JP3858606B2 - Method for manufacturing interference filter, interference filter, method for manufacturing variable wavelength interference filter, and variable wavelength interference filter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wavelength selective interference filter and optical communication.
[0002]
[Prior art]
Conventionally, interference filters using this type of Fabry-Perot resonator have been widely used from spectroscopes to optical communications because they exhibit wavelength selectivity with a very low half-value width by increasing the reflectivity. . This interference filter multi-reflects between reflection films and transmits only wavelengths that satisfy the phase matching condition (the phase difference of light when reciprocating is an integer multiple of 2π). Conventional configurations have been made by a method in which glass is polished on both sides and a reflective film is deposited on both ends thereof. In addition, as a method of changing the selection wavelength, it is created by a method in which one side of glass is wedge-polished at a slight angle with respect to the other side and a reflecting film is deposited on both ends thereof, and the light incident position is made parallel. Alternatively, a means for changing only the wavelength satisfying the phase matching condition by changing the distance between the reflecting films by rotating is used.
However, this interference filter is expensive because it is necessary to polish the glass very flatly with high surface accuracy and it is very difficult to control the distance.
Further, the wavelength variable interference filter has a problem that it takes time to change the wavelength because it is rotated or translated by a motor or the like.
[0003]
[Problems to be solved by the invention]
The present invention is for solving the above-mentioned problems, is inexpensive, has no deviation in reflection and transmission wavelengths depending on the location, realizes an accurate interference filter, and can switch the selection wavelength at a very high speed. The main object is to realize a wavelength tunable interference filter, and to realize a color sequential wavelength tunable interference filter that is small and can perform selective wavelength switching at high speed.
[0004]
[Means for Solving the Problems]
In order to solve the above-described problem, a first interference filter manufacturing method of the present invention includes:
Forming a first reflective film on a transparent substrate in a first step;
Forming a sacrificial layer film corresponding to a thickness satisfying a phase matching condition for a wavelength to be transmitted or reflected on the first reflective film in the second step;
Forming an anchor hole in the sacrificial layer film in a third step;
Forming a film along the anchor hole on the sacrificial layer film having the anchor hole in a fourth step;
Removing a portion that transmits or reflects light of the film formed in the fourth step by patterning in the fifth step;
Forming a second reflective film on the sacrificial layer and the film patterned in the fifth step in a sixth step;
Forming a resin film by applying and curing a transparent resin on the second reflective film in a seventh step;
Removing the sacrificial layer film in an eighth step;
Characterized by.
In the manufacturing method of the first interference filter,
The sacrificial layer film is made of silicon,
In the eighth step, the sacrificial layer film is removed by a xenon fluoride gas;
Is preferred.
[0005]
The second interference filter manufacturing method of the present invention includes:
Forming a first reflective film on a transparent substrate in a first step;
Forming a sacrificial layer film corresponding to a thickness satisfying a phase matching condition for a wavelength to be transmitted or reflected on the first reflective film in the second step;
Forming an anchor hole in the sacrificial layer film in a third step;
Forming a second reflective film along the anchor hole on the sacrificial layer film having the anchor hole in a fourth step;
In the fifth step, a transparent resin is applied and cured to form a resin film on the second reflective film, and the anchor hole is filled with the resin.
Removing the sacrificial layer film in a sixth step;
It is characterized by.
[0006]
In addition, the third interference filter manufacturing method of the present invention includes:
Forming a first reflective film on the first transparent substrate in the first step;
Forming a sacrificial layer film corresponding to a thickness satisfying a phase matching condition for a wavelength to be transmitted or reflected on the first reflective film in the second step;
Forming an anchor hole in the sacrificial layer film in a third step;
Forming a second reflective film along the anchor hole on the sacrificial layer film having the anchor hole in a fourth step;
Bonding a second transparent substrate on the second reflective film in a fifth step;
Removing the sacrificial layer film in a sixth step;
It is characterized by.
In the third interference filter manufacturing method,
In the fifth step, it is preferable that the refractive index after curing of the adhesive used for bonding the second transparent substrate is substantially equal to the refractive index of the second transparent substrate.
[0007]
The first interference filter of the present invention is an interference filter manufactured by the first to third interference filter manufacturing method,
The first reflective film and the second reflective film have an interval filled with a vacuum or transparent gas equivalent to a thickness that satisfies a phase matching condition with respect to a wavelength to be transmitted or reflected.
A second interference filter according to the present invention is an interference filter manufactured by the third interference filter manufacturing method,
Between the first reflective film and the second reflective film, there is an interval filled with a vacuum or transparent gas equivalent to a thickness that satisfies the phase matching condition for the wavelength to be transmitted or reflected,
A surface of the first transparent substrate on which the first reflective film is not formed or a surface of the second transparent substrate on which the second reflective film is not formed, on which light enters or exits A non-reflective coating is provided.
[0008]
The manufacturing method of the 1st wavelength variable interference filter of this invention is the following.
Forming a first reflective film on a transparent substrate in a first step;
Forming a wiring line at a position where the first reflective film is not formed on the transparent substrate in a second step;
Forming a sacrificial layer on the transparent substrate on which the first reflective film and the wiring lines are formed in a third step;
Forming an anchor hole in the sacrificial layer film in a fourth step;
Forming a film along the anchor hole on the sacrificial layer film having the anchor hole in a fifth step;
In the sixth step, patterning the film formed in the fifth step to create a column and a spring part;
Forming a second reflective film on the sacrificial layer and the film patterned in the fifth step in a seventh step;
Forming a resin film by applying and curing a resin on the second reflective film in an eighth step;
In the ninth step, removing the resin film on the support column and the spring portion;
Removing the sacrificial layer in a tenth step;
A method of manufacturing a wavelength tunable interference filter characterized by the above.
The second tunable interference filter manufacturing method of the present invention is as follows.
Forming a base, a first reflective film, and a first wiring pattern on a transparent substrate in a first step;
Forming a sacrificial layer film on the transparent substrate on which the base, the reflective film, and the wiring pattern are formed in a second step;
Removing the sacrificial layer film on the foundation in a third step to form an anchor hole;
Forming a second reflective film, a second wiring pattern, and a film constituting a spring portion on the sacrificial film having the anchor hole in a fourth step;
In the fifth step, a transparent resin is applied and cured to form a resin film on the second reflective film, the second wiring pattern, and the film constituting the spring portion, and Filling the anchor hole with the resin,
Removing the resin film on the film constituting the spring portion in a sixth step;
Removing the sacrificial layer in a seventh step;
It is characterized by.
[0009]
The third tunable interference filter manufacturing method of the present invention is as follows.
Forming a first reflective film on a transparent substrate in a first step;
In the second step, a conductive film is provided on the first reflective film, leaving an electrode and a wiring pattern, and removing a conductive film present on a light reflecting or transmitting surface;
In a third step, bonding one surface of the piezoelectric element to the electrode;
Forming a sacrificial layer film on the transparent substrate on which the electrode, the wiring pattern, and the piezoelectric element are formed in a fourth step, and removing the sacrificial layer film on the surface of the piezoelectric element;
Forming a second reflective film on the sacrificial layer film and the piezoelectric element in a fifth step;
Providing an organic or inorganic transparent member on the second reflective film in the sixth step;
Removing the sacrificial layer film that has not been removed in the fourth step in the seventh configuration;
It is characterized by.
A fourth method of manufacturing a wavelength tunable interference filter according to the present invention is as follows.
Forming a first reflective film on a transparent substrate in a first step;
In the second step, a conductive film is provided on the first reflective film, leaving an electrode and a wiring pattern, and removing a conductive film present on a light reflecting or transmitting surface;
In a third step, bonding one surface of the piezoelectric element to the electrode;
Forming a sacrificial layer film on the transparent substrate on which the electrode, the wiring pattern, and the piezoelectric element are formed in a fourth step, and removing the sacrificial layer film on the surface of the piezoelectric element;
Forming a second reflective film on the sacrificial layer film and the piezoelectric element in a fifth step;
Adhering an organic or inorganic transparent member on the second reflective film in the sixth step;
Removing the sacrificial layer film that has not been removed in the fourth step in the seventh configuration;
It is characterized by.
In the third and fourth variable wavelength interference filter manufacturing methods,
The sacrificial layer is made of silicon;
In the seventh step, the sacrificial layer film is preferably removed by a xenon fluoride gas.
[0010]
Further, the present invention is a wavelength tunable interference filter manufactured by the first to fourth wavelength tunable interference filter manufacturing method,
The transmission wavelength is changed by changing the distance between the first reflection film and the second reflection film.
It is characterized by that.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
(Example 1)
FIG. 1 is a schematic diagram for explaining an interference filter manufacturing means in Embodiment 1 of the present invention. Here, an example of an interference filter that selectively transmits light having a wavelength of 500 nm will be described. A first reflective film 102 is deposited on the transparent substrate 101. Next, a sacrificial layer 103 is formed to a thickness of 250 nm by CVD. The sacrificial layer 103 is patterned to form anchor holes 104. On the patterned sacrificial layer 103, a metal film 105 is formed along the anchor hole. Although a metal film is used here, any material may be used as the film material as long as it does not deteriorate with environmental changes. Also, a method of applying a resin by spin coating or the like and curing it may be used. Next, this metal film is patterned to remove the light transmitting portion. After the second reflective film 106 is deposited on the upper surface of the patterned metal film, the sacrificial layer 103 is removed by etching, whereby an air layer having a spacing of 250 nm shown in 107 is obtained. According to such a manufacturing means, even if there is a slight undulation on the surface of the transparent substrate 101, the sacrificial layer 103 is deposited along the undulation. Interference filters with uniform spacing can be manufactured.
[0012]
(Example 2)
FIG. 2 is a schematic diagram for explaining interference filter manufacturing means in the second embodiment. Here, an example of an interference filter that selectively transmits light having a wavelength of 500 nm will be described. A first reflective film 102 is deposited on the transparent substrate 101. Next, a sacrificial layer 103 is formed to a thickness of 250 nm by CVD. Here, anchor holes 104 are provided in the sacrificial layer 103. The metal film 105 is formed along the anchor hole, and a portion through which light is transmitted is removed by etching. Next, after depositing the second reflective film 106, a transparent resin is spin-coated on the second reflective film and cured. Here, an example in which a transparent resin is spin-coated has been shown, but an inorganic film such as SiO2 may be formed. Finally, the space 107 is obtained by removing the sacrificial layer 103 by etching. Since the resin film is present on the second reflective film 106, the second reflective film becomes strong, and a large-area interference filter can be manufactured. In addition, since the resin film 201 also functions as a protective layer, a more reliable interference filter can be realized.
[0013]
(Example 3)
FIG. 3 is a schematic diagram illustrating an interference filter according to the third embodiment. The interference filter created by the means of the first and second embodiments has a first reflective film 302 on the transparent substrate 301 and a space 303 that satisfies the phase matching condition, and a transparent member is provided above the second reflective film 304. And is supported by struts. The interval 303 is 250 nm in order to selectively transmit light having a wavelength of 500 nm. The incident light 305 is repeatedly reflected and interfered between the reflective films 302 and 304 as indicated by 306, and selectively transmits only the wavelength that meets the phase matching condition, and is obtained as the outgoing light 309.
[0014]
Even if undulation is present on the surface of the transparent substrate 301, the sacrificial layer follows the undulation, and the reflective film 304 deposited on the sacrificial layer also reflects the undulation. The distance 307 between the two positions is equal to the distance 308 between other places. Therefore, an accurate interference filter can be obtained in which the interference wavelength does not shift depending on the location. A graph showing the transmittance with respect to the wavelength of the interference filter obtained here is shown in FIG.
[0015]
(Example 4)
FIG. 5 is a schematic diagram for explaining interference filter manufacturing means in the fourth embodiment. A first reflective film 502 is deposited on the transparent substrate 501. Next, an amorphous silicon film 503 is formed by CVD using an amorphous silicon film as a sacrificial layer. Here, an anchor hole 504 is provided in the amorphous silicon sacrificial layer 503. A metal film 505 is formed on the patterned sacrificial layer 303 so as to follow the anchor holes. Next, this metal film is patterned to remove the light transmitting portion. After the second reflective film 506 is deposited on the upper surface of the patterned metal film, the amorphous silicon sacrificial layer 503 is removed by etching with a xenon fluoride gas, so that a space indicated by 507 can be secured. Since amorphous silicon can be formed at 300 ° C. or lower, an aluminum alloy film that melts at a high temperature can be used for the upper and lower reflective films. In addition, since etching with xenon fluoride gas is a dry process, an adsorption phenomenon or the like, which is seen in a liquid process, does not occur and a manufacturing process with a high yield can be obtained. Further, since it is not a dry process using plasma, the reflecting film, the transparent resin, and the like can be manufactured without damage, and a manufacturing means that does not impair the flatness can be obtained.
[0016]
(Example 5)
The interference filter manufacturing means in the fifth embodiment will be described with reference to FIG. Anchor holes are created in the amorphous silicon sacrificial layer 503, and a reflective film 601 is formed. At this time, film formation is performed in which the reflective film surely enters the anchor hole. The shape after the film formation follows the anchor hole of the sacrificial layer. Even when the transparent resin 602 is applied thereon, the resin is filled so as to fill the recess of the reflective film. After the resin is cured, the amorphous silicon sacrificial layer 503 is removed by etching with a xenon fluoride gas, whereby the interval indicated by 603 can be secured.
[0017]
By this method, a support and a wall for maintaining an accurate interval without requiring a new member can be obtained by the reflection film 601 and the resin film 602. In this example, both the reflective film and the upper transparent resin were filled in the anchor hole, but the reflective film was not formed in the anchor hole part, and even if only the transparent resin was filled in the anchor hole, the same support, And walls can be formed.
[0018]
(Example 6)
The interference filter manufacturing means in Embodiment 6 will be described with reference to FIG. A first reflective film 502 is deposited on the transparent substrate 501. Next, an amorphous silicon film 503 is formed by CVD using an amorphous silicon film as a sacrificial layer. Here, an anchor hole is provided in the amorphous silicon sacrificial layer 503. Next, after the second reflective film 601 is deposited, a transparent adhesive 701 is applied thereto, and the glass plate 702 is adhered thereto. In this example, a glass plate is used, but other inorganic materials and organic materials function in the same manner. After bonding the glass plate 702, the amorphous silicon sacrificial layer 503 is removed by etching with xenon fluoride gas, whereby the interval shown in 703 can be secured, and a means for manufacturing an interference filter having a very small wavelength distribution depending on the transmission location. can get. Since the glass plate is bonded to the reflective film 601 in the manufacturing means of the present embodiment, an interference filter that is hardly subject to strong deformation can be manufactured.
[0019]
(Example 7)
The interference filter manufacturing means in Embodiment 7 will be described with reference to FIG. A first reflective film 502 is deposited on the transparent substrate 501. Next, an amorphous silicon film 503 is formed by CVD using an amorphous silicon film as a sacrificial layer. Here, an anchor hole is provided in the amorphous silicon sacrificial layer 503. Next, after the second reflective film 601 is deposited, a transparent adhesive 701 is applied thereto, and the glass plate 702 is adhered thereto. Here, the transparent adhesive has a refractive index after curing substantially equal to the refractive index of the glass plate 702. In this example, a glass plate is used, but the same function as in this embodiment can be achieved by using an adhesive that is substantially matched to the refractive index of the substrate to which other inorganic materials or organic materials are bonded. After bonding the glass plate 702, the amorphous silicon sacrificial layer 503 is removed by etching with a xenon fluoride gas to obtain an interference filter manufacturing means having a distance indicated by 703. According to the present embodiment, the reflection / refraction at the boundary of the adhesive layer is extremely reduced, and an interference filter with almost no light loss is obtained.
[0020]
(Example 8)
An interference filter according to the eighth embodiment will be described with reference to FIG. The light 807 enters the transparent member 801 and reaches the reflective film 802. Between the reflective film 802 and the reflective film 805, there is a space 803 in which the amorphous silicon sacrificial layer is removed by etching with xenon fluoride gas. The light transmitted through the reflective film 802 causes interference due to the reflective films 802 and 805 and the interval 803, and only the wavelength satisfying the phase matching condition is transmitted as the outgoing light 808.
In this embodiment, even if the surface of the transparent member 806 has irregularities 809, the reflective film 805, the sacrificial layer, and the upper reflective film 802 are all deposited and manufactured along the irregularities 809. And the interval which permeate | transmits a target wavelength can be maintained in any place, without producing a difference in the space | interval 811 of a recessed part. Therefore, it is possible to obtain an interference filter with little variation in transmission wavelength in the plane of the interference filter.
[0021]
Example 9
The interference filter according to the ninth embodiment will be described with reference to FIG. Light 909 enters the transparent member. At this time, since the non-reflective coating 901 is provided on the light incident side of the transparent member 902, the surface reflection on the incident surface of the transparent member 902 is extremely small. The light incident on the transparent glass 902 passes through the adhesive layer 903 and reaches the reflective film 904. Between the reflective film 904 and the reflective film 906, there is a space 905 in which the amorphous silicon sacrificial layer is removed by etching with xenon fluoride gas. The light transmitted through the reflection film 904 causes interference at the time of multiple reflection as indicated by 910 by the reflection films 904 and 906 and the interval 905, and only the wavelength satisfying the phase matching condition becomes the output light 911 and passes through the transparent substrate 907. A non-reflective coating 911 is attached to the light exit surface of the transparent substrate 907. As described above, in this embodiment, it is possible to substantially eliminate the light amount loss that occurred at several percent on the incident side and the emission side of the interference filter, and to obtain an interference filter with higher light utilization efficiency.
[0022]
(Example 10)
The variable wavelength interference filter according to the tenth embodiment will be described with reference to FIG. The wavelength tunable interference filter of the present embodiment has a structure in which a reflective film 1003 and a lower electrode 1002 are provided on a transparent substrate 1001, and an upper electrode 1005 and a transparent member 1009 are supported by a spring structure 1008 supported by a column 1010. Have. The transparent member 1009 has an upper electrode 1005 and a reflective film 1006. In this structure, when a voltage is applied to the upper electrode 1005 and the lower electrode 1002, an attractive force is generated between the two electrodes, and the reflective film 1006 connected via the transparent member 1009 can also be moved up and down in the direction of 1007. When the distance 1004 between the reflective films 1006 and 1003 changes, the wavelength that satisfies the phase matching condition changes, and a wavelength variable interference filter can be realized.
To explain with a theoretical formula, the interference filter has a transmittance peak at a wavelength that satisfies the phase matching condition. Therefore, if the wavelength at which the transmittance reaches a peak is λ,
λ = 2 × L / n
It becomes.
Here, n: 1, 2, 3,..., L: 1004.
If the distance L changes, the wavelength satisfying the phase matching condition changes, and the peak of the transmission wavelength also changes.
[0023]
(Example 11)
A means for manufacturing the wavelength tunable interference filter according to the eleventh embodiment will be described with reference to FIG. A conductive reflective film is applied on the transparent substrate 1101, and the reflective film is patterned into a shape indicated by 1102. Thereafter, the base of the anchor and the conductive film to be the wiring are put on and patterned to obtain the shape shown in 1103. Here, a reflective film 1102, a wiring pattern, or an anchor 1103 is completed. Next, the sacrificial layer 1104 is applied and the anchor holes are patterned. A conductive film is put on the sacrificial layer, and the pillar 1105 and the spring structure 1106 are patterned. Next, a conductive reflective film 1107 is attached. Thereby, the reflective film 1107, the spring portion 1106, and the support column 1105 are electrically connected. The sacrificial layer 1104 is removed by etching, and a space 1108 is created between the spring portion and the reflective films 1102 and 1107. By this manufacturing process, an electrostatic actuator having a spring structure of 1106 can be manufactured using the reflective films 1002 and 1107 as upper and lower electrodes, and the reflective films 1102 and 1107 also function as a reflective film of the interference filter. By applying a voltage between the reflective film 1102 and the reflective film 1107, the distance between the reflective film 1102 and the reflective film 1107 can be controlled, and a variable wavelength interference filter capable of changing the transmission wavelength can be created. According to this embodiment, since the reflective film is used as an electrode, it is possible to realize a wavelength variable interference filter manufacturing means that does not require a new electrode for driving the electrostatic actuator.
[0024]
(Example 12)
The wavelength variable interference filter manufacturing means in Embodiment 12 will be described with reference to FIG. A conductive film is applied on the transparent substrate 1101 and a conductive film is patterned, and then a conductive film to be a base of an anchor and a wiring is applied and patterned. Here, it is separated into a reflective film, a wiring pattern, or an anchor base. Next, the sacrificial layer 1104 is applied and the anchor holes are patterned. A conductive film is put on the sacrificial layer, and a pillar and a spring structure 1204 are patterned. Next, a conductive reflective film 1107 is attached. Thereby, the reflective film 1107, the spring part 1106, and the support | pillar conduct. The resin 1201 is applied on the second reflective film 1107, and the resin on the spring portion 1204 is removed by patterning so that there is no resin in the 1202 portion. Thereafter, the sacrificial layer 1104 is removed by etching, and a space 1108 is created between the spring portion 1204 and the first reflective film and the second reflective film. Due to this manufacturing process, the movement of the spring portion 1204 is not restrained by the resin 1203. Therefore, an electrostatic actuator having the first and second reflective films as upper and lower electrodes and a spring structure of 1204 can be manufactured, and at the same time, the first and second The reflective film also functions as a reflective film for the interference filter. By applying a voltage between the first and second reflective films, an attractive force is generated between the first and second reflective films, and the spring 1204 is bent. The second reflective film 1107 stops at a balance between the attractive force due to the applied voltage and the spring force, and maintains a constant interval. In this way, by controlling the applied voltage, it is possible to create a variable wavelength interference filter that can control the distance between the first and second reflective film and change the transmission wavelength.
[0025]
(Example 13)
The wavelength variable interference filter manufacturing means in Embodiment 13 will be described with reference to FIG. By attaching a conductive reflective film on the transparent substrate 1301 and patterning the conductive reflective film, it is separated into an anchor base 1302, a reflective film 1303, and a wiring pattern. Next, the sacrificial layer 1305 is applied and the anchor 1304 is patterned. A conductive reflective film 1306 is placed on the sacrificial layer, and the reflective film part, the wiring part, and the spring part are patterned. Thereafter, a transparent member is applied to the upper portion, and after curing, 1308 parts are removed by patterning. This portion corresponds to the upper portion of the spring portion. By removing the sacrificial layer 1305, an electrostatic actuator having the reflective films 1309 and 1310 as upper and lower electrodes can be manufactured, and at the same time, the reflective films 1309 and 1310 also function as a reflective film of the interference filter. Moreover, since the resin which suppresses a displacement is removed, the spring part 1311 can function normally as a spring. Accordingly, by applying a voltage between the reflective film 1309 and the reflective film 1310, the spring portion 1311 of the reflective film is bent, and the reflective film 1309 can be moved as indicated by 1312. Thereby, the interval between the reflective film 1309 and the reflective film 1310 can be controlled, and a wavelength variable interference filter capable of changing the transmission wavelength by voltage control can be created. In addition, the electrostatic actuator and the variable wavelength interference filter can be manufactured with the same conductive film. The manufacturing process can be greatly reduced.
[0026]
(Example 14)
The wavelength variable interference filter manufacturing means in Embodiment 14 will be described with reference to FIG. After the reflective film is formed and patterned, an amorphous silicon film is deposited by CVD as a sacrificial layer. Since amorphous silicon can be formed at 300 ° C. or less, an aluminum-based film can be used. Thereafter, the anchor 1304 is patterned. A conductive film 1306 is applied on the upper part of the sacrificial layer, the reflective film part, the wiring part, and the spring part are patterned, and a transparent member is applied on the upper part and then cured. Thereafter, a transparent member is applied to the upper portion, and after curing, 1308 parts are removed by patterning. In this state, the amorphous silicon sacrificial layer is removed with xenon fluoride gas. In the sacrificial layer removal step using xenon fluoride gas, since it is not a liquid process, problems such as adsorption do not occur. Moreover, since no plasma is used, the design reflectance can be maintained without damaging the reflective film. Also, since an aluminum-based reflective film can be used, the spring constant can be reduced, thereby reducing the electrostatic actuator drive voltage.
[0027]
(Example 15)
The wavelength variable interference filter manufacturing means in the fifteenth embodiment will be described with reference to FIG. After forming a reflective film on the transparent substrate 1401, patterning is performed to obtain the shape shown in 1402. Next, after forming a conductive film, 1403 parts are formed by patterning the conductive film. A piezoelectric element 1404 is bonded onto 1403, a sacrificial layer 1405 is formed on the top, and then an anchor hole 1406 is patterned to expose the upper surface of the piezoelectric element 1404. A reflective film 1406 is formed thereon, and then a transparent resin 1407 is applied. In this embodiment, a transparent resin is used, but an inorganic material film represented by SiO 2 may be used. After the transparent resin is cured, the sacrificial layer 1405 is removed by etching. Accordingly, a space 1409 is generated between the reflective films, and the reflective film 1408 can be moved up and down by applying a voltage to the piezoelectric elements and expanding and contracting the piezoelectric elements. Therefore, a tunable interference filter that can control the distance between the reflective film 1402 and the reflective film 1408 and change the transmission wavelength by voltage control can be created.
[0028]
(Example 16)
The variable wavelength interference filter manufacturing means in the sixteenth embodiment will be described with reference to FIG. A reflective film is formed on the transparent substrate, and the piezoelectric element 1501 is bonded. After the amorphous silicon sacrificial layer 1502 is formed on the upper portion, an anchor hole 1503 is formed by patterning in order to expose the upper surface of the piezoelectric element 1501. An adhesive 1505 is applied after forming a reflective film 1504 thereon. The adhesive 1505 is UV curable. The transparent glass 1506 is provided with a step 1507 according to the difference between the height of the piezoelectric element 1501 and the thickness of the light interference portion sandwiched between the reflection films, and the unevenness is engaged through the applied adhesive 1505. Are joined together. After the transparent glass 1506 is bonded, the amorphous silicon sacrificial layer 1502 is removed with a xenon fluoride gas to create a gap 1509 between the upper and lower reflective films. In this embodiment, an ultraviolet curing type adhesive is used, but any type of adhesive may be used as long as it has a refractive index substantially the same as the refractive index of the transparent member 1306 provided with a depression. According to this embodiment, the thickness of the piezoelectric actuator can be increased, the displacement amount of the interval 1509 is large, and the driving voltage can be lowered.
[0029]
Therefore, the wavelength tunable interference filter manufactured in this embodiment can be driven with a low voltage and can change the transmission wavelength in a wide range from ultraviolet light to infrared light because it can take a large amount of change in the distance between the reflective films. You can make it.
[0030]
(Example 17)
The color sequential wavelength selection filter in Example 17 will be described with reference to FIG. The transparent substrate 1601 has a reflective film 1602 and a piezoelectric element 1603, and the piezoelectric element 1603 supports the transparent member 1605, and the distance between the reflective film 1602 and the reflective film 1604 is maintained. When a voltage is applied to the piezoelectric element 1603 in this state, the distance between the reflective film 1602 and the reflective film 1604 changes. When the distance between the reflective film 1602 and the reflective film 1604 is changed, the wavelength satisfying the phase matching condition is changed, so that the transmission wavelength is changed. The distance between the reflective film 1602 and the reflective film 1604 is 200 nm when the voltage is 0 V, 250 nm when the voltage is 10 V, and 300 nm when the voltage is 20 V. FIG. 17 shows the transmission wavelength characteristics for each voltage. In this embodiment, three primary colors are displayed when the voltage is 0V (blue), when the voltage is 10V (green), and when the voltage is 20V (red). A schematic diagram showing timing signals and drive voltages is shown in FIG. A red timing signal 1801 is generated by a timing generation circuit from an image driving circuit such as a projector. At this timing, the driving voltage becomes 20 V indicated by 1802. At this time, the distance between the reflective film 1602 and the reflective film 1604 is 300 nm, and the wavelength that satisfies the phase matching condition is 600 nm in red. Further, at the timing of the green timing signal 1803, the drive voltage becomes 10V shown by 1804, the interval between the reflective film 1602 and the reflective film 1604 becomes 250 nm, and the wavelength satisfying the phase matching condition becomes 500 nm green. Similarly, in the blue timing signal 1805, the driving voltage is 1806 of 1806, the distance between the reflective film 1602 and the reflective film 1604 is 200 nm, and the wavelength satisfying the phase matching condition is blue of 400 nm.
[0031]
As described above, in this embodiment, it is possible to realize a color sequential wavelength selection filter that changes colors in a temporally sequential manner. The color change time is equal to the actuator movement time, and color switching can be performed at a very high speed of light. In addition, as compared with a conventional type in which a color filter is rotated by a motor, it is not necessary to focus the light beam on the color filter, so that the light use efficiency can be increased.
[0032]
(Example 18)
The wavelength selection filter in Example 18 will be described with reference to FIG. Since the light emitted from the optical fiber 1906 is wavelength-multiplexed, light having a peak is overlapped every several wavelength intervals. This light becomes parallel or converged light 1908 by the lens 1907 and enters the transparent member 1905. The transparent substrate 1905 has a reflective film 1904 with high reflectivity. The transparent member 1905 includes a piezoelectric element 1903, and the piezoelectric element 1903 supports the transparent member 1901 so that the distance between the reflective films 1902 and 1904 is maintained. When a voltage is applied to the piezoelectric element 1903 in this state, the distance between the reflective film 1902 and the reflective film 1904 changes. When the distance between the reflective film 1902 and the reflective film 1604 is changed, the wavelength satisfying the phase matching condition is changed, and thus the transmission wavelength is changed. Therefore, the wavelength-multiplexed light 1908 is also separated from the output light 1909 only by the necessary light. . The outgoing light 1909 is inserted into the optical fiber 1911 by the lens 1910. Since the reflection film 1902 and the reflection film 1604 have high reflectivity, the half width of the transmission spectrum distribution can be very narrow, and the distance between the reflection film 1902 and the reflection film 1604 can be controlled with high accuracy by a piezoelectric actuator. Light having a peak in the interval can also be separated into individual spectral waveforms and transmitted.
[0033]
【The invention's effect】
As described above, according to the present invention,
1) Since the interval satisfying the phase matching condition is formed by the sacrificial layer, a very accurate interval can be obtained in a wide range.
2) An anchor hole is provided in the sacrificial layer, and thereby a support or wall for maintaining a space is created, and a stable distance between the reflective films can be obtained.
3) The reflective film can be protected by applying a transparent member on the second reflective film.
4) By using an amorphous silicon sacrificial layer that can be deposited at a low temperature when creating the distance between the reflective films, an aluminum-based film that can be damaged at a high temperature can be used. Was realized as a reflective film.
5) Since the sacrificial layer etching process using the amorphous silicon sacrificial layer and the xenon fluoride gas is a dry process, an adsorption phenomenon or the like, which is seen in a liquid process, does not occur and a manufacturing process with a high yield can be obtained. Further, since it is not a dry process using plasma, the reflecting film, the transparent resin, and the like can be manufactured without damage, and a manufacturing means that does not impair the flatness can be obtained.
6) By the manufacturing method in which the anchor hole is filled with a reflective film or transparent resin, a support and a wall for maintaining an accurate interval without requiring a new member can be obtained.
7) By adjusting the refractive index of the adhesive to the refractive index of the transparent member, the reflection refraction at the boundary of the adhesive layer becomes very small, and an interference filter with almost no light loss is obtained.
8) Even if there is some waviness on the surface of the transparent substrate, the sacrificial layer accumulates along the waviness, so that interference filters that do not cause a gap error due to waviness even on optical components with curved surfaces. Manufacturing means are obtained.
9) By providing a non-reflective coating on the light incident side of the transparent member and the output side of the other transparent member, it is possible to almost eliminate the light quantity loss that occurred at several percent on the incident side and the output side of the interference filter, An interference filter with higher light utilization efficiency can be obtained.
10) The transmission wavelength can be changed by changing the interval between the reflective films by a voltage using an electrostatic actuator or a piezoelectric actuator.
11) By making the reflecting film also serve as the electrode of the electrostatic actuator, a means for manufacturing a wavelength variable interference filter that does not require a new electrode for driving the electrostatic actuator can be realized.
12) Since the reflective film is patterned and wirings, electrodes, and pillars are created, a means for manufacturing a wavelength tunable interference filter with a shorter manufacturing process can be realized.
13) Since a step corresponding to the thickness of the piezoelectric element is provided in the transparent member, and the piezoelectric element is bonded to the step with an adhesive, the thickness of the piezoelectric element can be increased with respect to the distance between the reflective films. It becomes possible. In addition, since the amount of change in the interval between the reflection films can be increased, a variable wavelength interference filter having a wide long range can be realized from ultraviolet light to infrared light.
14) The color-sequential wavelength tunable filter of the present invention can obtain a very high color switching speed. In addition, since it is not necessary to focus the light beam on the color filter, the light utilization efficiency can be increased.
14) Since the transmission spectrum width (half-value width at the transmitted light wavelength) is very small and the actuator can be moved with high accuracy, a wavelength selective filter with high wavelength selection resolution can be realized.
[Brief description of the drawings]
FIG. 1 is a schematic diagram for explaining interference filter manufacturing means in Embodiment 1 of the present invention.
FIG. 2 is a schematic diagram for explaining interference filter manufacturing means in Embodiment 2 of the present invention.
FIG. 3 is a schematic diagram illustrating an interference filter according to a third embodiment of the present invention.
FIG. 4 is a graph showing the transmittance in Example 3 of the present invention.
FIG. 5 is a schematic diagram for explaining interference filter manufacturing means in Embodiment 4 of the present invention.
FIG. 6 is a schematic diagram for explaining interference filter manufacturing means in Embodiment 5 of the present invention.
FIG. 7 is a schematic diagram for explaining interference filter manufacturing means in Embodiments 6 and 7 of the present invention.
FIG. 8 is a schematic diagram illustrating an interference filter according to an eighth embodiment of the present invention.
FIG. 9 is a schematic diagram illustrating an interference filter according to a ninth embodiment of the present invention.
FIG. 10 is a schematic diagram showing a variable wavelength interference filter according to a tenth embodiment of the present invention.
FIG. 11 is a schematic diagram for explaining a means for manufacturing a wavelength variable interference filter according to an eleventh embodiment of the present invention.
FIG. 12 is a schematic diagram for explaining means for manufacturing a wavelength variable interference filter according to a twelfth embodiment of the present invention.
FIG. 13 is a schematic view for explaining means for manufacturing a wavelength tunable interference filter according to Examples 13 and 14 of the present invention.
FIG. 14 is a schematic diagram for explaining a means for manufacturing a wavelength variable interference filter according to a fifteenth embodiment of the present invention.
FIG. 15 is a schematic diagram for explaining means for manufacturing a wavelength tunable interference filter according to a sixteenth embodiment of the present invention.
FIG. 16 is a diagram showing a wavelength-sequential wavelength selection filter in Embodiment 17 of the present invention.
FIG. 17 is a graph showing transmission wavelength characteristics with respect to voltages in Example 17 of the present invention.
FIG. 18 is a diagram showing timing signals and drive voltages in Example 17 of the present invention.
FIG. 19 is a diagram illustrating a wavelength selection filter according to an eighteenth embodiment of the present invention.
[Explanation of symbols]
101 Transparent substrate
102, 106 Reflective film
103 Sacrificial layer
104 Anchor hole
105 Metal film
201 resin film
301 Transparent substrate
302, 304 Second reflective film
501 Transparent substrate
502, 506 Reflective film
503 Amorphous silicon film
504 Anchor hole
505 Metal film
601 reflective film
602 Resin film
701 Transparent adhesive
702 glass plate
801 Transparent member
802, 805 reflective film
806 Transparent member
901 Non-reflective coating
902 Transparent member
903 Adhesive layer
904, 906 Reflective film
907 transparent substrate
1001 Transparent substrate
1002 Lower electrode
1003, 1006 Reflective film
1005 Upper electrode
1009 Transparent member
1010 prop
1101 Transparent substrate
1102, 1107 Reflective film
1104 Sacrificial layer
1105 Prop
1106 Spring part
1201 resin
1301 Transparent substrate
1302 Anchor base
1303, 1306, 1309, 1310 Reflective film
1304 Anchor
1305 Sacrificial layer
1311 Spring part
1401 Transparent substrate
1402, 1408 Reflective layer
1404 Piezoelectric element
1405 Sacrificial layer
1406 Anchor hole
1407 Resin layer
1501 Piezoelectric element
1502 Sacrificial layer
1503 Anchor hole
1504 reflective film
1505 Adhesive
1506 transparent glass
1601 Transparent substrate
1602, 1604 Reflective film
1603 Piezoelectric element
1605 Transparent member
1901 Transparent member
1902, 1904 Reflective film
1903 Piezoelectric element
1905 Transparent substrate
1906, 1911 Optical fiber
1907, 1910 Lens

Claims (13)

Forming a first reflective film on a transparent substrate in a first step;
Forming a sacrificial layer film corresponding to a thickness satisfying a phase matching condition for a wavelength to be transmitted or reflected on the first reflective film in the second step;
Forming an anchor hole in the sacrificial layer film in a third step;
In the fourth step, the film to be formed along the anchor hole on the sacrificial layer film having the anchor hole,
Removing a portion that transmits or reflects light of the film formed in the fourth step by patterning in the fifth step;
Forming a second reflective film on the sacrificial layer and the film patterned in the fifth step in a sixth step;
Forming a resin film by applying and curing a transparent resin on the second reflective film in a seventh step;
Removing the sacrificial layer film in an eighth step ;
Method for producing an interference filter according to claim. In the manufacturing method of the interference filter according to claim 1,
The sacrificial layer film is made of silicon,
In the eighth step, the sacrificial layer film is removed by a xenon fluoride gas ;
Method for producing an interference filter according to claim.   In the first step, the first reflective film is formed on the transparent substrate.FormationTo do,
In the second step,On the first reflective film,Thickness equivalent to the phase matching condition for the wavelength to be transmitted or reflectedSacrificial layer film is formedTo do,
In the third step,Sacrificial layer filmForming an anchor hole in the
In the fourth step, having the anchor holeSaidSacrificial layerfilmabove,A second reflective film along the anchor holeFormationTo do,
In the fifth step,A transparent resin is applied and cured to form a resin film on the second reflective film, andAnchor holeThe resinFilling,
In the sixth step,Remove the sacrificial layer filmTo do,
TheA method for manufacturing an interference filter. Forming a first reflective film on the first transparent substrate in the first step;
Forming a sacrificial layer film corresponding to a thickness satisfying a phase matching condition for a wavelength to be transmitted or reflected on the first reflective film in the second step;
Forming an anchor hole in the sacrificial layer film in a third step;
Forming a second reflective film along the anchor hole on the sacrificial layer film having the anchor hole in a fourth step;
Bonding a second transparent substrate on the second reflective film in a fifth step;
Removing the sacrificial layer film in a sixth step ;
Method for producing an interference filter according to claim. In the manufacturing method of the interference filter according to claim 4 ,
In the fifth step, the refractive index after curing of the adhesive used for bonding the second transparent substrate is made substantially equal to the refractive index of the second transparent substrate . Production method. An interference filter manufactured by the method for manufacturing an interference filter according to any one of claims 1 to 5 ,
The interference having a space filled with a vacuum or a transparent gas corresponding to a thickness satisfying a phase matching condition with respect to a wavelength to be transmitted or reflected between the first reflective film and the second reflective film filter. A interference filter manufactured by the manufacturing method of the interference filter according to claim 4 or claim 5,
Between the first reflective film and the second reflective film, there is an interval filled with a vacuum or transparent gas equivalent to a thickness that satisfies a phase matching condition with respect to a wavelength to be transmitted or reflected ,
A surface of the first transparent substrate on which the first reflective film is not formed or a surface of the second transparent substrate on which the second reflective film is not formed, on which light enters or exits An interference filter provided with a non-reflective coating. Forming a first reflective film on a transparent substrate in a first step;
Forming a wiring line at a position where the first reflective film is not formed on the transparent substrate in a second step;
Forming a sacrificial layer on the transparent substrate on which the first reflective film and the wiring lines are formed in a third step;
Forming an anchor hole in the sacrificial layer film in a fourth step;
Forming a film along the anchor hole on the sacrificial layer film having the anchor hole in a fifth step;
In the sixth step, patterning the film formed in the fifth step to create a column and a spring part;
Forming a second reflective film on the sacrificial layer and the film patterned in the fifth step in a seventh step;
Forming a resin film by applying and curing a resin on the second reflective film in an eighth step;
In the ninth step, removing the resin film present on the strut and spring unit,
Removing the sacrificial layer in a tenth step;
A method of manufacturing a wavelength tunable interference filter characterized by the above. Forming a base, a first reflective film, and a first wiring pattern on a transparent substrate in a first step;
  Forming a sacrificial layer film on the transparent substrate on which the base, the reflective film, and the wiring pattern are formed in a second step;
  Removing the sacrificial layer film on the foundation in a third step to form an anchor hole;
  Forming a second reflective film, a second wiring pattern, and a film constituting a spring portion on the sacrificial film having the anchor hole in a fourth step;
  In the fifth step, a transparent resin is applied and cured to form a resin film on the second reflective film, the second wiring pattern, and the film constituting the spring portion, and Filling the anchor hole with the resin,
  Removing the resin film on the film constituting the spring portion in a sixth step;
  Removing the sacrificial layer in a seventh step;
A method of manufacturing a wavelength tunable interference filter characterized by Forming a first reflective film on a transparent substrate in a first step;
In the second step, a conductive film is provided on the first reflective film, leaving an electrode and a wiring pattern, and removing a conductive film present on a light reflecting or transmitting surface;
Bonding one surface of the piezoelectric element to the electrode in a third step;
In the fourth step, the electrode, the wiring pattern, and a sacrificial layer film is formed on the piezoelectric element is formed the transparent substrate, removing the sacrificial layer film present on the surface of the piezoelectric element that,
Forming a second reflective film on the sacrificial layer film and the piezoelectric element in a fifth step;
Forming a resin film by applying and curing a transparent resin on the second reflective film in a sixth step;
Removing the sacrificial layer film that has not been removed in the fourth step in the seventh configuration;
A method of manufacturing a wavelength tunable interference filter characterized by the above. Forming a first reflective film on a transparent substrate in a first step ;
In the second step, a conductive film is provided on the first reflective film, leaving an electrode and a wiring pattern, and removing a conductive film present on a light reflecting or transmitting surface;
Bonding one surface of the piezoelectric element to the electrode in a third step;
In the fourth step, the electrode, the wiring pattern, and a sacrificial layer film is formed on the piezoelectric element is formed the transparent substrate, removing the sacrificial layer film present on the surface of the piezoelectric element that,
Forming a second reflective film on the sacrificial layer film and the piezoelectric element in a fifth step;
In the sixth step, on the second reflection film, adhering the transparent member of an organic or inorganic,
Removing the sacrificial layer film that has not been removed in the fourth step in the seventh configuration;
A method of manufacturing a wavelength tunable interference filter characterized by the above. In the manufacturing method of the wavelength tunable interference filter according to claim 10 or 11 ,
The sacrificial layer is made of silicon,
In the seventh step, the sacrificial layer film is removed by a xenon fluoride gas ;
A method of manufacturing a wavelength tunable interference filter characterized by the above. A tunable interference filter manufactured by the manufacturing method according to any one of claims 9 to 12,
  The transmission wavelength is changed by changing the distance between the first reflection film and the second reflection film.
A tunable interference filter characterized by the above.

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