the plurality of removal scheduled portions 50 arranged in two dimensions, and the process simultaneously progresses for the portion of the substrate 11 in the substrate layer 110 and the portion of the substrate 11 surrounding the same, and thus the stress deviation in the plane of the substrate layer 110 can be reduced. Thus, according to the method of manufacturing the wafer 100, a wafer 100 that can stably mass-produce high-quality Fabry-Perot interference filters 1 can be obtained.

[0118] In addition, by irradiation of the laser L, a modified region 7 is formed inside the substrate layer 110 along each line 5, and thus cutting the wafer 100 along each line 5 is extremely effective in terms of manufacturing the Fabry-Perot interference filter 1 for the following reason. That is, in the cutting of the wafer 100 using the laser L, since water is not required, there is no risk that the second mirror portion 32, which is suspended over the void S, will be broken by water pressure, or that the water will penetrate into the void S and cause adhesion (a phenomenon in which the second mirror portion 32 comes into contact with the first mirror portion 31 and cannot move). Thus, the cutting of the wafer 100 using the laser L is extremely effective in terms of manufacturing the Fabry-Perot interference filter 1.

[0119] [Modifications]

[0120] While the above description focuses on one embodiment of the present disclosure, the present disclosure is not limited to the aforementioned embodiment. For example, the materials and shapes of the various components are not limited to those described above, and various materials and shapes may be used. In the wafer 100, when viewed from the thickness direction of the substrate layer 110, the outer shape of the Fabry-Perot interference filter portion 1A and the outer shape of the dummy filter portion 2A may be different. In addition, when a plurality of Fabry-Perot interference filters 1 are cut out from the wafer 100, not all of the dummy filter portions 2A may be cut out (i.e., not all of the dummy filter portions 2A may be monolithic).

[0121] In addition, if Figure 14 As shown, in wafer 100, modified regions 7 can also be formed within substrate layer 110 in a manner corresponding to first grooves 290. Here, "modified regions 7 correspond to first grooves 290" means that modified regions 7 overlap with first grooves 290 when viewed from opposite directions, and more specifically, means that modified regions 7 are formed along lines 5. This allows cracks to extend from modified regions 7 in the thickness direction of substrate layer 110, making it possible to easily and accurately cut multiple Fabry-Perot interference filters 1 from wafer 100. In this case, expandable tape 60 can also be attached to the second surface 110b of substrate layer 110. In this case, the outer edge of expandable tape 60 attached to wafer 100 is retained by an annular frame. This allows easy handling of wafer 100 even with modified regions 7 formed within substrate layer 110. Furthermore, in wafer 100 having modified region 7 formed within substrate layer 110, there is concern that cracks may unexpectedly extend from modified region 7. In wafer 100, since multiple dummy filter portions 2A, first grooves 290, and second grooves 470 are not provided in a pair of regions 102a within dummy region 102, the generation of cracks is suppressed, and even if cracks do develop, their extension is stopped by the pair of regions 102a.

[0122] In addition, if Figure 17 As shown, the mirror removal portion 2X may be formed in a portion of the dummy region 102. The mirror removal portion 2X is formed by not providing the second mirror portion 32 and the intermediate layer 23 and exposing the surface of the first mirror portion 31 (see FIG. 2 ). Figure 19 (b)) That is, the mirror removal portion 2X is not provided in the second mirror portion 32 and the intermediate layer 23, which is different from the dummy filter portion 2A. Figure 17 In the wafer 100 shown, in the annular region ( Figure 17, the area outside the dotted line), is provided with a plurality of mirror removed portions 2X. Furthermore, the mirror removed portion 2X is not limited to a structure formed by removing the entirety of the second mirror portion 32 and the intermediate layer 23. The mirror removed portion 2X may also be formed by removing at least a portion of the second mirror portion 32. That is, in the mirror removed portion 2X, a portion of the surface of the second mirror portion 32 on the opposite side to the first mirror portion 31 is removed in a layered manner, without providing a layer on the first mirror portion 31, or the layer on the first mirror portion 31 is thinned. In addition, in the mirror removed portion 2X, not only the laminate on the first surface 110a side of the substrate layer 110 but also the laminate on the second surface 110b side of the substrate layer 110 is thinned. For example, the stress adjustment layer 400 may not be provided, or the stress adjustment layer 400 may be thinned.

[0123] exist Figure 17 In the wafer 100 shown, a mirror-elimination portion 2X can also be formed by removing at least a portion of the second mirror portion 32 in a portion of the dummy region 102. Thus, for example, a gap S is formed by etching between the first mirror portion 31 and the second mirror portion 32, which face each other, in the portion corresponding to each Fabry-Perot interference filter portion 1A. Therefore, when forming multiple through-holes 24b in the second mirror portion 32, the removal status of the second mirror portion 32 can be monitored in the portion corresponding to the mirror-elimination portion 2X, and multiple through-holes 24b can be reliably formed in the second mirror portion 32 in the portion corresponding to each Fabry-Perot interference filter portion 1A (details will be described below). Thus, the wafer 100 includes multiple Fabry-Perot interference filter portions 1A with gaps S reliably formed between the first mirror portion 31 and the second mirror portion 32, which face each other.

[0124] In addition, Figure 17 In the wafer 100 shown, in the mirror removed portion 2X, at least the first mirror portion 31 is surrounded by the first groove 290. This reduces stress in the mirror removed portion 2X, thereby suppressing warping of the wafer 100.

[0125] In addition, Figure 17In the wafer 100 shown, the mirror removing portions 2X are provided in a plurality of locations in the dummy area 102 in a manner so as to follow the outer edge 110c of the substrate layer 110, and the first grooves 290 are connected in the active area 101 and the dummy area 102 and reach the outer edge 110c of the substrate layer 110 when viewed from the opposite direction. As an example, the plurality of mirror removing portions 2X are arranged in series along the outer edge 110c, thereby constituting an area that surrounds the area other than the active area 101 and the dummy area 102 when viewed from the opposite direction. Thus, the plurality of dummy filter portions 2A are arranged outside the plurality of Fabry-Perot interference filter portions 1A, the plurality of mirror removing portions 2X are arranged outside the plurality of dummy filter portions 2A, and the first grooves 290 are also connected and reach the outer edge 110c of the substrate layer 110, so that the stress balance of the entire wafer 100 is improved and the warping of the wafer 100 is more reliably suppressed.

[0126] For Figure 17 An example of a method of manufacturing the wafer 100 shown will be described. First, as shown in Figures 8-11 on the first surface 110a of the substrate layer 110, the antireflection layer 210 and the device layer 200 are formed, and the first grooves 290 are formed in the device layer 200. However, in the area in which the plurality of mirror removing portions 2X are provided (here, the area outside the broken line in the dummy area 102), the first electrode 12, the second electrode 13, the third electrode 14, the plurality of terminals 15, 16 (the metal film such as aluminum that constitutes each terminal 15, 16, the through hole for arranging each terminal 15, 16, and the like), and the opening 40a and the like related thereto do not need to be provided. Figure 17

[0127] Next, as shown in Figure 18 (a), in the portions corresponding to the respective Fabry-Perot interference filter portions 1A, a plurality of through holes 24b from the surface 24a of the second laminate 24 to the predetermined portions 50 are formed in the second laminate 24 by etching. On the other hand, as shown in Figure 18 (b), in the portions corresponding to the respective mirror removing portions 2X, the shield is removed in advance, and the second laminate 24 is removed by etching. At this time, in order to determine the timing at which etching is completed, the emission spectrum of the plasma (emission depending on the material of the layer being etched) in the portions corresponding to the respective mirror removing portions 2X is monitored.

[0128] ​The reason for monitoring the luminescence spectrum of the plasma in the portion corresponding to each mirror removal portion 2X is as follows. That is, since each through hole 24b is formed to a size that does not affect the functional essence of the second mirror portion 32, even if the luminescence spectrum of the plasma emitted from the portion corresponding to each through hole 24b is monitored, it is not easy to know the intensity change. Therefore, by monitoring the luminescence spectrum of the plasma in the portion corresponding to each mirror removal portion 2X provided with the same second stack 24, the time point when etching ends can be accurately judged, and a plurality of through holes 24b can be formed with good precision in the second stack 24 in the portion corresponding to each Fabry-Perot interference filter portion 1A. Furthermore, in the portion corresponding to each dummy filter portion 2A, as described above, a plurality of through holes 24b are not formed in the second stack 24 (refer to Figure 12 (b)).

[0129] Then, if Figure 18 As shown, a light-shielding layer 450 is formed on layer 440. Subsequently, portions of the light-shielding layer 450 and the stress-adjusting layer 400 (i.e., layers 420, 430, and 440) along each line 5 are removed by etching, exposing the surface of the anti-reflection layer 410. Furthermore, this etching process forms openings 40a in portions corresponding to the substrate 11. Subsequently, a protective layer 460 is formed on the light-shielding layer 450, covering the exposed surface of the anti-reflection layer 410, the inner surfaces of the openings 40a, and the side surfaces of the stress-adjusting layer 400 facing the second grooves 470.

[0130] Then, if Figure 19 As shown in (a), in the portion corresponding to each Fabry-Perot interference filter unit 1A, a plurality of planned removal portions 50 are simultaneously removed from the intermediate layer 230 by etching (for example, vapor phase etching using hydrogen fluoride gas) through the plurality of through holes 24b. As a result, a gap S is formed in the portion corresponding to each Fabry-Perot interference filter unit 1A, for each portion corresponding to the substrate 11. At this time, as shown in FIG. Figure 19 As shown in FIG. 2( b ), since the second laminate 24 is removed at the portion corresponding to each mirror removal portion 2X, the intermediate layer 23 is removed, and the surface of the first mirror portion 31 is exposed. Furthermore, since the plurality of through holes 24b are not formed in the second laminate 24 at the portion corresponding to each dummy filter portion 2A as described above, no gap S is formed in the intermediate layer 230 (see FIG. 2( b )). Figure 13 (b)).

[0131] From the above, in the effective area 101, if Figure 7 As shown in FIG. 1 , a plurality of Fabry-Perot interference filter sections 1A are formed by forming a gap S between the first mirror section 31 and the second mirror section 32 facing each other. Figure 7(b) shown, a plurality of dummy filter portions 2A are configured by providing the intermediate layer 23 between the first mirror portion 31 and the second mirror portion 32 which are opposite to each other. Further, in a part of the dummy region 102, as shown in (c), a mirror removing portion 2X is configured by not providing the second mirror portion 32 and the intermediate layer 23 so that the surface of the first mirror portion 31 is exposed. Figure 19 (b) shown, a plurality of dummy filter portions 2A are configured by providing the intermediate layer 23 between the first mirror portion 31 and the second mirror portion 32 which are opposite to each other. Further, in a part of the dummy region 102, as shown in (c), a mirror removing portion 2X is configured by not providing the second mirror portion 32 and the intermediate layer 23 so that the surface of the first mirror portion 31 is exposed.

[0132] Symbol Explanation

[0133] 1 Fabry-Perot interference filter

[0134] 1A Fabry-Perot interference filter portion

[0135] 2 Dummy filter

[0136] 2A Dummy filter portion

[0137] 2X Mirror removing portion

[0138] 3 First straight line

[0139] 4 Second straight line

[0140] 7 Modified region

[0141] 23 Intermediate layer

[0142] 31 First mirror portion

[0143] 32 Second mirror portion

[0144] 60 Expansion band

[0145] 100 Wafer

[0146] 101 Active region

[0147] 102 Dummy region

[0148] 110 Substrate layer

[0149] 110a First surface

[0150] 110b Second surface

[0151] 110c Outer edge

[0152] 220 First mirror layer

[0153] 240 Second mirror layer

[0154] 290 First groove

[0155] 400 Stress adjustment layer

[0156] 470 Second groove

[0157] S Space.

Claims

1. A wafer, characterized in that: have: a substrate layer having a first surface and a second surface facing each other; a first mirror layer having a plurality of first mirror portions two-dimensionally arranged on the first surface; and a second mirror layer having a plurality of second mirror portions two-dimensionally arranged on the first mirror layer, In the effective area, a gap is formed between the first mirror portion and the second mirror portion facing each other, thereby forming a plurality of Fabry-Perot interference filter portions in which the distance between the first mirror portion and the second mirror portion facing each other is changed by electrostatic force. In a dummy area along the outer edge of the substrate layer and surrounding the effective area, a plurality of dummy filter portions are formed by providing an intermediate layer between the first mirror portion and the second mirror portion facing each other. At a boundary portion between the active area and the dummy area, a groove opened on an opposite side of the substrate layer extends along the boundary portion.

2. The wafer according to claim 1, wherein The groove comprises a plurality of straight sections, Each of the plurality of straight line portions extends along two or more of the plurality of Fabry-Perot interference filter portions.

3. The wafer according to claim 1, wherein In each of the plurality of Fabry-Perot interference filter portions, at least the second mirror portion is surrounded by a first groove opened on the opposite side of the substrate layer. The groove extending along the boundary portion constitutes a part of the first groove.

4. The wafer according to claim 2, wherein: In each of the plurality of Fabry-Perot interference filter portions, at least the second mirror portion is surrounded by a first groove opened on the opposite side of the substrate layer. The groove extending along the boundary portion constitutes a part of the first groove.

5. The wafer according to claim 3, wherein: The plurality of dummy filter portions are provided in regions other than the first region and the second region in the dummy region. The first region is a region along an orientation plane formed on a portion of the substrate layer. The second region is a region along a portion of the outer edge of the substrate layer that is opposite to the orientation plane. In each of the plurality of dummy filter portions, at least the second mirror portion is surrounded by the first groove.

6. The wafer according to claim 4, wherein: The plurality of dummy filter portions are provided in regions other than the first region and the second region in the dummy region. The first region is a region along an orientation plane formed on a portion of the substrate layer. The second region is a region along a portion of the outer edge of the substrate layer that is opposite to the orientation plane. In each of the plurality of dummy filter portions, at least the second mirror portion is surrounded by the first groove.

7. The wafer according to any one of claims 1 to 6, wherein further comprising a stress adjustment layer provided on the second surface, The stress adjustment layer is formed with a second groove that opens on the side opposite to the substrate layer. The second groove is formed so as to correspond to the groove extending along the boundary portion.

8. The wafer according to any one of claims 1 to 6, wherein The plurality of Fabry-Perot interference filter portions and the plurality of dummy filter portions are arranged symmetrically with respect to a first straight line and a second straight line passing through the center of the substrate layer and orthogonal to each other when viewed from a direction in which the first mirror portion and the second mirror portion are opposite to each other.

9. The wafer according to claim 7, wherein: The plurality of Fabry-Perot interference filter portions and the plurality of dummy filter portions are arranged symmetrically with respect to a first straight line and a second straight line passing through the center of the substrate layer and orthogonal to each other when viewed from a direction in which the first mirror portion and the second mirror portion are opposite to each other.

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