JP2008158460A - Method of manufacturing polarizing element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing polarizing element capable of obtaining a polarizing element which is excellent in a heat radiation characteristic, has a large area, has uniform in-plain spectral characteristic distribution and has high reliability. <P>SOLUTION: The method includes: a step of pressing a mold 21 against a resist layer 12a while heating a transparent quartz substrate 11a and a resist layer 12a to at least the temperature of softening the resist layer 12a, subsequently, cooling the resist layer 12b until the resist layer 12b is cured, thereafter, drawing the mold 21 and, thereby, forming the grid-like first irregularities 13 transferred from the mold 21 on the resist layer 12b; a step of etching the quartz substrate 11a by using the resist layer 12b as a mask and, thereby, forming the grid-like second irregularities 14 corresponding to the first irregularities 13 on the surface of a quartz substrate 11b; and a step of performing sputter-film forming for the surface of the quartz substrate 11b from an oblique direction and, thereby, forming an inorganic fine particle layer 15 on an apex or at least one side surface part of the second irregularities 14. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an inorganic absorption type polarizing element.

  In a liquid crystal display device (particularly a transmissive liquid crystal display device), it is indispensable to dispose a polarizing element (polarizing plate) on the surface of the liquid crystal panel from the principle of image formation. The function of the polarizing plate is to absorb one of the orthogonally polarized components (so-called P-polarized wave and S-polarized wave) and transmit the other. As such a polarizing plate, conventionally, a dichroic polarizing plate in which an iodine-based or dye-based high molecular organic substance is contained in a film is often used.

  As these general production methods, a method is used in which a polyvinyl alcohol film and a dichroic material such as iodine are dyed, followed by crosslinking using a crosslinking agent and uniaxial stretching. Since this is produced by stretching, this type of polarizing plate generally tends to shrink. In addition, since the polyvinyl alcohol film uses a hydrophilic polymer, it is very easily deformed under heating and humidification conditions. Moreover, since the film is fundamentally used, the mechanical strength as a device is weak. In order to avoid this, a method of adhering a transparent protective film may be used.

  In recent years, the use of liquid crystal display devices has expanded and their functions have increased, and accordingly, high reliability and durability have been required for individual devices constituting the liquid crystal display device. For example, in the case of a liquid crystal display device using a light source with a large amount of light, such as a transmissive liquid crystal projector, the polarizing plate receives strong radiation. Therefore, excellent heat resistance is required for the polarizing plate used in these. However, since the film-based polarizing plate as described above is an organic substance, there is a limit to improving these characteristics.

  In response to this problem, Corning Corporation in the United States sells a highly heat-resistant inorganic polarizing plate under the name Polarcor. This polarizing plate has a structure in which silver fine particles are diffused in glass, and does not use an organic substance such as a film, and its principle uses plasma resonance of island-like fine particles. That is, light absorption by surface plasma resonance when light is incident on noble metal or transition metal island-like particles is used, and the absorption wavelength is affected by the particle shape and the surrounding dielectric constant. Here, when the shape of the island-shaped fine particles is elliptical, the resonance wavelengths in the major axis direction and the minor axis direction are different, and thereby deflection characteristics are obtained. Specifically, a polarization component parallel to the major axis on the long wavelength side is obtained. A polarization characteristic of absorbing and transmitting a polarization component parallel to the minor axis is obtained. However, in the case of Polarcor, the wavelength range in which the polarization characteristics can be obtained is a region close to the infrared region, and does not cover the visible light range required for a liquid crystal display device. This is due to the physical properties of silver used in the island-shaped fine particles.

  Here, in order to function as a polarizing plate, the shape anisotropy of the metal fine particles used as a polarizer is extremely important. Patent Document 1 discloses several methods for producing a polarizing plate using aluminum fine particles, in which glass based on silicate is not desirable as a substrate because aluminum and glass react. Calcium aluminoborate glasses are described as suitable (paragraphs 0018, 0019). However, glass using silicate is widely distributed as optical glass, and it is economically undesirable that a highly reliable product can be obtained at a low cost and this is not suitable. Further, a method for forming island-like particles by etching a resist pattern is described (paragraphs 0037 and 0038). Usually, a polarizing plate used in a projector needs to have a size of about several centimeters and a high extinction ratio. Therefore, for the purpose of a visible light polarizing plate, the resist pattern size needs to be sufficiently shorter than the visible light wavelength, that is, several tens of nanometers. In order to obtain a high extinction ratio, it is necessary to form a pattern with high density. Moreover, when using it for projectors, a large area is required. However, in the method of applying high-density fine pattern formation by lithography as described herein, it is necessary to use electron beam drawing or the like to obtain such a pattern. Electron beam drawing is a method of drawing individual patterns from an electron beam, and is not practical because of poor productivity.

  In addition, long-term use of liquid crystal projector devices, etc., causes the polarizing plate to be exposed to the vicinity of the light source for a long time and heated, so that even with the above heat-resistant inorganic polarizing plate, problems occur. There was a possibility.

JP 2000-147253 A

  The present invention has been made in view of the above problems in the prior art, and is a manufacturing method of a polarizing element that has excellent heat radiation characteristics, a large area, a uniform in-plane spectral characteristic distribution, and a highly reliable polarizing element. It aims to provide a method.

  The inventor has focused on the nanoimprint method as one of the methods for solving the above-described problems. In other words, the nanoimprint method is a technology that achieves both high density formation of a resist pattern size of several tens of nanometers and mass productivity. As one of the nanoimprint methods, a mold (mold) on which a pattern to be transferred is formed is formed on a substrate. There is a thermal imprint method in which a pattern is transferred to a resist layer by pressing the thermoplastic resist layer applied thereon and curing the resist layer (see, for example, JP-A-2003-77807). Further, the idea of using a quartz substrate having higher heat dissipation than glass as a substrate was obtained, and as a result of intensive studies in combination with the nanoimprint method, the present invention was achieved.

  That is, the present invention provided to solve the above-described problems is that the transparent quartz substrate and the resist layer provided on one main surface of the quartz substrate are heated to a temperature higher than the temperature at which the resist layer is softened. A step of forming a grid-like uneven part A on the resist layer by transferring from the die by pressing the die and then cooling until the resist layer is cured (thermal nanoimprinting step) ), Etching the crystal substrate using the resist layer as a mask to form a lattice-shaped uneven portion B corresponding to the uneven portion A on the surface of the crystal substrate (etching step), and the surface of the crystal substrate A step of forming an inorganic fine particle layer on the top portion or at least one side surface portion of the concavo-convex portion B by performing sputtering film formation from an oblique direction (oblique sputtering step). It is a manufacturing method of the polarizing element characterized.

  Here, it is preferable to dispose the mold so that the longitudinal direction of the lattice of the uneven portion A is parallel to the optical axis of the quartz substrate.

  Further, it is preferable that the heating temperature of the quartz substrate and the resist layer is 150 ° C. or lower.

  The size of the mold may be larger than the size of the quartz substrate.

According to the invention of claim 1, by applying thermal nanoimprint, a lattice pattern for obtaining polarization characteristics can be easily formed on a quartz substrate having higher heat dissipation than glass as an inorganic absorption polarizing plate. Can do.
According to the invention of claim 2, in the thermal nanoimprint process, by aligning the optical axis of the quartz substrate and the longitudinal direction of the grating pattern of the mold in the parallel direction, the heat in the parallel and perpendicular directions to the optical axis of the quartz substrate is obtained. Pattern transfer failure due to the difference in expansion coefficient can be suppressed, and in-plane spectral characteristic distribution having polarization characteristics can be further improved as an inorganic absorption polarizing plate. It is also possible to suppress defects due to missing lattice patterns.
According to the invention of claim 3, by controlling the heating temperature, good transferability can be obtained even in a quartz substrate having a large thermal expansion coefficient.
According to invention of Claim 4, it becomes possible to enlarge more the area from which a polarization characteristic is acquired with respect to a quartz substrate.

Below, the structure in one Embodiment of the manufacturing method of the polarizing element which concerns on this invention is demonstrated.
The method for producing a polarizing element according to the present invention includes a transparent quartz substrate and a resist layer provided on one main surface of the quartz substrate that is heated above a temperature at which the resist layer is softened, and a mold is pressed against the resist layer. Then, after cooling until the resist layer is cured, the mold is removed, thereby forming a lattice-shaped uneven portion A by transfer from the mold on the resist layer (thermal nanoimprint process), and the resist Etching the quartz substrate using the layer as a mask to form a lattice-like irregular portion B corresponding to the irregular portion A on the surface of the quartz substrate (etching step), and obliquely with respect to the surface of the quartz substrate A step of forming an inorganic fine particle layer on the top portion or at least one side surface portion of the concavo-convex portion B (an oblique sputtering step).

  The manufacturing method of the polarizing element of this invention is demonstrated based on the schematic which shows the manufacturing procedure of the polarizing element which concerns on this invention of FIG.

(S11) After the resist layer 12a is formed on the transparent quartz substrate 11a, the quartz substrate 11a and the resist layer 12a are heated to a temperature at which the resist layer 12a is softened (FIG. 1A).

  Here, the quartz substrate 11a is a high-purity quartz substrate having a crystal structure. For example, an optical artificial quartz substrate may be used. Further, the crystal substrate 11a is X-cut as the surface orientation, and has an optical axis in the plate surface direction as shown in FIG. 2A, for example.

  As will be described later, the resist layer 12a is a layer that can be etched together with the quartz crystal substrate 11a by a reactive gas, an ion beam, or the like, and is formed, for example, by application of a thermoplastic polymer material. The resist layer 12a is softened by heating, but is preferably softened to such an extent that it is deformed by a mold press at 150 ° C. or lower. Thereby, good transferability can be obtained even in the quartz substrate 11a having a large thermal expansion coefficient. Note that the thickness of the resist layer 12a is preferably 1 to 1.5 times the height of the uneven pattern of the mold 21.

(S12) A mold 21 on which a lattice-shaped uneven pattern is formed is prepared, and the uneven pattern surface of the mold 21 is pressed against the resist layer 12a with a press machine or the like (FIG. 1B). Accordingly, since the resist layer 12a is softened by heating, the resist layer 12a is deformed according to the uneven pattern (mold pattern) of the mold 21 to be a resist layer 12b having the first uneven portion (uneven portion A) 13.

  The mold 21 has a grid-like concavo-convex pattern for forming a first concavo-convex portion 13 having a predetermined lattice pattern by transferring a mold pattern to the resist layer 12a by press molding. The cross-sectional shape is, for example, a rectangular uneven pattern as shown in FIG. 1B, and the dimensions such as the pitch, line width / pitch, lattice depth, and lattice length are finally obtained. It is good to set according to each dimension of uneven part 14. For example, the pitch is 100 to 400 nm and the height (depth) is 100 to 200 nm. In addition, the uneven | corrugated pattern of the metal mold | die 21 is not limited to a rectangle, It is good to make it the shape where the resist layer 12b is not damaged when the metal mold | die 21 is extracted, for example, the top part of the convex part 21a is the cross-sectional shape May be triangular, or the cross-sectional shape of the concave portion of the concave / convex pattern may be triangular.

  Further, when pressing the mold 21 against the resist layer 12a, the mold 21 is set so that the longitudinal direction of the lattice of the first uneven portion 13 of the resist layer 12b is parallel to the optical axis of the quartz substrate 11a. It is preferable to arrange. Specifically, when the quartz substrate 11a and the mold 21 face each other through the resist layer 12a, the direction of the optical axis of the quartz substrate 11a (the arrow direction in FIG. 1 (a)) and the mold as shown in FIG. The mold 21 is arranged with respect to the crystal substrate 11a so that the longitudinal direction (FIG. 1 (b)) of the convex portions 21a of 21 coincides. Thereby, it is possible to suppress pattern transfer failure due to the difference in thermal expansion coefficient between the direction parallel to the optical axis of the quartz crystal substrate 11a and the direction perpendicular to the optical axis in the thermal nanoimprint process, and as a result, it has polarization characteristics as an inorganic absorption polarizing plate. The in-plane spectral characteristic distribution can be further improved. Specifically, when the longitudinal direction of the convex portion 21a of the mold 21 is arranged in a direction perpendicular to the optical axis of the quartz substrate 11a, the thermal expansion coefficient between the parallel direction and the perpendicular direction in the longitudinal direction of the convex portion 21a. When the mold 21 is pulled out due to the difference, the shape of the first concavo-convex portion 13 of the resist layer 12b collapses or the lattice pattern is lost, for example, the resist layer 12a adheres to the mold 21. As a result, the uniformity of the lattice pattern of the inorganic fine particle layer 15 is eventually lost, which adversely affects the polarization characteristics. In the present invention, it is possible to suppress the defect, and good polarization characteristics can be obtained. Moreover, it is preferable to make the size of the mold 21 larger than the size of the quartz substrate 11a.

(S13) The quartz substrate 11a and the resist layer 12b are cooled (FIG. 1C). As a result, the resist layer 12b is cured.
(S14) The mold 21 is removed from the resist layer 12b (FIG. 1 (d)). Thus, the thermal nanoimprint process is completed. According to thermal nanoimprinting, once a mold is produced, a fine pattern can be obtained without a complicated process, so that productivity is very high. In particular, when a simple lattice pattern mold is produced as in the present invention, an expensive method such as electron beam drawing is not used, and a lattice pattern on a large area is produced by a single exposure, for example, by interference exposure. can do. Moreover, since the shape of the first concavo-convex portion 13 is a simple shape such as a lattice shape, it is advantageous in that a pattern can be formed with high accuracy even with a single exposure.

(S15) Next, the resist layer 12b is etched from the first concavo-convex portion 13 side (FIG. 1E), and the quartz crystal substrate 11a is further etched using the resist layer 12b as a mask (FIG. 1F). Etching may be performed by any method that allows the resist layer 12b and the quartz substrate 11a to be sequentially removed from the surface layer by etching. For example, RIE (reactive ion etching) or reactivity using fluorine-based gas such as CF ₄ , Ar gas, or a mixed gas thereof. Gas etching) or ion beam etching may be used. By this etching process, the crystal substrate 12b having the second uneven portion (uneven portion B) 14 is obtained. The second concavo-convex portion 14 imparts shape anisotropy of the inorganic fine particle layer 15 and is important for obtaining the desired polarization characteristics of the polarizing element 10. That is, the processing size and pattern shape of the second uneven portion 14 are appropriately set according to the target polarization characteristics (extinction ratio) and the target visible light wavelength region. Specifically, in FIG. 3, the pitch (in the X and Y directions) of the grooves of the second concavo-convex portion 14 is 0.5 μm or less, and the line width of the concavo-convex portion 14 (formation width of the convex portion 14a) is 0.25 μm or less. The formation depth of the concavo-convex portion 14 is 1 nm or more.

In addition, it is preferable that the pitch, the line width / pitch, the lattice depth, the lattice length, and the top line width / bottom line width of the second concavo-convex portion 14 are in the following ranges, respectively.
0.05 μm <pitch <2 μm,
0.1 <(line width / pitch) <0.9,
0.01 μm <lattice depth <0.2 μm,
0.05 μm <grid length,
1.0 ≤ (top line width / bottom line width)
This completes the etching process.

(S16) Sputter film formation is performed in which the inorganic fine particles p are incident on the top of the second concavo-convex portion 14 of the quartz substrate 12b or at least one side surface thereof at a predetermined angle from an oblique direction (FIG. 1 (g)). The state of oblique sputtering film formation is shown in FIG. Here, an example of ion beam sputtering is shown.

  In FIG. 4, 1 is a stage that supports the quartz substrate 11b, 2 is a target, 3 is a beam source (ion source), and 4 is a control plate. The stage 1 is inclined at a predetermined angle θ with respect to the normal direction of the target 2, and the quartz substrate 11 b has a lattice direction (longitudinal direction) of the second uneven portion 14 with respect to the incident direction of the inorganic fine particles from the target 2. Are arranged in an orthogonal direction. The angle θ is, for example, 0 ° to 15 °. Ions extracted from the beam source 3 are irradiated to the target 2. The inorganic fine particles knocked out from the target 2 by the irradiation of the ion beam are incident and attached to the surface of the quartz substrate 11b from an oblique direction. At this time, if the flat control plate 4 is arranged on the quartz substrate 11b at regular intervals (for example, 50 mm), the direction of the incident particles on the surface of the quartz substrate 11b is controlled, and only on the side wall portion of the second uneven portion 14. Particles can be deposited.

  As described above, by tilting the quartz substrate 11b with respect to the target 2 at the time of film formation and restricting the incident direction of the inorganic fine particles, the inorganic fine particle layer 15 made of inorganic fine particles is formed on the top of the second concavo-convex portion 14 or on one side. It can be selectively formed on the side portion. FIG. 5 shows an example of the polarizing element 10 in which the inorganic fine particle layer 15 is selectively formed on one side surface portion of the second uneven portion 14. As a result, the inorganic fine particle layer 15 having shape anisotropy can be distributed in an island shape on the surface of the quartz crystal substrate 11b in a desired fine shape, and isolation of the inorganic fine particles can be realized.

  Further, since the film formation is performed by the sputtering method, the adhesion strength of the inorganic fine particles to the quartz substrate 11b can be improved, and the degree of freedom in selecting the material as the inorganic fine particles is wide. Further, the inorganic fine particle layer 15 is formed as a thin film by oblique sputter deposition so as to be orthogonal to the transmission axis direction of the polarizing element 10 (the lattice direction (longitudinal direction) of the second uneven portion 14) so as to improve the polarization characteristics of the polarizing element 10. Direction) optical constant is smaller than the optical constant in the absorption axis direction (lattice direction (longitudinal direction) of the second uneven portion 14). Specifically, the relationship of (transmission axis direction refractive index) <(absorption axis direction refractive index) and (transmission axis direction extinction coefficient) <(absorption axis direction extinction coefficient) is satisfied.

  In addition, since the inorganic fine particle layer 15 is formed on the second uneven portion 14 mechanically formed in advance, the second uneven portion 14 can be stably formed and formed thereon. The shape control of the inorganic fine particle layer 15 can be easily performed.

Here, as the material used for the inorganic fine particle layer 15, an appropriate material needs to be selected according to the use band. Metal materials and semiconductor materials satisfy these requirements. Specifically, in the case of metals, Al, Ag, Cu, Au, Mo, Cr, Ti, W, Ni, Fe, Si, Ge, Te, Sn, Au , Ag, Cu alone or an alloy containing them. The semiconductor material is Si, Ge, Te, ZnO. Furthermore, silicide materials such as FeSi ₂ (particularly β-FeSi ₂ ), MgSi ₂ , NiSi ₂ , BaSi ₂ , CrSi ₂ , CoSi ₂ are suitable. In the present invention, the target 2 made of these materials is used in the oblique sputtering film formation of FIG.

  In the polarizing element 10 manufactured by the above method, the inorganic fine particle layer 15 formed on the surface of the quartz substrate 11b has an anisotropic shape in the in-plane X and Y directions as shown in FIG. Distributed. These inorganic fine particle layers 15 exhibit a characteristic of absorbing a polarized component having an electromagnetic traveling direction in the major axis direction (Y direction) and transmitting a polarized component having an electromagnetic traveling direction in the minor axis direction (X direction). Further, since the quartz substrate 11b having excellent heat dissipation is used as the substrate of the polarizing element 10, it has better heat resistance than the conventional inorganic absorption type polarizing element. For example, it is used in a liquid crystal projector device or the like and is in the vicinity of the light source for a long time. Even if it is exposed to heat and heated, it is possible to obtain a polarizing element that is less susceptible to problems than a glass substrate because of its good heat dissipation.

  In addition, the shape of the convex part of the 2nd uneven | corrugated | grooved part 14 can be formed in rectangular shapes, such as a rectangle and a trapezoid, or a sawtooth shape and a triangular shape. FIG. 6A shows an example in which the convex portion 14a of the second concave-convex portion 14 has a rectangular cross section, and the inorganic fine particle layer 15 is formed on one side surface portion thereof. FIG. 6B shows an example in which the convex portion 16a of the second concave-convex portion 16 has a sawtooth cross-sectional shape, and the inorganic fine particle layer 15 is formed on one side surface standing in the vertical direction. By forming the cross section of the convex portion in a sawtooth shape, adhesion of the film to the top of the convex portion can be avoided. FIG. 6C shows an example in which the convex portion 17a of the second concave-convex portion 17 has a triangular cross section and the inorganic fine particle layer 15 is formed on one side surface thereof.

  Further, after the structure shown in FIG. 5, a protective layer made of an inorganic material may be formed by a spin coating method or a dipping method.

An example in which a polarizing element is actually manufactured by applying the method for manufacturing a polarizing element of the present invention is shown below.
(Example 1)
A polarizing element was produced by the following procedure.
(S21) Resist material (trade name: mr-1 7000E, manufacturer recommended) manufactured by micro resist technology on a quartz crystal substrate 11a (x-cut, c grade or higher) of an optical artificial crystal having an optical axis in the plate surface direction. The resist layer 12a was formed using the operating temperature 125-150 degreeC. Subsequently, the quartz substrate 11a and the resist layer 12a were heated to 150 ° C. (FIG. 1A).
(S22) A mold 21 having a lattice-shaped uneven pattern was prepared. This mold 21 has a mold surface of 10 mm × 10 mm, and its lattice pattern has a pitch of 150 nm, a line width of 75 nm, a space width of 75 nm, a lattice depth of 150 nm, and a lattice length of 10 mm. Then, the mold 21 is arranged so that the lattice direction of the uneven pattern of the mold 21 is parallel to the optical axis of the quartz substrate 11a, and the uneven pattern surface of the mold 21 is pressed against the resist layer 12a by a press machine. A resist layer 12b having a first concavo-convex portion 13 was formed (FIG. 1B).
(S23) The quartz substrate 11a and the resist layer 12b were cooled until the resist layer 12b was cured (FIG. 1C).
(S24) Next, the mold 21 was removed from the resist layer 12b (FIG. 1D).
(S25) Next, the resist layer 12b was etched from the first uneven portion 13 side (FIG. 1E), and the quartz substrate 11a was further etched using the resist layer 12b as a mask (FIG. 1F). Etching was performed under the following conditions.
Etching method: RIE
・ Used gas: CF ₄
・ RF power: 400-1300W
By this etching process, a crystal substrate 12b having the second uneven portion 14 was obtained.
(S26) Next, by the sputter film formation shown in FIG. 4, the sputter film formation is performed in which the inorganic fine particles p are incident on one side surface of the second concavo-convex part 14 of the quartz substrate 12b (FIG. 1 (g)). The polarizing element 10 of the present invention was obtained. The sputtering conditions were as follows.
-Target 2: Ge
・ Inclination angle θ: 15 °
Inorganic fine particle layer 15 thickness: 30 nm

The obtained polarizing element sample had a uniform appearance as shown in FIG. Further, when the cross section was observed, as shown in FIG. 8, the surface of the quartz substrate had a regular second shape with a regular shape and a certain thickness on one side surface of the second surface. The state that the inorganic fine particle layer 15 was formed was observed. In this embodiment, as shown in FIG. 6C, the convex portion 17a of the second concave-convex portion 17 has a triangular cross section, and the inorganic fine particle layer 15 is formed on one side surface thereof.
Moreover, the transmittance | permeability and the reflectance of each of the absorption axis direction of the obtained polarizing element sample and a transmission axis direction were measured. The result is shown in FIG. The polarizing element sample of this example showed almost the same value regardless of the spectral characteristics at any position in the plane.

  Of the manufacturing conditions in this example, the resist material in step S21 was also examined using a resist material manufactured by micro resist technology (trade name: mr-8000E, manufacturer recommended operating temperature 170-190 ° C.). However, when a quartz substrate is used as the substrate, transferability is poor and unsuitable.

  Also, in the thermal nanoimprint process in this embodiment, the crystal substrate dimension is larger than the mold dimension, the crystal substrate dimension is the mold dimension, and the crystal substrate dimension is less than the mold dimension. A wide range of good transferability could be obtained. If the transfer property to the resist layer is poor, the shape of the first concavo-convex portion 13 of the resist layer directly affects the surface shape of the crystal substrate after etching, and an inorganic material used as a polarizer that functions as a polarizing element. In order to cause variation in the shape of the fine particles and to deteriorate the characteristics as a polarizing element, good transferability is required.

(Reference Example 1)
In Example 1, the mold 21 is arranged so that the lattice direction of the concave-convex pattern of the mold 21 is perpendicular to the optical axis of the quartz substrate 11a, and the other conditions are the same as in Example 1. A device sample was prepared.
As shown in FIG. 10, the obtained polarizing element sample had a non-uniform appearance in which the viewing state was different between the place A and the place B. Moreover, when the cross section was observed, the regularity of the 2nd uneven | corrugated | grooved part collapse | crumbled in the surface of a quartz substrate as shown in FIG. 11, and the inorganic fine particle layer 15 provided in the one side part of the 2nd uneven | corrugated | grooved part of Variations in thickness were observed.
Moreover, the transmittance | permeability and the reflectance of each of the absorption axis direction of the obtained polarizing element sample and a transmission axis direction were measured. The result is shown in FIG. In this polarizing element sample, the spectral characteristic data varied depending on the position in the plane, and a variation of 15% at maximum was observed.

It is the schematic which shows the manufacturing procedure of the polarizing element which concerns on this invention. It is a figure which shows the relationship between the optical axis of the quartz substrate used by this invention, and the lattice direction of the uneven | corrugated pattern of a metal mold | die. It is sectional drawing of the uneven | corrugated | grooved part of a quartz substrate. It is the schematic which shows the structure of oblique sputtering film-forming. It is the schematic which shows the structure of the polarizing element which concerns on this invention. It is sectional drawing which shows the uneven | corrugated shape of the polarizing element surface which concerns on this invention. FIG. 3 is a diagram illustrating an appearance of a polarizing element sample of Example 1. FIG. 3 is a diagram showing a cross-sectional state of a polarizing element sample of Example 1. 6 is a spectral characteristic diagram of a polarizing element sample of Example 1. FIG. It is a figure which shows the polarizing element sample external appearance of the reference example 1. FIG. It is a figure which shows the cross-sectional state of the polarizing element sample of the reference example 1. FIG. 6 is a spectral characteristic diagram of a polarizing element sample of Reference Example 1. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Stage, 2 ... Target, 3 ... Beam source (ion source), 4 ... Control board, 11a, 11b ... Quartz substrate, 12a, 12b ... Resist layer, 13. .. First concavo-convex portion, 14, 16, 17... Second concavo-convex portion, 14a, 16a, 17a... Convex portion, 15... Inorganic fine particle layer, 21. ..Inorganic fine particles

Claims (4)

A transparent quartz substrate and a resist layer provided on one main surface of the quartz substrate are heated to a temperature higher than the temperature at which the resist layer is softened, and a mold is pressed against the resist layer until the resist layer is cured. Removing the mold after cooling to form a lattice-shaped uneven portion A by transfer from the mold on the resist layer; and
Etching the quartz substrate using the resist layer as a mask to form a lattice-like irregular portion B corresponding to the irregular portion A on the surface of the quartz substrate;
And a step of forming an inorganic fine particle layer on the top portion or at least one side surface portion of the concavo-convex portion B by performing sputter deposition on the surface of the quartz substrate from an oblique direction. Method.   The method for manufacturing a polarizing element according to claim 1, wherein the mold is disposed so that a longitudinal direction of the grating of the uneven portion A is parallel to the optical axis of the quartz substrate.   The method for manufacturing a polarizing element according to claim 1, wherein a heating temperature of the quartz substrate and the resist layer is 150 ° C. or less.   The method for manufacturing a polarizing element according to claim 1, wherein a size of the mold is made larger than a size of the quartz substrate.