JP2024041379A - drawing device - Google Patents

Abstract

[Problem] There is provided a technology that makes it easy to check whether the correction of the focal position in a drawing device is appropriate. [Solution] A modulator spatially modulates a first light based on a pattern and emits a drawing light. A first optical system receives the drawing light and the second light, and emits the drawing light and the second light. A second optical system receives the drawing light and the second light emitted from the first optical system, and guides the drawing light emitted from the first optical system to a substrate, and emits the second light emitted from the first optical system while avoiding the substrate. A detection unit detects the focal position of the first optical system based on the second light emitted from the second optical system. The first wavelength of the first light is different from the second wavelength of the second light. [Selected Figure] Figure 6

Description

This disclosure relates to a technique for pattern-based exposure of a photosensitive substrate. The substrate has, for example, a layer using a photosensitive material (hereinafter also referred to as a "photosensitive layer"). For example, semiconductor substrates, printed circuit boards, color filter substrates included in liquid crystal display devices, glass substrates for flat panel displays included in liquid crystal display devices, plasma display devices, etc., magnetic disk substrates, optical disk substrates, solar cells. Various types of substrates, such as panels for electronic devices, have a photosensitive layer.

Exposure apparatuses are known that expose a photosensitive layer of a photosensitive substrate in a desired pattern. A so-called drawing device is known as the exposure device. The drawing device does not use a mask that selectively blocks exposure, but instead irradiates the photosensitive layer with light (hereinafter also referred to as "drawing light") that is spatially modulated according to data describing a desired pattern. Through such irradiation, the writing device directly exposes the photosensitive layer to a desired pattern. The exposed photosensitive layer is developed to leave a desired pattern or its inverse pattern on the substrate.

In order to accurately pattern the developed photosensitive layer, it is desirable that the photosensitive layer be appropriately exposed. In order to perform appropriate exposure, it is desirable that the focus of the drawing light be appropriately positioned on the photosensitive layer.

In order to improve the productivity of various substrates, it is desirable that the energy of the drawing light be high, for example, that the intensity of the light received by the photosensitive layer be high. Drawing light with high energy may increase the influence of the thermal lens effect in the optical system of the drawing device on the focus of the drawing light.

Thermal lens effect is an increase in the temperature of the lens in an optical system, which causes changes in the refractive index of the lens and changes in the shape of the surface of the lens, resulting in a change in the position of the focal point formed by the optical system (hereinafter referred to as "thermal lens effect"). This is a phenomenon in which the focal point (also called "focal position") moves.

For example, when drawing a desired pattern is repeatedly performed while changing the position of the photosensitive layer, the contrast of the pattern obtained by the drawing depends on the timing at which the pattern is drawn. This tends to hinder the uniformity of patterning quality. In particular, there is a possibility that it becomes impossible to draw a desired pattern.

Techniques have been proposed for correcting focal position shifts due to thermal lens effects. As an example of a technique for correcting such movement, the amount of movement of the focal position is estimated from the temperature of the lens barrel of the optical system, the temperature of the lens, and the temperature of the water that cools the lens barrel, and the focal position is corrected using a correction mechanism. Techniques have been proposed (for example, Patent Documents 1 to 3 below).

In the technique of correcting such movement, the amount of movement of the focal position with respect to the temperature of the target portion whose temperature is measured is measured in advance, and a correction table is obtained. Using the correction table, the amount of movement is estimated from the measured temperature of the measurement target. A correction mechanism that corrects the estimated amount of movement is used to correct the focal position due to the thermal lens effect.

Techniques have also been proposed for suppressing thermal lens effects through lens design. As an example of a technique for suppressing the thermal lens effect, a technique has been proposed that controls the positive and negative powers of a lens, the rate of change in refractive index due to temperature changes, and the curvature of a lens (for example, Patent Document 4 below) ~6).

Note that Patent Document 7 discloses a technique for determining a temperature-dependent positional shift amount between a viewing position and a drawing position.

Japanese Patent Application Publication No. 63-93492 Japanese Patent Application Publication No. 2000-244847 Japanese Patent Application Publication No. 2012-181362 JP 2019-60972 Publication Japanese Patent Application Publication No. 2011-33891 Japanese Patent Application Publication No. 2013-68689 Japanese Patent Application Publication No. 2014-197136

In the technique of correcting the amount of movement estimated using a correction table, the corrected focus position is not detected, and it is difficult to confirm whether the correction of the focus position is appropriate.

In order to suppress the thermal lens effect through lens design, conditional expressions necessary for the suppression must be set. Glass materials suitable for the designed lens are limited, making design difficult.

The present disclosure has been made in view of these points, and an object of the present disclosure is to provide a technique that makes it easy to confirm whether correction of the focal position in a drawing device is appropriate.

A drawing apparatus according to a first aspect of the present disclosure is an apparatus that exposes a photosensitive substrate using drawing light based on a pattern. The drawing device includes a first light source, a second light source, a modulator, a first optical system, a second optical system, and a detection section.

The first light source emits first light having a first wavelength. The second light source emits second light having a second wavelength different from the first wavelength. The modulator spatially modulates the first light based on the pattern and emits the drawing light. The first optical system receives the drawing light and the second light, and outputs the drawing light and the second light. The second optical system receives the drawing light emitted from the first optical system and the second light, and guides the drawing light emitted from the first optical system to the substrate. , the second light emitted from the first optical system is emitted while avoiding the substrate. The detection unit detects a focal position of the first optical system based on the second light emitted from the second optical system.

A drawing device according to a second aspect of the present disclosure is the drawing device according to the first aspect, in which the second light enters the first optical system via the modulator.

A drawing apparatus according to a third aspect of the present disclosure is the drawing apparatus according to the second aspect, in which the modulator has a first area and a second area. The first region spatially modulates the first light based on the pattern and emits the drawing light. The second region emits the second light to the first optical system regardless of the pattern.

A drawing device according to a fourth aspect of the present disclosure is the drawing device according to the first aspect, and further includes a filter. The filter is located between the modulator and the first optical system, and transmits the drawing light and reflects the second light from the second light source to the first optical system. and lead.

A drawing device according to a fifth aspect of the present disclosure is a drawing device according to the fourth aspect, in which each of the second optical system and the filter has the first wavelength and the second wavelength. A low-pass filter having a cutoff wavelength between the two is employed. The first wavelength is shorter than the second wavelength.

A drawing device according to a sixth aspect of the present disclosure is any one of the first to fifth aspects, and the detection section includes a prism and a detector. The prism has a ridgeline on which the second light emitted from the second optical system enters, and a ridgeline that faces the ridgeline and branches the second light into third light and fourth light. and a surface from which the radiation is emitted. The detector receives the third light and the fourth light and detects a position where the third light and the fourth light enter.

A drawing device according to a seventh aspect of the present disclosure is any one of the first to fifth aspects, and the detection unit includes a shield and a detector. The shield partially blocks the second light emitted from the second optical system while transmitting the second light. The detector receives the second light that has passed through the shielding object and detects a position where the second light enters.

A drawing device according to an eighth aspect of the present disclosure is any one of the first to seventh aspects, wherein the first optical system includes a first lens barrel and a second lens barrel. , and a moving mechanism. The second lens barrel constitutes a double-sided telecentric optical system together with the first lens barrel. The moving mechanism moves the second lens barrel relative to the first lens barrel along the optical axis of the double-sided telecentric optical system. The distance between the first lens barrel and the second lens barrel along the optical axis of the double-sided telecentric optical system is such that the focal position detected by the detection unit is close to the second lens barrel. The more the distance is reduced by the moving mechanism.

According to the drawing device according to the first aspect, it is easy to confirm whether the focal position of the first optical system has been appropriately corrected.

According to the drawing device according to the second aspect, there is no need to separately provide a component that allows the second light to enter the second optical system.

According to the drawing device according to the third aspect, the second light enters the second optical system with a desired intensity or more.

According to the drawing device according to the fourth aspect, the second light enters the second optical system with a desired intensity or more.

The drawing device according to the fifth aspect contributes to realizing the drawing device according to the fourth aspect.

According to the drawing device according to the sixth aspect, the focal position of the first optical system is detected from the positions of the third light and the fourth light.

According to the drawing device according to the seventh aspect, the focal position of the first optical system is detected from the position of the second light that has been vignetted by the shielding object.

According to the drawing device according to the eighth aspect, the focal position of the first optical system is corrected by the moving mechanism.

FIG. 1 is a schematic perspective view of a drawing device according to the present disclosure. FIG. 2 is a plan view of the drawing device. FIG. 2 is a perspective view schematically showing an optical unit. FIG. 2 is a side view illustrating the configuration of a light modulation section. FIG. 3 is a side view illustrating light incident on a spatial light modulation element and light emitted from the spatial light modulation element. FIG. 2 is a side view schematically showing a drawing head. FIG. 2 is a bus wiring diagram conceptually showing a connection relationship between a control unit and other components constituting the drawing device. FIG. 3 is a schematic diagram illustrating a mode of detection in the detection system. 12 is a flowchart illustrating a process for adjusting a focal position. FIG. 7 is a side view illustrating another configuration of the detection system. FIG. 7 is a side view illustrating another configuration of the detection system. FIG. 7 is a side view illustrating another configuration of the detection system. FIG. 3 is a schematic diagram illustrating a detection mode in another detection system. 12 is a flowchart illustrating another process for adjusting the focal position. FIG. 3 is a side view illustrating a positional relationship among a light modulation section, a filter, and a projection optical system. FIG. 7 is a plan view illustrating a modification of the spatial light modulation element. FIG. 7 is a side view illustrating another autofocus technique.

Embodiments of the present disclosure will be described below with reference to the drawings. Note that in the drawings, the dimensions and numbers of each part may be exaggerated or simplified for ease of understanding.

<1. Example of device configuration>
FIG. 1 is a schematic perspective view of a drawing apparatus 100 according to the present disclosure. FIG. 2 is a schematic plan view of the drawing apparatus 100.

The drawing device 100 is a device that exposes a photosensitive substrate 90 to light, and more specifically, draws a desired pattern on the substrate 90. For example, when the drawing device 100 is in charge of a part of the process of manufacturing a printed circuit board, drawing light is applied from the photosensitive layer side to a substrate 90 in which a photosensitive layer, a metal foil, and an insulating substrate are laminated in this order in a desired pattern. to selectively expose the photosensitive layer. The exposed photosensitive layer is selectively removed in a desired pattern or its inverse pattern in a post-exposure development process. The photosensitive layer left after the development process is, for example, a photoresist, and functions as a mask in etching the metal foil.

In FIGS. 1 and 2, for convenience of illustration and explanation, the Z-axis direction is taken to be vertically upward, and both the X-axis direction and the Y-axis direction are taken to be orthogonal to the Z-axis direction. The X-axis direction and the Y-axis direction are orthogonal to each other, and the X-axis, Y-axis, and Z-axis determine a so-called left-handed coordinate system in this order. Hereinafter, the direction along the X axis will be simply referred to as the X direction or +X direction, the direction along the Y axis will be simply referred to as the Y direction or +Y direction, and the direction along the Z axis will simply be referred to as the Z direction or +Z direction. It is called. The direction opposite to the +X direction is referred to as the -X direction, the direction opposite to the +Y direction is referred to as the -Y direction, and the direction opposite to the +Z direction is referred to as the -Z direction.

However, these directions are set for convenience in understanding the positional relationship, and are not intended to limit the directions described below. The same applies to other figures.

The drawing apparatus 100 includes a pedestal 1, a moving plate group 2, an exposure section 3, and a control section 5.

<1-1. Frame 1>
The frame 1 has a substantially rectangular parallelepiped outer shape, and a bridge structure 11 and a movable plate group 2 are fixed to a substantially horizontal region of its Z-direction side surface (hereinafter also referred to as "upper surface") 1a. be done. The bridge structure 11 spans the movable plate group 2 above the movable plate group 2 substantially horizontally. For example, the pedestal 1 integrally supports the moving plate group 2 and the bridge structure 11. In FIG. 2, the crosslinked structure 11 is illustrated by a two-dot chain line in order to improve visibility.

<1-2. Moving plate group 2>
The moving plate group 2 includes a holding plate 21, a support plate 22, a base plate 23, a base 24, a rotating mechanism 211, a sub-scanning mechanism 221, and a main scanning mechanism 231.

The holding plate 21 has a substantially horizontal upper surface 21a, and the upper surface 21a holds the substrate 90 from the −Z direction side (from below). The support plate 22 has a substantially horizontal upper surface 22a, and the upper surface 22a supports the holding plate 21 from below. The base plate 23 has a substantially horizontal upper surface 23a, and the upper surface 23a supports the support plate 22 from below. The base 24 has a substantially horizontal upper surface 24a, and the upper surface 24a supports the base plate 23 from below. The rotation mechanism 211 has a function of rotating the holding plate 21 around the Z axis. The sub-scanning mechanism 221 has a function of moving the support plate 22 in the X direction and the -X direction. The main scanning mechanism 231 has a function of moving the base plate 23 in the Y direction and the -Y direction.

For example, the holding plate 21 holds the substrate 90 by adsorbing it to the upper surface 21a. For example, a plurality of holes (not shown) are provided in a distributed manner on the upper surface 21a. These holes are connected to, for example, a vacuum pump, and the operation of the vacuum pump reduces the air pressure between the substrate 90 and the upper surface 21a. Due to the decrease in atmospheric pressure, the substrate 90 is attracted to and held by the upper surface 21a.

The rotation mechanism 211 has a linear motor 211a and a rotation shaft 211b (see FIG. 2). The linear motor 211a includes a mover and a stator. The mover is attached to the end of the holding plate 21 on the −Y direction side. A stator is provided on the upper surface 22a. The rotation axis 211b is located parallel to the Z-axis between the center portion of the holding plate 21 and the support plate 22, and is drawn by a broken line indicating a hidden line in FIG. By operating the linear motor 211a, the mover moves along the stator in the X direction or the -X direction. This movement causes the holding plate 21 to rotate around the Z-axis within a certain angular range around the rotation axis 211b.

The sub-scanning mechanism 221 includes a linear motor 221a and a pair of guides 221b (see FIG. 2). The linear motor 221a includes a mover 221c and a stator 221d. The mover 221c is attached to the lower surface of the support plate 22. The stator 221d is provided on the upper surface 23a. The pair of guides 221b extend along the X-axis between the support plate 22 and the base plate 23, and are fixed to the upper surface 23a. By operating the linear motor 221a, the mover 221c moves in the X direction or the -X direction along the stator 221d. This movement causes the support plate 22 to move in the X direction or the -X direction on the base plate 23 along the guide 221b.

The main scanning mechanism 231 includes a linear motor 231a and a pair of guides 231b (see FIG. 2). The linear motor 231a includes a mover (not shown) and a stator 231d. The mover is attached to the lower surface of the base plate 23. The stator 231d is provided on the upper surface 24a. The pair of guides 231b extend along the Y-axis between the base plate 23 and the base 24, and are fixed to the upper surface 24a. By operating the linear motor 231a, the movable element of the linear motor 231a moves in the Y direction or the -Y direction along the stator 231d. This movement causes the base plate 23 to move in the Y direction or -Y direction on the base 24 along the guide 231b.

Therefore, by operating the main scanning mechanism 231 while holding the substrate 90 on the holding plate 21, the substrate 90 can be moved along the Y direction or the -Y direction.

Any operation of the rotation mechanism 211, the sub-scanning mechanism 221, and the main scanning mechanism 231 described above is controlled by the control unit 5.

The driving of the rotation mechanism 211, the sub-scanning mechanism 221, and the main scanning mechanism 231 is not limited to using the linear motors 211a, 221a, and 231a described above. For example, in the rotation mechanism 211 and the sub-scanning mechanism 221, a servo motor and a ball screw drive may be used. Instead of moving the substrate 90, a moving mechanism that moves the exposure section 3 may be provided. A moving mechanism that moves both the substrate 90 and the exposure section 3 may be provided. A moving mechanism that moves the holding plate 21 up and down along the Z-axis may be provided to move the substrate 90 up and down.

<1-3. Exposure section 3>
The exposure section 3 includes a plurality of optical units 30, for example, five optical units. Each optical unit 30 has a light source 31, an illumination optical system 32, and a drawing head 33. Although not shown in FIG. 1, each drawing head 33 is provided with a light source 31 and an illumination optical system 32, respectively. In FIG. 2, the drawing head 33 is illustrated by a chain double-dashed line to improve visibility.

The light source 31 supplies light 35 having a required wavelength based on a required drive signal sent from the control unit 5. The wavelength is, for example, 365 to 405 nm. For example, a laser diode is used as the light source 31. In FIG. 1, light 35 is emitted from a light source 31, and its path is schematically drawn with an arrow pointing toward the destination to which the light 35 is transmitted.

The light 35 is guided to the drawing head 33 via the illumination optical system 32. The light 35 emitted from the light source 31 is shaped by the illumination optical system 32 into a rectangular shape, for example, in a plane perpendicular to the optical axis.

Each drawing head 33 has a function of modulating the light 35 emitted from the illumination optical system 32 and irradiating the upper surface of the substrate 90 with the modulated light. The drawing heads 33 are arranged at equal pitches on the upper side of the bridge structure 11 along the X axis, for example.

FIG. 3 is a perspective view schematically showing the optical unit 30. The drawing head 33 includes a light modulation section 4, a projection optical system 330, and an autofocus mechanism 6. The light modulator 4, the projection optical system 330, and the autofocus mechanism 6 are fixed to the fixing member 112. The fixing material 112 is fixed to the bridge structure 11 together with the fixing material 111 described later. Alternatively, the fixing material 112 may be a part of the bridge structure 11, for example, the side surface on the −Y direction side.

The illumination optical system 32 includes a rod integrator 321 placed on the light source 31 side and a lens barrel 322 placed on the drawing head 33 side. The rod integrator 321 increases the uniformity of the spatial distribution of the light 35 emitted from the light source 31. For example, the lens barrel 322 has lenses that implement a double-sided telecentric optical system.

Together, the light source 31 and the illumination optics 32 can be viewed as a first light source 34 that emits light 35. The first light source 34 may include components in addition to the light source 31 and the illumination optical system 32.

The optical unit 30 has a second light source 7. The second light source 7 is located, for example, below the illumination optical system 32 (on the −Z direction side). Only the schematic shape of the second light source 7 is shown in FIG. 3, and the specific configuration will be described later.

The light 35 is emitted to the light modulation section 4, undergoes light modulation (more specifically, spatial modulation) under the control of the control section 5, and becomes drawing light 351 (see FIG. 4; described later). The drawing light 351 enters the projection optical system 330. The projection optical system 330 magnifies the incident drawing light 351 at a required magnification and guides it onto the substrate 90 moving in the main scanning direction.

Projection optical system 330 has lens barrels 331 and 332. The lens barrel 331 is arranged closer to the light modulation section 4 than the lens barrel 332 is. Lens barrels 331 and 332 constitute a double-sided telecentric optical system.

<1-4. Light modulation section 4>
FIG. 4 is a side view illustrating the configuration of the light modulator 4. As shown in FIG. The light modulator 4 includes mirrors 41 and 42 and a spatial light modulator 43.

The light 35 is sequentially reflected by mirrors 41 and 42 and reaches the spatial light modulation element 43. Light 36 is emitted from the second light source 7. The light 36 reaches the spatial light modulation element 43. The wavelength of the light 36 is longer than the wavelength of the light 35, for example 450 nm. In FIG. 4, a case is illustrated in which the light 36 reaches the spatial light modulation element 43 without passing through the mirrors 41 and 42. The light 36 may be reflected by the mirrors 41 and 42 and reach the spatial light modulation element 43.

The second light source 7 includes, for example, a laser diode 710 that emits light 36 and lenses 711 and 712. Lenses 711 and 712 constitute a so-called 4f optical system. The light 36 travels through lenses 711 and 712 in this order and is emitted from the second light source 7.

The light 35 enters the spatial light modulator 43, and the spatial light modulator 43 optically modulates the light 35 to obtain drawing light 351. The spatial light modulator 43 emits drawing light 351. The spatial light modulation element 43 functions as a modulator that spatially modulates the light 35 based on a pattern and emits drawing light 351.

<1-4-1. First embodiment>
In the first embodiment, the light 36 passes through the spatial light modulation element 43 and enters the projection optical system 330 as detection light 361. Since the detection light 361 is used to detect the focal position of the projection optical system 330, it is also referred to as detection light 361.

The detection light 361 may be optically modulated when passing through the spatial light modulation element 43, or may not be optically modulated. First, the case where the light 36 is optically modulated in the spatial light modulation element 43 and the detection light 361 is emitted will be explained, and the case where the detection light 361 that is not optically modulated is emitted will be explained in <4-1 below. ．． Modification of spatial light modulation element 43> will be explained.

Note that the case where the light 36 enters the projection optical system 330 as the detection light 361 without passing through the spatial light modulation element 43 is explained in <3. Second Embodiment>. Furthermore, a summary of the first embodiment, second embodiment, and modifications will be provided in <5. GENERAL DESCRIPTION>.

The drawing light 351 and the detection light 361 enter the projection optical system 330, more specifically, the lens barrel 331.

FIG. 5 is a side view illustrating light incident on the spatial light modulation element 43 and light emitted from the spatial light modulation element 43. The incident light corresponds to the lights 35 and 36, and part of the output light corresponds to the drawing light 351 and the detection light 361.

For example, a digital mirror device is adopted as the spatial light modulation element 43. The digital mirror device includes square mirrors 43m each having a side of about 10 μm and arranged in a 1920×1080 matrix, for example. Each of the mirrors 43m is tilted at a required angle about the diagonal of the square in accordance with the data written in the memory cell. Each of the mirrors 43m is driven simultaneously by a reset signal from the control section 5. A digital mirror device reflects incident light onto itself in, for example, two directions.

When a digital mirror device is employed as the spatial light modulation element 43, each of the mirrors 43m reflects the light 35 in different directions: light employed as the drawing light 351, and light that does not contribute to exposure.

The mirrors 43m are arranged along a plane 43a that serves as a reference for their inclination. For example, the surface 43a is perpendicular to the Z direction, and the mirrors 43m are two-dimensionally arranged in the X direction and the Y direction.

The normal vector Nn of the mirror 43m marked with [on] (hereinafter also referred to as "mirror 43m in the on state") is inclined at an inferior angle θn with respect to the -Y direction and perpendicular to the X direction. It is. The normal vector Nf of the mirror 43m marked with [off] (hereinafter also referred to as "off-state mirror 43m") is inclined at an inferior angle θf to the Y direction and perpendicular to the X direction. be. For example, the inferior angles θn and θf are both 78 degrees, and the mirror 43m reflects the lights 35 and 36 with a surface inclined at 12 degrees or -12 degrees with respect to the Y direction with respect to the surface 43a.

Both of the lights 35 and 36 enter the spatial light modulator 43, more specifically, the mirror 43m, from the -Z direction side. For example, the light 35 is perpendicular to the X direction and incident on the −Z direction side surface of the mirror 43m at an angle of (θn−θ5n)=180 (degrees)−(θf+θ5f) with respect to the Y direction. For example, the light 36 is perpendicular to the X direction and is incident on the −Z direction side surface of the mirror 43m at an angle of (θn+θ6n)=180 (degrees)−(θf−θ6f) with respect to the −Y direction. The sum of the inferior angle θn and the angle θ5n and the sum of the inferior angle θf and the angle θ6f are both 90 degrees. For example, there is a relationship of θn=θf and θ5n=θ6f.

The light 35 enters the mirror 43m in the ON state at an incident angle of θ5n, and is emitted from the surface at a reflection angle of θ5n. The light 35 reflected by the mirror 43m in the on state advances to the projection optical system 330 as drawing light 351.

The light 35 is incident on the off-state mirror 43m at an incident angle of θ5f, and is emitted from the surface at a reflection angle of θ5f. The light 35 reflected by the off-state mirror 43m does not proceed to the projection optical system 330 and does not contribute to exposure.

The light 36 enters the off-state mirror 43m at an incident angle of θ6f, and is emitted from the surface at a reflection angle of θ6f. The light 36 reflected by the off-state mirror 43m advances to the projection optical system 330 as detection light 361.

The light 36 enters the mirror 43m in the on state at an incident angle of θ6n, and is emitted from the surface at a reflection angle of θ6n. The light 36 reflected by the on-state mirror 43m does not proceed to the projection optical system 330 and does not contribute to the detection of the focal position.

The pattern employed for light modulation in the spatial light modulation element 43 is projected onto the substrate 90 by the projection optical system 330. The pattern is continuously rewritten by a reset pulse. The reset pulse is generated based on the encoder signal of the main scanning mechanism 231 as the holding plate 21 is moved by the main scanning mechanism 231, as will be described later. By continuously rewriting the pattern and moving the holding plate 21, the drawing light 351 incident on the substrate 90 forms an image reflecting the pattern on the substrate 90.

The drawing light 351 reaches the substrate 90 from the light modulation section 4 via the projection optical system 330 and a second optical system described later.

The light 35 is modulated by the light modulator 4 to obtain drawing light 351, and the drawing light 351 is irradiated onto the substrate 90. The drawing light 351 is employed to expose the substrate 90, and the light 35 is used to generate the drawing light 351.

<1-5. Relative movement between substrate 90 and exposure section 3>
In the drawing process, under the control of the control unit 5, the main scanning mechanism 231 and the sub-scanning mechanism 221 move the substrate 90 placed on the holding plate 21 relative to the plurality of drawing heads 33, while This is performed by irradiating the exposure surface of the substrate 90 (the surface on the exposure unit 3 side: here, a part or all of the upper surface of the substrate 90) with the drawing light 351 from each of the drawing heads 33.

The moving direction of the drawing head 33 as seen from the substrate 90 when the substrate 90 is moved by the main scanning mechanism 231 is adopted as the main scanning direction. The sub-scanning mechanism 221 adopts the moving direction of the drawing head 33 as seen from the substrate 90 when the substrate 90 moves as the sub-scanning direction.

The main scanning mechanism 231 moves the holding plate 21 in the −Y direction. Thereby, the drawing head 33 moves in the Y direction relative to the substrate 90, and main scanning is realized. While main scanning is performed, the drawing head 33 continuously irradiates the exposure surface of the substrate 90 with drawing light 351. Thereby, the desired pattern is projected onto the exposure surface of the substrate 90. When each drawing head 33 crosses the substrate 90 once along the Y direction, a pattern corresponding to the drawing light 351 is drawn in a strip shape extending in the Y direction. By traversing the substrate 90 in parallel with the plurality of drawing heads 33, a plurality of strip-shaped patterns are drawn by one main scan.

After the above-described main scanning is completed, the holding plate 21 is moved in the +X direction by the sub-scanning mechanism 221. As a result, the drawing head 33 moves in the −X direction relative to the substrate 90, and sub-scanning is realized. The amount of movement of the drawing head 33 relative to the substrate 90 in the sub-scanning is, for example, greater than or equal to the width of the strip pattern obtained by one main-scanning.

After the above-described sub-scanning is completed, the main scanning mechanism 231 moves the holding plate 21 in the Y direction. Thereby, the drawing head 33 moves in the −Y direction relative to the substrate 90, and main scanning is realized. While main scanning is performed, each drawing head 33 continuously irradiates the substrate 90 with drawing light 351.

A plurality of such main scans are performed in which the main scanning directions are opposite to each other with the sub-scans in between (in the above example, two types of main scanning directions, -Y direction and Y direction, are adopted), and the substrate 90 is When the pattern is drawn over the entire region to be drawn on the exposure surface, the drawing process ends.

<1-6. Projection optical system 330 and autofocus mechanism 6>
FIG. 6 is a side view schematically showing the drawing head 33. As shown in FIG. As shown in FIG. 6, each of the drawing heads 33 is provided with an autofocus mechanism 6.

The autofocus mechanism 6 includes a detection system 60 and a movement mechanism 63. In FIG. 3, the approximate position of the detection system 60 is illustrated by a chain double-dashed line in order to improve visibility. In FIG. 6, in order to improve visibility, the detection system 60 is drawn enlarged and shifted in the Y direction from its actual position. In FIG. 6, the positional relationship between the detection system 60 and the fixing member 112 does not necessarily reflect the actual positional relationship.

The detection system 60 includes, for example, a low-pass filter 64 and a detection section 65A. The drawing light 351 and the detection light 361 both emitted from the projection optical system 330 enter the low-pass filter 64 . The low-pass filter 64 transmits the drawing light 351 and reflects the detection light 361. The cutoff wavelength of the low-pass filter 64 is set between the wavelength of the light 35 and the wavelength of the light 36, and is, for example, 440 nm.

The low-pass filter 64 functions as an optical system that guides the drawing light 351 to the substrate 90 and emits the detection light 361 while avoiding the substrate 90. From this viewpoint, the projection optical system 330 can be regarded as a first optical system, and the low-pass filter 64 can be regarded as a second optical system.

The detection unit 65A detects the focal position of the projection optical system 330. The moving mechanism 63 adjusts the focus of the drawing light 351 based on the focus position detected by the detection unit 65A. The moving mechanism 63 corrects the focal position of the projection optical system 330.

The detection unit 65A includes a prism 651 and a detector 652. The prism 651 includes, for example, a ridgeline 651a and a surface 651b facing the ridgeline 651a. The detection light 361 emitted from the low-pass filter 64 is incident on the ridge line 651a. The surface 651b branches the detection light 361 incident on the ridgeline 651a into lights 361a and 361b and emits the lights. Here, a case is exemplified in which the light 361a is emitted to the Z direction side more than the light 361b.

The detector 652 is, for example, a one-dimensional detector, and has a function of detecting the position of light in one direction. Lights 361a and 361b are incident on the detector 652. Here, a case is illustrated in which the positions where the lights 361a and 361b are incident on the detector 652 are detected along the Z direction. A method for detecting the focal position of the projection optical system 330 from this position will be described later.

For example, the detection system 60 is fixed to the drawing head 33, specifically to the lens barrel 332, by an attachment mechanism 62 that will be described later.

The autofocus mechanism 6 has a moving mechanism 63. The moving mechanism 63 moves the lens barrel 332 or both the lens barrels 331 and 332 in the Z direction or the -Z direction depending on the focal position detected by the detection unit 65A. By this movement, the focus of the drawing light 351 is adjusted.

The amount of variation detected by the detection unit 65A is transmitted to the control unit 5 or a dedicated arithmetic circuit (not shown), and arithmetic processing is performed according to a desired program. Through this calculation process, the amount of elevation of the lens barrel 332 or the lens barrels 331, 332 by the moving mechanism 63 is determined.

<1-7. Control unit 5>
FIG. 7 is a bus wiring diagram conceptually showing the connection relationship between the control unit 5 and other components constituting the drawing apparatus 100.

The control unit 5 includes a display unit 56, an operation unit 57, a rotation mechanism 211, a sub-scanning mechanism 221, a main scanning mechanism 231, a light source 31 (more specifically, a driver that drives the light source 31), and a light modulation unit 4 (more specifically, a driver that drives the light source 31). Specifically, the spatial light modulator 43), the autofocus mechanism 6, and the second light source 7 (more specifically, the laser diode 710) are connected, for example, by bus wiring, a network line, or a serial communication line. and controls the operation of each of these components.

The control unit 5 includes a central processing unit (Central Processing Unit: denoted as “CPU” in the figure) 51, a read-only memory (Read Only Memory: denoted as “ROM” in the figure) 52, and a volatile memory (for example, Random Access). Memory (denoted as "RAM" in the figure) 53 and non-volatile memory 54. The memory 53 is mainly used as a temporary working area for the central processing unit 51. A hard disk drive (HDD) or a solid state drive (SSD) may be used instead of the memory 54.

Memory 52 stores a program 55. The central processing unit 51 reads a program 55 from the memory 52 and executes the program 55 to perform calculations on various data stored in the memory 53 or the memory 54. The control unit 5 includes a central processing unit 51, a memory 52, a memory 53, and a memory 54, thereby having a configuration as a general computer.

The central processing unit 51 controls the operations of the rotating mechanism 211, the sub-scanning mechanism 221, the main scanning mechanism 231, and the autofocus mechanism 6. For example, the central processing unit 51 controls the operations of the linear motors 211a, 221a, 231a and the movement mechanism 63. This control function is depicted as a mechanism control section 511 which is a functional block realized by the central processing section 51 operating according to the program 55. Part or all of the mechanism control unit 511 may be realized by a logic circuit or the like.

The memory 54 stores pattern data 541 and drawing position information 545. A pattern reflecting the pattern data 541 is drawn on the substrate 90. The pattern data 541 is, for example, image data obtained by developing vector format data created by CAD software or the like into raster format data.

The pattern data 541 is generated individually for each drawing head 33 from one piece of pattern data, for example, as data regarding a portion that each drawing head 33 is in charge of drawing.

The control unit 5 causes the drawing light 351 to be emitted from the drawing head 33 by controlling the light modulation unit 4 based on the pattern data 541.

The central processing unit 51 modifies the pattern data 541 in synchronization with the position of the drawing light 351 that moves by main scanning, and controls the light modulation in the light modulation unit 4, more specifically, the spatial light modulation element 43. This control function is depicted as a drawing control section 513, which is a functional block realized by the central processing section 51 operating according to the program 55. Part or all of the drawing control unit 513 may be realized by a logic circuit or the like.

The drawing position information 545 reflects the position of the drawing light 351 that moves during main scanning. Alternatively, reflecting the drawing position information 545, the position of the drawing light 351 is moved by main scanning. For example, the drawing control unit 513 generates a reset pulse for light modulation and drawing position information 545 based on a linear scale signal sent from the linear motor 231a of the main scanning mechanism 231. The drawing position information 545 is stored in the memory 54.

Drawing light 351 modulated according to the position of the substrate 90 is emitted from each drawing head 33 by the light modulator 4 that operates based on this reset pulse.

For the display unit 56, for example, a general monitor or a liquid crystal display is used. The display unit 56 displays various data to the operator under the control of the control unit 5. The operation unit 57 uses, for example, buttons, keys, a mouse, or a touch panel. The operation unit 57 is operated by an operator, and instructions for the drawing apparatus 100 are input.

<2. Example of focus position adjustment>
<2-1. First example>
FIG. 8 is a schematic diagram illustrating a detection mode in the detection section 65A. Specifically, in FIG. 8, a surface 652a, regions 362a, 363a, 364a, 362b, 363b, and 364b are illustrated. Detector 652 has a surface 652a that detects the position of incident light. Light 361a and 361b enter the surface 652a from the prism 651. The closer the lights 361a and 361b incident on the surface 652a are, the closer the focal position of the projection optical system 330 is to the lens barrel 332.

With respect to the surface 652a, the lights 361a and 361b in the first situation are incident on the regions 362a and 362b, respectively. With respect to surface 652a, light 361a and 361b in the second situation are incident on regions 363a and 363b, respectively. With respect to surface 652a, light 361a and 361b in the third situation are incident on regions 364a and 364b, respectively.

In the first situation, the focus position is in the appropriate range. In the second situation, the focal position is in a range farther from the projection optical system 330 (this can also be said to be farther from the lens barrel 332) than an appropriate range. In the third situation, the focal position is in a range closer to the projection optical system 330 (which can also be said to be closer to the lens barrel 332) than the appropriate range.

Distance D2 indicates the interval between regions 362a and 362b. Distance D3 indicates the interval between regions 363a and 363b. Distance D4 indicates the interval between regions 364a and 364b. The distance D2 is within the range from the threshold value Dt1 to the threshold value Dt2 (>Dt1). Distance D3 is greater than threshold Dt2. Distance D4 is smaller than threshold Dt1.

FIG. 9 is a flowchart illustrating the process of adjusting the focus position. For convenience, this process is also referred to as "focus adjustment process" in the drawings and the following description. The focus adjustment process includes steps S11, S12, S13, and S14.

In the focus adjustment process, it is determined in step S11 whether the distance Di is smaller than the threshold Dt1. Here, the distance Di refers to the interval between regions on which the lights 361a and 361b are incident on the surface 652a. The distance Di in the first situation is exemplified by the distance D2, the distance Di in the second situation is exemplified by the distance D3, and the distance Di in the third situation is exemplified by the distance D4.

If the determination result in step S11 is positive (see areas 364a and 364b: D4<Dt1), the focal position is closer to the projection optical system 330 than the appropriate range corresponding to the third situation. In this case, in step S12, a process is performed to relatively separate the lens barrel 332 from the lens barrel 331 along the optical axis of the double-sided telecentric optical system constituted by the lens barrels 331 and 332. Specifically, the moving mechanism 63 moves, for example, the lens barrel 332 in the -Z direction (lower down). By separating the lens barrel 332 from the lens barrel 331, the focal position moves away from the projection optical system 330 and approaches an appropriate range. Step S12 can also be said to be a step of correcting the focal position. After step S12 is executed, the focus adjustment process ends.

If the determination result in step S11 is negative, it is determined in step S13 whether the distance Di is larger than the threshold Dt2.

If the determination result in step S13 is positive (see areas 363a and 363b: Dt2<D3), the focal position is farther from the projection optical system 330 than the appropriate range corresponding to the second situation. In this case, in step S14, a process of moving the lens barrel 332 relatively closer to the lens barrel 331 along the above-mentioned optical axis is executed. Specifically, the moving mechanism 63 moves the lens barrel 332 in the Z direction (raises it upward), for example. By bringing the lens barrel 332 closer to the lens barrel 331, the focal position moves closer to the projection optical system 330 and approaches an appropriate range. Step S14 can also be said to be a step of correcting the focal position. After step S14 is executed, the focus adjustment process ends.

If the determination result in step S13 is negative, Dt1≦Di≦Dt2 (see areas 362a and 362b: Dt1≦D2≦Dt2), and the focal position is within an appropriate range corresponding to the first situation. . In this case, the focus adjustment process ends without changing the distance between the lens barrels 331 and 332.

The focal position of the projection optical system 330, through which the drawing light 351 advances, is detected using the detection light 361, which travels through the projection optical system 330 in parallel with the drawing light 351. Through such detection, it is easy to confirm whether the correction of the focal position of the drawing light 351 is appropriate. The detection light 361 is not emitted to the substrate 90, and the detection and correction of the focal position does not easily affect the exposure of the substrate 90 by the drawing light 351.

The variation in the refractive index of a lens due to the thermal lens effect depends on the wavelength of light traveling through the lens. From this point of view, it is desirable that the wavelength of the detection light 361 is close to the wavelength of the drawing light 351, and that the difference in wavelength between the lights 35 and 36 is small. On the other hand, from the viewpoint of setting the cutoff wavelength of the low-pass filter 64 so that the detection light 361 is not emitted to the substrate 90, it is desirable that the difference in wavelength between the lights 35 and 36 is large.

In the focus adjustment process described above, detection and correction of the focus position are performed in parallel with the exposure process. For example, the focus adjustment process is repeatedly executed every cycle when the drawing apparatus 100 is controlled.

The order of execution of the pair of steps S11 and S12 and the pair of steps S13 and S14 may be reversed.

In steps S12 and S14, the amount by which the relative positions of the lens barrels 331 and 332 change is appropriately set. For example, in step S12, the relative positions of the lens barrels 331 and 332 are increased by an amount obtained by PID control (Proportional-Integral-Differential Controller) based on the difference between the distance Di and the threshold value Dt1. For example, in step S14, the relative positions of the lens barrels 331 and 332 are decreased by an amount obtained by PID control based on the difference between the distance Di and the threshold value Dt2.

<2-2. Second example>
10, 11, and 12 are side views illustrating other configurations of the detection system 60. In the following, a case will be exemplified in which the detection system 60 includes a low-pass filter 64 and a detection section 65B. In the detection system 60 according to the example, the detection section 65A (see FIG. 6) according to the first example is replaced with the detection section 65B.

The detection unit 65B detects the focal position of the projection optical system 330. The moving mechanism 63 adjusts the focus of the drawing light 351 based on the focus position detected by the detection unit 65B. The moving mechanism 63 corrects the focal position of the projection optical system 330.

The detection unit 65B has a knife edge 653 and a detector 654. The knife edge 653 transmits light 361c, which is part or all of the detection light 361 emitted from the low-pass filter 64. For example, the knife edge 653 is located at the same position Qj (see FIG. 10) where the detection light 361 is focused in the first situation (the focal length is in an appropriate range) in the direction of the optical axis C of the detection light 361. placed in position. The tip of the knife edge 653 is located slightly on the −Z side with respect to the optical axis C. The detection light 361 undergoes so-called vignetting due to the knife edge 653. When the position where the light 361c is focused deviates from the position Qj, the knife edge 653 partially blocks the detection light 361 on the −Z direction side (see FIGS. 11 and 12). From this point of view, the knife edge 653 can be said to be a shield that partially blocks the detection light 361 while transmitting it. However, when the detection light 361 is focused at the position Qj, the knife edge 653 does not substantially block the detection light 361.

Light 361c is incident on the detector 654. The detector 654 has a pair of light amount sensors 654a and 654b. The light amount sensors 654a and 654b have a function of outputting a signal according to the amount of incident light. Here, a case is illustrated in which the light amount sensor 654a is located closer to the Z direction than the light amount sensor 654b. The light receiving surface of the light amount sensor 654a and the light receiving surface of the light amount sensor 654b are provided adjacent to each other in the Z direction, and the position of the boundary between these light receiving surfaces in the Z direction is at a predetermined distance from the position of the optical axis C in the Z direction. Leave. In the following, for the sake of simplicity, a case will be exemplified in which the two positions in the Z direction match (the case where the above-mentioned predetermined distance is substantially zero).

The amount of light detected by the detection section 65B is transmitted to the control section 5 or a dedicated arithmetic circuit (not shown), and arithmetic processing is performed according to a desired program. Through this calculation process, the amount of elevation of the lens barrel 332 or the lens barrels 331, 332 by the moving mechanism 63 is determined.

FIG. 13 is a schematic diagram illustrating a detection mode in the detector 654. In FIG. 13, light receiving surfaces 654am and 654bm of light amount sensors 654a and 654b included in the detector 654 are shown. The light 361c is incident on the light receiving surfaces 654am and 654bm. A case will be described in which the boundary 654d between the light receiving surface 654am and the light receiving surface 654bm coincides with the position of the optical axis C in the Z direction, as described above.

Region Mj corresponds to the detection mode in FIG. 10, and the region where the light 361c is incident on the light receiving surfaces 654am and 654bm in the above-described first situation is indicated by a solid line. In the first situation, the detection light 361 is focused at a position Qj directly above the tip of the knife edge 653 (on the Z direction side), so the light 361c is not substantially blocked by the knife edge 653 and is received. The light is incident on surfaces 654am and 654bm. In this case, the light amount Ea of the light 361c detected on the light receiving surface 654am and the light amount Eb of the light 361c detected on the light receiving surface 654bm are approximately equal.

FIG. 11 illustrates focusing of the detection light 361 in the above-mentioned second situation (in which the focal position is farther from the projection optical system 330 than in the first situation). In the second situation, the position Qr where the detection light 361 is focused is located on the Y direction side from directly above the tip of the knife edge 653. The knife edge 653 blocks a portion of the detection light 361 on the −Z direction side.

Region Mr in FIG. 13 corresponds to the detection mode in FIG. 11, and a region where the light 361c is incident on the light receiving surfaces 654am and 654bm in the above-mentioned second situation is indicated by a chain line. Since the position Qr is on the Y direction side more than the position Qj, the diameter of the region Mr is smaller than the diameter of the region Mj.

The light amount Ea of the light 361c incident on the light receiving surface 654am is smaller than in the first situation because the detection light 361 is blocked by the knife edge 653. On the other hand, the light 361c incident on the light receiving surface 654bm is not blocked by the knife edge 653. Therefore, the light amount Eb of the light 361c incident on the light receiving surface 654bm is approximately the same as in the first situation. The more the focal point position shifts in the -Z direction of the projection optical system 330, the more the detection light 361 is blocked by the knife edge 635, and the light amount Ea becomes smaller than the light amount Eb.

FIG. 12 illustrates focusing of the detection light 361 in the above-mentioned third situation (a situation where the focal position is closer to the projection optical system 330 than in the first situation). In the third situation, the position Qs where the detection light 361 is focused is located on the −Y direction side from directly above the tip of the knife edge 653. The knife edge 653 blocks a portion of the detection light 361 on the Z direction side.

A region Ms in FIG. 13 corresponds to the detection mode in FIG. 12, and a region where the light 361c is incident on the light receiving surfaces 654am and 654bm in the above-mentioned third situation is indicated by a two-dot chain line. Since the position Qs is located on the -Y direction side of the position Qj, the diameter of the region Ms is larger than the diameter of the region Mj.

The light amount Eb is smaller than in the first situation because the detection light 361 is blocked by the knife edge 653. On the other hand, the light 361c incident on the light receiving surface 654am is not blocked by the knife edge 653. Therefore, the light amount Ea is approximately the same as in the first situation. As the focal position shifts in the Z direction of the projection optical system 330, the proportion of the detection light 361 that is blocked by the knife edge 635 increases, and the light amount Eb becomes smaller than the light amount Ea.

From the above, the focal position can be detected by detecting the light amounts Ea and Eb or by detecting the ratio of the two.

FIG. 14 is a flowchart illustrating the process of adjusting the focus position. Similar to the flowchart illustrated in FIG. 9, this process is also referred to as "focus adjustment process" for convenience. The focus adjustment process includes steps S21, S22, S23, and S24.

In the focus adjustment process, in step S21, the light quantities Ea and Eb are detected, and it is determined whether their ratio Ea/Eb is larger than a predetermined threshold T1. The threshold T1 is a predetermined value larger than 1, and is set in advance in consideration of detection errors in the light amounts Ea and Eb, an allowable amount of shift in the focal position, and the like.

If the determination result in step S21 is affirmative, the focal position is closer to the projection optical system 330 than the appropriate range corresponding to the third situation described above. In this case, in step S22, similarly to step S12, a process of relatively separating the lens barrel 332 from the lens barrel 331 is performed along the optical axis of the double-sided telecentric optical system constituted by the lens barrels 331 and 332. Specifically, the moving mechanism 63 moves, for example, the lens barrel 332 in the -Z direction (lower down). By separating the lens barrel 332 from the lens barrel 331, the focal position moves away from the projection optical system 330 and approaches an appropriate range. Step S22 can also be said to be a step of correcting the focal position. After step S22 is executed, the focus adjustment process ends.

If the determination result in step S21 is negative, it is determined in step S23 whether the ratio Ea/Eb is smaller than a threshold value T2. The threshold T2 is a predetermined value greater than 0 and less than 1, and is set in advance in consideration of detection errors in the light quantities Ea and Eb, an allowable amount of shift in the focal position, and the like.

If the determination result in step S23 is positive, the focal position is farther from the projection optical system 330 than the appropriate range corresponding to the second situation described above. In this case, in step S24, similarly to step S14, a process of moving the lens barrel 332 relatively closer to the lens barrel 331 along the above-mentioned optical axis is executed. Specifically, the moving mechanism 63 moves the lens barrel 332 in the Z direction (raises it upward), for example. By bringing the lens barrel 332 closer to the lens barrel 331, the focal position moves closer to the projection optical system 330 and approaches an appropriate range. Step S24 can also be said to be a step of correcting the focal position. After step S24 is executed, the focus adjustment process ends.

If the determination result in step S23 is negative, the focus position is within an appropriate range corresponding to the first situation described above. In this case, the focus adjustment process ends without changing the distance between the lens barrels 331 and 332.

In the focus adjustment process in the second example, as well as in the focus adjustment process in the first example, the focal position of the projection optical system 330 where the drawing light 351 advances is determined by the focus position of the projection optical system 330 where the drawing light 351 advances in parallel with the projection optical system 330. It is detected using the detection light 361. Through such detection, it is easy to confirm whether the correction of the focal position of the drawing light 351 is appropriate. The detection light 361 is not emitted to the substrate 90, and the detection and correction of the focal position does not easily affect the exposure of the substrate 90 by the drawing light 351.

Also in the focus adjustment process in the second example, detection and correction of the focus position are performed in parallel with the exposure process. For example, the focus adjustment process is repeatedly executed every cycle when the drawing apparatus 100 is controlled.

The order of execution of the pair of steps S21 and S22 and the pair of steps S23 and S24 may be reversed.

In steps S22 and S24, the amount by which the relative positions of the lens barrels 331 and 332 change is appropriately set. For example, the amount by which the relative positions of the lens barrels 331 and 332 change is adjusted depending on the value of the ratio Ea/Eb. For example, the adjustment is made such that the farther the value of the ratio Ea/Eb is from 1, the greater the amount by which the relative positions of the lens barrels 331 and 332 change.

<3. Second embodiment>
In the second embodiment, a case is illustrated in which the detection light 361 enters the projection optical system 330 without passing through the spatial light modulation element 43. Other configurations and functions are common between the first embodiment and the second embodiment. For example, in the second embodiment, similarly to the first embodiment, the detection system 60 has either a detection section 65A or 65B, and the distance between the lens barrels 331 and 332 is determined based on the focal position. be adjusted.

FIG. 15 is a side view illustrating the configuration of the light modulator 4. As shown in FIG. For example, the configuration shown using FIG. 4 is adopted as the configuration of the light modulation section 4. In the second embodiment, the drawing device 100 includes a low-pass filter 46. The low-pass filter 46 is located between the spatial light modulation element 43 and the projection optical system 330 (more specifically, the lens barrel 331). The low-pass filter 46 transmits the drawing light 351, reflects the light 36 emitted from the second light source 7, and emits the detection light 361 to the projection optical system 330 (more specifically, the lens barrel 331). It functions as a filter that guides you.

For example, the cutoff wavelength of the low-pass filter 46 is also set between the wavelength of the light 35 and the wavelength of the light 36, similar to the cutoff wavelength of the low-pass filter 64. For example, the wavelength of the light 35 is 365 to 405 nm, the wavelength of the light 36 is 450 nm, and the cutoff wavelength is 440 nm.

In the first embodiment, the detection light 361 emitted from the spatial light modulation element 43 is obtained by reflection of the light 36 by the mirror 43m in the OFF state. In the second embodiment, much of the light 36 can be used as the detection light 361 emitted from the low-pass filter 46. The second embodiment is superior to the first embodiment in that detection light 361 having a desired intensity or higher can be obtained. The first embodiment is different from the second embodiment in that there is no need to separately provide a component (low-pass filter 46 in this case) that makes the light 36 enter the projection optical system 330 as the detection light 361. Excellent at

<4. Transformation＞
<4-1. Modification of spatial light modulation element 43>
FIG. 16 is a plan view illustrating a modification of the first embodiment. FIG. 16 is a plan view of the spatial light modulation element 43 as seen along the Z direction.

In this modification, the spatial light modulator 43 has a region 430 in which mirrors 43m (see FIG. 5) are arranged in a matrix. The region 430 appears on the −Z direction side in the spatial light modulation element 43. For example, light 35 enters the region 430 perpendicular to the X direction and along the Y direction in plan view, and light 36 enters the region 430 perpendicular to the X direction and along the −Y direction in plan view (see FIG. 5).

The region 430 has a first region 431 and a second region 432 that are different from each other. The first region 431 spatially modulates the light 35 based on a pattern used for exposure and emits drawing light 351. The second region 432 emits the light 36 as the detection light 361 to the projection optical system 330 regardless of the pattern. The light 36 that enters the first region 431 may be reflected by the off-state mirror 43m and output as detection light 361 to the projection optical system 330.

Since the light 36 incident on the second region 432 is reflected as the detection light 361, this modification is different from the first embodiment in that the detection light 361 having a desired intensity or more can be obtained. Excellent. Furthermore, this modification is superior to the second embodiment in that there is no need to separately provide a component (for example, a low-pass filter 46) that makes the light 36 enter the projection optical system 330 as the detection light 361.

<4-2. Use with other autofocus technologies>
FIG. 17 is a side view illustrating a case where the autofocus mechanism 6 is used in combination with other autofocus techniques. The moving mechanism 63 may move the lens barrel 332 not only based on the focal position of the projection optical system 330 but also based on the distance between the substrate 90 and the projection optical system 330.

In FIG. 17, for ease of illustration, the approximate position of the detection system 60 is indicated by a chain double-dashed line (see also FIG. 3). In FIG. 17, the optical axis L3 of the drawing light 351 is also indicated by a chain double-dashed line.

The autofocus mechanism 6 includes a detector 61 and a mounting mechanism 62. The attachment mechanism 62 is provided on the outer peripheral surface of the lens barrel 332. The detection system 60 and the detector 61 are fixed to the drawing head 33, specifically to the lens barrel 332, by an attachment mechanism 62.

The detector 61 detects a change in the distance L1 between the drawing head 33 and the substrate 90 (specifically, the exposure surface). The moving mechanism 63 moves the lens barrel 332 based on the variation in the distance L1 detected by the detector 61, and adjusts the focus of the drawing light 351.

The amount of variation detected by the detector 61 is transmitted together with the focal position detected by the detection system 60 to the control unit 5 or a dedicated arithmetic circuit (not shown), where arithmetic processing is performed according to a desired program. Through this calculation process, the amount of elevation of the lens barrel 332 or the lens barrels 331, 332 by the moving mechanism 63 is determined.

The detector 61 includes an irradiation section 611 that irradiates the substrate 90 with laser light, and a light receiving section 613 that receives the laser light reflected from the substrate 90.

The irradiation unit 611 makes laser light incident on the upper surface of the substrate 90 along an axis inclined at an acute angle θ with respect to the normal direction to the exposure surface of the substrate 90 (here, the Z direction). The laser beam irradiates the position 91 in a spot shape, is reflected, and enters the light receiving section 613. Here, a case is illustrated in which the laser beam is perpendicular to the Y axis.

The light receiving section 613 includes, for example, a line sensor (not shown). Changes in the exposed surface of the substrate 90 are detected based on the incident position of the laser beam reflected from the position 91 on the line sensor.

<5. General explanation>
The above disclosure can be explained as follows from the perspective of the configuration of the drawing apparatus 100.

The drawing device 100 is a device that exposes a photosensitive substrate 90 with drawing light 351 based on a pattern. The pattern reflects pattern data 541 stored in the memory 54, for example.

The drawing device 100 includes a first light source 34 . The first light source 34 emits light 35 having a first wavelength. In the above example, the first light source 34 includes a light source 31 and an illumination optical system 32. The first wavelength is, for example, 365 to 405 nm.

The drawing device 100 includes a spatial light modulation element 43. The spatial light modulation element 43 is a modulator that spatially modulates the light 35 based on the above-described pattern and emits the drawing light 351.

The drawing device 100 includes a second light source 7. The second light source 7 emits light 36 having a second wavelength. The second wavelength is different from the first wavelength and is, for example, 440 nm.

The drawing device 100 includes a projection optical system 330. The projection optical system 330 is a first optical system that receives the drawing light 351 and the detection light 361 and outputs the drawing light 351 and the detection light 361.

The detection light 361 may be obtained when the light 36 is obtained by spatial light modulation by the spatial light modulation element 43 (see <1-4-1. First Embodiment>) or when the light 36 is reflected by the low-pass filter 46. (see <3. Second Embodiment>) or when the spatial light is reflected without being modulated by the spatial light modulation element 43 (<4-1. Modification of the spatial light modulation element 43 >Reference). Whether the light 36 is obtained by spatial light modulation by the spatial light modulation element 43 or the light 36 is obtained by being reflected without being spatially modulated, the light 36 passes through the spatial light modulation element 43 and becomes detection light. They are common in that they enter the projection optical system 330 as 361.

The light 35 used as the drawing light 351 can be called first light, and correspondingly, the light 36 used as the detection light 361 can be called second light. The optical modulation in the present disclosure is spatial modulation, and the wavelength of the detection light 361 is maintained at the wavelength of the light 36 regardless of whether spatial modulation or reflection is used. Further, as in the second embodiment, the light 36 may be employed as the detection light 361 without being spatially modulated. From these facts, it can be said that the second light source 7 emits second light having a second wavelength.

The drawing device 100 includes a low-pass filter 64. The low-pass filter 64 receives the drawing light 351 emitted from the projection optical system 330, which is the first optical system, and the detection light 361, which is the second light, and outputs the drawing light 351 and the detection light 361. This is the second optical system. The second optical system guides the drawing light 351 emitted from the first optical system to the substrate 90 and emit the detection light 361 emitted from the first optical system while avoiding the substrate 90 .

The drawing device 100 includes a detection section 65A or a detection section 65B. Both of the detection units 65A and 65B detect the focal position of the projection optical system 330, which is the first optical system, based on the detection light 361 emitted from the low-pass filter 64, which is the second optical system.

As illustrated in the second embodiment, the drawing device 100 may include the low-pass filter 46. The low-pass filter 46 is located between the spatial light modulation element 43, which is a modulator, and the projection optical system 330, which is a first optical system. The low-pass filter 46 is a filter that transmits the drawing light 351, reflects the light 36, and guides it from the second light source 7 to the first optical system.

Both low pass filters 46 and 64 have a cutoff wavelength between the first wavelength and the second wavelength. In the present disclosure, 440 nm is exemplified as the cutoff wavelength.

The detection unit 65A includes a prism 651 and a detector 652. The prism 651 branches the detection light 361 into third light and fourth light 361a and 361b. In the detection unit 65A, a detector 652 detects the position where the lights 361a and 361b are incident. The narrower the positions of both, the closer the focal position of the projection optical system 330, which is the first optical system, is to the projection optical system 330.

The detection section 65B has a knife edge 653 and a detector 652. The knife edge 653 functions as a shield that partially blocks the detection light 361, which is the second light emitted from the low-pass filter 64, which is the second optical system, while transmitting it as light 361c. In the detection unit 65B, the detector 652 detects the position where the light 361c is incident.

The first optical system may further include a moving mechanism 63 in addition to the projection optical system 330. The moving mechanism 63 moves the first lens barrel and second lens barrels 331 and 332, which constitute the double-sided telecentric optical system in the projection optical system 330, along the optical axis of the double-sided telecentric optical system.

For example, the distance between the lens barrels 331 and 332 along the optical axis is such that the closer the focal position of the projection optical system 330 detected by the detection unit 65A or the detection unit 65B is to the lens barrel 332, the closer the moving mechanism 63 is reduced by

Although the present disclosure has been described in detail, the above description is illustrative in all aspects, and the present disclosure is not limited thereto. It is understood that countless variations not illustrated can be envisioned without departing from the scope of this disclosure.

7 Second light source 34 First light source 35 Light (first light)
36 Light (Second Light)
43 Spatial light modulator (modulator)
46 Low-pass filter (filter)
63 Moving mechanism 64 Low pass filter (second optical system)
65A, 65B Detection unit 100 Drawing device 330 Projection optical system (first optical system)
331 Lens barrel (first lens barrel)
332 Lens barrel (second lens barrel)
351 Drawing light 361 Detection light (second light)
361a, 361b light (third light, fourth light)
361c light (second light)
431 First region 432 Second region 651 Prism 652, 654 Detector 653 Knife edge (shielding object)

Claims (10)

A device for exposing a photosensitive substrate with pattern-based drawing light, the device comprising:
a first light source that emits first light having a first wavelength;
a second light source that emits second light having a second wavelength different from the first wavelength;
a modulator that spatially modulates the first light based on the pattern and emits the drawing light;
a first optical system into which the drawing light and the second light enter and output the drawing light and the second light;
The drawing light emitted from the first optical system and the second light enter, and the drawing light emitted from the first optical system is guided to the substrate, and the drawing light emitted from the first optical system is guided to the substrate. a second optical system that emits the emitted second light while avoiding the substrate;
A drawing device comprising: a detection unit that detects a focal position of the first optical system based on the second light emitted from the second optical system. The drawing apparatus according to claim 1, wherein the second light enters the first optical system via the modulator. The modulator comprises:
a first region that spatially modulates the first light based on the pattern and emits the drawing light;
The imaging device according to claim 2 , further comprising a second region for emitting the second light to the first optical system regardless of the pattern. a filter located between the modulator and the first optical system, transmitting the drawing light, reflecting the second light and guiding it from the second light source to the first optical system; The drawing device according to claim 1, further comprising: a drawing device according to claim 1; the first wavelength is shorter than the second wavelength;
5. The drawing apparatus according to claim 4, wherein each of the second optical system and the filter includes a low-pass filter having a cutoff wavelength between the first wavelength and the second wavelength. The detection unit includes:
A ridgeline on which the second light emitted from the second optical system enters, and a ridgeline that faces the ridgeline and branches the second light into a third light and a fourth light and emits them. a prism including a surface;
Any one of claims 1 to 5, further comprising a detector that receives the third light and the fourth light and detects a position where the third light and the fourth light enter. The drawing device according to item 1. The detection unit includes:
a shield that partially blocks the second light emitted from the second optical system and transmits the second light;
The drawing according to any one of claims 1 to 5, further comprising a detector for detecting a position where the second light that has passed through the shield is incident and the second light is incident. Device. The first optical system is
a first lens barrel;
a second lens barrel that constitutes a double-sided telecentric optical system together with the first lens barrel;
a moving mechanism that moves the second lens barrel relative to the first lens barrel along the optical axis of the double-sided telecentric optical system;
The distance between the first lens barrel and the second lens barrel along the optical axis is such that the closer the focal position detected by the detection unit is to the second lens barrel, the closer the moving mechanism is to the distance between the first lens barrel and the second lens barrel. The drawing device according to any one of claims 1 to 5, wherein the drawing device is shrunk by. The first optical system is
a first lens barrel;
a second lens barrel that constitutes a double-sided telecentric optical system together with the first lens barrel;
a moving mechanism that moves the second lens barrel relative to the first lens barrel along the optical axis of the double-sided telecentric optical system;
The distance between the first lens barrel and the second lens barrel along the optical axis is such that the closer the focal position detected by the detection unit is to the second lens barrel, the closer the moving mechanism is to the distance between the first lens barrel and the second lens barrel. The drawing device according to claim 6, wherein the drawing device is shrunk by. The first optical system is
a first lens barrel;
a second lens barrel that constitutes a double-sided telecentric optical system together with the first lens barrel;
a moving mechanism that moves the second lens barrel relative to the first lens barrel along the optical axis of the double-sided telecentric optical system;
The distance between the first lens barrel and the second lens barrel along the optical axis is such that the closer the focal position detected by the detection unit is to the second lens barrel, the closer the moving mechanism is to the distance between the first lens barrel and the second lens barrel. The drawing device according to claim 7, wherein the drawing device is shrunk by.

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