JP5060091B2 - Method for producing porous thin film and method for producing optical member provided with porous thin film - Google Patents

Description

The present invention relates to a process for producing a porous film, and a method for manufacturing an optical member having a porous membrane.

  A porous thin film having optical properties for various purposes is formed on the surface of the optical component. As such, for example, an antireflection film for an optical element for a high-power laser, an optical thin film for improving the laser resistance of a polarizing element for a high-power laser or a reflecting mirror, and an eye for reducing the brightness of a display screen. 2. Description of the Related Art There are known optical thin films used for an antireflection film for reducing the reflection attenuation of an antireflection film formed on a protective filter, a panel used in a solar system, and the like.

  These porous thin films are conventionally produced by a vacuum deposition method or a chemical method.

  Among these, an optical thin film formed by vacuum vapor deposition is formed by depositing a vapor deposition material lower than the refractive index of the substrate on the vapor deposition substrate so as to have a thickness of λ / 4 (λ is the wavelength of incident light). There are a single layer film and a multilayer film formed by vapor-depositing two or more layers of a low refractive index material and a high refractive index material.

  Further, in Patent Document 1, as a combination of a vacuum deposition method and a chemical treatment method, a water-soluble material and a water-insoluble material are simultaneously vapor-deposited to form a mixed film, and then a water-soluble substance in the mixed film is formed. A method of dissolving and removing a substance to form a porous thin film of a water-insoluble substance on a substrate is disclosed.

  Furthermore, in Patent Document 2, a water-insoluble substance for antireflection is deposited on an optical element substrate, a water-soluble substance having a higher particle energy is deposited on the surface, and the water-soluble substance is a non-water-soluble substance. A method for forming a porous thin film by deeply penetrating into the interior to form a mixed film and then dissolving and removing the water-soluble substance is disclosed.

  Further, in Non-Patent Document 1, as a chemical treatment method, an antireflection film is produced by forming a porous silica thin film having a reflectance of 0.1 to 0.3% on a quartz glass substrate surface by a sol-gel method. Are disclosed.

Furthermore, Non-Patent Document 2 discloses a method of forming porous MgF ₂ and CaF ₂ thin films that are fluorides on quartz glass and a CaF 2 crystal substrate by a sol-gel method.
Japanese Patent Laid-Open No. 06-167601 International Publication No. 02/018981 Pamphlet D. Milam et al., CLEO'84 Technical Digest, THB2 (1984) Ian M. Thomas, Appl. Opt, Vol. 27, No. 16, P3356-3358 (1988)

  However, the porous thin film produced by the above-described conventional vacuum vapor deposition method has low laser resistance, and three or more layers of vapor deposition are required to form a broadband antireflection film. Furthermore, once the film is damaged, there arises a problem that the substrate must be restored by performing two processes of rough polishing and ultraprecision polishing. This is because, in the conventional vacuum deposition method, the absorbing layer locally formed at the boundary between the substrate surface and the deposited thin film is covered with a high-density deposited film. This is because it cannot be removed by the laser cleaning according to, and remains as it is, so that it is turned into plasma by irradiation with high-power laser light and destroys the deposited film.

  In addition, the broadband antireflection film is formed by laminating about two to seven layers of two kinds of vapor deposition materials of a high refractive index material and a low refractive index material, or 1/100 to 1/300 of the film thickness of a single layer film. A method of laminating 100 to 300 layers of two kinds of materials having a thickness of 1 mm is used, but this method significantly increases the manufacturing cost as compared with a single layer film.

  Furthermore, in the method according to Patent Document 1 described above, it is necessary to perform evaporation while changing the mixing ratio of two kinds of substances in the process of forming the mixed film, and the desired reflectance can be stably achieved from the viewpoint of controlling the evaporation rate. Is difficult to get.

  Further, in the method according to Patent Document 2 described above, two kinds of vapor deposition materials are required for the production of a single layer film, which is problematic in terms of manufacturing cost.

  Further, the reflective film produced by the method disclosed in Non-Patent Documents 1 and 2 described above has a reflectance at a predetermined wavelength of 0.5% or less, and the laser resistance is 2% of a thin film formed by vacuum deposition. Although it has a yield strength more than double, the mechanical strength of the surface is very weak. In this method, colloidal particles adhere to the substrate surface by van der Waals force to form a porous thin film, which easily peels off when external force is applied mechanically, making the production procedure difficult and extremely time consuming. It takes. Furthermore, since work is performed in a high temperature environment, a problem occurs in workability.

The present invention has been made in view of the above problems, it is an object with good production efficiency and workability, and a process for producing excellent porous film in laser resistance, etc., and a porous it is to provide a method of manufacturing an optical member having a thin film.

The method for producing a porous thin film according to the present invention is a method for producing a porous thin film provided on the surface of a substrate, the step of forming a thin film on the surface of the substrate by vapor deposition, and the formation on the surface of the substrate. Forming a hole in the thin film, and the hole is formed by immersing the thin film in warm water at 80 ° C. or higher for a predetermined time, and the surface of the thin film immersed in warm water is heated in warm water. It is characterized in that bubbles are supplied for a predetermined time .

  According to such a configuration, a porous thin film having excellent laser resistance and the like can be obtained stably by forming the holes. Also, a porous thin film having good laser resistance can be formed by using only one vapor deposition material. For this reason, manufacturing efficiency becomes favorable. Further, workability is improved because work in a high temperature environment is unnecessary.

Further, since the pores are formed by immersing the thin film in warm water at 80 ° C. or higher for a predetermined time, the pores can be formed in the thin film with a simple apparatus configuration. For this reason, manufacturing efficiency becomes favorable.

Moreover, since air bubbles are supplied to the surface of the thin film immersed in warm water for a predetermined time, it is possible to form pores in the thin film more satisfactorily.

  In the method for producing a porous thin film according to the present invention, the vapor deposition may be vacuum vapor deposition.

According to such a configuration, a thin film formed on the substrate has a pore from the beginning to some extent, that then Do is easy to form into further membrane pores.

Et al is, the production method of the porous film according to the present invention, the pores may be formed by immersing a predetermined time in boiling water a thin film.

  According to such a configuration, since the pores are formed by immersing the thin film in boiling water for a predetermined time, a porous thin film having excellent laser resistance and the like can be formed more satisfactorily.

A method of manufacturing a porous thin film according to the present invention, a thin film _may be formed by SiO _2, MgF _2, CaF ₂ or _Al 2 _{O 3.}

According to such a configuration, since the thin film is formed of SiO ₂ , MgF ₂ , CaF _2, or Al ₂ O _3, it is easy to form vacancies in the thin film.

According to the present invention, a method of manufacturing an optical member including a porous thin film includes a step of preparing a base material, a step of forming a thin film by vapor deposition on the surface of the base material, and a pore in the thin film formed on the surface of the base material. possess forming a porous thin film is formed and the, holes are formed by a predetermined time immersed film in hot water of more than 80 ° C., to a thin film was immersed in warm water, warm water Then, bubbles are supplied to the surface for a predetermined time .

  According to such a configuration, it is possible to obtain an optical member including a porous thin film having excellent laser resistance and the like by forming holes. Further, a porous thin film of an optical member having good laser resistance can be formed by using only one vapor deposition material. For this reason, manufacturing efficiency becomes favorable. Further, workability is improved because work in a high temperature environment is unnecessary.

Further, since the pores are formed by immersing the thin film in warm water at 80 ° C. or higher for a predetermined time, the pores can be formed in the thin film with a simple apparatus configuration. For this reason, manufacturing efficiency becomes favorable.

Moreover, since air bubbles are supplied to the surface of the thin film immersed in warm water for a predetermined time, it is possible to form pores in the thin film more satisfactorily.

  Moreover, in the method for producing an optical member provided with the porous thin film according to the present invention, a barrier member for further restricting the entry of moisture into the porous thin film may be formed on at least one surface of the porous thin film.

  According to such a configuration, since the intrusion of moisture into the porous thin film due to being left in the atmosphere or the like is restricted, it is possible to suppress a decrease in the antireflection characteristic (AR characteristic).

  Furthermore, the manufacturing method of the optical member provided with the porous thin film according to the present invention may form the barrier member on both surfaces of the porous thin film.

  According to such a configuration, since the barrier member is formed on both surfaces of the porous thin film, the intrusion of moisture on both surfaces of the porous thin film is regulated, so that the antireflection characteristic (AR characteristic) is more effectively reduced. Can be suppressed.

  Moreover, the manufacturing method of the optical member provided with the porous thin film which concerns on this invention may form the auxiliary member which raises the adhesive force of a base material and a porous thin film further between a base material and a porous thin film. Good.

  According to such a configuration, an auxiliary member that further increases the adhesion between the base material and the porous thin film is formed between the base material and the porous thin film. And peeling of the porous thin film can be suppressed.

  Furthermore, in the method for producing an optical member provided with the porous thin film according to the present invention, the auxiliary member may be formed of the same material as the porous thin film.

According to such a configuration, since the auxiliary member is formed of the same material as the porous thin film, the adhesion between the auxiliary member and the porous thin film is further increased, and accordingly, the base material and the porous thin film are better to enhance the adhesion of Ru can be suppressed peeling of the porous film.

According to the present invention, a good production efficiency and workability, and can provide a method for producing an optical member comprising the method of manufacturing excellent porous film in laser resistance, etc., and a porous thin film.

(Embodiment)
Next, an optical member provided with a porous thin film according to an embodiment of the present invention will be described in detail using an antireflection film as an example with reference to the drawings.

(Configuration of the antireflection film 20 including the porous thin film 10)
FIG. 1 shows a cross-sectional view of an antireflection film 20 provided with a porous thin film 10.

  The antireflection film 20 includes a glass substrate 30, an auxiliary member 40, a porous thin film 10, and a barrier member 50 that are laminated in this order from the lower layer to the upper layer.

  The glass substrate 30 is formed in a rectangular plate-shaped body made of a glass material.

The auxiliary member 40 is provided on the glass substrate 30 and constitutes a film with SiO ₂ . The auxiliary member 40 is preferably formed densely by ion-assisted vapor deposition or the like and has a higher adhesion.

The porous thin film 10 is provided on the auxiliary member 40 and constitutes a SiO ₂ film having pores. Here, as shown in FIG. 2, the porous thin film 10 is formed by a normal vapor deposition method, and pores are formed in a SiO ₂ film in which each molecule is densely formed, as shown in FIG. It has a porous structure. The porous thin film 10 is preferably formed to a thickness of about ¼ of the wavelength incident on the antireflection film 20.

The barrier member 50 is provided on the porous thin film 10 and constitutes a SiO ₂ film. The barrier member 50 is preferably formed densely by ion-assisted vapor deposition or the like to further improve the barrier property against moisture intrusion.

(Method for producing porous thin film 10 and antireflection film 20)
Next, the manufacturing method of the porous thin film 10 and the antireflection film 20 will be described in detail with reference to the drawings.

  First, a glass substrate 30 is prepared, and a predetermined etching process or the like is performed on the surface.

  Next, the vacuum evaporation apparatus 60 shown in FIG. 4 is prepared. The vacuum deposition apparatus 60 includes a processing tank 61, a substrate mounting dome 62, an ion gun 63 that supplies oxygen ions 74, an oxygen gas supply device 64, an argon supply device (not shown), and a substrate mounting dome 62, respectively. Argon supply pipe, crucible 65, electron gun 66, film thickness control monitor glass 67, rate control crystal monitor 68, vacuum pump 69 for sucking air in the processing tank 61, and processing tank 61 are provided. The light source 70, the reflecting mirror 71, and the detector 72 are included.

On the crucible 65 in the vacuum vapor deposition apparatus 60, SiO _{2 serving} as the vapor deposition source 73 is placed. Further, the glass substrate 30 is placed on the substrate placement dome 62.

  Subsequently, the inside of the processing tank 61 is evacuated by the vacuum pump 69 while the vapor deposition source 73 is heated by the crucible 65.

Then, on the glass substrate 30, oxygen gas, by depositing a SiO ₂ film by ion-assisted deposition of a SiO ₂ as an evaporation source in an oxygen ion and argon ion supplying, to form an auxiliary member 40.

  Specifically, first, the electron gun 66 supplies electrons to the surface of the vapor deposition source 73.

The vapor deposition source 73 supplied with electrons on the surface sends SiO ₂ vapor 75 to the glass substrate 30, and an SiO ₂ film is deposited on the glass substrate 30 under supply of oxygen gas, oxygen ions and argon ions. During this time, the light source 70 is turned on, and it is confirmed whether the desired film thickness is obtained using the rate control crystal monitor 68, the detector 72, and the like.

  Next, the glass substrate 30 on which the auxiliary member 40 is formed is placed on the substrate mounting dome 62, and oxygen gas is supplied to the glass substrate 30 by the oxygen gas supply device 64, while the electron gun 66 is used. Electrons are supplied to the surface of the vapor deposition source 73.

The evaporation source 73 supplied with electrons on the surface sends SiO ₂ vapor 75 to the glass substrate 30, and an SiO ₂ film is evaporated on the glass substrate 30 under supply of oxygen gas. During this time, similarly to the formation of the auxiliary member 40 described above, the light source 70 is turned on, and it is confirmed whether the desired film thickness is obtained using the rate control crystal monitor 68, the detector 72, and the like.

Next, the glass substrate 30 on which the SiO ₂ film is formed on the auxiliary member 40 is immersed in boiling water, for example, for about four and a half hours to form pores in the film, thereby forming the porous thin film 10.

  Next, the glass substrate 30 is taken out from the boiling water.

Next, on the porous thin film 10 of the glass substrate 30 taken out from boiling water, SiO ₂ is used as a deposition source under the supply of oxygen gas, oxygen ions, and argon ions, and the same ion assist as in the above-described auxiliary member 40 forming step. A barrier member 50 is formed by vapor-depositing a SiO ₂ film having a desired film thickness by vapor deposition, and the antireflection film 20 is produced.

  The antireflection film 20 produced in this way can be used for antireflection at the time of incidence and reflection of a fiber end face of a laser or the like, for example, by being provided on both end faces of an optical fiber.

  In addition, the antireflection film 20 including the porous thin film 10 described in the present embodiment is not limited to the configuration described above. For example, the barrier member 50 may be provided on both surfaces of the porous thin film 10.

The auxiliary member 40, the porous film 10 and the barrier member 50 has formed in the SiO _{2, respectively,} may be formed respectively with MgF 2, CaF ₂ or _Al 2 _{O 3.}

  Furthermore, although the ion assist vapor deposition method was used for vapor deposition of the auxiliary member 40 and the barrier member 50, other vapor deposition methods may be used.

Although the deposition of the SiO ₂ film constituting the porous film 10 was performed by a vacuum deposition method, it may be used other than vapor deposition.

  Furthermore, in the present embodiment, the optical member including the porous thin film has been described with respect to the antireflection film. However, the optical member is not limited to this, and for improving the laser resistance of the high-power laser polarizer and the reflecting mirror. It may be an optical member related to an optical element or the like.

(Test evaluation)
An evaluation test for examining the spectral characteristics of the porous thin film was performed using an optical member provided with the porous thin film having the same configuration as that shown in the embodiment.

<Optical member for test evaluation>
First, an optical member A produced as shown below as an example was prepared.

In the production of the optical member of the example, first, amorphous SiO ₂ of a low refractive material was used. A quartz glass substrate was used as the base material.

Next, the above-mentioned SiO ₂ was produced on a quartz glass substrate by an electron beam evaporation method. The conditions at that time were as follows: the degree of vacuum during film formation was 1.0 × 10 ⁻² Pa, the film formation rate was 1 Å / s, and the film formation temperature was about 25 ° C. (non-heated film formation). Here, in this case, since the film is formed so as to be an AR film of 1064 nm, the physical film thickness is about 210 nm.

Next, the quartz glass substrate on which the SiO ₂ film was formed as described above was immersed in boiling water for a predetermined time to form pores in the film. Here, the immersion time in boiling water was divided into 120 minutes, 240 minutes, and 270 minutes to prepare three types.

  In addition, as a hole forming treatment, the product was immersed while supplying bubbles in 70 ° C. warm water without using boiling water (optical member A (4)), and about 80% in the 80 ° C. warm water without supplying bubbles. What was immersed for 13 hours (optical member A (5)) was produced.

Next, as a comparative example, an optical member B on which a SiO ₂ film was deposited by vacuum deposition on an identical glass substrate and an optical member C on which a SiO ₂ film was deposited by ion-assisted deposition were prepared. did.

<Test evaluation method>
The optical members A (1) to (3) according to the three different examples with different immersion times in the boiling water produced as described above, the optical members B and C according to the comparative examples, and further the boiling water treatment. The optical member A (0) according to the example before application and the optical member A (4), (5) subjected to the hot water treatment are subjected to the wavelength of incident light and the reflectance of the thin film by the experimental apparatus shown in FIG. I investigated the relationship with.

  The experimental apparatus in FIG. 5 includes an Nd: YAG laser (1064 nm) irradiation unit, a prism, a 1 / 2λ plate, a polarizer, a biplanar, quartz glass, a reflecting mirror 71, a condenser lens, a CCD camera, and the like.

  Optical members A, B, and C as samples were installed in front of the condenser lens of this experimental apparatus, and each was irradiated with laser beams having different fluences from the Nd: YAG laser irradiation unit. The value observed with the biplanar for each irradiation was read with an oscilloscope. The presence or absence of damage on the thin film was determined by plasma emission and a CCD camera.

  In addition, a similar experiment was performed without placing a sample for laser beam energy calibration.

<Test evaluation results>
The above experimental results are shown in FIGS.

  Here, FIG. 6 shows the relationship between the wavelength of incident light and the reflectance of the optical members A (0) to (3) of the example.

  According to FIG. 6, it can be seen that the reflectance gradually decreases as the optical member A (0) moves to the optical member A (1), the optical member A (2), and the optical member A (3). In particular, in the optical member A (3) subjected to boiling water treatment for 270 minutes, the reflectance at a wavelength of 1064 nm is reduced to about 0.27% (refractive index of about 1.27). For this reason, it turns out that a boiling water process is effective as a means to form a void | hole in a thin film, and to make it porous. Furthermore, in the optical member A (3) having the lowest reflectance, the refractive index when the reflectance is 0.5017% is 1.293, and the refractive index when the reflectance is 0.4956% is 1. 292. For this reason, it turns out that the refractive index of the porous thin film of the optical member A (3) whose reflectance is 0.5% or less is 1.292 or less.

  FIG. 7 shows the relationship between the wavelength of incident light and the reflectance of the optical member A (3) of the example and the optical members B and C of the comparative example.

  As can be seen from FIG. 7, the reflectance gradually decreases as the optical member C moves from the optical member B to the optical member A (3). It can also be seen that the band gradually becomes wider and the oblique incidence loss is further reduced.

  Next, Table 1 shows the observation results of the presence or absence of thin film damage in the above test.

  From Table 1, it can be seen that damage occurs when the energy of the laser beam exceeds 122.4 mV. Therefore, it can be said that 122.4 mV is a damage threshold value based on actual measurement values.

  Here, Table 2 shows the results of experiments conducted for energy calibration.

The values in Table 2 are drawn in graphs, respectively, in the energy calibration graph of FIG. In the straight line of this graph, the observed energy corresponding to the measured value of the damage threshold value of 122.4 mV is 25.38 mJ. Then, divide this value by 0.000686Cm ² is a spot area of the laser beam irradiation, to obtain a damage threshold 36.99J / cm ² after energy calibration.

  This damage threshold is larger than the damage threshold of the conventional thin film, and it can be seen that the laser resistance is better.

  Furthermore, according to the experiment relating to the optical member A (4), the result that the reflectivity decrease is almost the same as that of the optical member A (0) was obtained. Further, according to the experiment relating to the optical member A (5), the decrease in the reflectance was significantly observed as compared with the optical member A (0).

  Therefore, it was found that the condition for vacancy formation treatment was to immerse in warm water of 80 ° C. or higher.

(Function and effect)
The manufacturing method of the porous thin film 10 which concerns on embodiment of this invention is a manufacturing method of the porous thin film provided in the surface of the glass base material 30, Comprising: The step which forms a thin film on the surface of the glass base material 30 by vapor deposition And a step of forming holes in the thin film formed on the surface of the glass substrate 30.

  According to such a configuration, it is possible to obtain a porous thin film 10 having excellent laser resistance and the like by forming holes. Further, the porous thin film 10 having good laser resistance can be formed by using only one vapor deposition material. For this reason, manufacturing efficiency becomes favorable. Further, workability is improved because work in a high temperature environment is unnecessary.

  Moreover, the manufacturing method of the porous thin film 10 which concerns on embodiment of this invention is characterized by vapor deposition being vacuum deposition.

  According to such a configuration, the thin film formed on the glass substrate 30 has pores to some extent from the beginning, and thereafter, it becomes easier to further form the pores in the film.

  Furthermore, the manufacturing method of the porous thin film 10 which concerns on embodiment of this invention forms a void | hole by immersing a thin film in boiling water for a predetermined time.

  According to such a configuration, since the pores are formed by immersing the thin film in boiling water for a predetermined time, the porous thin film 10 having excellent laser resistance and the like can be formed more satisfactorily.

A method of manufacturing a porous thin film 10 according to the embodiment of the present invention, a thin _film, and forming with SiO _2, MgF _2, CaF ₂ or _Al 2 _{O 3.}

According to such a configuration, since the thin film is formed of SiO ₂ , MgF ₂ , CaF _2, or Al ₂ O _3, it is easy to form vacancies in the thin film.

  The manufacturing method of the optical member provided with the porous thin film 10 which concerns on embodiment of this invention is a step which prepares the glass base material 30, the step which forms a thin film by vapor deposition on the surface of the glass base material 30, and a glass base material And forming a porous thin film 10 by forming pores in the thin film formed on the surface of 30.

  According to such a configuration, it is possible to obtain an optical member including the porous thin film 10 having excellent laser resistance and the like by forming holes. Further, the porous thin film 10 of an optical member having good laser resistance can be formed by using only one vapor deposition material. For this reason, manufacturing efficiency becomes favorable. Further, workability is improved because work in a high temperature environment is unnecessary.

  Moreover, the manufacturing method of the optical member provided with the porous thin film 10 which concerns on embodiment of this invention is the barrier member 50 which regulates the penetration | invasion of the water | moisture content to the porous thin film 10 on the at least one surface of the porous thin film 10 further. It is characterized by forming.

  According to such a configuration, since the intrusion of moisture into the porous thin film 10 due to being left in the atmosphere or the like is restricted, it is possible to suppress a decrease in the antireflection characteristic (AR characteristic).

  Moreover, the manufacturing method of the optical member provided with the porous thin film 10 which concerns on embodiment of this invention is contact | adherence between the glass base material 30 and the porous thin film 10 between the glass base material 30 and the porous thin film 10 further. The auxiliary member 40 for increasing the force is formed.

  According to such a configuration, since the auxiliary member 40 that further increases the adhesion between the glass substrate 30 and the porous thin film 10 is formed between the glass substrate 30 and the porous thin film 10, a hole forming process is performed. It is possible to prevent the glass substrate 30 and the porous thin film 10 from being peeled off during or after the process.

  Furthermore, the manufacturing method of the optical member provided with the porous thin film 10 according to the embodiment of the present invention is characterized in that the auxiliary member 40 is formed of the same material as that of the porous thin film 10.

  According to such a configuration, since the auxiliary member 40 is formed of the same material as that of the porous thin film 10, the adhesion between the auxiliary member 40 and the porous thin film 10 is further increased. It is possible to increase the adhesion between the porous thin film 10 and the porous thin film 10 and suppress the peeling of the porous thin film 10.

  An optical member provided with a porous thin film 10 according to an embodiment of the present invention includes a porous thin film 10 including a glass substrate 30 and a porous thin film 10 formed on the surface of the glass substrate 30. The refractive index of the porous thin film 10 is 1.292 or less.

  According to such a configuration, since the refractive index of the porous thin film 10 is 1.292 or less, an optical member including the porous thin film 10 having a reflectance of about 0.5% or less can be obtained. Therefore, the laser resistance of the porous thin film 10 of the optical member becomes good, and the broadband of the porous thin film 10 and the oblique incidence loss can be reduced accordingly.

  Further, in the optical member including the porous thin film 10 according to the embodiment of the present invention, the barrier member 50 that restricts the intrusion of moisture into the porous thin film 10 is formed on at least one surface of the porous thin film 10. It is characterized by being.

  According to such a structure, the penetration | invasion of the water | moisture content to the porous thin film 10 by leaving in air | atmosphere etc. is controlled, and the fall of an antireflection characteristic (AR characteristic) can be suppressed.

  Moreover, the optical member provided with the porous thin film 10 according to the embodiment of the present invention further increases the adhesion between the glass substrate 30 and the porous thin film 10 between the glass substrate 30 and the porous thin film 10. An auxiliary member 40 is formed.

  According to such a configuration, the auxiliary member 40 that further increases the adhesion between the glass base material 30 and the porous thin film 10 is formed between the glass base material 30 and the porous thin film 10. And the porous thin film 10 can be prevented from peeling off.

  Furthermore, the optical member provided with the porous thin film 10 according to the embodiment of the present invention is characterized in that the auxiliary member 40 is formed of the same material as that of the porous thin film 10.

  According to such a configuration, the adhesion force between the auxiliary member 40 and the porous thin film 10 is further increased, and accordingly, the adhesion force between the glass substrate 30 and the porous thin film 10 is improved more favorably. 10 peeling can be suppressed.

As described above, the present invention is useful for a manufacturing method of the optical member with a method of producing a porous film, and a porous thin film.

It is sectional drawing of the antireflection film 20 provided with the porous thin film 10 which concerns on embodiment of this invention. Each molecule each other are formed by a conventional vapor deposition method is a sectional view of a SiO ₂ film which is densely formed. Pores are formed is a cross-sectional view of a SiO ₂ film having a porous structure. It is a schematic diagram of the vacuum evaporation system 60 which concerns on embodiment of this invention. It is a schematic diagram of the experimental apparatus which concerns on the Example of this invention. It is a graph which shows the relationship between the wavelength of the incident light of optical member A (0)-(3) which concerns on the Example of this invention, and a reflectance. It is a graph which shows the relationship between the wavelength of incident light of the optical member A (3) which concerns on the Example of this invention, and the optical members B and C of a comparative example, and a reflectance. It is an energy calibration graph which concerns on the Example of this invention.

DESCRIPTION OF SYMBOLS 10 Porous thin film 20 Antireflection film 30 Glass base material 40 Auxiliary member 50 Barrier member

Claims (9)

A method for producing a porous thin film provided on the surface of a substrate,
Forming a thin film by vapor deposition on the surface of the substrate;
Forming pores in the thin film formed on the surface of the substrate;
Equipped with a,
The pores are formed by immersing the thin film in warm water of 80 ° C. or higher for a predetermined time, and supplying bubbles to the surface of the thin film immersed in the warm water for a predetermined time in the warm water. A method for producing a porous thin film. In the manufacturing method of the porous thin film of Claim 1,
A method for producing a porous thin film, wherein the deposition is vacuum deposition. In the manufacturing method of the porous thin film of Claim 1 ,
The pore is a method for producing a porous thin film formed by immersing the thin film in boiling water for a predetermined time. In the manufacturing method of the porous thin film of Claim 1,
The thin _film, SiO _2, MgF _2, a manufacturing method of a porous thin film formed by CaF _2, or _Al 2 _{O 3.} Preparing a substrate;
Forming a thin film by vapor deposition on the surface of the substrate;
Forming a pore in the thin film formed on the surface of the substrate to form a porous thin film;
I have a,
The pores are formed by immersing the thin film in warm water of 80 ° C. or higher for a predetermined time, and supplying bubbles to the surface of the thin film immersed in the warm water for a predetermined time in the warm water. The manufacturing method of the optical member provided with the porous thin film to make . In the manufacturing method of the optical member provided with the porous thin film according to claim 5 ,
The manufacturing method of the optical member provided with the porous thin film which further forms the barrier member which controls the penetration | invasion of the water | moisture content to this porous thin film on the surface of at least one of the said porous thin film. In the manufacturing method of the optical member provided with the porous thin film according to claim 6 ,
The manufacturing method of the optical member provided with the porous thin film which forms the said barrier member in the both surfaces of the said porous thin film. In the manufacturing method of the optical member provided with the porous thin film according to claim 5 ,
The manufacturing method of the optical member provided with the porous thin film which forms the auxiliary member which raises the adhesive force of this base material and a porous thin film further between the said base material and a porous thin film. In the manufacturing method of the optical member provided with the porous thin film according to claim 8 ,
The manufacturing method of the optical member provided with the porous thin film which forms the said auxiliary member with the same material as the said porous thin film.

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