JP6610702B2 - Manufacturing method of wire grid polarization element - Google Patents

Description

  The present invention relates to a method for manufacturing a wire grid polarizing element including a wire grid in which a plurality of fine metal wires extend in parallel, and a substrate for manufacturing a wire grid polarizing element.

  The projection display device includes a liquid crystal panel, a light source unit that emits light supplied to the liquid crystal panel, and a projection optical system that projects light modulated by the ride valve. A polarizing element is arranged in the optical path that reaches the projection optical system via the via. For such a polarizing element, a polarizing element made of an organic material is frequently used. However, a polarizing element made of an organic material has low heat resistance. Therefore, it has been proposed to use a wire grid polarizing element (inorganic polarizing element) in which a metal wire grid made of aluminum, an aluminum alloy, or the like is formed on a translucent substrate.

  As a method for manufacturing a wire grid polarizing element, there is a method in which a metal film is formed on a substrate, a resist mask is directly formed using e-beam lithography, and then the metal film is patterned by reactive ion etching (RIE). It has been proposed (see Patent Document 1). Patent Document 1 describes that the polarization characteristics change depending on the width of the fine metal wires with respect to the pitch of the fine metal wires.

  In addition, as a method for manufacturing a wire grid polarizing element, a nanoimprint method has been proposed in which a metal film is formed on a substrate, and then a concavity and convexity of the mold material is transferred to the applied photocurable resist to form a resist mask. . According to this method, the resist mask can be efficiently formed by the technique described in Patent Document 1. Patent Document 2 discloses a resist that remains on the bottom of a concave portion sandwiched between adjacent convex portions after the concave and convex portions are transferred to the resist by performing a transfer process in an environment that suppresses volatilization of components contained in the resist. A method for reducing the thickness of the mask (the thickness of the remaining film) is described.

Special table 2003-502708 gazette JP2013-14984A

  The inventor of the present application is examining a method of manufacturing a plurality of wire grid polarizing elements by dividing a mother substrate after forming a metal thin wire in a state of a mother substrate larger than the substrate of the wire grid polarizing element. In the process, it was found that the thickness of the remaining film varies depending on the position on the mother substrate due to variations in transfer pressure and the like. When such variation occurs, the dry etching amount is set in accordance with the thickest remaining film. As a result, in the wire grid polarizing element obtained from the region where the remaining film is thin, the width of the thin metal wire is reduced and the optical characteristics are reduced. There is a problem of deterioration. However, in the method described in Patent Document 2, it is difficult to eliminate the variation in the thickness of the remaining film even when a special environment that suppresses the volatilization of the components contained in the resist is prepared at a great cost. is there.

  In view of the above problems, an object of the present invention is to obtain a plurality of wire grid polarizing elements having appropriate polarization characteristics from a mother substrate when the thickness of the remaining film varies depending on the position on the mother substrate. It is providing the manufacturing method of the wire grid polarizing element which can be performed, and the board | substrate for wire grid polarizing element manufacture.

  In order to solve the above-described problem, one aspect of the present invention is a method for manufacturing a wire grid polarizing element including a wire grid in which a plurality of fine metal wires are arranged in parallel at an equal pitch on one surface of a substrate, which is larger than the substrate. A film forming step of sequentially forming a metal film and an inorganic material film for a hard mask on one surface of the mother substrate, and after the film forming step, a resist layer is applied to one surface of the mother substrate, After pressing a mold for nanoimprint against the resist layer to transfer a plurality of convex portions arranged in parallel at the same pitch as the pitch of the plurality of fine metal wires to the resist layer, the resist layer is solidified to form a resist. A resist mask forming step for forming a mask, and a driver for patterning the metal film into the plurality of thin metal wires by performing dry etching with the resist mask formed. An etching step and a dividing step of dividing the mother substrate into a plurality of wire grid polarizing elements, and in the resist mask forming step, of the plurality of convex portions, a concave portion sandwiched between adjacent convex portions. The resist mask is left at the bottom, the thickness of the resist mask remaining at the bottom of the recess is t (nm), the difference between the maximum value and the minimum value of the thickness t is Δt (nm), and the pitch is When P (nm), Δt / P (%) is 13.4% or less.

  In the present invention, when the resist mask is formed using the nanoimprint method, the resist mask is left at the bottom of the concave portion sandwiched between the convex portions transferred to the resist layer. They are connected via a resist layer constituting the bottom. For this reason, after the mold material is pressed against the resist layer to transfer the convex portion to the resist layer, the resist layer constituting the convex portion is unlikely to peel off when the mold material is released. Here, when the thickness of the resist mask (residual film) remaining on the bottom of the concave portion in the mother substrate varies, the polarization characteristics vary in a plurality of wire grid polarizing elements obtained from the same mother substrate. However, in the present invention, the difference Δt (nm) between the maximum value and the minimum value of the thickness t (nm) of the resist mask remaining at the bottom of the recess is associated with the pitch P, and Δt / P (%) is 13.4%. Control to: For this reason, it can suppress that a polarization characteristic varies in the some wire grid polarizing element obtained from the same mother board | substrate. Therefore, it is possible to stably manufacture a wire grid polarizing element having a contrast ratio CR of 100 or more, which is a ratio of the transmittance of the polarizing element to two linearly polarized lights whose electric field vibration directions are orthogonal to each other.

  In the present invention, an aspect in which Δt / P is 9.7% or less can be employed. According to this aspect, it is possible to stably manufacture a wire grid polarizing element having a contrast ratio CR of 500 or more, which is a ratio of the transmittance of the polarizing element to two linearly polarized lights whose electric field vibration directions are orthogonal to each other. it can.

Another aspect of the present invention is a method for manufacturing a wire grid polarizing element comprising a wire grid in which a plurality of fine metal wires are arranged in parallel at an equal pitch on one surface of a substrate, and a metal film on one surface of a mother substrate larger than the substrate, and A film forming step for sequentially forming an inorganic material film for a hard mask, and after the film forming step, a resist layer is applied to one surface of the mother substrate, and then a mold material for nanoimprinting is applied to the resist layer A resist mask forming step of forming a resist mask by solidifying the resist layer after forming a plurality of convex portions parallel to each other at the same pitch as the pitch of the plurality of fine metal wires in the resist layer; A dry etching step of performing dry etching in a state where the resist mask is formed to pattern the metal film into the plurality of thin metal wires; A dividing step of dividing the substrate into a plurality of wire grid polarizing elements, wherein, in the resist mask forming step, the resist mask is formed on a bottom of a concave portion sandwiched between adjacent convex portions among the plurality of convex portions. , The thickness of the resist mask remaining at the bottom of the recess is t (nm), the difference between the maximum value and the minimum value of the thickness t is Δt (nm), and the pitch is P (nm) When the pitch P (nm) and the difference Δt are as follows, the following conditional expression Δt ≦ (0.14 × P−0.3)
It is characterized by satisfying.

  In the present invention, when the resist mask is formed using the nanoimprint method, the resist mask is left at the bottom of the concave portion sandwiched between the convex portions transferred to the resist layer. They are connected via a resist layer constituting the bottom. For this reason, after the mold material is pressed against the resist layer to transfer the convex portion to the resist layer, the resist layer constituting the convex portion is unlikely to peel off when the mold material is released. Here, when the thickness of the resist mask (residual film) remaining on the bottom of the concave portion in the mother substrate varies, the polarization characteristics vary in a plurality of wire grid polarizing elements obtained from the same mother substrate. However, in the present invention, the difference Δt (nm) between the maximum value and the minimum value of the thickness t (nm) of the resist mask remaining at the bottom of the concave portion is associated with the pitch P, and Δt is (0.14 × P-0. 3) Control to the following. For this reason, it can suppress that a polarization characteristic varies in the some wire grid polarizing element obtained from the same mother board | substrate. Therefore, it is possible to stably manufacture a wire grid polarizing element having a contrast ratio CR of 100 or more, which is a ratio of the transmittance of the polarizing element to two linearly polarized lights whose electric field vibration directions are orthogonal to each other.

In the present invention, the pitch P (nm) and the difference Δt are the following conditional expressions: Δt ≦ (0.11 × P−1.4)
A mode that satisfies the above can be adopted. According to this aspect, it is possible to stably manufacture a wire grid polarizing element having a contrast ratio CR of 500 or more, which is a ratio of the transmittance of the polarizing element to two linearly polarized lights whose electric field vibration directions are orthogonal to each other. it can.

  In the present invention, the film forming step may adopt an aspect in which the metal film, the light absorption film, and the inorganic material film are formed in order. According to this aspect, since the light absorption film remains at the end of the metal thin wire opposite to the substrate, it is possible to suppress the light incident from the one surface side of the substrate from being reflected by the metal thin wire.

  Another aspect of the present invention is a wire grid polarizing element manufacturing substrate used for manufacturing a wire grid polarizing element provided with a wire grid in which a plurality of fine metal wires are arranged in parallel on one side of the substrate, and is provided on one side of the mother substrate. A metal film, an inorganic material film for a hard mask, and a resist mask in which a plurality of convex portions are arranged at an equal pitch are provided in order, and the resist mask is sandwiched between adjacent convex portions among the plurality of convex portions. The thickness of the resist mask remaining at the bottom of the concave portion is t (nm), the difference between the maximum value and the minimum value of the thickness t is Δt (nm), and the pitch of the convex portions is P (nm). In this case, Δt / P (%) is 13.4% or less.

Still another embodiment of the present invention is a wire grid polarizing element manufacturing substrate used for manufacturing a wire grid polarizing element including a wire grid in which a plurality of fine metal wires are arranged in parallel at an equal pitch on one side of the substrate, the mother substrate A metal film, an inorganic material film for a hard mask, and a resist mask having a plurality of convex portions arranged in parallel at an equal pitch are sequentially provided on one surface of the plurality of convex portions, and the resist mask is adjacent to the plurality of convex portions. The thickness of the resist mask remaining at the bottom of the concave portion sandwiched between the convex portions is t (nm), the difference between the maximum value and the minimum value of the thickness t is Δt (nm), and the pitch of the convex portions is When P (nm), the pitch P (nm) and the difference Δt are the following conditional expressions: Δt ≦ (0.14 × P−0.3)
It is characterized by satisfying.

  In the present invention, the difference Δt is a maximum value when the thickness t of the resist mask remaining at the bottom of the recess is measured at a plurality of locations in the effective region where a plurality of the substrates are obtained from the mother substrate. A mode that is a difference from the minimum value can be adopted.

  In the present invention, it is possible to adopt an aspect in which the plurality of locations include at least a central portion in the effective region and a first end portion of the effective region spaced from the central portion to one side in the first direction. .

  In the present invention, when the direction perpendicular to the first direction is the second direction, the plurality of locations are at least the central portion, the first end portion, and the other side in the first direction from the central portion. A second end of the effective region that is spaced apart, a third end of the effective region that is spaced from the central portion to one side in the second direction, and a second end of the effective region that is spaced from the central portion to the other side in the second direction. A mode including the fourth end of the effective area can be employed.

  In the present invention, the plurality of locations may further include a first intermediate position that is 1 cm or more away from the central portion and the first end portion between the central portion and the first end portion, the central portion and the second end portion. A second intermediate position that is 1 cm or more away from the central portion and the second end portion between the central portion and the second end portion, and 1 cm or more from the central portion and the third end portion between the central portion and the third end portion. A mode including a third intermediate position that is spaced apart and a fourth intermediate position that is spaced 1 cm or more from the central portion and the fourth end portion between the central portion and the fourth end portion can be employed.

  In the present invention, when one of two directions intersecting the first direction and the second direction is a third direction and the other is a fourth direction, the plurality of locations are further separated from the central portion. A fifth end portion of the effective area that is separated from one side in the third direction, a sixth end portion of the effective area that is separated from the central portion to the other side in the third direction, and a fourth direction from the central portion. It is possible to adopt a mode that includes a seventh end portion of the effective area that is separated to one side of the effective area and an eighth end portion of the effective area that is separated from the central portion to the other side in the fourth direction.

  In the present invention, as the plurality of locations, a mode in which the thickness t of the resist mask is measured in each of the plurality of regions obtained by the substrate in the effective region may be employed.

  In the present invention, it is possible to adopt a mode in which the thickness t of the resist mask is measured by a focused ion beam scanning electron microscope.

Explanatory drawing of the wire grid polarizing element to which this invention is applied. Sectional drawing of the wire grid polarizing element shown in FIG. Explanatory drawing of the mother board | substrate used for the manufacturing method of the wire grid polarizing element shown in FIG. Process sectional drawing which shows a film-forming process and a resist mask formation process among the manufacturing processes of the wire grid polarizing element shown in FIG. Process sectional drawing which shows an etching process among the manufacturing processes of the wire grid polarizing element 1 shown in FIG. Explanatory drawing which shows the relationship between the difference of the thickness of the residual film shown in FIG. 5, and the width | variety of a metal fine wire. Explanatory drawing which shows the relationship between the width | variety of a metal fine wire, and a polarization characteristic when the pitch of a metal fine wire is 140 nm. Explanatory drawing which shows the relationship between the dispersion | variation in a residual film, and a polarization characteristic when the pitch of a metal fine wire is 140 nm. Explanatory drawing which shows the relationship between the width | variety of a metal fine wire, and a polarization characteristic when the pitch of a metal fine wire is 120 nm. Explanatory drawing which shows the relationship between the dispersion | variation in a residual film, and a polarization characteristic when the pitch of a metal fine wire is 120 nm. Explanatory drawing which shows the relationship between the width | variety of a metal fine wire, and a polarization characteristic when the pitch of a metal fine wire is 100 nm. Explanatory drawing which shows the relationship between the dispersion | variation in a residual film, and a polarization characteristic when the pitch of a metal fine wire is 100 nm. The graph which shows the relationship between the pitch, the difference of the thickness of a residual film, etc. when contrast is set to 100. The graph which shows the relationship between the pitch, the difference of the thickness of residual film, etc. when contrast is set to 500. Explanatory drawing which shows the measuring method of the thickness of a resist mask. Explanatory drawing which shows the 1st example of the measurement location of the thickness of a residual film. Explanatory drawing which shows the 2nd example of the measurement location of the thickness of a residual film. Explanatory drawing which shows the 3rd example of the measurement location of the thickness of a residual film. Explanatory drawing which shows the 4th example of the measurement location of the thickness of a residual film. Explanatory drawing which shows the 5th example of the measurement location of the thickness of a residual film. Explanatory drawing of the projection type display apparatus using a transmissive liquid crystal panel. Explanatory drawing of the projection type display apparatus using a reflective liquid crystal panel.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings to be referred to in the following description, the scales are different for each layer and each member so that each layer and each member have a size that can be recognized on the drawing. Moreover, in the following description, the direction in which the wire grid 4 (metal thin wire 41) extends is defined as the Y direction, and the direction in which the metal thin wires 41 are arranged in parallel is defined as the X direction.

  Further, when the width W41 of the fine metal wire 41 of the wire grid 4 is described, when the width W41 of the fine metal wire 41 of the wire grid 4 is different in the thickness direction, at the center of the fine metal wire 41 in the thickness direction. The width is the width W41 of the fine metal wire 41.

[Configuration of Wire Grid Polarizing Element 1]
FIG. 1 is an explanatory diagram of a wire grid polarizing element 1 to which the present invention is applied. FIG. 2 is a cross-sectional view of the wire grid polarizing element 1 shown in FIG. A wire grid polarizing element 1 shown in FIG. 1 and FIG. 2 has a translucent substrate 2 and a metal wire grid 4 formed on one surface 2 a of the substrate 2. The wire grid 4 includes a plurality of fine metal wires 41 arranged in parallel at equal pitches.

  As the substrate 2, a light-transmitting substrate such as a glass substrate, a quartz substrate, or a quartz substrate is used. The substrate 2 has, for example, a square shape with one side of about 20 mm to 30 mm and a thickness of 0.5 mm to 0.8 mm. The thickness and space of the fine metal wires 41 (interval between the fine metal wires 41) are, for example, 400 nm or less. In the present embodiment, the thickness and space of the thin metal wire 41 are each 20 nm to 300 nm, for example, and the thickness of the thin metal wire 41 is 150 nm to 400 nm. The wire grid 4 (fine metal wire 41) is aluminum, silver, copper, platinum, gold, or an alloy containing them as a main component. In this embodiment, from the viewpoint of suppressing absorption loss in the wire grid 4 in the visible light wavelength region, aluminum, an alloy containing aluminum as a main component, silver, or an alloy containing silver as a main component is used.

  In the wire grid 4 configured as described above, if the pitch of the fine metal wires 41 is sufficiently shorter than the wavelength of the incident light, the first straight line which is a component having an electric field vector orthogonal to the longitudinal direction of the fine metal wires 41 in the incident light. The polarized light is transmitted, and the second linearly polarized light that is a component having an electric field vector parallel to the longitudinal direction of the thin metal wire 41 is reflected.

  As shown in FIG. 2, in the wire grid polarizing element 1 of this embodiment, the light absorption layer which consists of semiconductor films, such as a silicon | silicone and germanium, in the edge part (tip part of the metal fine wire 41) on the opposite side to the board | substrate 2 of the wire grid 4. FIG. 51 (not shown in FIG. 1) is formed. Therefore, the light absorption layer 51 can suppress the light incident on the wire grid polarization element 1 from the side opposite to the substrate 2 from being reflected by the thin metal wire 41.

[Method for Manufacturing Wire Grid Polarizing Element 1]
FIG. 3 is an explanatory diagram of the mother substrate 20 used in the method for manufacturing the wire grid polarizing element 1 shown in FIG. FIG. 4 is a process cross-sectional view showing a film forming process and a resist mask forming process in the manufacturing process of the wire grid polarizing element 1 shown in FIG. FIG. 5 is a process cross-sectional view illustrating an etching process among the manufacturing processes of the wire grid polarizing element 1 illustrated in FIG. 1. 4 and 5 show the central region (for example, region 201 shown in FIG. 3) of the mother substrate 20 shown in FIG. 3 on the left side (a), and the peripheral region of the mother substrate 20 (for example, FIG. 3). The area 202 shown is shown on the right (b).

  In manufacturing the wire grid polarizing element 1 shown in FIG. 1, in this embodiment, after forming the wire grid 4 using the mother substrate 20 shown in FIG. 3 at least until the wire grid 4 shown in FIG. 1 is formed. The mother substrate 20 is divided to obtain a plurality of wire grid polarizing elements 1. The mother substrate 20 is a large substrate on which a large number of substrates 2 indicated by a solid line L11 can be obtained, and has a disk shape like a silicon wafer. In the mother substrate 20, a region where the plurality of substrates 2 are cut out (a region surrounded by a one-dot chain line Ly) is an effective region 20y, and other regions are invalid regions 20z (material removal region / single point) that is removed in the dividing step. The outside of the region surrounded by the chain line Ly).

  In forming the wire grid 4 on the mother substrate 20 shown in FIG. 3, first, in the film forming step ST1 shown in FIG. 4, the metal film 40, the light absorbing film 50, and the hard mask inorganic material film 60 are sequentially formed. Film. In this embodiment, the metal film 40 is an aluminum film having a thickness of 240 nm. The light absorption film 50 is a semiconductor film such as a silicon film or a germanium film having a thickness of 26 nm. The hard mask inorganic material film 60 is a silicon oxide film having a thickness of 100 nm.

  Next, a resist mask forming step ST2 shown in FIG. 4 is performed. In the resist mask forming step ST2, the resist layer 70 is applied to the one surface 20a of the mother substrate 20 in the resist applying step ST21. Next, in the transfer step ST22, the nanoimprint mold 8 is pressed against the resist layer 70. Then, the plurality of convex portions 71 arranged in parallel at the same pitch as the pitch of the plurality of fine metal wires 41 are transferred to the resist layer 70. Next, in the mold release step ST <b> 23, the mold material 8 is separated from the resist layer 70. The resist layer 70 is solidified after the transfer step ST22 and before the release step ST23. Further, the resist layer 70 may be solidified after the release step ST23. In this embodiment, the resist layer 70 is a UV curable resist. Therefore, if the mold material 8 having ultraviolet transparency is used, the resist layer 70 is cured by irradiating the resist layer 70 from the side opposite to the resist layer 70 with respect to the mold material 8 before performing the mold release step ST23. Can be made. Moreover, after performing mold release process ST23, the ultraviolet rays UV may be irradiated to the resist layer 70 from the opposite side to the mother substrate 20, and the resist layer 70 may be hardened.

  In this embodiment, when the resist mask 7 is formed, the resist mask 7 (residual film 75) is left at the bottom of the concave portion 72 sandwiched between the adjacent convex portions 71. Therefore, the resist layer 70 constituting the convex portion 71 is connected via the resist layer 70 constituting the bottom portion of the concave portion 72. For this reason, after the mold material 8 is pressed against the resist layer 70 to transfer the convex portion 71 to the resist layer 70, the resist layer constituting the convex portion 71 is unlikely to peel off when the mold material 8 is released.

  Next, in the etching process ST3 shown in FIG. 5, dry etching is performed with the resist mask 7 formed, and the metal film 40 and the light absorption film 50 are patterned into a shape corresponding to the pattern shape of the resist mask 7 to form a wire grid. 4 is formed. In the etching step ST3, first, first anisotropic dry etching using an etching gas containing fluorine and oxygen is performed, and then second anisotropic dry etching using an etching gas containing chlorine is performed.

  In the first anisotropic dry etching, the resist mask 7 and the inorganic material film 60 are etched, and the inorganic material film 60 is patterned into the hard mask 6 having a shape corresponding to the pattern shape of the resist mask 7. In the second anisotropic dry etching, the metal film 40 is etched, and the metal film 40 is patterned with a metal fine wire 41 having a shape corresponding to the pattern shape of the hard mask 6 (pattern shape of the resist mask 7). At this time, the light absorption film 50 is also patterned into a shape corresponding to the pattern shape of the hard mask 6 (pattern shape of the resist mask 7).

  Next, third anisotropic dry etching using an etching gas containing fluorine is performed to remove the hard mask 6 remaining on the thin metal wire 41. Meanwhile, on one surface 20a of the mother substrate 20, a portion sandwiched between the metal thin wires 41 is etched to a depth of 70 nm, for example. Thereafter, the mother substrate 20 is divided to obtain a plurality of wire grid polarizing elements 1.

[Results of study on residual film 75]
(Variation in the thickness t of the remaining film 75 and the width W41 of the thin metal wire 41)
FIG. 5 shows a case where the maximum thickness of the resist mask 7 is 150 nm, the width WL of the convex portion 71 in the resist mask 7 is 40 nm, and the width WS of the concave portion 72 is 100 nm (the pitch P of the fine metal wires 41 is 140 nm). ). In the resist mask 7, the width WL of the convex portion 71, the width WS of the concave portion 72, and the pitch P of the thin metal wires 41 are equal in the central region 201 and the peripheral region 202 of the mother substrate 20 shown in FIG. 3.

  However, when the resist mask 7 (residual film 75) is left at the bottom of the recess 72, the thickness of the residual film 75 may vary depending on the position on the mother substrate 20. For example, the thickness t of the remaining film 75 is 30 nm in the central region 201 of the mother substrate 20, whereas the thickness t of the remaining film 75 is 20 nm in the peripheral region 202 of the mother substrate 20. The difference Δt between the maximum value and the minimum value of the thickness t of the remaining film 75 is 10 nm. In this case, when the hard mask 6 is formed by performing the etching process ST3, the timing of removing the remaining film 75 is earlier in the peripheral region 202 than in the central region 201. The etching time is set according to the thickness of the thicker remaining film 75.

  Therefore, in the hard mask 6, the width W 61 of the linear portion 61 that overlaps the resist mask 7 in the peripheral region 202 is narrower than the width W 61 of the linear portion 61 that overlaps the resist mask 7 in the central region 201. In other words, the width W62 of the space 62 sandwiched between the linear portions 61 in the peripheral region 202 is wider than the width W62 of the space 62 sandwiched between the linear portions 61 in the central region 201. For example, in the central region 201, the width W61 of the linear portion 61 is 39 nm, whereas in the peripheral region 202, the width W61 of the linear portion 61 is 29 nm. In other words, in the peripheral region 202, the width W62 of the space 62 is 101 nm, while in the central region 201, the width W62 of the space 62 is 111 nm.

  Therefore, when the etching with respect to the metal film 40 is completed, the width WL41 of the fine metal wire 41 in the peripheral region 202 becomes narrower than the width WL41 of the fine metal wire 41 in the central region 201. In other words, the width W42 of the space 42 sandwiched between the thin metal wires 41 in the peripheral region 202 is wider than the width W42 of the space 42 sandwiched between the thin metal wires 41 in the central region 201. For example, the width WL41 of the fine metal wire 41 in the central region 201 is 38 nm, whereas the width WL41 of the fine metal wire 41 in the peripheral region 202 is 28 nm. In other words, in the central region 201, the width WS42 of the space 42 sandwiched between the adjacent thin metal wires 41 is 102 nm, whereas in the peripheral region 202, the width 42 of the space 42 sandwiched between the adjacent thin metal wires 41 is. The width WS42 is 112 nm.

  As described above, when the remaining film 75 is thinner, the width W61 of the linear portion 61 of the hard mask 6 becomes narrower. Therefore, in the wire grid 4, the width WL41 of the metal thin wire 41 becomes narrower. Therefore, the wire grid polarizing element 1 divided from the central region 201 of the mother substrate 20 and the wire grid polarizing element 1 divided from the peripheral region 202 of the mother substrate 20 have different widths W41 of the metal thin wires 41. It will be. For example, the wire grid polarizing element 1 divided from the area 202 around the mother substrate 20 has a narrower width W41 of the metal thin wire 41 than the wire grid polarizing element 1 divided from the central area 201. As a result, there is a difference in optical characteristics between the wire grid polarizing element 1 obtained from the central region 201 and the wire grid polarizing element 1 obtained from the peripheral region 202.

(Relationship between the difference Δt in the thickness t of the remaining film 75 and the width W41 of the thin metal wire 41)
FIG. 6 is an explanatory view showing the relationship between the difference Δt in the thickness t of the remaining film 75 shown in FIG. 5 and the width W41 of the thin metal wire 41. In the region 201 where the thickness t of the remaining film 75 is thick, the fine metal wire 41 is shown. When the etching time or the like is set so that the width W41 of the thin film becomes 38 nm, the relationship between the difference Δt in the thickness t of the remaining film 75 and the width W41 of the thin metal wire 41 in the thin region 202 is shown.

  As shown in FIG. 6, under the condition that the difference Δt between the maximum value and the minimum value of the thickness t of the residual film 75 is changed from 5 nm to 30 nm, the central region 201 where the thickness t of the residual film 75 is thick is obtained. When the condition is set so that the width W41 of the thin metal wire 41 is 38 nm, the metal wire in the peripheral region 202 where the thickness t of the remaining film 75 is thinner increases as the difference Δt in the thickness t of the remaining film 75 increases. The width W41 of 41 becomes narrower from 33 nm to 8 nm. Further, the difference in the width W41 of the thin metal wire 41 between the region 201 and the region 202 is substantially equal to the difference Δt in the thickness t of the remaining film 75. This tendency is the same even if the pitch P is changed.

(Upper limit of variation of the remaining film 75 when the pitch P is 140 nm)
FIG. 7 is an explanatory diagram showing the relationship between the width WL41 of the metal fine wire 41 and the polarization characteristics when the pitch P of the metal fine wire 41 is 140 nm. FIG. 8 is an explanatory view showing the relationship between the variation (difference Δt) of the remaining film 75 and the polarization characteristics when the pitch P of the fine metal wires 41 is 140 nm, and is a wire grid polarizing element obtained from the peripheral region 202 The characteristic of 1 is shown. The polarization characteristics, contrast CR, and the like described below are average values for light having a wavelength of 500 nm to 590 nm.

  First, as shown in FIG. 7, when the width WL41 of the thin metal wire 41 is narrowed from 38 nm to 18 nm, the transmittance Tp of p-polarized light and the reflectance Rs of s-polarized light increase. In addition, the contrast ratio CR, which is the ratio of the transmittance of the wire grid polarizing element 1 to the light of two linearly polarized light (p-polarized light and s-polarized light) whose electric field vibration directions are orthogonal to each other, is lowered. Therefore, when the Δ difference in the thickness t of the remaining film 75 is large, the remaining time is set when the etching time is set so that the width W41 of the thin metal wire 41 is 38 nm in the region 201 where the thickness t of the remaining film 75 is thick. In the region 202 where the thickness t of the film 75 is thin, the width W41 of the fine metal wire 41 becomes narrow. For this reason, as shown in FIG. 8, the contrast ratio CR decreases in the wire grid polarizing element 1 obtained from the peripheral region 202 as the difference Δt in the thickness t of the remaining film 75 increases.

Therefore, when the condition (width WL41 of the thin metal wire 41) for ensuring the contrast ratio CR of 100 or 500 or more is obtained based on the results shown in FIGS. 7 and 8, the following results are obtained.
CR is 100 or more (pitch P = 140 nm)
The width of the thin metal wire 41 WL41 ≧ 19 nm
CR is 500 or more (pitch P = 140 nm)
The width WL41 ≧ 25 nm of the thin metal wire 41

The conditions of the remaining film 75 corresponding to the above conditions (thickness t difference Δt and Δt / P) are as follows.
CR is 100 or more (pitch P = 140 nm)
Difference Δt ≦ 19.5nm
Δt / P ≦ 13.9%
CR is 500 or more (pitch P = 140 nm)
Difference Δt ≦ 14.1 nm
Δt / P ≦ 10.1%

(Upper limit of variation of the remaining film 75 when the pitch P is 120 nm)
FIG. 9 is an explanatory diagram showing the relationship between the width WL41 of the metal fine wire 41 and the polarization characteristics when the pitch P of the metal fine wire 41 is 120 nm. FIG. 10 is an explanatory diagram showing the relationship between the dispersion (difference Δt) of the remaining film 75 and the polarization characteristics when the pitch P of the fine metal wires 41 is 120 nm, and is a wire grid polarizing element obtained from the peripheral region 202 The characteristic of 1 is shown. When the pitch P is 120 nm, the height of the thin metal wires 41 is 215 nm, and the thickness of the light absorption layer 5 is 27 nm. The target value of the width W41 of the fine metal wire 41 is set to 34 nm. Further, the width WL of the projection 71 in the resist mask 7 shown in FIG. 5 is set to 36 nm, and the thickness t of the remaining film 75 is set to 30 nm in the central region 201 of the mother substrate 20.

  First, as shown in FIG. 9, even when the pitch P is 120 nm, as in the case where the pitch P is 140 nm, when the width WL41 of the thin metal wire 41 is reduced from 34 nm to 16 nm, the transmittance Tp of p-polarized light, and The reflectance Rs of s-polarized light increases. In addition, the contrast ratio CR, which is the ratio of the transmittance of the wire grid polarizing element 1 to the light of two linearly polarized light (p-polarized light and s-polarized light) whose electric field vibration directions are orthogonal to each other, is lowered. Therefore, when the Δ difference in the thickness t of the remaining film 75 is large, the remaining time is set when the etching time is set so that the width W41 of the thin metal wire 41 is 34 nm in the region 201 where the thickness t of the remaining film 75 is thick. In the region 202 where the thickness t of the film 75 is thin, the width W41 of the fine metal wire 41 becomes narrow. Therefore, as shown in FIG. 10, the contrast ratio CR decreases in the wire grid polarizing element 1 obtained from the peripheral region 202 as the difference Δt in the thickness t of the remaining film 75 increases.

Therefore, when the condition (width WL41 of the thin metal wire 41) for ensuring the contrast ratio CR of 100 or 500 or more is obtained based on the results shown in FIGS. 9 and 10, the following results are obtained.
CR is 100 or more (pitch P = 120 nm)
The width of the metal thin wire 41 WL41 ≧ 18 nm
CR is 500 or more (pitch P = 120 nm)
The width of the metal thin wire 41 WL41 ≧ 23 nm

The conditions of the remaining film 75 corresponding to the above conditions (thickness t difference Δt and Δt / P) are as follows.
CR is 100 or more (pitch P = 120 nm)
Difference Δt ≦ 16.1 nm
Δt / P ≦ 13.4%
CR is 500 or more (pitch P = 120 nm)
Difference Δt ≦ 11.6nm
Δt / P ≦ 9.7%

(Upper limit of variation of remaining film 75 when pitch P is 100 nm)
FIG. 11 is an explanatory diagram showing the relationship between the width WL41 of the metal fine wire 41 and the polarization characteristics when the pitch P of the metal fine wire 41 is 100 nm. FIG. 12 is an explanatory diagram showing the relationship between the variation (difference Δt) of the remaining film 75 and the polarization characteristics when the pitch P of the fine metal wires 41 is 100 nm, and is a wire grid polarizing element obtained from the peripheral region 202 The characteristic of 1 is shown. When the pitch P is 100 nm, the height of the fine metal wires 41 is 195 nm, and the thickness of the light absorption layer 5 is 27 nm. Further, the target value of the width W41 of the fine metal wire 41 is set to 30 nm. Further, the width WL of the protrusion 71 in the resist mask 7 shown in FIG. 5 is set to 32 nm, and the thickness t of the remaining film 75 is set to 30 nm in the central region 201 of the mother substrate 20.

  First, as shown in FIG. 11, even when the pitch P is 100 nm, as in the case where the pitch P is 120 nm and 140 nm, when the width WL41 of the thin metal wire 41 is reduced from 30 nm to 15 nm, the transmittance Tp of p-polarized light , And s-polarized light reflectivity Rs increases. In addition, the contrast ratio CR, which is the ratio of the transmittance of the wire grid polarizing element 1 to the light of two linearly polarized light (p-polarized light and s-polarized light) whose electric field vibration directions are orthogonal to each other, is lowered. Therefore, when the Δ difference in the thickness t of the remaining film 75 is large, the remaining time is set when the etching time is set so that the width W41 of the thin metal wire 41 is 30 nm in the region 201 where the thickness t of the remaining film 75 is thick. In the region 202 where the thickness t of the film 75 is thin, the width W41 of the fine metal wire 41 becomes narrow. For this reason, as shown in FIG. 12, the contrast ratio CR decreases in the wire grid polarizing element 1 obtained from the peripheral region 202 as the difference Δt in the thickness t of the remaining film 75 increases.

Therefore, when the condition (width WL41 of the thin metal wire 41) for securing the contrast ratio CR of 100 or 500 or more is obtained based on the results shown in FIGS. 11 and 12, the following results are obtained.
CR is 100 or more (pitch P = 100 nm)
The width WL41 ≧ 17 nm of the thin metal wire 41
CR is 500 or more (pitch P = 100 nm)
The width of the thin metal wire 41 WL41 ≧ 21 nm

The conditions of the remaining film 75 corresponding to the above conditions (thickness t difference Δt and Δt / P) are as follows.
CR is 100 or more (pitch P = 100 nm)
Difference Δt ≦ 13.9 nm
Δt / P ≦ 13.9%
CR is 500 or more (pitch P = 100 nm)
Difference Δt ≦ 9.7 nm
Δt / P ≦ 9.7%

(Upper limit of difference Δt of thickness t of remaining film 75)
The above results are summarized in FIG. 13 and FIG. FIG. 13 is a graph showing the relationship between the pitch P and the difference Δt in the thickness t of the remaining film 75 when the contrast CR is 100. FIG. 14 is a graph showing the relationship between the pitch P when the contrast CR is 500, the difference Δt between the thicknesses t of the remaining films 75, and the like.

As shown in FIG. 13, the contrast CR of each of the plurality of wire grid polarizing elements 1 obtained from the same mother substrate is set to 100 or more under the following conditions by controlling or managing the conditions in the manufacturing process. be able to.
When the pitch P is 100 nm to 120 nm
Δt / P ≦ −0.025 × P + 16.4
When pitch P is 120nm to 140nm
Δt / P ≦ 0.025 × P + 10.4

  Accordingly, if the difference Δt / P in the thickness t of the remaining film 75 is 13.4% or less in a wide range including the pitch P from 100 nm to 140 nm, a plurality of wire grid polarizers obtained from the same mother substrate Each contrast CR of 1 can be 100 or more. Further, when the relationship between the pitch P and the difference Δt in the thickness t of the remaining film 75 is expressed by a linear function by the least square method, the difference Δt (nm) in the thickness t of the remaining film 75 is (0.14 × P If it is −0.3) nm or less, the contrast CR of each of the plurality of wire grid polarizing elements 1 obtained from the same mother substrate can be set to 100 or more.

Further, as shown in FIG. 14, the contrast CR of each of the plurality of wire grid polarizing elements 1 obtained from the same mother substrate is set to 500 or more if the following conditions are set by controlling or managing the conditions in the manufacturing process. It can be.
When the pitch P is 100 nm to 120 nm
Δt / P ≦ 9.71
When pitch P is 120nm to 140nm
Δt / P ≦ 0.02 × P + 7.3

  Therefore, when the difference Δt / P in the thickness t of the remaining film 75 is 9.7% or less in a wide range including the pitch P from 100 nm to 140 nm, a plurality of wire grid polarizers obtained from the same mother substrate Each contrast CR of 1 can be 500 or more. When the relationship between the pitch P and the difference Δt in the thickness t of the remaining film 75 is expressed by a linear function by the least square method, the difference Δt (nm) in the thickness t of the remaining film 75 is expressed as (0.11 × P When the thickness is −1.4) nm or less, the contrast CR500 of each of the plurality of wire grid polarizing elements 1 obtained from the same mother substrate can be set.

(Board Grid Polarizing Element Manufacturing Substrate 200)
According to this manufacturing method, when the resist mask forming step ST2 shown in FIG. 4 is performed in the course of manufacturing the wire grid polarizing element 1, the metal film 40 and the hard mask inorganic material film 60 are formed on one surface of the mother substrate 20. And the board | substrate 200 for wire-grid polarizing element manufacture in which the resist mask 7 in which the some convex part 71 was arranged in parallel was provided in order is obtained.

  In the wire grid polarizing element manufacturing substrate 200, the maximum value on the mother substrate 20 of the thickness t (thickness of the remaining film 75) of the resist mask 7 remaining on the bottom of the concave portion 72 sandwiched between the adjacent convex portions 71 is obtained. When the difference from the minimum value is Δt (nm) and the pitch of the convex portions 71 is P (nm), if Δt / P (%) is 13.4% or less, the wire grid polarizing element 1 is Can be obtained.

Further, in the wire grid polarizing element manufacturing substrate 200, the maximum value on the mother substrate 20 of the thickness t (the thickness of the remaining film 75) of the resist mask 7 remaining on the bottom of the concave portion 72 sandwiched between the adjacent convex portions 71. And the minimum value is Δt (nm), the pitch P (nm) of the convex portion 71 and the difference Δt are the following conditional expressions: Δt ≦ (0.14 × P−0.3)
If it satisfy | fills, said wire grid polarizing element 1 can be obtained.

(Measurement method of difference Δt in thickness t of remaining film 75)
FIG. 15 is an explanatory diagram illustrating a method for measuring the thickness t of the resist mask, and is an explanatory diagram illustrating an imaging result of a focused ion beam scanning electron microscope. In FIG. 15, an imaging result (a) and an explanatory diagram (b) of the imaging result are shown.

  In the manufacturing method of the wire grid polarizing element 1 to which the present invention is applied, the difference between the maximum value and the minimum value on the mother substrate 20 of the thickness t (thickness of the remaining film 75) of the resist mask 7 remaining at the bottom of the recess 72. Δt (nm) is the difference between the maximum value and the minimum value when the thickness t of the resist mask remaining at the bottom of the recess 72 is measured at a plurality of locations in the effective area 20 y of the mother substrate 20. In this embodiment, a focused ion beam scanning electron microscope is used for measuring the thickness t.

  According to the focused ion beam scanning electron microscope, the cross section of the resist mask 7 is imaged as shown in the imaging result (a) of FIG. According to such an imaging result, as shown in the explanatory diagram (b) of FIG. 15, the thickness t of the resist mask remaining at the bottom of the recess 72 can be measured.

(First example of measurement location of thickness t of residual film 75)
FIG. 16 is an explanatory diagram illustrating a first example of a measurement location of the thickness t of the remaining film 75. In this embodiment, as shown in FIG. 16, when measuring the thickness t of the resist mask remaining at the bottom of the recess 72 at a plurality of locations in the effective region 20y of the mother substrate 20, the plurality of locations to be measured are at least the effective region. The embodiment includes a central portion C0 in 20y and a first end C1 of the effective region 20y that is spaced from the central portion C0 to one side in the first direction D1 in the in-plane direction of the mother substrate 20. According to the nanoimprint method, variations in the thickness t are likely to occur between the central portion C0 and the end of the effective region 20y, but variations in the circumferential direction are unlikely to occur. Therefore, if the thickness t is measured at least at the central portion C0 and the first end C1, the variation in the thickness t in the entire effective area 20y of the mother substrate 20 can be grasped.

(Second example of measurement location of thickness t of remaining film 75)
FIG. 17 is an explanatory diagram illustrating a second example of the measurement location of the thickness t of the remaining film 75. In this embodiment, as shown in FIG. 17, when measuring the thickness t of the resist mask remaining at the bottom of the recess 72 at a plurality of locations in the effective area 20y of the mother substrate 20, the plurality of locations to be measured are shown in FIG. Let it be a place. Specifically, a plurality of points to be measured are at least a central portion C0 in the effective region 20y, a first end C1 of the effective region 20y spaced from the central portion C0 to one side in the first direction D1, and a central portion. A second end C2 of the effective region 20y that is spaced from C0 to the other side in the first direction D1, and one of the second direction D2 that is orthogonal to the first direction D1 in the in-plane direction of the mother substrate 20 from the central portion C0. A third end C3 of the effective region 20y that is spaced apart to the side and a fourth end C4 of the effective region 20y that is spaced from the central portion C0 to the other side in the second direction D2.

  According to this aspect, even when the number of measurement locations is small, it is possible to more appropriately grasp the variation in the thickness t in the entire effective area 20y of the mother substrate 20.

(Third example of measurement location of thickness t of remaining film 75)
FIG. 18 is an explanatory diagram showing a third example of the measurement location of the thickness t of the remaining film 75. In this embodiment, as shown in FIG. 18, when measuring the thickness t of the resist mask remaining at the bottom of the concave portion 72 at a plurality of locations in the effective area 20y of the mother substrate 20, the plurality of locations to be measured are center portions C0, There are a total of nine locations including the first end C1, the second end C2, the third end C3, and the fourth end C4. More specifically, as a plurality of locations to be measured, a first intermediate position C5 that is separated from the central portion C0 and the first end C1 by 1 cm or more between the central portion C0 and the first end C1, and a central portion C0 A second intermediate position C6 that is 1 cm or more away from the central portion C0 and the second end C2 between the second end C2 and a central portion C0 and a third end between the central portion C0 and the third end C3 A third intermediate position C7 separated by 1 cm or more from the part C3 and a fourth intermediate position C8 separated by 1 cm or more from the central part C0 and the fourth end part C4 are added between the central part C0 and the fourth end part C4.

  According to this aspect, it is possible to more appropriately grasp the variation in the thickness t in the entire effective area 20y of the mother substrate 20.

(Fourth example of measurement location of thickness t of remaining film 75)
FIG. 19 is an explanatory diagram showing a fourth example of the measurement location of the thickness t of the remaining film 75. In this embodiment, as shown in FIG. 19, when measuring the thickness t of the resist mask remaining at the bottom of the recess 72 at a plurality of locations in the effective area 20y of the mother substrate 20, the plurality of locations to be measured are the central portion C0, There are a total of nine locations including the first end C1, the second end C2, the third end C3, and the fourth end C4. In this embodiment, when one of the two directions intersecting the first direction D1 and the second direction D2 is the third direction D3 and the other is the fourth direction D4 in the in-plane direction of the mother substrate 20. The positions separated from the central portion C0 in the third direction D3 and the fourth direction D4 are also measurement points. More specifically, as a plurality of points to be measured, the fifth end C50 of the effective region 20y that is separated from the central portion C0 to one side in the third direction D3 and the central portion C0 are separated from the other side in the third direction D3. 6th end C60 of the effective area 20y to be separated, 7th end C70 of the effective area 20y spaced from the central part C0 to the one side in the fourth direction D4, and separated from the central part C0 to the other side in the fourth direction D4 And an eighth end C80 of the effective area 20y to be added.

  According to this aspect, it is possible to more appropriately grasp the variation in the thickness t in the entire effective area 20y of the mother substrate 20.

(Fifth example of measurement location of thickness t of remaining film 75)
FIG. 20 is an explanatory diagram illustrating a fifth example of the measurement location of the thickness t of the remaining film 75. In this embodiment, as shown in FIG. 20, a plurality of substrates 2 (wire grid polarization elements 1) obtained from the effective area 20y of the mother substrate 20 are obtained as a plurality of locations where the thickness t of the remaining film 75 is measured. The thickness t of the resist mask is measured in each of the regions. At that time, each of the substrates 2 (wire grid polarization elements 1) measures the thickness t of the resist mask at one location C in each obtained region. According to this aspect, it is possible to more appropriately grasp the variation in the thickness t in the entire effective area 20y of the mother substrate 20, and it is possible to reliably grasp the characteristics of the wire grid polarizing element 1.

[Other Embodiments]
In the said embodiment, although the light absorption layer 51 was provided in the edge part of the metal fine wire 41, when the light absorption layer 51 is not provided, you may apply this invention.

[Configuration Example 1 of Projection Display Device]
A projection display device (liquid crystal projector) using the wire grid polarizing element 1 according to the above-described embodiment will be described. FIG. 21 is an explanatory diagram of a projection display device using a transmissive liquid crystal panel.

  Note that in any of the projection display device 110 shown in FIG. 21 and the projection display device 1000 described later with reference to FIG. 22, a liquid crystal panel, a light source unit that emits light supplied to the liquid crystal panel, and a liquid crystal display A projection optical system for projecting light modulated by the panel, and a wire grid polarization element described with reference to FIGS. 1 to 20 in an optical path from the light source unit to the projection optical system via the liquid crystal panel 1 is arranged.

  A projection display device 110 shown in FIG. 21 is a liquid crystal projector using a transmissive liquid crystal panel, and irradiates light onto a projection target member 111 including a screen and displays an image. In the projection display device 110, the wire grid polarizing element 1 in which the present invention is applied to one or the other of the first polarizing plates 115b, 116b, 117b and the second polarizing plates 115d, 116d, 117d described below is used. It is done.

  The projection display device 110 includes an illumination device 160, a plurality of light valves (liquid crystal light valves 115 to 117) to which light emitted from the illumination device 160 is supplied, and a liquid crystal light valve 115 along the device optical axis L0. The cross dichroic prism 119 (light combining optical system) that synthesizes and outputs the light emitted from .about.117, and the projection optical system 118 that projects the light synthesized by the cross dichroic prism 119. In addition, the projection display device 110 includes dichroic mirrors 113 and 114 and a relay system 120. In the projection display device 110, the liquid crystal light valves 115 to 117 and the cross dichroic prism 119 constitute an optical unit 150.

  In the illumination device 160, along the device optical axis L0, a light source unit 161, a first integrator lens 162 composed of a lens array such as a fly-eye lens, a second integrator lens 163 composed of a lens array such as a fly-eye lens, and a polarization conversion element 164 and a condenser lens 165 are arranged in this order. The light source unit 161 includes a light source 168 that emits white light including red light R, green light G, and blue light B, and a reflector 169. The light source 168 is configured by an ultra-high pressure mercury lamp or the like, and the reflector 169 has a parabolic cross section. The first integrator lens 162 and the second integrator lens 163 make the illuminance distribution of the light emitted from the light source unit 161 uniform. The polarization conversion element 164 turns the light emitted from the light source unit 161 into polarized light having a specific vibration direction such as s-polarized light.

  The dichroic mirror 113 transmits the red light R included in the light emitted from the illumination device 160 and reflects the green light G and the blue light B. The dichroic mirror 114 transmits the blue light B and reflects the green light G out of the green light G and the blue light B reflected by the dichroic mirror 113. As described above, the dichroic mirrors 113 and 114 constitute a color separation optical system that separates the light emitted from the illumination device 160 into red light R, green light G, and blue light B.

  The liquid crystal light valve 115 is a transmissive liquid crystal device that modulates the red light R transmitted through the dichroic mirror 113 and reflected by the reflection mirror 123 in accordance with an image signal. The liquid crystal light valve 115 includes a λ / 2 phase difference plate 115a, a first polarizing plate 115b, a liquid crystal panel 100R, and a second polarizing plate 115d. Here, the red light R incident on the liquid crystal light valve 115 remains as s-polarized light because the polarization of the light does not change even if it passes through the dichroic mirror 113.

  The λ / 2 phase difference plate 115a is an optical element that converts s-polarized light incident on the liquid crystal light valve 115 into p-polarized light. The first polarizing plate 115b is a polarizing plate that blocks s-polarized light and transmits p-polarized light. The liquid crystal panel 100R is configured to convert p-polarized light into s-polarized light (circularly polarized light or elliptically polarized light in the case of halftone) by modulation according to an image signal. The second polarizing plate 115d is a polarizing plate that blocks p-polarized light and transmits s-polarized light. Accordingly, the liquid crystal light valve 115 modulates the red light R according to the image signal, and emits the modulated red light R toward the cross dichroic prism 119.

  The liquid crystal light valve 116 is a transmissive liquid crystal device that modulates green light G reflected by the dichroic mirror 114 after being reflected by the dichroic mirror 113 in accordance with an image signal. Similarly to the liquid crystal light valve 115, the liquid crystal light valve 116 includes a first polarizing plate 116b, a liquid crystal panel 100G, and a second polarizing plate 116d. Green light G incident on the liquid crystal light valve 116 is s-polarized light that is reflected by the dichroic mirrors 113 and 114 and then incident. The first polarizing plate 116b is a polarizing plate that blocks p-polarized light and transmits s-polarized light. The liquid crystal panel 100G is configured to convert s-polarized light into p-polarized light (circularly polarized light or elliptically polarized light in the case of halftone) by modulation according to an image signal. The second polarizing plate 116d is a polarizing plate that blocks s-polarized light and transmits p-polarized light. Therefore, the liquid crystal light valve 116 modulates the green light G according to the image signal, and emits the modulated green light G toward the cross dichroic prism 119.

  The liquid crystal light valve 117 is a transmissive liquid crystal device that modulates the blue light B reflected by the dichroic mirror 113, transmitted through the dichroic mirror 114, and then passed through the relay system 120 in accordance with an image signal. Similar to the liquid crystal light valves 115 and 116, the liquid crystal light valve 117 includes a λ / 2 phase difference plate 117a, a first polarizing plate 117b, a liquid crystal panel 100B, and a second polarizing plate 117d. Since the blue light B incident on the liquid crystal light valve 117 is reflected by the dichroic mirror 113 and transmitted through the dichroic mirror 114 and then reflected by the two reflection mirrors 125a and 125b of the relay system 120, it is s-polarized light.

  The λ / 2 phase difference plate 117a is an optical element that converts s-polarized light incident on the liquid crystal light valve 117 into p-polarized light. The first polarizing plate 117b is a polarizing plate that blocks s-polarized light and transmits p-polarized light. The liquid crystal panel 100B is configured to convert p-polarized light into s-polarized light (circularly polarized light or elliptically polarized light in the case of halftone) by modulation according to an image signal. The second polarizing plate 117d is a polarizing plate that blocks p-polarized light and transmits s-polarized light. Accordingly, the liquid crystal light valve 117 modulates the blue light B according to the image signal, and emits the modulated blue light B toward the cross dichroic prism 119.

  The relay system 120 includes relay lenses 124a and 124b and reflection mirrors 125a and 125b. The relay lenses 124a and 124b are provided to prevent light loss due to the long optical path of the blue light B. The relay lens 124a is disposed between the dichroic mirror 114 and the reflection mirror 125a. The relay lens 124b is disposed between the reflection mirrors 125a and 125b. The reflection mirror 125a reflects the blue light B transmitted through the dichroic mirror 114 and emitted from the relay lens 124a toward the relay lens 124b. The reflection mirror 125b reflects the blue light B emitted from the relay lens 124b toward the liquid crystal light valve 117.

  The cross dichroic prism 119 is a color combining optical system in which two dichroic films 119a and 119b are arranged orthogonally in an X shape. The dichroic film 119a is a film that reflects blue light B and transmits green light G, and the dichroic film 119b is a film that reflects red light R and transmits green light G. Accordingly, the cross dichroic prism 119 combines the red light R, the green light G, and the blue light B that are modulated by the liquid crystal light valves 115 to 117, and emits the resultant light toward the projection optical system 118.

  Note that light incident on the cross dichroic prism 119 from the liquid crystal light valves 115 and 117 is s-polarized light, and light incident on the cross dichroic prism 119 from the liquid crystal light valve 116 is p-polarized light. Thus, by making the light incident on the cross dichroic prism 119 into different types of polarized light, the light incident from the liquid crystal light valves 115 to 117 can be synthesized in the cross dichroic prism 119. Here, generally, the dichroic films 119a and 119b are excellent in the reflection characteristic of s-polarized light. For this reason, red light R and blue light B reflected by the dichroic films 119a and 119b are s-polarized light, and green light G transmitted through the dichroic films 119a and 119b is p-polarized light. The projection optical system 118 has a projection lens (not shown), and projects the light combined by the cross dichroic prism 119 onto a projection target 111 such as a screen.

[Configuration Example 2 of Projection Display Device]
FIG. 22 is an explanatory diagram of a projection display device using a reflective liquid crystal panel, and a wire grid polarizing element 1 to which the present invention is applied is used for wire grid polarizing plates 1032r, 1032g, and 1032b described below. Moreover, you may use the wire grid polarizing element 1 which applied this invention to one or both of the incident side polarizing plate 1037b, 1037g, 1037r and the output side polarizing plate 1038b, 1038g, 1038r.

  A projection display apparatus 1000 shown in FIG. 22 includes a light source unit 1021 that generates light source light, a color separation light guide optical system 1023 that separates the light source light emitted from the light source unit 1021 into three colors of red, green, and blue. And a light modulator 1025 that is illuminated by the light source light of each color emitted from the color separation light guide optical system 1023. Further, the projection display apparatus 1000 uses a cross dichroic prism 1027 (combining optical system) that synthesizes the image light of each color emitted from the light modulation unit 1025 and the image light that has passed through the cross dichroic prism 1027 on a screen (not shown). A projection optical system 1029 which is a projection optical system for projecting.

  In the projection display apparatus 1000, the light source unit 1021 includes a light source 1021a, a pair of fly-eye optical systems 1021d and 1021e, a polarization conversion member 1021g, and a superimposing lens 1021i. In the present embodiment, the light source unit 1021 includes a reflector 1021f having a paraboloid and emits parallel light. The fly-eye optical systems 1021d and 1021e are composed of a plurality of element lenses arranged in a matrix in a plane orthogonal to the system optical axis, and the light source light is divided and condensed and diverged individually by these element lenses. The polarization conversion member 1021g converts the light source light emitted from the fly-eye optical system 1021e into, for example, only a p-polarized component parallel to the drawing, and supplies it to the optical path downstream optical system. The superimposing lens 1021i uniformly superimposes a plurality of liquid crystal panels 100 (R), (G), and (B) provided in the light modulation unit 1025 by appropriately converging the light source light that has passed through the polarization conversion member 1021g as a whole. Enable lighting.

  The color separation light guide optical system 1023 includes a cross dichroic mirror 1023a, a dichroic mirror 1023b, and reflection mirrors 1023j and 1023k. In the color separation light guide optical system 1023, the substantially white light source light from the light source unit 1021 enters the cross dichroic mirror 1023a. The red (R) light reflected by one of the first dichroic mirrors 1031a constituting the cross dichroic mirror 1023a is reflected by the reflecting mirror 1023j, then passes through the dichroic mirror 1023b, and is incident on the polarizing plate 1037r and the wire. The light is incident on the red (R) liquid crystal panel 100 (R) as p-polarized light through the grid polarizing plate 1032 r and the optical compensation plate 1039 r.

  The green (G) light reflected by the first dichroic mirror 1031a is reflected by the reflection mirror 1023j and then by the dichroic mirror 1023b, and is incident side polarizing plate 1037g, wire grid polarizing plate 1032g, and optical. The light is incident on the green (G) liquid crystal panel 100 (G) through the compensation plate 1039 g as p-polarized light.

  On the other hand, the blue (B) light reflected by the other second dichroic mirror 1031b constituting the cross dichroic mirror 1023a is reflected by the reflection mirror 1023k, and is incident side polarizing plate 1037b and wire grid polarizing plate 1032b. , And the optical compensator 1039b, is incident on the blue (B) liquid crystal panel 100 (B) as p-polarized light. Note that the optical compensation plates 1039r, 1039g, and 1039b optically compensate for the characteristics of the liquid crystal layer by adjusting the polarization states of the incident light and the emitted light to the liquid crystal panel 100 (B).

  In the projection display apparatus 1000 configured as described above, the three colors of light incident through the optical compensation plates 1039r, 1039g, and 1039b are modulated in the liquid crystal panels 100 (R), (G), and (B), respectively. . At that time, of the modulated light emitted from the liquid crystal panels 100 (R), (G), and (B), the s-polarized component light is reflected by the wire grid polarizing plates 1032r, 1032g, and 1032b, and the outgoing side polarizing plate. It enters the cross dichroic prism 1027 through 1038r, 1038g, and 1038b. In the cross dichroic prism 1027, a first dielectric multilayer film 1027a and a second dielectric multilayer film 1027b intersecting in an X shape are formed, and the first dielectric multilayer film 1027a reflects R light, The other second dielectric multilayer film 1027b reflects B light. Therefore, the three colors of light are combined by the cross dichroic prism 1027 and emitted to the projection optical system 1029. The projection optical system 1029 projects the color image light combined by the cross dichroic prism 1027 onto a screen (not shown) at a desired magnification.

(Other projection display devices)
In addition, about a projection type display apparatus, you may comprise the LED light source etc. which radiate | emit the light of each color as a light source part, and supply each color light radiate | emitted from this LED light source to another liquid crystal device. .

DESCRIPTION OF SYMBOLS 1 ... Wire grid polarizing element, 2 ... Board | substrate, 4 ... Wire grid, 6 ... Hard mask, 7 ... Resist mask, 8 ... Mold material, 20 ... Mother board | substrate, 75 ... Residual film, 40 ... Metal film, 41 ... Metal fine wire, 42, 62 ... space, 50 ... light absorbing film, 51 ... light absorbing layer, 60 ... inorganic material film, 61 ... linear part, 70 ... resist layer, 71 ... convex part, 72 ... concave part, 100, 100B, 100G, 100R ... Liquid crystal panel, 200 ... Wire grid polarizing element manufacturing substrate,
DESCRIPTION OF SYMBOLS 201 ... Center area | region, 202 ... Peripheral area | region, 110, 1000 ... Projection type display apparatus, ST1 ... Film-forming process, ST2 ... Resist mask formation process, ST21 ... Resist application process, ST3 ... Dry etching process, ST22 ... Transfer process , ST23 ... mold release step, C0 ... center portion, C1 ... first end, C2 ... second end, C3 ... third end, C4 ... fourth end, C5 ... first intermediate position, C6 ... first 2 intermediate positions, C7 ... 3rd intermediate position, C8 ... 4th intermediate position, C50 ... 5th end, C60 ... 6th end, C70 ... 7th end, C80 ... 8th end.

Claims (7)

In the manufacturing method of the wire grid polarization element provided with a wire grid in which a plurality of fine metal wires are arranged in parallel at an equal pitch on one side of the substrate,
A film forming step of sequentially forming a metal film and an inorganic material film for a hard mask on one surface of a mother substrate larger than the substrate;
After the film forming step, a resist layer is applied to one surface of the mother substrate, and then a nanoimprint mold is pressed against the resist layer so that the pitch is equal to the pitch of the plurality of fine metal wires. A resist mask forming step of forming a resist mask by solidifying the resist layer after forming a plurality of parallel convex portions on the resist layer;
A dry etching step of patterning the metal film into the plurality of thin metal wires by performing dry etching in a state where the resist mask is formed;
A dividing step of dividing the mother substrate into a plurality of wire grid polarizing elements;
Have
In the resist mask forming step, the resist mask is left at the bottom of a concave portion sandwiched between adjacent convex portions among the plurality of convex portions,
Of the mother substrate, a thickness t (nm) of the resist mask remaining at the bottom of the concave portion at a central portion in a region where a plurality of the substrates are obtained and an end portion in the region separated from the central portion. measured, the difference between the thickness t and Delta] t (nm), when the pitch was P (nm), Δt / P (%) , wherein the to Rukoto so becomes 13.4% or less Manufacturing method of wire grid polarizing element. In the manufacturing method of the wire grid polarizing element according to claim 1,
Delta] t / P is, the manufacturing method of a wire grid polarization element according to claim to Rukoto so that 9.7% or less. In the manufacturing method of the wire grid polarization element provided with a wire grid in which a plurality of fine metal wires are arranged in parallel at an equal pitch on one side of the substrate,
A film forming step of sequentially forming a metal film and an inorganic material film for a hard mask on one surface of a mother substrate larger than the substrate;
After the film forming step, a resist layer is applied to one surface of the mother substrate, and then a nanoimprint mold is pressed against the resist layer so that the pitch is equal to the pitch of the plurality of fine metal wires. A resist mask forming step of forming a resist mask by solidifying the resist layer after forming a plurality of parallel convex portions on the resist layer;
A dry etching step of patterning the metal film into the plurality of thin metal wires by performing dry etching in a state where the resist mask is formed;
A dividing step of dividing the mother substrate into a plurality of wire grid polarizing elements;
Have
In the resist mask forming step, the resist mask is left at the bottom of a concave portion sandwiched between adjacent convex portions among the plurality of convex portions,
Of the mother substrate, the thickness t (nm) of the resist mask remaining at the bottom of the recess is measured at a central portion in a region where a plurality of the substrates are obtained and at an end portion of the region separated from the central portion. When the difference in thickness t is Δt (nm) and the pitch is P (nm), the pitch P (nm) and the difference Δt are expressed by the following conditional expression: Δt ≦ (0.14 × P-0. 3)
Method for producing a wire-grid polarizing element, characterized in that to satisfy the. In the manufacturing method of the wire grid polarizing element according to claim 3 ,
Pitch P (nm) and difference Δt are the following conditional expressions: Δt ≦ (0.11 × P−1.4)
Method for producing a wire-grid polarizing element, characterized in that to satisfy the.   In the manufacturing method of the wire grid polarizing element according to any one of claims 1 to 4,
  A method of manufacturing a wire grid polarizing element, wherein the thickness t of the resist mask is measured by a focused ion beam scanning electron microscope. In the manufacturing method of the wire grid polarization element according to any one of claims 1 to 5 ,
In the film forming step, the metal film, the light absorption film, and the inorganic material film are formed in this order.   In the manufacturing method of the wire grid polarizing element according to claim 6,
  The dry etching process includes
  A first dry etching step of etching the resist mask and the inorganic material film to pattern the inorganic material film into a hard mask shape;
  The light absorbing film and the metal film are etched to pattern the light absorbing film into a shape corresponding to the shape of the hard mask, and the metal film is patterned into the shape of the thin metal wire corresponding to the shape of the hard mask. A second dry etching step,
  A third dry etching step of removing the hard mask and etching a portion sandwiched between the adjacent fine metal wires of the substrate.