JP2006220907A - Method for manufacturing electrooptical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an electrooptical device with which a reflective display is realized with desired directivity. <P>SOLUTION: In the method for manufacturing the electrooptical device, a substrate D for the electrooptical device is irradiated with exposure light L via a mask 10 having a mask pattern 11 composed of a light shielding portion and a light transmitting portion formed on a translucent member 10A so as to transfer an exposure pattern corresponding to the mask pattern 11 to the substrate D for the electrooptical device and to expose it, wherein the mask 10 has a lens portion 12 having curved faces C1, C2 arranged on a face of the translucent member 10A opposite to the face where the mask pattern 11 is formed, and the method for manufacturing the electrooptical device is characterized by transferring the exposure pattern corresponding to the mask pattern 11 to the substrate D for the electrooptical device via the lens portion 12 and exposing it. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an electro-optical device.

In recent years, in a liquid crystal device that is one of the electro-optical devices, a reflective liquid crystal device that displays an image using external light, or a transflective type that displays an image using both external light and illumination light A liquid crystal device is known. As a structure of such a liquid crystal device, a resin layer having a concavo-convex surface is formed at a portion where reflection display is performed, and a reflection film made of a metal film such as aluminum covering the resin layer is further formed. (For example, refer to Patent Document 1). By adopting such a configuration, a reflective film having an uneven surface is formed, and a light scattering function can be imparted to the reflective film.

On the other hand, a photolithography technique has been conventionally used as a circuit pattern forming method for semiconductor devices and various electro-optical devices (see, for example, Patent Document 2). This is a technique in which a mask is disposed between an exposure light source and a photosensitive member, and a mask pattern formed on the mask is transferred to the photosensitive member via a projection optical system.
JP 2003-177396 A JP-A-7-72429

By the way, there is a problem that the directivity of the reflected light with respect to the observer side cannot be obtained in the reflective or transflective liquid crystal device.
SUMMARY An advantage of some aspects of the invention is that it provides an electro-optical device manufacturing method capable of realizing reflective display with desired directivity.

The present inventor has adopted a configuration in which a reflective film is formed on a concavo-convex resin film in a reflective or transflective liquid crystal device, although the light scattering property is improved, but the reflected light is scattered irregularly. Therefore, attention was paid to the fact that the directivity toward the observer side could not be obtained. And, the present inventor cannot obtain such directivity of the reflected light, if the uneven shape of the resin film is uniform, the reflective film is formed in a uniform uneven pattern following this, Therefore, it has been found that incident light is scattered uniformly, and as a result, directivity cannot be obtained.
Therefore, the present inventor has come up with the present invention having the following means based on the above.

In other words, the electro-optical device manufacturing method of the present invention irradiates the electro-optical device substrate with exposure light through a mask having a mask pattern including a light-shielding portion and a light-transmitting portion formed on the light-transmitting member. Accordingly, an electro-optical device manufacturing method for transferring an exposure pattern corresponding to the mask pattern onto the electro-optical device substrate for exposure, wherein the mask pattern of the translucent member is formed on the mask. A lens portion having a curved surface on a surface opposite to the opposite surface, and exposing an exposure pattern corresponding to the mask pattern to the electro-optical device substrate via the lens portion. It is characterized by.
In the method of manufacturing the electro-optical device according to the aspect of the invention, the lens unit may have a curvature from the first point to the second point in a curve from the first point to the second point on the curved surface of the lens unit. It is preferable that the exposure pattern corresponding to the mask pattern is transferred to the electro-optical device substrate through at least a portion that is continuously different, and a portion in which the curvature is continuously different.
In the method of manufacturing the electro-optical device according to the aspect of the invention, the lens unit may include a portion in which the curvature of the curved surface is continuously different, and the exposure corresponding to the mask pattern according to the curvature. It is preferable that the pattern is distorted in density and irradiated to the electro-optical device substrate as the exposure light.

In the present invention, the substrate for an electro-optical device or the electro-optical device has an electro-optic effect that changes the light transmittance by changing the refractive index of a substance by an electric field, and converts electric energy into optical energy. It is a general term including things.
The mask pattern is provided on the side opposite to the side on which the lens portion is formed, and is provided on the exposure light incident side of the translucent member.
The lens portion is provided on the exposure light emitting side of the translucent member. As such a lens portion, a convex lens formed in a convex shape or a concave lens formed in a concave shape with respect to the electro-optical device substrate from the translucent member is employed.
The translucent member is made of a material having a refractive index different from that of the gas existing between the translucent member and the electro-optical device substrate.

In a mask having such a lens portion, when exposure light is irradiated from the mask pattern forming surface, the light shielding portion blocks the exposure light, and the light transmitting portion transmits the exposure light. As a result, an exposure pattern having the same size as the mask pattern is generated on the exposure light incident side of the translucent member. Furthermore, the exposure pattern is transmitted through the translucent member according to the traveling direction of the exposure light,
The light is emitted through the lens unit and transferred to the electro-optical device substrate through the gas.

Here, the exposure pattern emitted from the lens unit is refracted by the emission angle on the curved surface of the lens unit and transferred to the electro-optical device substrate. Moreover, since the lens unit has at least a portion where the curvature is continuously different from the first point to the second point on the curved surface, in other words,
It has at least a curvature gradient from the first point to the second point, and the exposure pattern can be transferred to the electro-optical device substrate with the exit angle from the curved surface formed according to the curvature gradient. In the exposure pattern transferred by the exposure light, the exposure pattern can be distorted and transferred at a portion where the emission angle of the exposure light is relatively large. Also,
Of the exposure pattern transferred by the exposure light, the exposure pattern can be distorted and transferred at a portion where the emission angle of the exposure light is relatively small.
Accordingly, since the lens portion has a predetermined curvature gradient from the first point to the second point, the exposure pattern can be distorted as desired and transferred to the electro-optical device substrate. Further, since the curvatures are continuously different, the exposure pattern can be transferred with continuously different distortions. In other words, the exposure pattern can be transferred with the density of the distortion of the exposure pattern.

When the lens unit is a convex lens, an exposure pattern having a size smaller than the mask pattern can be transferred to the electro-optical device substrate. Furthermore, in the case of the convex lens, the exposure light is refracted toward the apex side of the lens portion as the emission angle of the exposure light increases. Further, the smaller the exit angle of the exposure light, the more difficult it is to refract the exposure light. Therefore, as a whole of the exposure pattern, a portion having a larger emission angle is distorted.

When the lens portion is a concave lens, an exposure pattern having a size larger than the mask pattern can be transferred to the electro-optical device substrate. Further, in the case of the concave lens, the exposure light is refracted in a direction away from the apex of the lens portion as the exposure light exit angle is larger. Further, the smaller the exit angle of the exposure light, the more difficult it is to refract the exposure light. Therefore, as a whole of the exposure pattern, a portion having a larger emission angle is distorted.

In the present invention, it is necessary to adjust the scale of the width of the light shielding portion and the light transmitting portion without changing the scale of the mask pattern partially or forming the mask pattern in a distorted manner. However, the exposure pattern can be distorted and transferred to the electro-optical device substrate simply by providing the lens portion with the curved surface structure.

In general, the refractive index of a solid such as a translucent member is larger than the refractive index of a gas, but the lens portion is a convex lens under the condition that such a refractive index magnitude relationship is established. In some cases, the exposure light that passes through the periphery of the convex lens is refracted toward the center of the exposure pattern,
The exposure pattern can be transferred to the electro-optical device substrate. When the lens unit is a concave lens, the exposure light transmitted through the peripheral part of the concave lens can be refracted to the peripheral side of the exposure pattern, and the exposure pattern can be transferred to the electro-optical device substrate.

In the present invention, the mask may have a plurality of mask patterns. In this way, a plurality of exposure patterns corresponding to the plurality of mask patterns can be transferred to the electro-optical device substrate.

In the electro-optical device manufacturing method of the present invention, the electro-optical device substrate has a plurality of exposure regions on the same surface, and the mask has a plurality of exposure regions corresponding to the plurality of exposure regions. It has the mask pattern, and the exposure pattern is transferred to each of the plurality of exposed areas by collectively exposing the plurality of exposed areas through the mask. It is said.
In this way, the exposure pattern can be distorted as desired and transferred to the electro-optical device substrate. In addition, a plurality of exposure patterns corresponding to a plurality of mask patterns can be applied to a plurality of exposure patterns. It is possible to transfer to the area at once.

In the electro-optical device manufacturing method of the present invention, the electro-optical device substrate has a plurality of exposed regions on the same surface, and the structural unit of the plurality of exposed regions via the mask. It is characterized in that the exposure pattern is transferred to each of the plurality of exposed areas by sequentially performing exposure for each time a plurality of times.
According to the present invention, not only the same effects as in the above manufacturing method can be obtained, but also so-called step exposure can be realized.
Here, the “structural unit of a plurality of exposure target regions” means a region where an exposure pattern is transferred by one exposure, and the number of exposure target regions is one or more than the number of the plurality of exposure target regions. Means. In other words, among the plurality of exposure target areas, the exposure pattern is sequentially transferred for each exposure target area, or the exposure pattern is sequentially transferred for every two or three exposure target areas. Means.
Therefore, according to the present invention, the exposure pattern can be distorted as desired and transferred to the exposure object. Further, not only the effect can be obtained, but also the exposure pattern can be transferred to the entire exposure target region using a smaller number of mask patterns than the entire exposure target region on the exposure target.

In the electro-optical device manufacturing method of the present invention, on the electro-optical device substrate,
It is characterized in that a photosensitive member is formed in advance.
In the present invention, it is preferable to perform development and baking after exposing the electro-optical device substrate.
Here, a positive type or a negative type is adopted as the photosensitive member. Therefore, only the portion irradiated with the exposure light can be removed or thinned, or can be left or thickened. In addition, the thin film and thick film said here mean the relative film thickness between both.

When the exposure pattern is transferred to the photosensitive member formed on the electro-optical device substrate and developed, the photosensitive member is exposed from the boundary between the photosensitive portion and the non-photosensitive portion of the photosensitive member. Is dissolved, and a convex portion is formed according to the photosensitive portion or the non-photosensitive portion, and the convex portion is formed with different curvatures of the curved surface according to the density of the exposure pattern. Thereby, the convex part pattern which consists of a photosensitive member is formed.
Here, in the exposed portion where the exposure pattern is dense, the convex pattern is dense, that is, the gap between the convex portions is small, and flattening is likely to occur after firing. As a result, a convex portion having a curved surface with a small curvature is formed. In addition, by forming the reflection portion on the surface having a small curvature, reflected light with a small reflection angle is likely to be generated.
Further, in the portion exposed by the sparse exposure pattern, the convex pattern becomes sparse, that is, the gap between the convex portions becomes large, and flattening hardly occurs after baking. As a result, a convex portion having a large curvature is formed. In addition, since the reflection portion is formed on the surface having the large curvature, reflected light having a large reflection angle is easily generated.
Further, in the portion where the exposure pattern is continuously dense to sparse, the convex pattern gradually becomes sparse, that is, the gap between the convex portions gradually increases, and the flatness is continuously after baking. It is falling. As a result, a plurality of convex portions whose curvature is continuously increased are formed. In addition, the reflection angle is continuously increased by forming the reflection portion in the portion where the curvature is continuously increased.

In the electro-optical device manufacturing method of the present invention, an electro-optical device substrate and a counter substrate facing each other, and an electro-optical element sandwiched between the electro-optical device substrate and the counter substrate are provided. In the method of manufacturing an optical device, the electro-optical device substrate includes a reflecting portion that reflects incident light incident from the counter substrate side. By using the manufacturing method described above, It is preferable to form a reflection part.

Here, the reflecting portion is constituted by a concavo-convex member whose surface is formed in a concavo-convex shape and a light reflecting member formed on the concavo-convex member. The concavo-convex member has a concavo-convex pattern corresponding to the mask pattern, and is formed by the manufacturing method described above.
The light reflecting member is formed following the surface of the concavo-convex member. Thereby, the reflection part has both light reflectivity and light scattering properties.
And this invention can implement | achieve a suitable uneven | corrugated member by utilizing said manufacturing method.

Specifically, the above manufacturing method uses a lens portion having at least a curvature gradient from the first point toward the second point. Accordingly, the exposure pattern can be transferred to the electro-optical device substrate at an emission angle from the curved surface corresponding to the curvature gradient, and the exposure pattern distorted as desired can be transferred to the electro-optical device substrate. Further, since the curvature is continuously different, the exposure pattern can be transferred by continuously varying the distortion of the exposure pattern, and the distortion of the exposure pattern can be generated.

Then, by using this manufacturing method, when exposure light is irradiated through the mask pattern that is the original image of the concavo-convex member, the exposure pattern corresponding to the mask pattern is transferred onto the photosensitive member, and the photosensitive member's photosensitivity. An uneven member corresponding to (positive / negative) is formed. here,
By performing exposure with the lens unit, an exposure pattern in which distortion is continuously generated can be transferred to the concavo-convex member. That is, an uneven pattern corresponding to the distortion of the exposure pattern is formed on the uneven member. Then, in consideration of the directivity of the reflection portion, the reflection portion having a desired reflection characteristic can be formed by performing exposure using a lens portion having a predetermined curvature. Furthermore, in the present invention, it is not necessary to adjust the scales of the light shielding part and the light transmitting part in the mask pattern, and it is possible to form a reflective film having a desired directivity only by changing the curvature of the lens part. .

Hereinafter, a method for manufacturing an electro-optical device according to the invention will be described with reference to the drawings.
In each drawing, the thicknesses and dimensional ratios of the components are appropriately changed in order to make the drawings easy to see. Moreover, in each embodiment, the same code | symbol is attached | subjected to the same structure and detailed description is abbreviate | omitted.

(First Embodiment of Mask)
FIG. 1 is a perspective view showing a first embodiment of a mask used in the method of manufacturing an electro-optical device according to the present invention, and FIG. 2 is a cross-sectional view of the mask taken along the line GG ′ in FIG.
As shown in FIG. 1, the mask 10 includes a mask main body (translucent member) 10 </ b> A, a mask pattern 11, and a lens unit 12.
Next, the configuration of the mask 10 will be described in detail with reference to FIG. FIG. 2 is a diagram illustrating a state in which the mask 10 and the electro-optical device substrate d are arranged to face each other, and the exposure light l is exposed to the electro-optical device substrate d through the mask 10.
As shown in FIG. 2, the mask 10 has an upper surface (mask pattern forming surface) 10.
The exposure light L passes through the mask main body 10A from a to the lower surface (curved surface of the lens portion 12) 10b, so that the electro-optical device substrate D disposed to face the mask 10 corresponds to the mask pattern 11. An exposure pattern is exposed.

Here, the mask body 10A is made of a material having excellent translucency,
For example, it is made of hard glass or the like. Further, the refractive index n1 of the mask main body 10A is larger than the refractive index n2 of the gas through which the exposure light L emitted from the lens unit 12 passes (n1> n2).

The mask pattern 11 is formed by patterning a light shielding portion 11a that blocks the exposure light L and a light transmitting portion 11b that transmits the exposure light L. Thereby, the exposure light irradiated to the mask pattern 11 becomes the exposure pattern of the same pattern as the mask pattern 11,
The light passes through the mask body 10A. The mask pattern 11 is formed by uniformly forming a light-shielding metal film such as chromium on the upper surface 10a of the mask body 10 and then partially removing the chromium film by a photolithography technique. is there.

The lens unit 12 is a part provided on the lower surface 10b of the mask main body 10A, and an exposure pattern formed by the exposure light L passing through the mask pattern 11 is emitted toward the lower side of the mask main body 10A. It is like that. The lens unit 12 in the present embodiment is a convex lens having a convex shape toward the traveling direction of exposure light, that is, toward the electro-optical device substrate. The convex lens has a smooth curved surface from the apex T (the portion where the convex lens protrudes most) toward the right end S1 and the left end S2 of the mask 10.
Here, in the vertical direction of the upper surface 10a, a line passing through the center of the mask 10 is a center line CL.
Assuming that the line passing through the apex T of the lens unit 12 is a top line TL, the center line CL and the top line TL do not coincide with each other in the left-right direction on the paper surface, and are shifted by the length of the distance d1. Yes.
Thereby, the length of the curve from the right end S1 to the vertex T in the lens unit 12 is longer than the length of the curve from the left end S2 to the vertex T. Further, when comparing the curved surface C1 from the vertex T to the right end S1 and the curved surface C2 from the vertex T to the left end S2, the curved surface C1 has at least a surface with a smaller curvature than the curved surface C2 and is gentler than the curved surface C2. Has a surface.
On the other hand, the curved surface C2 has at least a surface having a larger curvature than the curved surface C1, and has a steeper surface than the curved surface C1. Therefore, the entire lens portion 12 is not formed with the same curvature, but the curved surfaces C1 and C2 are formed with partially different curvatures, and the curvatures are formed so as to be continuously different.

Next, the emission angle of the exposure light L that passes through the mask 10 will be described in detail.
FIG. 3 is a cross-sectional view of the mask 10 for explaining the emission angle of the exposure light L. FIG.
Here, a case where the exposure light L is irradiated to each of points A and B separated by a distance d2 on both the left and right sides of the top line TL on the upper surface 10a will be described.

の関係が成立することが知られている。更に、本実施形態では、ｎ１＞ｎ２、また、θ_ａ
１は、０＜θ_ａ１＜π／２であるので、

の関係が成立する。 First, the point A will be described.
As shown in FIG. 3, the exposure light L irradiated to the point A on the upper surface 10 a passes through the mask body 10 </ b> A and enters the point A ′ (first point) on the curved surface of the lens unit 12. Here, an angle formed by the normal direction of the tangent to the lens unit 12 at the point A ′ and the traveling direction of the exposure light L incident on the point A ′ is defined as an incident angle θ _a1 . Further, an angle formed by the normal direction of the tangent line of the lens unit 12 and the traveling direction of the exposure light L emitted from the point A ′ is defined as an emission angle θ _a2 . The refractive index of the mask body 10A is n
1. When the refractive index n2 of the gas through which the exposure light L passes is

It is known that this relationship is established. Furthermore, in this embodiment, n1> n2 and θ _{a
Since 1} is 0 <θ _a1 <π / 2,

The relationship is established.

の関係が成立し、従って、

の関係が成立する。 Next, the point B will be described.
In the same relationship as described above, the exposure light L irradiated to the point B on the upper surface 10a passes through the mask main body 10A and enters the point B ′ (second point) on the curved surface of the lens unit 12. Here, an angle formed by the normal direction of the tangent to the lens unit 12 at the point B ′ and the traveling direction of the exposure light L incident on the point B ′ is defined as an incident angle θ _b1 . Further, when an angle formed by the normal direction of the tangent line of the lens unit 12 and the traveling direction of the exposure light L emitted from the point B ′ is an emission angle θ _b2 ,

The relationship of

The relationship is established.

Here, the lens unit 12 as described above, since the curved surface C2 than curved C1 has a steep surface, 'the incident angle theta _a1 in, point B' point A greater than the incident angle theta _b1 in (Θ _a1 > θ _b1 ). Here, in (Equation 1) to (Equation 4), the sine function is 0 <θ <π /
Since it is an increasing function under the condition of 2, the exit angle θ _{a2 at the} point A ′ is larger than the exit angle θ _{b2 at the} point B ′ (θ _a2 > θ _b2 ). Therefore, the curved surface C2 can refract the exposure light L at an exit angle larger than that of the curved surface C1 at portions (points A and B) separated by a distance d2 on both the left and right sides of the top line TL.

Furthermore, since the exposure light L passing through the vertex T is emitted without being refracted in the vertical direction of the upper surface 10a (emission angle 0 °), the curvature gradient from the vertex T to the point A ′ is a point from the vertex T to the point A ′. It is larger than the curvature gradient up to B ′. That is, on the curved surface C2 that is steeper than the curved surface C1, the exposure light L is transferred to the electro-optical device substrate D with a larger emission angle. Curved surface C2
On a gentler curved surface C1, the exposure angle L is transferred to the electro-optical device substrate D with a smaller emission angle. Due to the difference in the emission angle, the exposure pattern transmitted through the lens unit 12 and transferred to the electro-optical device substrate D is distorted and transferred. Further, the distortion is continuously generated.

In the present embodiment, since the lens unit 12 is a convex lens, the exposure pattern emitted from the lens unit 12 has a smaller size than the mask pattern, that is, the focused pattern. Further, in the case of such a convex lens, for example, the exposure light L on the curved surface C2 is refracted toward the apex T side of the lens portion 12 as the emission angle of the exposure light L increases. Further, as the exit angle of the exposure light L is smaller, for example, the exposure light L on the curved surface C1 is refracted toward the apex T side of the lens unit 12, but the exit angle is smaller and is less likely to be refracted than the curved surface C2. . Therefore, as a whole of the exposure pattern, the portion with the larger emission angle is distorted toward the apex T side.

Referring to FIG. 2, the exposure pattern emitted from the curved surface C1 is transferred onto the region D1 of the electro-optical device substrate D, and the exposure pattern emitted from the curved surface C2 is the region D2 of the electro-optical device substrate D. Transcribed above. Since the exposure pattern transferred to the area D1 is transferred by exposure light having a smaller exit angle than the exposure pattern transferred to the area D2, the density becomes sparser than the exposure pattern of the area D2. Yes. The exposure pattern transferred to the region D2 has a high density. The pattern density is continuously different.

As described above, in the mask of the present embodiment, the lens unit 12 has a curvature gradient from the point A ′ to the point B ′, so that an exposure pattern is desired with an exit angle from a curved surface corresponding to the curvature gradient. And can be transferred to the electro-optical device substrate D. Further, since the curvatures are continuously different, the exposure pattern can be transferred with continuously different distortions. In other words, the exposure pattern can be transferred to the electro-optical device substrate D by causing distortion of the exposure pattern.
In such a mask 10, the mask pattern 11 is not partially reduced in scale, or the mask pattern 11 is not distorted and formed, in other words, the width of the light shielding portion and the light transmitting portion. There is no need to adjust the scale, and the lens unit 12 has the curved surface structure described above.
The exposure pattern can be distorted and transferred to the electro-optical device substrate D.

(Second Embodiment of Mask)
FIG. 4 is a cross-sectional view showing a second embodiment of a mask used in the method for manufacturing an electro-optical device according to the invention.
The lens unit 12 in the present embodiment is a concave lens having a concave shape toward the traveling direction of exposure light, that is, toward the electro-optical device substrate. The concave lens has a smooth curved surface from the apex T (the portion where the concave lens is most concave) toward the right end S1 and the left end S2 of the mask 10.

Here, in the vertical direction of the upper surface 10a, the center line CL and the line passing through the apex T of the lens portion 12 are deviated by the length of the distance d1. Thereby, the length of the curve from the right end S1 to the vertex T in the lens unit 12 is longer than the length of the curve from the left end S2 to the vertex T. Further, the curved surface C1 from the vertex T to the right end S1, and the left end S2 from the vertex T.
In comparison with the curved surface C2, the curved surface C1 has at least a surface with a smaller curvature than the curved surface C2, and has a more gentle surface than the curved surface C2. On the other hand, the curved surface C2 has at least a surface having a larger curvature than the curved surface C1, and has a steeper surface than the curved surface C1. Therefore,
The entire lens portion 12 is not formed with the same curvature, but is formed with a curved surface with partially different curvatures, and with the curvature continuously different.

In such a concave lens, the emission direction of the exposure light L is different from that in the case of a convex lens, and the exposure pattern emitted from the lens unit 12 is larger in size than the mask pattern and is applied to the electro-optical device substrate D. It will be transferred.
Specifically, in the case of such a concave lens, for example, the exposure light L on the curved surface C2 is refracted toward the outside of the lens unit 12 as the emission angle of the exposure light L increases. Further, as the exit angle of the exposure light L is smaller, for example, the exposure light L on the curved surface C1 is refracted toward the outside of the lens unit 12, but the exit angle is smaller and is less likely to be refracted than the curved surface C2. Therefore, as a whole of the exposure pattern, a portion having a larger emission angle is distorted toward the outside of the lens portion 12.

Referring to FIG. 4, the exposure pattern emitted from the curved surface C1 is transferred onto the region D1 of the electro-optical device substrate D, and the exposure pattern emitted from the curved surface C2 is the region D2 of the electro-optical device substrate D. Transcribed above. Since the exposure pattern transferred to the region D1 is transferred by exposure light having a smaller emission angle than the exposure pattern transferred to the region D2, the density becomes denser than the exposure pattern of the region D2. Yes. The exposure pattern transferred to the region D2 has a sparse density. Furthermore, the density of the pattern varies continuously.
In the lens portion 12 composed of such a concave lens, the curved surface C2 has a steeper surface than the curved surface C1, and therefore the angle of the exposure light L emitted from the point A ′ (first point) is the point B ′. (Second
It becomes larger than the angle emitted from the point.

As described above, in the present embodiment, although the emission direction of the exposure light L is different from that of the convex lens and the size of the exposure pattern to be transferred is different, the same effect as in the first embodiment can be obtained. Further, the exposure light L can be refracted more largely by the curved surface C2 than by the curved surface C1. In addition, the difference in emission angle between the curved surface C1 and the curved surface C2 allows the exposure pattern transmitted through the lens portion 12 and transferred to the electro-optical device substrate D to be continuously distorted and transferred.

In the first embodiment and the second embodiment of the mask described above, the exposure patterns transferred to the electro-optical device substrate D are reversed from each other. Specifically, FIG.
In the case of the convex lens shown in FIG. 2, the exposure pattern transferred through the steep curved surface C2 is denser than the curved surface C1 in FIG. On the other hand, in the case of the concave lens shown in FIG. 4, the exposure pattern transferred via the steep curved surface C2 is sparse compared to the curved surface C1 of FIG.
Therefore, by properly using the convex lens or the concave lens, the portion that causes the density of the mask pattern 11 can be made different.

(Method for manufacturing electro-optical device)
Next, a method for manufacturing an electro-optical device using the above mask will be described with reference to FIGS.
The electro-optical device shown in this embodiment is a reflective liquid crystal device as an example. Further, the reflective liquid crystal device is an active matrix type reflective liquid crystal device of a built-in reflective plate type in which a pixel electrode on an element substrate also serves as a reflective plate.

First, the configuration of a reflective liquid crystal device manufactured by the manufacturing method of the present invention will be described.
FIG. 5 is a plan view of the reflective liquid crystal device according to the present embodiment as viewed from the counter substrate side together with the respective components. FIG. 6 is a cross-sectional view taken along the line HH ′ of FIG. FIG. 7 is an equivalent circuit diagram of various elements and wirings in a plurality of pixels formed in a matrix in the image display region of the reflective liquid crystal device. In each drawing used in the following description, the scale is different for each layer and each member so that each layer and each member can be recognized on the drawing.

(Reflective liquid crystal device)
5 and 6, the reflective liquid crystal device 100 of the present embodiment includes a TFT array substrate (
The electro-optical device substrate) 40 and the counter substrate 20 are bonded together by a sealing material 52, and a liquid crystal (electro-optical element) 50 is sealed and held in a region partitioned by the sealing material 52. A peripheral parting 53 made of a light shielding material is formed in a region inside the region where the sealing material 52 is formed. A data line driving circuit 201 and a mounting terminal 202 are formed along one side of the TFT array substrate 40 in a region outside the sealing material 52, and 2 adjacent to the one side.
A scanning line driving circuit 204 is formed along the side. On the remaining side of the TFT array substrate 40, a plurality of wirings 205 are provided for connecting the scanning line driving circuits 204 provided on both sides of the image display area. Further, at least one corner of the counter substrate 20 is provided with an inter-substrate conductive material 206 for establishing electrical continuity between the TFT array substrate 40 and the counter substrate 20.

Instead of forming the data line driving circuit 201 and the scanning line driving circuit 204 on the TFT array substrate 40, for example, a TAB (Tape Automated Bonn) on which a driving LSI is mounted is used.
ding) The substrate and a terminal group formed on the periphery of the TFT array substrate 40 may be electrically and mechanically connected via an anisotropic conductive film.
In the reflective liquid crystal device 100, the type of the liquid crystal layer 50 to be used, that is, TN
Depending on the operation mode such as (Twisted Nematic) mode, STN (Super Twisted Nematic) mode, and normally white mode / normally black mode, a phase difference plate, a polarizing plate, etc. are arranged in a predetermined direction. Illustration is omitted here.

When the reflective liquid crystal device 100 is configured for color display, for example, red (R) is formed in a region of the counter substrate 20 facing each pixel electrode (to be described later) of the TFT array substrate 40.
), Green (G), and blue (B) color filters are formed together with the protective film.

In the image display region of the reflective liquid crystal device 100 having such a structure, as shown in FIG. 7, a plurality of pixels 100a are configured in a matrix and these pixels 1
Each of 00a is provided with a pixel switching TFT 30 and a pixel signal S1,
A data line 6 a for supplying S 2,..., Sn is electrically connected to the source of the TFT 30. Pixel signals S1, S2,..., Sn to be written to the data lines 6a may be supplied line-sequentially in this order, or may be supplied for each group to a plurality of adjacent data lines 6a. . Further, the scanning line 3a is electrically connected to the gate of the TFT 30, and the scanning signals G1, G2,..., Gm are applied to the scanning line 3a in a pulse-sequential manner in this order at a predetermined timing. It is configured. The pixel electrode (reflecting part) 9 is electrically connected to the drain of the TFT 30, and by turning on the TFT 30 as a switching element for a certain period, the pixel signals S1, S2,. ..., Sn is written to each pixel at a predetermined timing. The pixel signals S1, S2,..., Sn written in the liquid crystal via the pixel electrode 9 in this way are held for a certain period with the counter electrode 21 of the counter substrate 20 shown in FIG.

In order to prevent the retained pixel signals S1, S2,..., Sn from leaking, a storage capacitor 60 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 9 and the counter electrode. For example, the voltage of the pixel electrode 9 is held by the storage capacitor 60 for a time that is three orders of magnitude longer than the time when the source voltage is applied. Thereby, the charge retention characteristics are improved, and the reflective liquid crystal device 100 with a high contrast ratio can be realized. As a method of forming the storage capacitor 60, as shown in FIG. 7, when the storage capacitor 60 is formed between the capacitor line 3b, which is a wiring for forming the storage capacitor 60, or between the scanning line 3a in the previous stage. Any of the above may be used.

(Configuration of TFT array substrate)
FIG. 8 is a plan view showing one pixel of the TFT array substrate used in this embodiment. FIG.
FIG. 9 is a cross-sectional view of a pixel taken along line AA ′ in FIG. 8. In FIGS. 8 and 9, a case where a plurality of convex portions are formed using a photosensitive resin is shown as an example.
In FIG. 8, on the TFT array substrate 40, a pixel electrode 9 composed of aluminum, silver, or an alloy thereof, or a laminated film of the above metal film and a metal film of titanium, titanium nitride, molybdenum, tantalum or the like. Are formed in a matrix, and the pixel switching TFTs 30 are electrically connected to the pixel electrodes 9, respectively. A data line 6a, a scanning line 3a, and a capacitor line 3b are formed along the vertical and horizontal boundaries of the region where the pixel electrode 9 is formed, and the TFT 30 is connected to the data line 6a and the scanning line 3a.
That is, the data line 6a is electrically connected to the high-concentration source region 1a of the TFT 30 through the contact hole 8, and the pixel electrode 9 includes the contact hole 45 and the drain electrode 6b.
Is electrically connected to the high-concentration drain region 1d of the TFT 30. TFT
The scanning line 3a extends so as to face 30 channel forming regions 1a ′. The storage capacitor 60 has an extended portion 1 of the semiconductor film 1 for forming the pixel switching TFT 30.
A structure in which f is made conductive is used as a lower electrode, and a capacitance line 3b in the same layer as the scanning line 3a overlaps with the lower electrode 1f as an upper electrode. As shown in FIG. 8, a pixel electrode 9 is formed for each pixel 100a configured as described above, and the surface thereof is not flat, and a plurality of reflection convex pattern 9g having a circular shape in plan view, which will be described later, is randomly formed. ing.

As shown in FIG. 9, the cross section of the reflective region taken along the line AA ′ has a thickness on the surface of a transparent glass substrate 40 ′ for a TFT array substrate as a base of the TFT array substrate 40. A base protective film 41 made of a silicon oxide film (insulating film) having a thickness of 100 nm to 500 nm is formed. On the surface of the base protective film 41, an island-shaped semiconductor film 1 having a thickness of 30 nm to 100 nm is formed. A gate insulating film 2 made of a silicon oxide film having a thickness of about 50 to 150 nm is formed on the surface of the semiconductor film 1, and a thickness of 100 nm to 80 nm is formed on the surface of the gate insulating film 2.
A scanning line 3a of 0 nm is formed as a gate electrode. Of the semiconductor film 1, the scanning line 3a
On the other hand, a region facing through the gate insulating film 2 is a channel forming region 1a ′. A source region including a low concentration region 1b and a high concentration source region 1a is formed on one side of the channel forming region 1a ', and a drain including a low concentration region 1b and a high concentration drain region 1d on the other side. A region is formed, and a high-concentration region 1c that does not belong to either the source or drain region is formed in the middle.

A first interlayer insulating film 4 made of a silicon oxide film having a thickness of 300 nm to 800 nm and a second interlayer insulating film 5 made of a silicon nitride film having a thickness of 100 nm to 800 nm are formed on the surface side of the TFT 30 for pixel switching. Is formed. A data line 6 a having a thickness of 100 nm to 800 nm is formed on the surface of the first interlayer insulating film 4, and the data line 6 a is connected to the high concentration source region via a contact hole 8 formed in the first interlayer insulating film 4. It is electrically connected to 1a.

On the second interlayer insulating film 5, a convex portion forming layer (photosensitive member, concave / convex member) 7 and a pixel electrode (light reflecting member) 9 are sequentially laminated.
Here, the convex portion forming layer 7 is made of a photosensitive resin such as an organic resin typified by an acrylic resin, for example, and a plurality of resin convex portions having curved surfaces are formed on the surface thereof. Yes. The plurality of resin convex portions are formed on the entire surface in a plan view of the convex portion forming layer 7, and constitute a resin convex portion pattern (convex portion pattern) 7g. Such resin convex pattern 7
g is formed by a manufacturing method described later.

The pixel electrode 9 is a reflective conductive film formed in the upper layer of the convex portion forming layer 7. As such a material, aluminum, silver, or an alloy thereof may be used, or a laminated film of these metal films and a metal film such as titanium, titanium nitride, molybdenum, or tantalum may be used. it can.
The pixel electrode 9 has a plurality of reflective convex portions formed on the surface of the convex portion forming layer 7 so as to follow the resin convex portions. The plurality of reflective convex portions are formed on the entire surface in a plan view of the pixel electrode 9, and constitute a reflective convex portion pattern 9g.

An alignment film 42 made of a polyimide film is formed on the surface side of the pixel electrode 9. On the surface side of the alignment film 42, a rubbing process or a vertical alignment process according to the mode of the liquid crystal molecules is performed. For example, when the liquid crystal molecules are in TN mode or STN, the alignment film 42 is rubbed, and VA (Vertical A) having liquid crystal molecules with negative dielectric anisotropy.
In the case of the (ignition) mode, vertical alignment processing is performed.
In the case where the alignment film 42 is a vertical alignment film, an inorganic film may be employed in addition to the polyimide film.

The TFT 30 preferably has an LDD structure (Lightly Doped Drain structure) as described above, but may have an offset structure in which impurity ions are not implanted into a region corresponding to the low concentration region 1b. Further, the TFT 30 may be a self-aligned TFT in which impurity ions are implanted at a high concentration using a gate electrode (a part of the scanning line 3a) as a mask to form high-concentration source and drain regions in a self-aligned manner. .

In this embodiment, the dual gate (double gate) structure in which two gate electrodes (scanning lines 3a) of the TFT 30 are arranged between the source and drain regions is used. Alternatively, a triple gate or more structure in which three or more gate electrodes are arranged between them may be used. When a plurality of gate electrodes are arranged, the same signal is applied to each gate electrode. If the TFT 30 is configured with dual gates (double gates) or triple gates or more in this way, leakage current at the junction between the channel and the source-drain region can be prevented, and the current during OFF can be reduced. If at least one of these gate electrodes has an LDD structure or an offset structure, the off-current can be further reduced and a stable switching element can be obtained.

8 and 9, among the surfaces of the pixel electrode 9 in the TFT array substrate 40, the TFT
As described above, the reflective convex pattern 9g is formed in the formation region 30 and the region outside the contact hole 45.

(Configuration of counter substrate)
As shown in FIG. 9, in the counter substrate 20, T on the glass substrate 20 ′ on the counter substrate side.
A light shielding film 23 called a black matrix or black stripe is formed in a region facing the vertical and horizontal boundary regions of the pixel electrode 9 on the FT array substrate 40, and an IT layer is formed on the upper layer side thereof.
A counter electrode 21 made of an O film is formed. An alignment film 22 made of a polyimide film is formed on the upper layer side of the counter electrode 21. A liquid crystal layer 50 is sealed between the TFT array substrate 40 and the counter substrate 20.

(First Embodiment of Method for Manufacturing Electro-Optical Device)
A method of manufacturing the reflective liquid crystal device (electro-optical device) 100 having the above-described configuration is illustrated in FIGS.
It demonstrates concretely, referring to. 10 to 14 show the TFT array substrate 40 of the present embodiment.
It is sectional drawing which shows these manufacturing methods in process order. FIG. 15 is a process flow diagram showing a process for forming the convex formation layer 7. FIG. 16 is a schematic cross-sectional view for explaining an exposure method using the mask. FIG. 17 is a schematic cross-sectional view for explaining the directivity of the reflected light of the pixel electrode. FIG. 18 is a schematic cross-sectional view for explaining the directivity of the reflective liquid crystal device.

First, as shown in FIG. 10 (A), after preparing a glass substrate 40 ′ for a TFT array substrate cleaned by ultrasonic cleaning or the like, TF is used under a temperature condition of 150 ° C. to 450 ° C.
A base protective film 41 made of a silicon oxide film is formed on the entire surface of the glass substrate 40 ′ for the T array substrate to a thickness of 100 nm to 500 nm by plasma CVD. As the source gas at this time, for example, a mixed gas of monosilane and laughing gas (dinitrogen monoxide), TEOS (tetraethoxysilane: Si (OC ₂ H ₅ ) ₄ ) and oxygen, or disilane and ammonia are used. be able to.

Next, under the temperature condition of the substrate temperature of 150 ° C. to 450 ° C., the semiconductor film 1 made of an amorphous silicon film is formed on the entire surface of the glass substrate 40 ′ for the TFT array substrate by plasma CVD.
It is formed to a thickness of nm to 100 nm. As the source gas at this time, for example, disilane or monosilane can be used. Next, laser annealing is performed by irradiating the semiconductor film 1 with laser light. As a result, the amorphous semiconductor film 1 is once melted and crystallized through a cooling and solidifying process.

Next, the island-shaped semiconductor film 1 is formed on the surface of the semiconductor film 1 by etching the semiconductor film 1 through the resist mask 551 using a photolithography technique as illustrated in FIG. The semiconductor films are formed in a separated state.

Next, under a temperature condition of 350 ° C. or lower, the gate insulating film 2 made of a silicon oxide film or the like is formed on the entire surface of the glass substrate 40 ′ for the TFT array substrate including the surface of the semiconductor film 1 by a CVD method or the like by 50 nm to 150 nm. The thickness is formed. As the source gas at this time, for example, a mixed gas of TEOS and oxygen gas can be used. The gate insulating film 2 may be a silicon nitride film instead of the silicon oxide film.

Next, although not shown, impurity ions are implanted into the extended portion 1f of the semiconductor film 1 through a predetermined resist mask, and a lower electrode for forming the storage capacitor 60 is formed between the capacitor line 3b. (See FIGS. 8 and 9).

Next, as shown in FIG. 10C, a metal film made of aluminum, tantalum, molybdenum or the like for forming the scanning lines 3a and the like on the entire surface of the glass substrate 40 'for the TFT array substrate by sputtering or the like. Alternatively, after forming the conductive film 3 made of an alloy film containing either of these metals as a main component to a thickness of 100 nm to 800 nm, a resist mask 552 is formed using a photolithography technique.

Next, the conductive film 3 is dry-etched through a resist mask to form a scanning line 3a (gate electrode), a capacitor line 3b, and the like as shown in FIG.

Next, on the side of the pixel TFT portion and the N-channel TFT portion (not shown) of the drive circuit, about 0.1 × 10 ¹³ / cm ² to about 10 × 10 ^{13 using the} scanning line 3a and the gate electrode as a mask. /
Low-concentration impurity ions (phosphorus ions) are implanted at a dose of cm ² to form the low-concentration region 1b in a self-aligned manner with respect to the scanning line 3a. Here, the portion that is located immediately below the scanning line 3 a and into which the impurity ions are not introduced becomes the channel forming region 1 a ′ that remains the semiconductor film 1.

Next, as shown in FIG. 11A, in the pixel TFT portion, a resist mask 553 having a width wider than that of the scanning line 3a (gate electrode) is formed so that high-concentration impurity ions (phosphorus ions) are about 0.
A high concentration source region 1a, a high concentration region 1c and a high concentration drain region 1d are formed by implanting at a dose of 1 × 10 ¹⁵ / cm ² to about 10 × 10 ¹⁵ / cm ² .

In place of these impurity introduction steps, high-concentration impurities (phosphorus ions) are implanted in a state where a resist mask wider than the gate electrode is formed without implanting low-concentration impurities,
A source region and a drain region having an offset structure may be formed. Alternatively, a high concentration impurity may be implanted using the scanning line 3a as a mask to form a source region and a drain region having a self-aligned structure.

Next, as shown in FIG. 11B, an interlayer insulating film 4 made of a silicon oxide film or the like is formed to a thickness of 300 nm to 800 nm on the surface side of the scanning line 3a by a CVD method or the like. As the source gas at this time, for example, a mixed gas of TEOS and oxygen gas can be used. next,
A resist mask 554 is formed using a photolithography technique.

Next, the interlayer insulating film 4 is dry-etched through the resist mask 554, and FIG.
As shown in FIG. 3C, contact holes are formed in portions corresponding to the source region and the drain region in the interlayer insulating film 4, respectively.

Next, as shown in FIG. 11D, an aluminum film, a titanium film, a titanium nitride film, a tantalum film, and a molybdenum film for forming the data line 6a (source electrode) and the like on the surface side of the interlayer insulating film 4 Or a metal film 6 composed of an alloy film or a laminated film containing any of these metals as a main component is formed to a thickness of 100 nm to 800 nm by a sputtering method or the like, and then a resist mask 555 is formed using a photolithography technique. Form.

Next, dry etching is performed on the metal film 6 through the resist mask 555, and FIG.
), The data line 6a and the drain electrode 6b are formed.

Next, as shown in FIG. 12B, a second interlayer insulating film 5 made of a silicon nitride film is formed to a thickness of 100 nm to 800 nm on the surface side of the data line 6a and the drain electrode 6b by a CVD method or the like. .

Next, based on the process flow diagram shown in FIG. 15, the convex portion forming layer 7 is formed on the second interlayer insulating film 5 as shown in FIGS. 13A to 13C.
First, the surface of the TFT array substrate 40 on which the second interlayer insulating film 5 is formed is cleaned (step S1).
Next, a photosensitive resin (photosensitive member) 7b is applied and formed on the second interlayer insulating film 5 by spin coating (step S2).
Thus, the photosensitive resin 7a is applied and formed following the surface shape on the second interlayer insulating film 5 as shown in FIG. In the present embodiment, a positive organic translucent resin such as an acrylic resin is employed as the photosensitive resin 7a. As a specific material, PC405G (manufactured by JSR) is employed in the present embodiment. Further, the spin coating method is performed so that the film thickness of the photosensitive resin 7a is about 1.2 to 2.2 μm. The photosensitive resin 7a having such a film thickness can be formed, for example, by performing a spin coating process of 8.5 seconds at a rotation speed of 700 to 1000 rpm.

Next, the photosensitive resin 7a is pre-baked and preliminarily dried (step S3).
Here, the pre-baking of the present embodiment is performed at 90 ° C. under processing conditions of 120 seconds.
Next, an exposure process is performed on the photosensitive resin 7a (step S4).
Here, in this embodiment, processing is performed with an exposure time of 1000 to 3000 msec. By performing the exposure process, the mask pattern 11 is transferred to the photosensitive resin 7a with the mask 10 having the lens portion 12 interposed. Thereby, the convex part formation layer 7 mentioned later is formed. In the exposure process, the photosensitive resin 7a is exposed by setting a focus position in an area out of the depth of focus of the exposure apparatus used. For example, the distance from which the depth of focus is removed is preferably about several tens of μm.

Next, a development process is performed on the convex portion forming layer 7 (step S5).
Here, in the present embodiment, TM having an alkali concentration of 0.2 to 0.4 wt% (weight%).
Using AH (tetramethylammonium hydride), development processing is performed in a processing time of 50 to 80 sec.
Next, bleach exposure processing is performed on the convex portion forming layer 7 (step S6).
In general, the positive photosensitive resin 7a has a characteristic that coloring (yellow) remains after development processing. The bleach exposure process is a process for irradiating the photosensitive resin 7a with such coloring remaining with UV light to make the photosensitive resin 7a transparent. In the present embodiment, the total irradiation amount of UV light is about 330 mJ.
Next, a melt baking process is performed with respect to the convex formation layer 7 (step S7).
The melt baking process is performed as a calcination for stabilizing the shape of the projection forming layer 7. The melt baking process is performed under the conditions of 120 ° C. to 140 ° C. for 120 seconds.
Next, the convex part formation layer 7 is baked (step S8).
The said baking process is performed on the conditions of 220 degreeC and 40min-50min.

Here, with reference to FIG. 16, the exposure process of the photosensitive resin 7a in said step S4 is explained in full detail.
FIG. 16 is a schematic cross-sectional view for explaining the exposure processing in the present embodiment, and is a view showing a state where collective exposure is performed on the entire surface of the TFT array substrate 40 using the mask 10 described above.
In such an exposure process, the exposure light L is refracted in the lens unit 12, and the exposure pattern emitted from the lens unit 12 is distorted, and the exposure pattern is transferred to the photosensitive resin 7a. More specifically, the mask 10 has a lens portion 12 made of a convex lens on the surface facing the TFT array substrate 40, and has a curved surface C1, which is formed so that its curvature is continuously different. C2. Then, an exposure pattern having a high density is transferred to the photosensitive resin 7a exposed through the curved surface C2, and an exposure pattern having a low density is transferred to the photosensitive resin 7a exposed through the curved surface C1. Become. Furthermore, curved surfaces C1, C2
Therefore, the exposure pattern in the photosensitive resin 7a is formed so as to be continuously dense.
In the present embodiment, the exposure processing is performed on the positive photosensitive resin 7a, but a negative type may be adopted. In this case, only the portion irradiated with the exposure light L in the photosensitive resin 7a is recessed, and only the portion where the exposure light L is shielded is convex. Therefore, the resin convex pattern 7
What is necessary is just to use the mask which has the mask pattern 11 in which the location of g becomes a translucent part.

Furthermore, steps S5 to S8 are performed on the photosensitive resin 7a to which the density of the exposure pattern is transferred.
By performing the process, the photosensitive portion or the non-photosensitive portion in the photosensitive resin 7a is removed, and the convex portion forming layer 7 having the resin convex portion pattern 7g is formed.
Here, in the portion where the density of the exposure pattern is large, the gap between the convex portions in the resin convex portion pattern 7g becomes small, the fine convex portions are formed, and the resin convex portion pattern 7 having relatively high flatness.
g is formed. In such a resin convex portion pattern 7g, a convex portion having a curved surface with a small curvature is formed.
On the other hand, in the portion where the density of the exposure pattern is low, the gap between the convex portions in the resin convex portion pattern 7g becomes large, wide convex portions are formed, and the resin convex portion pattern 7g having relatively low flatness.
Is formed. In such a resin convex pattern 7g, a convex part having a curved surface with a large curvature is formed.
Further, in the portion where the density of the exposure pattern changes continuously, the density of the exposure pattern continuously decreases as the density of the exposure pattern decreases, and the gap between the convex portions in the resin convex portion pattern 7g. Is continuously increased, the flatness is continuously decreased, and the curvature is gradually increased.

Here, returning to FIG. 13C again, a manufacturing method of the reflective liquid crystal device will be described.
As shown in FIG. 13C, the photosensitive resin 7a is opened until reaching the surface of the drain electrode 6b by using the photolithography technique, and the contact hole 45 is formed.

Next, as shown in FIG. 14A, aluminum, silver, or an alloy thereof, or titanium, titanium nitride, molybdenum, tantalum, or the like is formed on the surface of the convex portion forming layer 7 and the contact hole 45 by sputtering or the like. A metal film (reflecting part, light reflecting member) 9a having reflectivity like the laminated film is formed.

Next, as shown in FIG. 14B, the pixel electrode 9 is formed by patterning the metal film 9a using a photolithography technique and an etching technique. The pixel electrode 9 formed in this way is electrically connected to the drain electrode 6b, and the surface thereof is a reflective convex pattern formed by following the resin convex pattern 7g on the surface of the convex forming layer 7. 9g is formed.
Such a pixel electrode 9 is formed by following the resin convex pattern 7g on the surface of the convex forming layer 7, that is, the reflection convex pattern 9g is less dense than the resin convex pattern 7g. It will be formed. The pixel electrode 9 having such a reflective convex pattern 9g has directivity that reflects reflected light in a predetermined direction.

Here, the directivity of reflected light will be described in detail with reference to FIG.
FIG. 17 is a diagram for explaining the directivity of the reflected light of the pixel electrode 9.
FIG. 17 shows only the TFT array substrate 40, the convex portion forming layer 7, and the pixel electrode 9, and the various layer films formed between the TFT array substrate 40 and the convex portion forming layer 7 It is assumed that the semiconductor 1 is formed on the TFT array substrate 40.
In FIG. 17, the pixel electrode 9 is divided and formed for each of a plurality of pixels in a matrix form.

As shown in FIG. 17, the pixel electrode 9 is formed with a reflective convex pattern 9g having the same density as the resin convex pattern 7g.
Since the reflective convex pattern 9g is formed following the convex forming layer 7 shown in FIG. 16, there is a gap between the convex parts in the reflective convex pattern 9g in the portion where the density of the exposure pattern is high. Reflective convex pattern 9g that is small, has fine convex portions, and has relatively high flatness
Is formed. In such a reflective convex pattern 9g, a convex part having a curved surface with a small curvature is formed.
On the other hand, in the portion where the density of the exposure pattern is low, the gap between the convex portions in the reflective convex pattern 9g is large, wide convex portions are formed, and the reflective convex pattern 9g having relatively low flatness.
Is formed. In such a reflective convex pattern 9g, a convex part having a curved surface with a large curvature is formed.
Further, in the portion where the density of the exposure pattern changes continuously, the density of the exposure pattern decreases continuously as the density of the exposure pattern decreases, and the convex portions in the reflective convex pattern 9g continuously. The gap between them becomes large, the flatness continuously decreases, and the curvature increases. Accordingly, the flatness distribution in the plane of the reflective convex pattern 9g is the same as that of the convex forming layer 7.
And in the part with high flatness of the reflective convex pattern 9g, the reflected light is reflected at the reflection angle θ _h1.
The reflected light is reflected at an angle of the reflection angle θ _{h2 at} the portion where the flatness of the reflecting convex pattern 9g is low. In addition, in the portion where the flatness continuously changes, the reflection angle also changes continuously. The reflected light has directivity at a reflection angle satisfying the relationship of θ _h1 > θ _h2 .
Therefore, the pixel electrode 9 having such a reflective convex pattern 9g can have a predetermined directivity toward the viewer and direct reflected light.

Here, returning to FIG. 14B again, a manufacturing method of the reflective liquid crystal device will be described.
After the pixel electrode 9 is formed, an alignment film 42 made of polyimide is formed on the surface thereof. Further, the alignment film 42 is rubbed according to the mode of the liquid crystal molecules. For example, when the liquid crystal molecules are TN mode or STN, the alignment film 42 is rubbed. In the case of a VA (Vertical Alignment) mode having liquid crystal molecules having negative dielectric anisotropy, a vertical alignment process is performed.
Through the above steps, the TFT array substrate 40 is completed.

On the other hand, for the counter substrate 20, a substrate body 20 ′ made of glass or the like is prepared, a light shielding film 23 is formed in a region corresponding to the pixels on the surface of the substrate body 20 ′, and then a transparent conductive material such as ITO is formed by sputtering or the like. A common electrode 21 is formed on almost the entire surface of the substrate body 20 ′ by depositing a conductive material and patterning it using a photolithography method. Furthermore, the common electrode 2
After the alignment film forming coating solution is applied to the entire surface of 1, the alignment film 22 is formed by performing a rubbing process, and the counter substrate 20 is manufactured.

The TFT array substrate 40 and the counter substrate 20 manufactured as described above are connected to the alignment film 42,
The liquid crystal layer 50 is formed by injecting liquid crystal into a space between both substrates by a method such as a vacuum injection method. Finally, a retardation plate, a polarizing plate or the like is attached to the outside of the liquid crystal cell thus formed as necessary, and the reflective liquid crystal device 10 of the present embodiment.
0 is completed.

Since the reflective liquid crystal device 100 configured as described above includes the pixel electrode 9 that imparts directivity to the reflected light, external light incident from the counter substrate 20 is directed to the viewer as shown in FIG. It becomes possible to reflect toward.

As described above, in the present embodiment, the mask 10 including the lens unit 12 is used,
Since the resin convex portion pattern 7g of the convex portion forming layer 7 is formed, the pixel electrode 9 can impart directivity to the reflected light. Further, the directivity of the reflected light can be set as desired by changing the curvature of the lens unit 12 without changing the mask pattern 11.

In the present embodiment, the case where the lens unit 12 is a convex lens has been described. However, exposure processing may be performed using a concave lens.
In the case where the concave lens is used, as shown in FIG. 4, the portion where the exposure pattern is dense and the portion where the exposure pattern is sparse are reversed compared to the case where the convex lens is used. In the case of a convex lens,
Since the exposure light L is condensed, the exposure pattern is transferred to the photosensitive resin 7a with a size smaller than the mask pattern 11. On the other hand, in the case of a concave lens, since the exposure light L acts in the spreading direction, the exposure pattern is transferred to the photosensitive resin 7a with a size larger than the mask pattern 11.

(Second Embodiment of Manufacturing Method of Electro-Optical Device)
Next, a method for manufacturing the reflective liquid crystal device (electro-optical device) 100 according to the second embodiment of the present invention will be specifically described with reference to FIG. FIG. 19 is a schematic cross-sectional view in the present embodiment, and is a view for explaining an exposure process of the photosensitive resin 7a.
In the present embodiment, an exposure process is performed on a mother substrate on which a plurality of TFT array substrates 40 can be obtained.

As shown in FIG. 19, in the exposure process of the present embodiment, a mask holding member 200 and a mother substrate (electro-optical device substrate) 300 are arranged to face each other, and the mother substrate 30 is interposed through the mask 200.
The exposure light L is irradiated on 0.
Here, the mask holding member 200 includes a plurality of the masks 10 described above. Therefore, a plurality of mask patterns 11 and lens portions 12 are provided on each of the masks 10.
In the mother substrate 300, an area to be processed (exposed area) 310 is formed at a position facing the plurality of masks 10. Here, the region to be processed is the TF of the reflective liquid crystal device 100.
This is a region corresponding to the T array substrate 40 and is a region where various insulating films, semiconductor layers, and the like formed on the TFT array substrate 40 are already formed. Further, a photosensitive resin 7 a is applied and formed on the entire surface of the mother substrate 300.

When the exposure process is performed with the mask holding member 200 and the mother substrate 300 facing each other as described above, the exposure light L passes through each of the plurality of masks 10 and the processing target area 310 is exposed. Here, in each processing area 310, since the lens portions 12 having different curvatures are transmitted continuously, the exposure pattern becomes dense and the processing area 310 is exposed (step S <b> 4). Further, by performing the above steps S5 to S8, a portion with high and low flatness of the resin convex portion pattern 7g and a portion with continuously changing flatness are formed. In addition, by forming a metal film 9a on each of the regions to be processed 310 in a later process,
A pixel electrode 9 having a predetermined directivity is formed.
Further, as described above, since the exposure light L is irradiated in a lump, the exposure pattern is transferred to each of the plurality of regions to be processed 310 by one exposure process.
As described above, in this embodiment, not only the same effects as those of the above-described embodiments can be obtained, but also an exposure pattern having a density can be transferred to each of the plurality of regions to be processed 310.

(Third embodiment of manufacturing method of electro-optical device)
Next, a method for manufacturing the reflective liquid crystal device (electro-optical device) 100 according to the third embodiment of the present invention will be specifically described with reference to FIG. FIG. 20 is a schematic cross-sectional view in the present embodiment, and is a view for explaining an exposure process of the photosensitive resin 7a.
In the present embodiment, an exposure process is performed on a mother substrate on which a plurality of TFT array substrates 40 can be obtained.

As shown in FIG. 20, in the exposure processing of this embodiment, after exposing a part of the processing target area 310 on the mother substrate 300, the mask 10 and the mother substrate 300 are moved relative to each other so that another processing target area 310. This is a so-called step exposure method.

In the present embodiment, the moving mechanism 4 that moves the mask 10 and the mother substrate 300 relative to each other.
By using 00, step exposure is realized. The moving mechanism 400 is
The mask 10 is moved so that the first processed region 310a, the second processed region 310b, and the third
Are arranged opposite to the mask 10 in the order of the region to be processed 310c.
Further, in the present embodiment, the plurality of processing areas 310 on the mother substrate 300 are exposed for each area (for each structural unit).

Next, the step exposure operation will be described.
First, as shown in FIG. 20A, the moving mechanism 400 fixes the first process area 310a and the mask 10 so as to face each other. Immediately thereafter, the exposure light L is exposed to the first processing area 310a through the mask 10 (step S4). Here, the region 310 to be processed
In a, since it passes through the lens parts 12 having different curvatures continuously, the exposure pattern is sparse and dense, and the processing area 310a is exposed.

Next, as shown in FIG. 20B, the moving mechanism 400 fixes the second region to be processed 310b and the mask 10 to face each other. Immediately thereafter, the exposure light L is exposed to the first processing area 310a through the mask 10 (step S4).
Thereafter, similarly, in FIG. 20C, the third process area 310c is subjected to an exposure process (step S4).
Further, by applying the above steps S5 to S8 to the first to third processed areas 310a, 310b, and 310c in a lump, a portion where the flatness of the resin convex pattern 7g is high in each area and A low part and a part whose flatness continuously changes are formed.
In addition, the pixel electrode 9 having a predetermined directivity is formed by forming the metal film 9a in each of the processing regions 310 in a later process.

As described above, in the present embodiment, not only the same effects as those of the above-described embodiments can be obtained, but also an exposure pattern having a density in all exposed areas can be transferred using one mask 10. Can do.

In the above-described embodiment, the case where the exposure process is performed for each area to be processed 310 has been described, but the present invention is not limited thereto. Mask holding member 2 having a plurality of masks 10
By using 00, step exposure may be performed on the mother substrate 300 having the processing target areas 310 larger than the number of the masks 10.
Here, for example, by using a mask holding member 200 including two masks 10, 6
A case where step exposure is performed on a mother substrate 300 having two processing regions 310 will be described. In this case, every two regions (each structural unit) among the six regions to be processed 310
In addition, by performing the exposure process three times, all the processing target areas 310 on the mother substrate 300 are processed.
Can be exposed.
Further, if the mask holding member 200 can hold more masks 10, it becomes possible to more efficiently perform the exposure process on the plurality of processing areas 310 on the mother substrate 300.

In the above-described embodiment, the manufacturing method of the reflective liquid crystal device has been described as an example of the electro-optical device. However, the present invention does not limit the manufacturing method of the reflective liquid crystal device. The present invention can also be applied to a transflective liquid crystal device in which both can be realized. The transflective liquid crystal device has a configuration including a reflective display region and a transmissive display region, and has a configuration in which the above-described convex portion formation layer and metal film are formed only in the reflective display region.
Even in such a transflective liquid crystal device, a reflective display having directivity can be realized.

The perspective view which shows 1st Embodiment of the mask utilized in the manufacturing method of this invention. Sectional drawing which shows 1st Embodiment of the mask utilized in the manufacturing method of this invention. Explanatory drawing which shows 1st Embodiment of the mask utilized in a manufacturing method. Sectional drawing which shows 2nd Embodiment of the mask utilized in the manufacturing method of this invention. 1 is a plan view of a reflective liquid crystal device according to an embodiment of the present invention. 1 is a cross-sectional view of a reflective liquid crystal device according to an embodiment of the present invention. 1 is an equivalent circuit diagram of a reflective liquid crystal device according to an embodiment of the present invention. The top view which shows the principal part of the reflection type liquid crystal device which concerns on embodiment of this invention. Sectional drawing which shows the principal part of the reflection type liquid crystal device which concerns on embodiment of this invention. Process sectional drawing which shows the manufacturing method of the reflection type liquid crystal device which concerns on embodiment of this invention. Process sectional drawing which shows the manufacturing method of the reflection type liquid crystal device which concerns on embodiment of this invention. Process sectional drawing which shows the manufacturing method of the reflection type liquid crystal device which concerns on embodiment of this invention. Process sectional drawing which shows the manufacturing method of the reflection type liquid crystal device which concerns on embodiment of this invention. Process sectional drawing which shows the manufacturing method of the reflection type liquid crystal device which concerns on embodiment of this invention. The process flow figure of the manufacturing method of the reflection type liquid crystal device concerning the embodiment of the present invention. 1 is a schematic cross-sectional view illustrating an exposure method according to a first embodiment of the present invention. 4A and 4B are diagrams illustrating the directivity of reflected light of the reflective liquid crystal device according to the embodiment of the invention. 4A and 4B are diagrams illustrating the directivity of reflected light of the reflective liquid crystal device according to the embodiment of the invention. FIG. 9 is a schematic cross-sectional view illustrating an exposure method according to a second embodiment of the present invention. FIG. 9 is a schematic cross-sectional view illustrating an exposure method according to a third embodiment of the present invention.

Explanation of symbols

7 convex formation layer (photosensitive member), 7a photosensitive resin (photosensitive member), 10 mask,
10A mask body (translucent member), 11 mask pattern, 12 lens part,
20 counter substrate, 40 TFT array substrate (electro-optical device substrate), 50 liquid crystal layer (
Electro-optic element), 100 reflective liquid crystal device (electro-optic device), 300 mother substrate (
Electrooptic device substrate), 310, 310a, 310b, 310c Processed region (exposed region) D Electrooptic device substrate, L exposure light, C1, C2 curved surface, A ′ point (
1st point), B 'point (2nd point)

Claims (8)

The exposure pattern corresponding to the mask pattern is formed by irradiating the electro-optical device substrate with exposure light through a mask having a mask pattern including a light-shielding portion and a light-transmitting portion formed on the light-transmitting member. A method of manufacturing an electro-optical device, which is transferred to a substrate for an electro-optical device and exposed.
The mask has a lens portion having a curved surface on a surface opposite to the surface on which the mask pattern of the translucent member is formed, and corresponds to the mask pattern via the lens portion. A method of manufacturing an electro-optical device, wherein an exposure pattern is transferred to the electro-optical device substrate for exposure. The lens part is
In the curve from the first point to the second point on the curved surface of the lens part,
Having at least a portion where the curvature is continuously different from the first point toward the second point,
2. The method of manufacturing an electro-optical device according to claim 1, wherein the exposure pattern corresponding to the mask pattern is transferred to the electro-optical device substrate through a portion where the curvature is continuously different. The lens portion has a portion where the curvature of the curved surface is continuously different, and causes the exposure pattern corresponding to the mask pattern according to the curvature to produce distortion density, and the exposure pattern 2. The method of manufacturing an electro-optical device according to claim 1, wherein the electro-optical device substrate is irradiated as exposure light. The lens portion is a convex lens, and the exposure light corresponding to the mask pattern having a size smaller than the mask pattern is refracted toward the apex side of the convex portion of the convex lens, and the electro-optic The method for manufacturing an electro-optical device according to claim 1, wherein the exposure is performed by transferring to an apparatus substrate. The lens portion is a concave lens, and the exposure light is refracted in a direction away from the apex of the concave portion of the concave lens toward the outside, and the exposure pattern corresponding to the mask pattern having a size larger than the mask pattern is The method of manufacturing an electro-optical device according to claim 1, wherein the exposure is performed by transferring to a substrate for an electro-optical device. The electro-optical device substrate has a plurality of exposed areas on the same surface,
The mask has a plurality of the mask patterns corresponding to the plurality of exposed areas,
By performing a batch exposure on the plurality of exposed areas through the mask,
Transferring the exposure pattern to each of the plurality of exposed areas;
The method of manufacturing an electro-optical device according to any one of claims 1 to 3. The electro-optical device substrate has a plurality of exposed areas on the same surface,
By performing sequential exposure multiple times for each constituent unit of the plurality of exposed regions through the mask,
Transferring the exposure pattern to each of the plurality of exposed areas;
The method of manufacturing an electro-optical device according to any one of claims 1 to 3. A photosensitive member is previously formed on the electro-optical device substrate,
The method of manufacturing an electro-optical device according to claim 1, wherein:

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