JP3784118B2 - Exposure equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an alignment film for aligning liquid crystal molecules.Good for successSuitable exposure equipmentIn placeIt is related.
[0002]
[Prior art]
A typical method for forming an alignment film is a method (so-called rubbing method) in which a substrate or an alignment film forming material formed on the substrate is rubbed in a predetermined direction with a cloth or the like. However, the rubbing method has problems such that a subsequent cleaning step is essential, and it is difficult to mix minute regions having different orientation directions on the substrate.
[0003]
As a technique that can be expected to solve these problems, for example, a technique disclosed in Document I (Mol. Cryst. Liq. Cryst. 1994, Vol. 251, pp. 191-208, especially p. 191, pp. 195-198). There is. It is a technique using a material that, when irradiated with polarized light, that part exhibits a function as an alignment film for liquid crystals.
[0004]
More specifically, a film of a certain polymer (described as “proprietary polymer” in Document I) is formed on a substrate, and then a laser beam (hereinafter referred to as a polarized laser beam) that is polarized with a laser beam on the film. ) While scanning, and then a liquid crystal cell is constructed using the substrate thus treated. Then, the liquid crystal shows a tilt angle similar to that of the rubbing method (Table 3 on page 198 of Document I).
[0005]
[Problems to be solved by the invention]
However, in the case of the technique disclosed in Document I, it is necessary to scan a certain type of polymer with a polarized laser beam. Since the laser beam is scanned, the alignment film formation time becomes long.
[0006]
The reason why a polarized laser beam is used in the prior art is that there is currently no technology that can collectively expose polarized light over a wide area.
[0007]
A novel method that can easily form an alignment film and a novel exposure apparatus that can collectively expose polarized light in a wide area are desired.
[0008]
[Means for Solving the Problems]
Therefore, the inventors of this application have made various studies. As a result, attention has been paid to the fact that certain types of diffraction gratings mainly reflect the first polarized light (S-polarized light or P-polarized light) in the light when it is irradiated with light. Then, it was thought that this reflected light could be used as polarized light required when forming an alignment film from a material whose part shows a function as an alignment film for liquid crystal when irradiated with polarized light.
[0009]
  First, reference examples for understanding the present invention will be described. This reference exampleAccording to the method for forming an alignment film, a material that exhibits a function as an alignment film for liquid crystal when irradiated with polarized light.,sideIn the method of forming an alignment film by irradiating light, the light from the light source is irradiated to the reflective diffraction grating that mainly reflects the first polarized light.TimeThe light reflected by the folded lattice, AntiLightMaterialIrradiate the feeThe
[0010]
  In addition, thisReference exampleIn this case, “reflecting mainly the first polarized light” means including both the case where only the first polarized light is reflected, the case where the second polarized light is reflected to some extent, but the case where the first polarized light is mainly reflected (hereinafter referred to as “the first polarized light”). The same).
[0011]
  thisReference exampleAccording to the method for forming an alignment film, the reflected light reflected from a predetermined diffraction grating is used as polarized light for forming the alignment film.
[0012]
The reflected light from the predetermined diffraction grating is light having a sufficiently wide exposure range as compared with the laser beam. Accordingly, the area in which the polarized light can be exposed at once is increased, so that the formation time of the alignment film can be shortened.
[0013]
The fact that collective exposure is possible also means that selective exposure through a photomask is possible. Then, for example, when sequentially exposing a plurality of exposure areas adjacent to each other in a minute area, exposure can be sequentially performed by changing the polarization direction of exposure light for each exposure area as necessary. Therefore, it is considered that a state in which two or more polarization directions are mixed in a display region where the liquid crystal cell is present (so-called multi-domain) can be easily generated.
[0014]
  Here, as a means for generating polarized light, there is also a transmission type polarizing means. However, a transmissive polarizing means having a relatively large area is generally a dichroic polymer film. Such a polarizing means is considered to easily cause, for example, light degradation. On the other hand, thisReference exampleIn this forming method, polarized light is generated by a reflective diffraction grating. Since this reflection type diffraction grating is basically formed by forming a large number of grooves on the base so that these grooves are arranged at a predetermined pitch, it is easy to form the reflection diffraction grating with a strong material. Therefore, thisReference exampleThen, it is considered that the light deterioration of the polarizing means (reflection type diffraction grating) hardly occurs.
[0015]
Further, while it is difficult to obtain a transmission type polarization means for ultraviolet light, a reflection type diffraction grating realizes a diffraction grating that gives polarized light to ultraviolet light (for example, Milton Roy (USA) Diffraction grating manufactured by MILTON ROY), details will be described later. On the other hand, there are materials that are sensitive to ultraviolet light when the polarized light is irradiated so that the portion exhibits a function as an alignment film for the liquid crystal. Moreover, considering the use of technology cultivated in exposure apparatuses for semiconductor devices and liquid crystal devices in the construction of a new exposure apparatus for forming an alignment film (invention of an exposure apparatus described later), as a light source It is considered that a light source having a proven track record in these conventional exposure apparatuses, that is, a light source mainly emitting ultraviolet light such as an ultrahigh pressure mercury lamp is used. For this reason, it is considered preferable to use a reflective diffraction grating.
[0016]
  Also thisReference exampleExposure equipmentIn placeAccording to the light source,lightAn exposure apparatus comprising one or more reflecting means for guiding light emitted from a source to an object to be exposed1At least one of the reflecting means described above is composed of a reflective diffraction grating that mainly reflects the first polarized light.CompleteThe
[0017]
  thisReference exampleExposure equipment(Less than,Reference exampleExposure equipmentCalled) Realizes an exposure apparatus capable of performing batch exposure of polarized light in a wide exposure area.
[0018]
  Here, as a means for generating polarized light, there is also a transmission type polarizing means. However, a transmissive polarizing means having a relatively large area is generally a dichroic polymer film. Such a polarizing means is considered to easily cause, for example, light degradation. On the other hand, thisReference exampleExposure equipmentIn placeIncludes a reflective diffraction grating as a means for generating polarized light. Since this reflection type diffraction grating is basically formed by forming a large number of grooves on the base so that these grooves are arranged at a predetermined pitch, it is easy to form the reflection diffraction grating with a strong material. for that reason,Reference exampleExposure equipmentIn placeIt is considered that light deterioration of the polarizing means (reflection type diffraction grating) hardly occurs. Therefore, it is considered that an exposure apparatus with high durability can be realized.
[0019]
In addition, it is difficult to obtain a transmission type polarization means for ultraviolet light, whereas a reflection type diffraction grating realizes a diffraction grating that gives polarized light to ultraviolet light (for example, Milton Roy (USA) Diffraction grating manufactured by MILTON ROY), details will be described later. On the other hand, there are materials that are sensitive to ultraviolet light when the polarized light is irradiated so that the portion exhibits a function as an alignment film for the liquid crystal. Moreover, considering the use of the technology that has been cultivated in exposure apparatuses for semiconductor devices and liquid crystal devices in the construction of new exposure apparatuses for forming alignment films, these conventional exposure apparatuses are high in light source. It is preferable to use a light source having a track record, that is, a light source mainly emitting ultraviolet light such as a high-pressure mercury lamp. From this point of view, it is considered preferable to realize an exposure apparatus using a reflective diffraction grating.
[0020]
  The conventional typical exposure apparatus includes a multi-lens lens that has a large number of individual lenses that guide light from a light source toward the object to be exposed, and that outputs light so that the light emitted from the individual lenses overlap. The light source. In such an exposure apparatus,Reference exampleExposure equipmentPlaceIn the case of application, a reflective diffraction grating that mainly reflects the first polarized light in the light from the light source and guides it to the multi-lens lens is provided between the light source and the multi-lens lens. Is preferredThus, the exposure apparatus having this configuration is the first invention of this application.
[0021]
The multi-lens lens here is a known optical component called an integrator or a fly's eye lens. Typically, it is a lens group in which a plurality of fly-eye lenses and the like are combined. It is an optical component for uniformly irradiating an object to be exposed with light from a light source.
[0022]
In this preferred example, the reflective diffraction grating that mainly reflects the first polarized light is located on the input side of the multi-lens lens. Then, the diffraction grating does not directly affect the light emitted from the multi-lens lens. Therefore, there is little risk of impairing the above functions of the multi-lens lens. In general, the reflecting means is provided on the light source side so that the area of the reflecting means itself is small. This means that the area of the diffraction grating itself can be reduced. It is considered that the diffraction grating can be easily manufactured and the price can be reduced.
[0023]
  In this application, the invention of the following exposure apparatus (hereinafter referred to as the second invention of the exposure apparatus).ToiYeah. )TheInsist.
[0024]
That is, an exposure apparatus comprising a multi-lens lens that has a large number of individual lenses that guide light from the light source toward the object to be exposed and outputs light so that the light emitted from the individual lenses overlaps, and the light source In addition, an exposure apparatus including a transmission type polarization unit that mainly transmits first polarized light between the light source and the multi-lens lens is also claimed.
[0025]
In the present invention, mainly transmitting the first polarized light includes both transmitting only the first polarized light and transmitting the second polarized light to some extent but transmitting mainly the first polarized light. Yes (hereinafter the same).
[0026]
In the second aspect of the exposure apparatus, transmissive polarization means is used, but it is provided on the input side of the multi-lens lens, so that it can be relatively small. For this reason, it is considered that a polarizing means that is relatively less susceptible to light degradation can be used even if it is a transmission type. For example, a polarizing means using a crystal.
[0027]
Further, since the transmission type polarization means is provided on the input side of the multi-lens lens, the transmission type polarization means does not directly affect the light emitted from the multi-eye lens. Therefore, there is little risk of impairing the function of the multi-lens lens.
[0028]
In carrying out the second invention of the exposure apparatus, the transmission type polarization means may be a polarization means common to all the individual lenses included in the multi-lens type lens. However, the transmission type polarization means may be used for each individual lens. It is preferable to configure a polarizing element group in which the elements are opposed to each other. In this way, each polarizing element can be small. Large-size and high-performance transmission-type polarizing elements are difficult to obtain, but small-size transmission-type polarizing elements are easy to obtain. This preferred example is considered to enable the realization of an exposure apparatus using a transmission type polarizing means with good performance.
[0029]
In implementing the first and second aspects of the exposure apparatus, the light source provided in the exposure apparatus can be any light source that emits light having a wavelength required by the object to be exposed. However, the light source is preferably a light source that mainly emits ultraviolet rays. (1): It is expected that the material that exhibits a function as an alignment film for liquid crystal when irradiated with polarized light is expected to be mainly sensitive to ultraviolet light; (2): For semiconductor devices This is because, for example, it is preferable to use an ultraviolet light source having a proven track record in these conventional exposure apparatuses as a light source, considering the use of the technology cultivated in exposure apparatuses for liquid crystal devices. Examples of the ultraviolet light source include a discharge lamp lamp, specifically, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a Mercury xenon lamp, and the like.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
  Referring to the drawings belowReference examples andEmbodiments of each invention of this application will be described. However, the drawings used in the description are merely schematically shown so that the present invention can be understood. Moreover, in each figure used for description, about the same component, the same number is attached | subjected and the duplicate description may be abbreviate | omitted.
[0031]
  1. Explanation of reflection type diffraction grating and explanation of formation method of alignment film
  First,Reference exampleOf alignment filmLawAndReference exampleExposure equipmentNosoThe reflection type diffraction grating used in each will be described.
[0032]
  theseReference exampleExamples of the reflection type diffraction grating that can be used in (1) include a diffraction grating manufactured by Milton Roy (USA). Specific examples include a diffraction grating described in the company's catalog and referred to as serial number 5185-1-1 and a diffraction grating referred to as serial number 5188 / FZ10.
[0033]
It is described in the catalog that a diffraction grating called serial number 5185-1-1-1 is a diffraction grating having grooves at a density of 2400 lines / mm. On the other hand, it is described in the catalog that the diffraction grating called serial number 5188 / FZ10 is a diffraction grating having a density of 3600 grooves / mm.
[0034]
The reflection characteristics of the former diffraction grating are as shown in FIG. The reflection characteristics of the latter diffraction grating are as shown in FIG.
[0035]
1 and 2 show the reflection characteristics of the diffraction grating cited from the catalog. It is the figure which showed the wavelength dependence of the reflectance of each of S polarized light and P polarized light, with the wavelength (μm) on the horizontal axis and the reflectance (%) on the vertical axis. However, the reflection characteristics when the light irradiation object is aluminum are also shown as a comparative example.
[0036]
1 and 2, S is the wavelength dependence of the reflectance of S-polarized light at the diffraction grating, and P is the wavelength dependence of the reflectance of P-polarized light at the diffraction grating. Moreover, AL in FIG. 1, FIG. 2 is an above-described comparative example (reflection characteristic with respect to aluminum).
[0037]
1 and 2, it can be understood that the above-described diffraction grating can be a reflective diffraction grating that mainly reflects the first polarized light (S-polarized light or P-polarized light) according to the wavelength of incident light.
[0038]
Specifically, in the case of the former diffraction grating, as can be seen from FIG. 1, the reflectance for P-polarized light near the wavelength of 0.3 μm is about 90%, whereas the reflectance for S-polarized light near the same wavelength is about 90%. Is only about 30%. Furthermore, while the reflectance for P-polarized light in the vicinity of a wavelength of 0.5 to 0.7 μm is only about 35 to 10%, the reflectance for S-polarized light in the vicinity of the same wavelength is 90% or more.
[0039]
In the case of the latter diffraction grating, as can be seen from FIG. 2, the reflectance for P-polarized light near the wavelength of 0.25 μm is about 80%, whereas the reflectance for S-polarized light near the wavelength is about several percent. Only it is. Furthermore, while the reflectance for P-polarized light near the wavelength of 0.4 to 0.5 μm is only about 30 to 10%, the reflectance for S-polarized light near the wavelength is 90% or more.
[0040]
From this point, when the above diffraction grating is irradiated with light from a light source such as an ultra-high pressure mercury lamp to generate reflected light from the diffraction grating, the reflected light is converted into light mainly composed of the first polarized light. It is considered to be.
[0041]
The light from the light source is preferably irradiated through a suitable filter. This is because light having a large reflectance ratio of P-polarized light and S-polarized light can be selectively irradiated onto the diffraction grating.
[0042]
  On the other hand, the alignment film may be formed as follows, for example.
  For example, a film of a certain polymer (proprietary polymer in Document I) disclosed in Document I (Mol. Cryst. Liq. Cryst. 1994, Vol. 251, pp. 191-208) is formed on a suitable substrate. To do. Against this membrane, TimesIrradiate light reflected from the folded lattice. AntiBecause the incident light is mainly the first polarized lightAnti-membraneIt is considered that the portion irradiated with the incident light becomes an alignment film.
[0043]
When irradiating the reflected light, it is possible to irradiate through a photomask having a predetermined portion as a light transmission window. In this way, selective exposure can be easily performed.
[0044]
According to this method for forming an alignment film, polarized light can be collectively irradiated over a wide area, so that the time for forming the alignment film can be shortened compared to the case where a laser beam is used.
[0045]
  2.Example exposure apparatus andDescription of the first aspect of the exposure apparatus
  Here, the first embodiment of the exposure apparatus of the reference example, the first embodiment of the first invention of the exposure apparatus, the second embodiment of the exposure apparatus of the reference example, and the first of the exposure apparatus A second embodiment of the invention will be described respectively.
[0046]
    2-1.Of the exposure system of the reference exampleFirst embodiment
  FIG. 3 is a view showing one example of a typical exposure apparatus. It is the figure which quoted the exposure apparatus disclosed by literature II ("Electronic material", an industrial research meeting issue, the July, 1995 issue separate volume, p. 95). This apparatus is described as a proximity exposure type exposure apparatus in Document II.
[0047]
The exposure apparatus includes an ultrahigh pressure mercury lamp 11 as a light source, an elliptic concave mirror 13, a first reflecting means 15, a collimator 17, an integrator (flying eye lens) 19 as a multi-lens lens, and a second reflection. Means 21 and a condenser lens 23 are provided. In FIG. 3, reference numeral 25 denotes an object to be exposed.
[0048]
The elliptic concave mirror 13 is provided in the vicinity of the light source 11. The elliptic concave mirror 13 has a function of collecting the light of the ultrahigh pressure mercury lamp 11 in the direction of the first reflecting means 15.
[0049]
The first reflecting means 15 is disposed so as to face the elliptic concave mirror 13 at a predetermined angle. The first reflecting means 15 is one of the reflecting means for guiding the light from the light source 11 and the ellipsoidal concave boundary 13 to the object to be exposed 25, and here the light from the light source 11 is the second reflecting means 21. It has the function of reflecting in the direction of.
[0050]
The collimator 17 and the multi-lens lens 19 are provided between the first reflecting means 15 and the second reflecting means 21 in the order of the collimator 17 and the multi-lens lens 19 from the first reflecting means 15 side. .
[0051]
As described above, the multi-lens lens 19 has a number of individual lenses and has a function of outputting light so that light emitted from the individual lenses overlaps each other (see FIG. 8). When the multi-lens lens 19 is used, the light from the light source 11 can be evenly applied to the object to be exposed 25.
[0052]
The second reflecting means 21 has a function of guiding the light exiting the light source 11 and passing through the first reflecting means 15 and the like to the object to be exposed 25.
[0053]
The condenser lens 23 is provided between the second reflecting means 21 and the object to be exposed 25.
[0054]
In the case of this exposure apparatus, at least one of the first reflecting means 15 and the second reflecting means 21 has been described with reference to a reflective diffraction grating that mainly reflects the first polarized light, for example, FIG. 1 or FIG. It is preferable to use a diffraction grating. Which of the first reflecting means 15 and the second reflecting means 21 is constituted by a reflective diffraction grating that mainly reflects the first polarized light (hereinafter also referred to as “predetermined diffraction grating”)? Can be determined by design. A specific example will be described below.
[0055]
The first reflecting means 15 is generally smaller in area than the second reflecting means 21. Therefore, when the first reflecting means 15 is composed of a predetermined diffraction grating, there is an advantage that the predetermined diffraction grating needs only a small area. In this case, since the predetermined diffraction grating is located on the input side of the multi-lens lens 19, it is possible to prevent the predetermined diffraction grating from affecting the output light of the multi-lens lens. From these facts, the idea that the reflecting means (herein, the first reflecting means 15) closest to the light source 11 is constituted by a predetermined diffraction grating is also one suitable for designing the exposure apparatus of the present invention. It is a technique.
[0056]
Here, when the first reflecting means 15 is constituted by a predetermined diffraction grating, the polarized light generated by the predetermined diffraction grating reaches the object to be exposed after passing through the multi-lens lens 19 or the like. Inventor's experiment concerning this application has confirmed that the polarization is preserved (for details, see later examples).
[0057]
  Further, the second reflecting means 21 may be constituted by a predetermined diffraction grating. This is also because polarized light can be supplied to a wide area. Therefore, the idea that the reflecting means (herein, the second reflecting means 21) located closest to the object to be exposed 25 is constituted by a predetermined diffraction grating is also considered.Reference exampleIt can be said that this is one suitable method for designing the exposure apparatus.
[0058]
However, when the second reflecting means 21 is constituted by a predetermined diffraction grating, the predetermined diffraction grating is positioned on the output side of the multi-lens lens. Therefore, when the reflectance distribution of a predetermined diffraction grating is not good, the function of the multi-lens lens may be impaired. The reflecting means located near the object to be exposed 25 generally has a large area. Then, the predetermined diffraction grating needs to have a large area. The predetermined diffraction grating becomes expensive as the area increases. These points are limiting factors.
[0059]
Of course, both the first reflecting means 15 and the second reflecting means 21 may be constituted by a predetermined diffraction grating.
[0060]
  In the above description, an example in which at least one of the existing reflecting means 15 and 21 is replaced with a predetermined diffraction grating has been described. However, in addition to the existing reflecting means, the idea of newly providing a reflecting means constituted by a predetermined diffraction grating at a suitable position is also considered.Reference exampleOf course, it is included in the range (same in the following embodiments).
[0061]
Further, the configuration of the reflecting means with a predetermined diffraction grating includes the case where a diffraction grating is added as in the case where the predetermined diffraction grating is mounted on the existing reflecting means (in the following embodiments). the same).
[0062]
    2-2.Of the first invention of the exposure apparatusFirst1Embodiment
  FIG. 4 is a view showing another example of a typical exposure apparatus. It is the figure which quoted the exposure apparatus disclosed by literature II ("Electronic material", an industrial research meeting issue, the July, 1995 issue separate volume, the 96th page). This is an apparatus described in Document II as an exposure apparatus using a lens stepper division exposure system.
[0063]
In the case of this exposure apparatus, the configuration is almost the same as that in FIG. Specifically, an ultrahigh pressure mercury lamp 11, an elliptic concave mirror 13, a first reflecting means 15, an integrator 19 as a multi-lens lens, a second reflecting means 21, and a condenser lens 23 are provided. . Further, since this apparatus is a stepper type apparatus, it includes a reticle mounting base 27 and a projection lens 29.
[0064]
Also in the case of the exposure apparatus described with reference to FIG. 4, at least one of the first and second reflecting means 15 and 21 is constituted by a predetermined diffraction grating, or a new reflection using a predetermined diffraction grating. Means are provided at any suitable location. By doing so, the exposure apparatus of the present invention can be configured.
[0065]
Which of the first and second reflecting means 15 and 21 is a predetermined diffraction grating may be determined based on the same concept as described in the case of the exposure apparatus described with reference to FIG.
[0066]
    2-3.Of the exposure system of the reference exampleFirst2Embodiment
  FIG. 5 is a view showing still another example of a typical exposure apparatus. It is the figure which quoted the exposure apparatus disclosed by literature II ("Electronic material", an industrial research meeting issue, the July, 1995 issue separate volume, p. 97). This apparatus is described as a mirror projection exposure apparatus in Document II.
[0067]
This device includes a trapezoidal mirror 31 having first and second reflecting surfaces 31 a and 31 b, a concave mirror 33, and a convex mirror 35. In FIG. 5, reference numeral 37 denotes a photomask mounting table.
[0068]
The trapezoidal mirror 31 has a first reflecting surface 31a facing a light source (not shown) at a predetermined angle, and a second reflecting surface 31a facing the object to be exposed 25 at a predetermined angle. It is arranged.
[0069]
The concave mirror 33 is disposed so as to face the first and second reflecting surfaces 31 a and 31 b of the trapezoidal mirror 31.
[0070]
The convex mirror 35 is provided between the trapezoidal mirror 31 and the concave boundary 33. In addition, the trapezoidal mirror 31 and the concave boundary 33 are smaller lenses. In addition, the convex boundary 35 is arranged so that light travels along the path of the first reflecting surface 31a, the concave boundary 33, the convex mirror 35, and the concave mirror 33 and the second reflecting surface 31b again.
[0071]
  In the case of the exposure apparatus described with reference to FIG. 5, the first reflecting surface 31 a of the trapezoidal mirror 31, the second reflecting surface 31 b of the trapezoidal mirror 31, the concave boundary 33, and the convex boundary 35 among the respective reflecting means. At least one is constituted by a predetermined diffraction grating, or new reflecting means using the predetermined diffraction grating is provided at any suitable position. By doing this, thisReference exampleThe exposure apparatus can be configured.
[0072]
However, preferably, one of the first reflecting surface 31a and the second reflecting surface 31b of the trapezoidal mirror 31 is configured by a predetermined diffraction grating. It is considered that a predetermined diffraction grating having a concave shape or a convex shape can also be manufactured. However, it is considered that a predetermined diffraction grating having a planar shape is easier to manufacture and cheaper. More preferably, the second reflecting surface 31b of the trapezoidal mirror, that is, the reflecting means located closest to the object to be exposed may be constituted by a predetermined diffraction grating. This is because it is considered that polarized light in a better state can be obtained.
[0073]
    2-4.Of the first invention of the exposure apparatusFirst2Embodiment
  FIG. 6 is a view showing still another example of a typical exposure apparatus. The exposure apparatus includes a light source 11, an elliptic concave mirror 13, a first reflecting means 15, an integrator 19 as a multi-lens lens, and a second reflecting means 21a having a curvature. In FIG. 6, reference numeral 39 denotes a photomask. As is well known, since the second reflecting means 21a having a curvature is provided, the condenser lens can be omitted.
[0074]
In the case of the exposure apparatus described with reference to FIG. 6, at least one of the first and second reflecting means 15 and 21a is constituted by a predetermined diffraction grating, or a new reflection using a predetermined diffraction grating. Means are provided at any suitable location. By doing so, the exposure apparatus of the present invention can be configured.
[0075]
Which of the first and second reflecting means 15 and 21a is a predetermined diffraction grating may be determined based on the same concept as described in the case of the exposure apparatus described with reference to FIG.
[0076]
However, in this case, it is preferable that the first reflecting means 15 is composed of a predetermined diffraction grating for another reason described below. The second reflecting means 21a has a curvature. It is considered that a predetermined diffraction grating having a curvature can also be manufactured, but a flat predetermined diffraction grating is considered to be easier to manufacture and cheaper.
[0077]
3. Description of the second invention of the exposure apparatus
Next, a second invention of the exposure apparatus will be described. According to a second aspect of the present invention, there is provided an exposure apparatus comprising a light source and a multi-lens lens, wherein the exposure apparatus comprises a transmission type polarization means that mainly transmits the first polarized light between the light source and the multi-lens lens. It is invention characterized by these.
[0078]
An embodiment of the second invention of the exposure apparatus will be described with reference to FIG. FIG. 7 is a diagram in which the second invention is applied to the proximity exposure type exposure apparatus disclosed in Document II (“Electronic Materials”, published by the Industrial Research Council, July 1995 issue, page 95). .
[0079]
The exposure apparatus according to the second aspect of the present invention includes an ultrahigh pressure mercury lamp 11 as a light source, an elliptic concave mirror 13, a first reflecting means 41, a collimator 17, an integrator 19 as a multi-lens lens, and a second reflection. Means 43 and condenser lens 23 are provided. Furthermore, the exposure apparatus of the second aspect of the present invention further includes a transmission type polarization means 45 that mainly transmits the first polarized light between the light source 11 and the multi-lens lens 19.
[0080]
In the example of FIG. 7, the polarizing means 45 is provided between the multi-lens lens 19 and the collimator 17 and in the vicinity of the multi-lens lens 19.
[0081]
Here, the arrangement of each of the ultrahigh pressure mercury lamp 11, the elliptic concave mirror 13, the first reflecting means 41, the collimator 17, the multi-lens lens 19, the second reflecting means 43, and the condenser lens 23 is the configuration described with reference to FIG. Same as the ingredients.
[0082]
However, in the exposure apparatus described with reference to FIG. 3, at least one of the first reflecting means 15 and the second reflecting means 21 is constituted by a predetermined diffraction grating. In the case of this second invention, the first The reflecting means 41 and the second reflecting means 43 are constituted by reflecting means used in a conventional exposure apparatus.
[0083]
As the polarizing means 45, any suitable polarizing means can be used as long as it mainly transmits the first polarized light of the light from the light source 11. For example, a transmissive polarizing plate having the same area as or larger than the multi-lens lens 19 can be used.
[0084]
According to the second aspect of the exposure apparatus, the light emitted from the light source 11 is converted into linearly polarized light by the polarizing means 45. The polarized light reaches the object to be exposed 25. Therefore, an exposure apparatus that can perform exposure with polarized light is realized.
[0085]
The polarizing means 45 may be disposed between the collimator 17 and the multi-lens lens 19 and on the collimator 17 side. Alternatively, it may be arranged between the first reflecting means 41 and the collimator.
[0086]
The idea of the second invention of the exposure apparatus can also be applied to the exposure apparatus described with reference to FIG. 4 and the exposure apparatus described with reference to FIG. In either case, the transmissive polarizing means 45 is provided at a suitable position between the multi-lens lens 19 and the light source 11, for example, at a position near the multi-lens lens 19.
[0087]
In the above description, it has been described that the polarizing means 45 is composed of a polarizing plate having an area equal to or larger than that of the multi-lens lens 19, but is not limited to this example. FIG. 8 is a diagram for explaining another configuration example of the polarization unit 45.
[0088]
As is well known, the multi-lens lens 19 referred to as an integrator or the like is a lens that has a large number of individual lenses 19a and outputs light so that the lights emitted from the individual lenses 19a overlap each other. Therefore, the polarizing elements 45a are arranged to face each other directly or with a gap between the input side end faces of the individual lenses 19a. The group of the polarizing elements 45a constitutes the polarizing means 45.
[0089]
It is difficult to obtain a transmission type polarizing means having a large size and good characteristics. On the other hand, it is considered that a transmission type polarizing element having good characteristics is easily available if it is small. In the case where the polarizing means 45 is constituted by a group of polarizing elements 45a, it is considered that a transmissive polarizing element having a small size and good characteristics can be adopted.
[0090]
【Example】
Next, experimental results suggesting that an exposure apparatus capable of exposure by polarized light can be realized by using a diffraction grating that mainly reflects the first polarized light will be described. FIG. 9 is a view for explaining the exposure apparatus and measurement system used in this experiment.
[0091]
An exposure apparatus including a light source 11, an elliptic concave mirror 13, a first reflecting means 15, a multi-lens lens 19, a second reflecting means 21, and a condenser lens 23 was prepared.
[0092]
However, a part of the first reflecting means 15 is a diffraction grating called 5185-1-1 manufactured by MILTON ROY and having a size of 50 mm × 50 mm (in FIG. 1). Installed one with reflective characteristics. The diffraction grating was mounted so that the longitudinal direction of the groove was the P direction in FIG.
[0093]
Further, the region (indicated by Q in FIG. 9) that was not covered with the diffraction grating of the first reflecting means 15 was covered with aluminum (not shown). This is to prevent the reflected light from being generated from the region Q of the first reflecting means 15 that could not be covered by the diffraction grating.
[0094]
In addition, a light receiving element 51 is installed at a place where an object to be exposed is placed, and an analyzer 53 is installed slightly above the light receiving element 51. In FIG. 9, reference numeral 55 denotes a shutter mechanism that blocks light from the light source as necessary.
[0095]
As the light source 11, an ultrahigh pressure mercury lamp having an output of 250 W was used. In addition, since the light receiving element 51 and the analyzer 53 were not used for ultraviolet light here, a light receiving element having a main sensitivity at a wavelength of 436 nm and an analyzer capable of mainly examining polarized light near the wavelength of 436 nm were used. .
[0096]
The light intensity detected by the light receiving element when the polarization direction of the polarized light generated by the first reflecting means 15 (predetermined diffraction grating) and the analyzer 53 are in parallel (first state) is expressed as 100. I thought. Then, when the analyzer 53 was rotated 90 degrees with respect to the first state, the light intensity detected by the light receiving element 51 decreased to 15.
[0097]
Further, when the same experiment was performed by moving the light receiving element 51 and the analyzer 53 to a plurality of different positions in the exposure region, the same result as described above was obtained.
[0098]
As is clear from this experiment, when the first reflecting means 15 is constituted by a predetermined diffraction grating, polarized light can be obtained, and this polarized light can be preserved even if a multi-lens lens or the like exists in the middle. I understand. Further, it can be seen that uniform polarized light can be obtained over the entire exposure region.
[0100]
【The invention's effect】
  As is clear from the above description,According to the first invention of the exposure apparatus of this application,In an exposure apparatus including a light source and a multi-lens lens such as a fly-eye lens, a reflective diffraction grating that mainly reflects the first polarized light is provided between the light source and the multi-lens lens. Therefore, the area of the reflecting means itself can be small, and the area of the diffraction grating itself can be reduced. Therefore, the diffraction grating can be easily manufactured and the price can be reduced.
[0101]
According to the second invention of the exposure apparatus of this application, in the exposure apparatus including a light source and a multi-lens lens such as a fly-eye lens, the first polarized light is provided between the light source and the multi-lens lens. Transmissive polarization means that mainly transmits the light. For this reason, the exposure apparatus which can expose a wide area | region by polarized light is realizable.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram (part 1) of a reflective diffraction grating that mainly reflects first polarized light, and shows reflection characteristics;
FIG. 2 is an explanatory diagram (part 2) of a reflective diffraction grating that mainly reflects second polarized light, and shows reflection characteristics;
[Fig. 3]Reference exampleExposure equipmentThe firstIt is explanatory drawing of 1 embodiment.
FIG. 4 shows the first aspect of the first aspect of the exposure apparatus.1It is explanatory drawing of this embodiment.
[Figure 5]Reference exampleExposure equipmentSecond ofIt is explanatory drawing of this embodiment.
FIG. 6 shows the first aspect of the first aspect of the exposure apparatus.2It is explanatory drawing of this embodiment.
FIG. 7 is an explanatory view of an embodiment of the second invention of the exposure apparatus.
FIG. 8 is a main part explanatory view of another embodiment of the second invention of the exposure apparatus;
FIG. 9 is an explanatory diagram of an embodiment, and is a diagram for explaining an exposure apparatus and a measurement system used in an experiment.
[Explanation of symbols]
  11: Light source (eg ultra-high pressure mercury lamp)
  13: Elliptical concave mirror
  15: First reflecting means (diffraction grating mainly reflecting the first polarized light)
  17: Collimator
  19: Multi-lens lens
  19a: Individual lens
  21: Second reflecting means
  23: Condenser lens
  25: Object to be exposed
  45: Polarizing means that mainly transmits the first polarized light
  45a: Polarizing element

Claims (4)

In an exposure apparatus comprising a multi-lens lens that has a large number of individual lenses that guide light from the light source toward the object to be exposed and outputs light so that the light emitted from the individual lenses overlaps each other, and the light source,
A reflective diffraction grating that mainly reflects the first polarized light in the light from the light source and guides it to the multi-lens lens is provided between the light source and the multi-lens lens. Exposure equipment to do. In an exposure apparatus comprising a multi-lens lens that has a large number of individual lenses that guide light from the light source toward the object to be exposed and outputs light so that the light emitted from the individual lenses overlaps each other, and the light source,
An exposure apparatus comprising: a transmission type polarization unit that mainly transmits first polarized light between the light source and the multi-lens lens. The exposure apparatus according to claim 2 , wherein
An exposure apparatus characterized in that the polarizing means is a polarizing element group configured such that a transmissive polarizing element faces each of the individual lenses. In the exposure apparatus according to any one of claims 1 to 3 ,
An exposure apparatus characterized in that the light source is a light source that mainly emits ultraviolet rays.