JP2006011051A - Aspherical collimating mirror and method for adjusting same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aspherical collimating mirror with which the aspherical collimating mirror can be worked to an ideal parabolic surface by simple work and a method for adjusting the aspherical collimating mirror. <P>SOLUTION: The aspherical collimating mirror 1 has a base member 11, a mirror member 12 having flexibility and l3 pieces of supporting members 13 which are point symmetrically arranged. The base member 11 and the mirror member 12 are connected by the supporting members 13. Here, an ordinary spherical mirror having a spherical shape in the state free of stress is used for the mirror member 12. Each of the point symmetrically arranged 13 for supporting members 13 can be arbitrarily changed in the shape of the mirror member 12 by changing the spacing between a first fixing section fixed to the base member 11 and a second fixing section fixed to the back of the mirror member 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an aspheric collimating mirror and a method for adjusting an aspheric collimating mirror.

  For example, in an exposure apparatus used for baking a substrate in a manufacturing process of a glass substrate for a PDP (plasma display panel), a glass substrate for a liquid crystal display panel, a mask substrate for a semiconductor manufacturing apparatus, etc. In order to perform high-precision exposure after obtaining an illuminance distribution, light emitted from a light source such as an ultra-high pressure mercury lamp passes through a compound lens called a fly-eye lens, and then becomes parallel light by a collimator mirror. Thus, a configuration is employed in which the light is collimated and irradiated onto the substrate. In such an optical system, it is possible to obtain a uniform illuminance distribution on the substrate by arranging the substrate in a region where the light beams that have passed through the compound lens overlap each other.

  By the way, as a collimating mirror used in such an exposure apparatus, a spherical mirror is generally used. For this reason, since the light irradiated to the substrate is not ideal parallel light, the printing accuracy of the substrate is limited.

  In order to solve such a problem, it is preferable that the shape of the collimating mirror is an off-axis paraboloid. However, it is difficult to aspherically process the mirror on the paraboloid, and the manufacturing cost is extremely high.

For this reason, in Patent Document 1, a spherical collimating mirror is used, and the spherical collimating mirror is off-axis by applying a supporting force and the weight of the collimating mirror to the supporting member that supports the collimating mirror. An illumination optical system is disclosed that is deformed to a shape close to a paraboloid.
JP-A-9-304940

  In the illumination optical system described in Patent Document 1, it is difficult to process the collimating mirror into an ideal paraboloid because the collimating mirror cannot be freely deformed. In addition, since it has not been studied how the collimating mirror can be transformed into an ideal paraboloid, the deformation work of the collimating mirror must be trial and error. The adjustment takes an extremely long time.

  The present invention has been made to solve the above-described problems, and an aspherical collimating mirror capable of processing an aspherical collimating mirror into an ideal parabolic surface by a simple operation, and a method for adjusting the aspherical collimating mirror The purpose is to provide.

  The invention according to claim 1 is a base member, a flexible mirror member, a first fixing portion fixed to the base member, a second fixing portion fixed to the back surface of the mirror member, A plurality of support members including a connecting portion that connects the first fixing portion and the second fixing portion in a state in which a distance between the first fixing portion and the second fixing portion can be changed; It is characterized by.

  According to a second aspect of the present invention, in the first aspect of the present invention, the connecting portion and the first fixed portion of the support member are connected via a spherical bearing.

  According to a third aspect of the present invention, in the first aspect of the present invention, the connecting portion and the second fixing portion of the support member are connected via a spherical bearing.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the connecting portion includes a male screw connected to one of the first fixed portion and the second fixed portion, And a female screw connected to the other of the first fixed part and the second fixed part.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the mirror member is formed of a spherical mirror.

  According to a sixth aspect of the present invention, there is provided an exposure apparatus that irradiates an irradiation surface with light emitted from a light emitting portion as parallel light by an aspheric collimating mirror, and adjusts the surface shape of the aspheric collimating mirror. A method for adjusting a mirror, comprising: a base member; a mirror member having flexibility; a first fixing portion fixed to the base member; a second fixing portion fixed to a back surface of the mirror member; An aspherical surface including a plurality of support members including a connecting portion that connects the first fixing portion and the second fixing portion in a state in which a distance between the first fixing portion and the second fixing portion can be changed. An aspherical collimating mirror arranging step for arranging a collimating mirror in the optical path between the emitting part and the irradiation surface, and a plurality of laser emitting devices capable of emitting a laser beam in a direction normal to the reference surface The A laser emitter arrangement step of arranging the quasi-planes at positions separated from each other in a state where the quasi-plane is coincident with the irradiation surface, and a laser beam emitted from the plurality of laser emitters and reflected by the aspheric collimator mirror, And an interval adjusting step for adjusting an interval between the first fixing portion and the second fixing portion in the aspherical collimating mirror so as to irradiate a target provided in the emitting portion.

  According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the reference plane includes a laser emitter capable of emitting a laser beam in a direction normal to the reference plane after the interval adjustment step. The method further includes a confirmation step of confirming an irradiation position where the laser beam emitted from the laser emitter at that time is irradiated along the irradiation surface in a state of being coincident with the irradiation surface and irradiating the emission portion.

  According to the first aspect of the present invention, the mirror member can be processed into an ideal paraboloid by changing the distance between the first fixed portion and the second fixed portion in each support member.

  According to invention of Claim 2 and Claim 3, the influence which the space | interval of the 1st fixing | fixed part and 2nd fixing | fixed part in a certain supporting member has on the shape of the mirror member in the position corresponding to another supporting member Can be minimized.

  According to invention of Claim 4, it becomes possible to change the space | interval of the 1st fixing | fixed part in each support member and a 2nd fixing | fixed part with a simple structure.

  According to the fifth aspect of the present invention, it is possible to create an aspherical collimating mirror using a relatively inexpensive spherical mirror.

  According to the sixth aspect of the present invention, the mirror member can be processed into an ideal paraboloid by a simple operation.

  According to the seventh aspect of the present invention, it is possible to confirm whether the mirror member is actually an ideal paraboloid.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the configuration of an exposure apparatus using the aspheric collimating mirror according to the present invention will be described. FIG. 1 is a perspective view schematically showing an exposure apparatus 100 using an aspheric collimating mirror 1 according to the present invention.

  The exposure apparatus 100 is for exposing the pattern of the mask 3 to a substrate 2 such as a glass substrate for a plasma display panel (PDP), a glass substrate for a liquid crystal display panel, or a mask substrate for a semiconductor manufacturing apparatus. And a light source 4 such as an ultra-high pressure mercury lamp, a condensing mirror 5, a dichroic mirror 6, a fly-eye lens (composite lens) 7, and an aspherical collimating mirror 1 according to the present invention.

  In this exposure apparatus 100, the light emitted from the light source 4 is collected by the condenser mirror 5 and enters the dichroic mirror 6. In the dichroic mirror 6, only light having a wavelength necessary for exposure is reflected toward the fly-eye lens 7 out of the light incident thereon. The light that has passed through the fly-eye lens 7 is collimated by the aspherical collimating mirror 7 to become parallel light, and is irradiated onto the substrate 2 through the mask 3. At this time, the mask 3 and the substrate 2 are disposed in a region where the light beams that have passed through the compound lens overlap each other, and pattern exposure can be executed with a uniform illuminance distribution.

  In such an exposure apparatus 100, the substrate 2 and the mask 3 are arranged through a slight gap called a proximity gap. For this reason, it is preferable that the light used for pattern exposure is a collimated collimated light. Hereinafter, the configuration of the aspherical collimating mirror 1 that enables this will be described.

  FIG. 2 is an explanatory view showing the aspherical collimating mirror 1. 2A is a plan view of the aspherical collimating mirror 1, and FIG. 2B is a longitudinal sectional view of the aspherical collimating mirror 1.

  This aspherical collimating mirror 1 includes a base member 11, a mirror member 12 having flexibility, and 13 support members 13 arranged symmetrically with respect to a point. The base member 11 and the mirror member 12 are connected by a support member 13. Here, as the mirror member 12, a normal spherical mirror having a spherical shape is used when no stress is applied thereto.

  FIG. 3 is an explanatory view showing the support member 13 in an enlarged manner. 3A and 3B are views of the support member 13 viewed from directions orthogonal to each other.

  The support member 13 includes a first fixing portion 21, a second fixing portion 22, and a connecting portion 23. The first fixing portion 11 is fixed to the base member 11 with a plurality of screws 24. Moreover, the 2nd fixing | fixed part 22 is being fixed to the back surface of the mirror member 12 with the adhesive agent. The first fixing portion 21 and the second fixing portion 22 are connected by the connecting portion 23.

  The connecting portion 23 includes a male screw 25 connected to the first fixing portion 21 via the spherical bearing 27, and a female screw 26 screwed to the male screw 25 and connected to the second fixing portion 22 via the spherical bearing 28. Have For this reason, the connection part 23 and the 1st fixing | fixed part 21 or the 2nd fixing | fixed part 22 are connected so that inclination is mutually possible. And the substantial length of the connection part 23 is changed by rotating the internal thread 26 with respect to the external thread 25. For this reason, the space | interval of the 1st fixing | fixed part 21 and the 2nd fixing | fixed part 22 can be changed by rotating the internal thread 26 with respect to the external thread 25. FIG.

  The male screw 25 is formed with a chamfered portion 29, and a scale is displayed on the surface of the chamfered portion 29. By using the scale formed on the chamfered portion 29, it is possible to measure the amount of change in the distance between the first fixed portion 21 and the second fixed portion 22.

  In the aspherical collimating mirror 1 having the above-described configuration, by changing the distance between the first fixing portion 21 and the second fixing portion 22 for each of the 13 support members 13 arranged symmetrically with respect to the point. The shape of the mirror member 12 can be arbitrarily changed. At this time, since the connecting portion 23 and the first fixing portion 21 or the second fixing portion 22 are connected to each other by the spherical bearings 27 and 28 so as to be tiltable to each other, the first fixing portion 21 and the first fixing portion 21 in a certain support member 13 are connected. It is possible to minimize the influence of the change in the interval between the two fixing portions 22 on the shape of the mirror member 12 at a position corresponding to the other support member 13.

  Next, the configuration of the laser emitter used in the method for adjusting an aspheric collimating mirror according to the present invention will be described. 4 and 5 are longitudinal sectional views showing the configuration of the laser emitter 31 used in the method for adjusting the aspherical collimating mirror 1.

  The laser emitter 31 is for emitting a laser beam in a normal direction with respect to a bottom surface 32 serving as a reference surface, and is arranged so as to be inclined at a minute angle with respect to the base 33 and the base 33. The inclined plate 34, the inclined plate 35 configured to be tiltable by a minute angle in the direction orthogonal to the inclined direction of the inclined plate 34, the laser light source 36 supported by the inclined plate 35, and the top plate 37, and a connecting member 38 shown in the figure by omitting a part of connecting the top plate 37 and the base 33. In the laser emitter 31, the laser light source 36 is supported by the inclined plate 35 in a state in which the laser light source 36 faces in a substantially normal direction with respect to the bottom surface 32 serving as a reference surface.

  A pair of recesses are formed on the upper surface of the base 33 and the lower surface of the inclined plate 34, and steel balls 41 are disposed in these recesses. The inclined plate 34 can be inclined at a minute angle with respect to the base 33 around these steel balls 41. As shown in FIG. 5, one end of the base 33 and the inclined plate 34 is connected by a fixing screw 42, and the other end of the base 33 and the inclined plate 34 is connected by an adjusting screw 43. A spring 44 is disposed between the adjustment screw 43 and the base 33. For this reason, it is possible to adjust the inclination angle of the inclined plate 34 with respect to the base 33 by adjusting the rotation angle of the adjusting screw 43.

  Similarly, a pair of concave portions are formed on the upper surface of the inclined plate 34 and the lower surface of the inclined plate 35, and steel balls 45 are respectively disposed in these concave portions. The inclined plate 35 can be inclined at a minute angle with respect to the inclined plate 34 around these steel balls 45. As shown in FIG. 4, one end of the inclined plate 34 and the inclined plate 35 is connected by a fixing screw 46, and the other end of the inclined plate 34 and the inclined plate 35 is connected by an adjusting screw 47. A spring 48 is disposed between the adjustment screw 47 and the inclined plate 35. For this reason, by adjusting the rotation angle of the adjusting screw 47, the inclination angle of the inclined plate 35 with respect to the inclined plate 34 can be adjusted.

  In the laser emitter 31 having such a configuration, by adjusting the inclination angle of the inclined plates 34 and 35 by rotating the adjusting screws 43 and 47, the emission angle of the laser beam emitted from the laser light source 36 is It becomes possible to adjust with respect to the bottom face 32 used as a reference plane. Then, by executing the adjustment process described below, the laser beam can be accurately emitted in the normal direction with respect to the bottom surface 32 serving as the reference surface.

  Next, an adjustment process for adjusting the emission angle of the laser beam emitted from the laser emitter 31 will be described. FIG. 6 is an explanatory diagram showing this adjustment process.

  As shown in this figure, when adjusting the emission angle of the laser beam emitted from the laser emitter 31, the laser emitter 31 is placed on the surface plate 51. In this state, the laser light source 36 is directed in a substantially normal direction with respect to the surface of the surface plate 51. In this state, the laser light source 36 is turned on to irradiate the plane 52 with the laser beam. The flat surface 52 is installed at a position separated by a distance L from the laser beam emitting end of the laser emitter 31 placed on the surface plate 51. Then, the laser emitter 31 is rotated around the laser light source 36 with the bottom surface 32 serving as the reference surface kept in contact with the surface of the surface plate 51.

  At this time, when the emission direction of the laser beam emitted from the laser emitter 31 does not completely coincide with the normal direction, the locus of the image of the laser beam irradiated on the plane 52 draws a circle with a radius a. . For this reason, by adjusting the inclination angle of the inclined plates 34 and 35 by rotating and adjusting the adjustment screws 43 and 47, the emission angle of the laser beam emitted from the laser light source 36 with respect to the bottom surface 32 serving as the reference surface. Is adjusted so that the radius a of the circle is minimized. As a result, the emission direction of the laser beam emitted from the laser emitter 31 can be matched with the normal direction. The accuracy of the laser beam emission direction at this time is [arctan (a / L)] which is an arctangent of the radius a and the distance L.

  Next, a method for adjusting the aspheric collimating mirror 1 according to the present invention will be described.

  As described above, the exposure apparatus 100 using the aspheric collimating mirror 1 according to the present invention is for exposing the pattern of the mask 3 to the substrate 2, and includes a light source 4, a condensing mirror 5, A dichroic mirror 6, a fly-eye lens 7, and an aspherical collimator mirror 1 are provided, and light emitted from the fly-eye lens 7 is irradiated onto the substrate 2 through a mask 3. For this reason, the fly-eye lens 7 functions as a light emitting portion. The aspherical collimating mirror 1 is disposed between the fly-eye lens 7 as a light emitting portion and the mask 3 as a light irradiation surface.

  In this state, first, the target plate 54 is attached to the center of the fly-eye lens 7 as shown in FIG. The fly-eye lens 7 is a compound lens in which 5 × 5 lens units are combined, and a target plate 54 is attached to the central lens unit. The target is displayed at the center of the target plate 54.

  Next, the mask 3 shown in FIG. Then, as shown in FIG. 8, a plurality of (5 in this embodiment) laser emitters 31 whose emission angles have been adjusted previously are placed on the dummy glass 53, and laser light sources in the respective laser emitters 31. 36 is turned on. In this state, the bottom surface 32 serving as a reference surface in the laser emitter 31 is in a state of being coincident with the surface of the dummy glass 53 corresponding to the irradiation surface. The reason for exchanging the mask 3 and the dummy glass 53 is to prevent damage to the mask.

  In this state, when the shape of the mirror member 12 in the aspherical collimating mirror 1 is a parabola that can irradiate the mask 3 (dummy glass 53) with parallel light, each laser emitter 31 The emitted laser beam should be focused on the center of the target plate 54. However, when the mirror member 12 is not an ideal parabola such as when the shape of the mirror member 12 is spherical, the laser beam emitted from each laser emitter 31 is not condensed at the center of the target plate 54. .

  For this reason, the operator uses the support member 13 shown in FIGS. 2 and 3 to slightly change the shape of the mirror member 12 while confirming the position of the laser beam applied to the fly-eye lens 7. More specifically, in the support member 13, the substantial length of the connecting portion 23 is changed by rotating the female screw 26 with respect to the male screw 25. Thereby, the mirror member 12 approaches or separates from the base member 11, and the shape of the mirror member 12 is changed.

  The laser beam emitted from each laser emitter 31 is obtained by the operator slightly changing the shape of the mirror member 12 using the support member 13 while confirming the position of the laser beam applied to the fly-eye lens 7. Can be focused on the center of the target plate 54, one laser emitter 31 is left and the other laser emitters 31 are removed from the dummy glass 53. Then, the remaining laser emitter 31 is moved along the surface of the dummy glass 53 while the bottom surface 32 serving as the reference surface and the surface of the dummy glass 53 corresponding to the irradiation surface are in contact with each other.

  At this time, if the laser beam emitted from the laser emitter 31 is irradiated to the center of the target plate 54 regardless of the position of the laser emitter 31, the shape of the mirror member 12 in the aspheric collimating mirror 1 becomes the mask 3. This is a parabola that can be irradiated with parallel light on the (dummy glass 53). In this case, the dummy glass 53 is replaced with the mask 3 and the exposure operation is performed. On the other hand, when the laser beam emitted from the laser emitter 31 is not irradiated on the center of the target plate 54 due to the position of the laser emitter 31, the above-described adjustment operation is repeatedly performed.

1 is a perspective view schematically showing an exposure apparatus 100 using an aspheric collimating mirror 1 according to the present invention. It is explanatory drawing which shows the aspherical surface collimating mirror. It is explanatory drawing which expands and shows the supporting member. 2 is a longitudinal sectional view showing a configuration of a laser emitter 31. FIG. 2 is a longitudinal sectional view showing a configuration of a laser emitter 31. FIG. It is explanatory drawing which shows the adjustment process which adjusts the radiation | emission angle of a laser beam. FIG. 6 is an explanatory view showing a state where a target plate is mounted at the center of the fly-eye lens. 6 is an explanatory view showing a state in which a laser emitter 31 is placed on a dummy glass 53. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aspherical collimating mirror 2 Board | substrate 3 Mask 4 Light source 5 Condensing mirror 6 Dichroic mirror 7 Fly eye lens 11 Base member 12 Mirror member 13 Support member 21 1st fixing | fixed part 22 2nd fixing | fixed part 23 Connecting part 24 Screw 25 Male screw 26 Female screw 27 Spherical Bearing 28 Spherical Bearing 29 Chamfer 31 Laser Emitter 32 Bottom 33 Base 34 Inclined Plate 35 Inclined Plate 36 Laser Light Source 41 Steel Ball 43 Adjusting Screw 44 Spring 45 Steel Ball 47 Adjusting Screw 48 Spring 100 Exposure Device

Claims (7)

A base member;
A flexible mirror member;
The first fixing portion fixed to the base member, the second fixing portion fixed to the back surface of the mirror member, and the first fixing portion and the second fixing portion in a state where the distance between the first fixing portion and the second fixing portion can be changed. A plurality of support members including a connecting portion that connects the first fixing portion and the second fixing portion;
An aspherical collimating mirror characterized by comprising: The aspheric collimating mirror according to claim 1,
The connecting portion and the first fixed portion of the support member are aspheric collimating mirrors connected via a spherical bearing. The aspheric collimating mirror according to claim 1,
The connecting portion and the second fixed portion of the support member are aspheric collimating mirrors connected via a spherical bearing. In the aspherical collimating mirror according to any one of claims 1 to 3,
The connecting portion is
A male screw connected to one of the first fixed part or the second fixed part;
A female screw threadedly engaged with the male screw and connected to the other of the first fixed portion or the second fixed portion;
Aspheric collimating mirror with In the aspherical collimating mirror according to any one of claims 1 to 4,
The mirror member is an aspherical collimating mirror composed of a spherical mirror. In the exposure apparatus that irradiates the irradiation surface with the light emitted from the light emitting portion as parallel light by the aspheric collimating mirror, the method for adjusting the aspheric collimating mirror adjusts the surface shape of the aspheric collimating mirror,
A base member; a mirror member having flexibility; a first fixing portion fixed to the base member; a second fixing portion fixed to a back surface of the mirror member; the first fixing portion; An aspherical collimating mirror comprising a plurality of support members including a connecting portion that connects the first fixing portion and the second fixing portion in a state in which the interval between the fixing portion and the fixing portion can be changed. An aspherical collimating mirror arrangement step for arranging in an optical path between the irradiation surface;
A laser emitter arrangement step of arranging a plurality of laser emitters capable of emitting a laser beam in a direction normal to the reference surface at positions separated from each other in a state where the reference surface coincides with the irradiation surface; ,
The first fixed portion in the aspherical collimating mirror and the laser beam emitted from the plurality of laser emitters and reflected by the aspherical collimating mirror irradiate a target provided in the emitting portion. An interval adjusting step for adjusting the interval with the second fixing portion;
A method of adjusting an aspherical collimating mirror, comprising: In the adjustment method of the aspherical collimating mirror according to claim 6,
After the interval adjustment step, a laser emitter capable of emitting a laser beam in a direction normal to the reference surface is moved along the irradiation surface in a state where the reference surface coincides with the irradiation surface, A method for adjusting an aspherical collimating mirror, further comprising a confirmation step of confirming an irradiation position at which the laser beam emitted from the laser emitting device irradiates the emitting portion.

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