TW201314386A - Drawing apparatus and focus adjusting method of the drawing apparatus - Google Patents

Abstract

The present invention is to make the virtual substrate 801 of an observation optical system 80 moving up and down with an observation camera 803 as a whole. The upper surface 801a of the virtual substrate 801 is configured at approximately the same level as the surface S of the substrate W on the stage 10, and the drawing optical image on the surface 801a of the virtual substrate observed by the observation camera 803 is made to be minimized, so as to adjust the position of the focusing lens 431 of the optical head 40a. At this time, the distance between the optical head 40a and the upper surface 801a of the virtual substrate is employed as a reference distance for performing the automatic focusing operation of the automatic focusing portions 441 and 442.

Description

Drawing device and its focus adjustment method

The present invention relates to a drawing device for illuminating a surface of a substrate to perform drawing, and a method of adjusting a focus of the drawing device.

In a drawing device that converges a beam onto a surface of a substrate placed on a platform, the focus of the converging optical system used to properly converge the beam to the surface of the substrate must be adjusted. However, it is difficult to simultaneously detect whether the focus is consistent when drawing. Therefore, there is proposed an autofocus technique for indirectly adjusting the focus by feedback control of the relative position of the substrate of the relatively convergent optical system to the focus position of the convergence optical system.

For example, in the technique described in Japanese Laid-Open Patent Publication No. Hei 9-318839 (Patent Document 1), on the surface of the substrate irradiated with the laser beam for drawing, other light is irradiated from the direction inclined with respect to the optical axis, and the substrate is received from the substrate. Reflected light. Then, by adjusting the light receiving position of the reflected light according to the distance between the drawing head and the surface of the substrate, the height of the drawing head relative to the substrate is adjusted to perform focus adjustment.

In the technique described in Japanese Laid-Open Patent Publication No. 2009-246165 (Patent Document 2), the CCD sensor provided on the opposite side of the drawing head via the projection surface of the laser light from the drawing head is used. A convergent optical image of the projection surface is detected. Then, the position of the focus lens is adjusted in such a manner as to maximize the contrast of the image, and the laser light is converged on the projection surface.

In the technique described in Patent Document 1, the focus position of the convergence optical system of the drawing head is not changed. That is, the distance between the drawing head and the substrate is Control is maintained in a manner that maintains a predetermined value. However, in practice, since the focus position of the convergence optical system varies or changes with time, in the control in which only the distance between the drawing head and the substrate is kept constant, the focus position does not necessarily coincide with the surface of the substrate.

Further, in the technique described in Patent Document 2, the focus position of the actual convergence optical system including the change over time can be grasped, but the control of the focus point when drawing the substrate is not described in Patent Document 2. Therefore, it is not clear whether the focus position at the time of drawing can be made uniform on the surface of the substrate. In addition, since it is observed on a projection surface set in advance, it is considered that a configuration which is not disclosed in Patent Document 2 is required in addition to, for example, a change in the thickness of the substrate.

As described above, there is still room for improvement in the above prior art in that the focus position of the optical system on the surface of the substrate is appropriately adjusted while adjusting the temporal change of the convergence optical system. In particular, the focus adjustment technology for substrates of different thicknesses can be said to have not been established at this stage.

The present invention has been made in view of the above problems, and a first object thereof is to provide a drawing device for drawing a light beam on a surface of a substrate, and a focus adjustment method thereof, which can correspond to a temporal change of the convergence optical system, and can be plotted A technique for appropriately adjusting the focus position of the convergence optical system on the surface of the substrate. Further, a second object of the present invention is to provide a technique for appropriately adjusting the focus position of the convergence optical system on the surface of each substrate in accordance with substrates having different thicknesses.

The drawing device of the present invention is characterized in that the first and second objects are achieved. The invention includes a platform that can mount a substrate in a horizontal state, and a drawing mechanism that includes a converging optical system that converges light from the light source in a vertical direction on the surface of the substrate, and is on the surface of the substrate by a converged light beam a moving mechanism that causes an irradiation position of the light beam from the drawing mechanism to relatively move in a horizontal direction on the substrate placed on the platform; and an observation mechanism having a light beam received at a position different from the substrate Observing a light receiving surface and observing an optical image incident on the observation light receiving surface; and observing a height changing mechanism that changes a position in a vertical direction of the observation light receiving surface; and a focus adjustment mechanism that adjusts based on an optical image observed by the observation mechanism a focus position of the convergence optical system in a vertical direction; and a distance detecting mechanism respectively detecting a distance between the convergence optical system and the observation light receiving surface in a vertical direction and a distance between the convergence optical system and the substrate surface; And the above observation height changing mechanism receives the above observation light The vertical direction position is set to be equal to the vertical direction of the substrate surface, and the focus adjustment mechanism adjusts the focus of the convergence optical system based on the optical image in a state where the drawing means irradiates the observation light receiving surface with the light beam. a position detecting unit configured to detect a distance between the convergence optical system whose focus position is adjusted and a vertical direction of the observation light receiving surface as a reference distance; and the distance detecting mechanism when drawing the surface of the substrate by the drawing mechanism Detecting a distance between the convergence optical system and a surface of the substrate on which the light beam is irradiated as a distance in a drawing, wherein the focus adjustment mechanism adjusts a focus position of the convergence optical system in a vertical direction based on the distance between the drawing and the reference distance .

Further, in the focus adjustment method of the present invention, in order to achieve the above first and second objects, a focus adjustment method for a drawing device includes: a platform that can mount a substrate in a horizontal state; and a drawing mechanism that includes convergence Light from a light source converges from a substantially vertical direction to a converging optical system on the surface of the substrate, and is drawn on the surface of the substrate by a converged light beam; and a moving mechanism that causes an illumination position of the light beam from the drawing mechanism The substrate mounted on the platform is relatively moved in a horizontal direction; the focus adjustment method is characterized by comprising: a reference setting step of setting the observation light receiving surface at a horizontal position different from the substrate placed on the platform, And the position in the vertical direction is substantially equal to the position in the vertical direction of the substrate surface of the platform; the focus adjustment step is performed to observe the optical image of the light beam incident on the observation light receiving surface to minimize the optical image Adjusting the focus position of the above-mentioned convergence optical system in the vertical direction; a distance between the convergence optical system after adjusting the focus position and the vertical direction of the observation light-receiving surface as a reference distance; and a focus adjustment step in the drawing, irradiating the surface of the substrate placed on the platform with the light beam And mapping, detecting a distance between the surface of the substrate irradiated by the light beam and the vertical direction of the convergence optical system, and aligning the focus position of the convergence optical system with the substrate surface based on the detection result and the reference distance. In addition, "minimizing the optical image" here means a state in which the light beam is the most concentrated and the contrast of the image is the largest.

In the invention having such a configuration, as in the technique described in Patent Document 2, the optical image of the light beam imaged on the light receiving surface is observed, and the focus position of the convergence optical system is adjusted. In addition, observe the vertical direction of the light receiving surface When the position is substantially the same as the surface of the substrate of the platform, when the focus position of the convergence optical system is adjusted on the light-receiving surface, the distance between the convergence optical system and the observation light-receiving surface is set to be Base distance. Next, when the surface of the substrate is drawn by the drawing mechanism, the focus position of the convergence optical system is adjusted based on the distance between the convergence optical system and the surface of the substrate (distance at the time of drawing) and the reference distance. Thereby, the above first and second objects are achieved.

More specific content is as follows. First, a technique for detecting the distance between the convergence optical system and the substrate surface at the time of drawing and adjusting the focus position of the convergence optical system is also described in Patent Document 1. However, the technique described in Patent Document 1 does not have a method of reflecting the actual focus position of the convergence optical system at the target focus position corresponding to the reference distance of the present invention. On the other hand, in the present invention, the focus position of the actual convergence optical system is adjusted by observing the observation light receiving surface, and the distance between the convergence optical system and the observation light receiving surface at this time is set as the reference distance. Therefore, by adjusting the focus position at the time of drawing based on the reference distance, the focus position can be made uniform on the surface of the substrate. Further, even if the characteristics of the distance detecting means and the convergence optical system change over time, the reference distance corresponding to the temporal characteristic is set and the focus adjustment is performed by performing the above operation, so that it may correspond to the change with time of the device. . Thereby, the first purpose is achieved.

Further, the setting of the reference distance is used for the observation optical surface which is provided at substantially the same position as the surface of the substrate in the vertical direction, and since the position of the observation optical surface in the vertical direction is variable, even if the thickness of the substrate changes and the substrate In the case where the position of the surface in the vertical direction changes, the position can be surely set. The focus position. This achieves the second purpose.

In the drawing device according to the above aspect of the invention, for example, the light receiving surface is formed of a material that is transparent to the light beam, and the observation mechanism is configured to observe the optical image of the light receiving surface from the side opposite to the incident direction of the light beam. . Thereby, since the optical image can be observed on the optical axis of the light beam and the size can be accurately detected, the focus position can be adjusted with high precision.

Further, for example, the distance detecting mechanism includes: an illuminating unit that irradiates light from a surface of the substrate to which the light beam is irradiated from a direction different from a direction in which the light beam is incident; and a light receiving unit that receives the reflected optical image that the light is reflected by the surface of the substrate And the distance between the convergence optical system and the surface of the substrate may be detected based on the position of the reflected optical image of the light received by the light receiving portion. Thereby, since the distance between the convergence optical system and the surface of the substrate is reflected in the position of the reflected optical image incident on the light receiving portion, the detection result can grasp the distance between the convergence optical system and the surface of the substrate. Further, by receiving the reflected optical image from the observation light receiving surface by the same configuration, the distance between the convergence optical system and the observation light receiving surface can be obtained in the same manner.

Further, for example, the position detecting mechanism is configured to image the reference portion provided on the surface of the substrate placed on the platform to detect the relative position of the substrate in the horizontal direction of the irradiation position of the light beam; and the vertical direction of the position detecting mechanism The focus position may be configured to match the position of the observation light receiving surface in the vertical direction when the reference distance is detected. By providing such a position detecting mechanism, the position of the substrate in the horizontal direction of the beam irradiation position can be aligned, and calibration adjustment can be performed. Then, by observing the focus position of the position detecting mechanism and detecting the reference distance, the position of the light receiving surface in the vertical direction is observed. The position detecting mechanism, the focus adjusting mechanism, and the distance detecting mechanism are all operated based on the unified reference by observing the light receiving surface, so that the drawing operation for coordinating the above can be controlled with higher precision.

In this case, for example, a reference pattern for adjusting the focus position of the position detecting mechanism may be provided on the observation light receiving surface. Thereby, since the reference position on the light-receiving surface can be used, the focus position of the position detecting means can be adjusted and the reference setting by the focus adjusting means and the distance detecting means can be performed simultaneously, so that the adjustment operation before painting can be performed more efficiently.

In the drawing device, for example, the convergence optical system includes a focus lens that is movable in the vertical direction, and the focus adjustment mechanism also controls the vertical direction of the focus lens. Thereby, it is not necessary to move the light source or the convergence optical system as a whole, and the accuracy of the position control can be improved.

Further, in the focus adjustment method of the present invention, for example, in the focus adjustment step at the time of drawing, the focus can be adjusted only after the focus position set by the pre-adjustment step is moved only by the distance corresponding to the difference between the detection result and the reference distance. The focus position of the optical system. Thereby, the focus position is changed so as to converge the light beam on the surface of the substrate so as to eliminate the difference between the distance between the convergence optical system and the substrate surface and the reference distance during the drawing.

Further, for example, when the drawing device includes a position detecting means for imaging the reference portion provided on the surface of the substrate placed on the platform and detecting the relative position in the horizontal direction of the irradiation position of the light beam and the light beam, The focus position of the position detecting mechanism in the vertical direction coincides with the position in the vertical direction of the observation light receiving surface set in the reference setting step. Therefore, the above method can be used to position the horizontal direction and the focus position in the vertical direction based on the same reference. Adjustments can be made to improve the accuracy of the drawing.

In this case, for example, a reference pattern is provided on the observation light receiving surface, and the reference pattern is imaged by the position detecting mechanism, and the focus position may be adjusted based on the result.

In these cases, for example, the distance between the position detecting mechanism and the observation light receiving surface when the focus position in the vertical direction of the position detecting means is aligned with the vertical direction position of the observation light receiving surface set in the reference setting step may be memorized. This distance is the same as the reference distance for the focus adjustment of the convergence optical system as the reference for the focus adjustment in the position detecting mechanism. Therefore, by mesing it in advance with the reference distance, it is possible to control each unit while grasping the relative positional relationship between the convergence optical system and the position detecting mechanism in the vertical direction. Further, for example, in the case where the thickness of the substrate to be drawn is changed, the control for adding the fluctuation amount to the convergence optical system and the position detecting mechanism can be performed.

Further, in the focus adjustment method, when the first substrate is drawn by the drawing means, and the second substrate different from the first substrate is drawn by the drawing means, for example, if the substrates have the same In the thickness, the reference setting step, the pre-focus adjustment step, and the memory step for the second substrate are omitted, and the focus adjustment step is performed using the reference distance of the first substrate. On the other hand, if the thickness is different, the second step is performed. The substrate setting step, the prior focus adjustment step, the memory step, and the drawing focus adjustment step.

In the case of drawing back and forth on a plurality of substrates, if the thickness of the substrate is the same, since it is not necessary to change the adjustment result in the vertical direction, it can be omitted The focus position of the rear substrate is adjusted to increase the throughput. On the other hand, in the case where the thickness is different, the above-described operation is performed again, and the adjustment of the state of the device reflecting the time is performed. Therefore, it is possible to perform stable high-precision drawing in accordance with the temporal change of the device.

According to the present invention, the focus of the convergence optical system is adjusted based on the optical image of the light beam formed on the observation light receiving surface at substantially the same position as the substrate surface disposed in the vertical direction, and the convergence optical system and the observation light receiving at this time are adjusted. The distance of the surface is used as the reference distance. When drawing the surface of the substrate, the focus position of the convergence optical system is adjusted based on the distance from the convergence optical system to the substrate surface and the reference distance. Thereby, irrespective of the temporal change of the characteristics of the convergence optical system or the position detecting mechanism, the focus position of the convergence optical system at the time of drawing can be stabilized and uniform on the surface of the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a front elevational view showing an embodiment of a pattern drawing device of the present invention. 2 is a plan view of the pattern drawing device of FIG. 1. The pattern drawing device 100 is a device that draws light on a surface of a substrate W on which a layer of a photosensitive material such as a photoresist is formed, and draws a pattern. Further, the substrate W may be any of various substrates such as a semiconductor substrate, a printed substrate, a color filter substrate, a glass substrate for a flat panel display provided in a liquid crystal display device or a plasma display device, and a substrate for a disk. In the example of the figure, an upper layer pattern is drawn in overlap with a layer pattern formed on the surface of the circular semiconductor substrate.

The pattern drawing device 100 is attached to the inside of the main body formed on the top surface and the peripheral surface of the skeleton formed by the main body frame 101 by a cover plate (not shown), and the outer side of the main body of the main body frame 101. Configuration of various structures It is made up of components.

The inside of the body of the pattern drawing device 100 is divided into a processing area 102 and a handover area 103. The processing area 102 in these areas is mainly provided with a platform 10, a platform moving mechanism 20, a platform position measuring unit 30, an optical unit 40, and a calibration unit 60. On the other hand, in the delivery area 103, a transport device 70 such as a transport mechanism that carries in and out the substrate W to the processing area 102 is disposed.

Further, an illumination unit 61 that supplies illumination light to the calibration unit 60 is disposed outside the body of the pattern drawing device 100. Further, a control unit 90 is disposed outside the main body, and is electrically connected to each of the devices included in the pattern drawing device 100, and controls the operations of the respective units.

Further, a substrate 匣 mounting portion 104 on which the substrate 匣C is placed is disposed at a position outside the body of the pattern drawing device 100 adjacent to the delivery region 103. In addition, the transfer device 70 disposed in the transfer region 103 inside the main body is taken out from the substrate 匣 mounting portion 104, and the unprocessed substrate W stored in the substrate 匣C placed on the substrate 匣 mounting portion 104 is taken out and then carried in ( The processing area 102 is loaded, and the processed substrate W is carried out (unloaded) from the processing area 102 and stored in the substrate 匣C. The transfer of the substrate 匣C to the substrate 匣 mounting portion 104 is performed by an external transfer device (not shown). The loading process of the unprocessed substrate W and the unloading process of the processed substrate W are performed by the transfer device 70 in accordance with an instruction from the control unit 90.

The platform 10 has a flat outer shape, and its upper surface has a holding portion for holding the substrate W in a horizontal posture. A plurality of suction holes (not shown) are formed on the upper surface of the platform 10, and a negative pressure (suction pressure) is applied to the suction The lead hole can fix and hold the substrate W placed on the platform 10 on the upper surface of the platform 10. Next, the platform 10 is moved by the platform moving mechanism 20.

The stage moving mechanism 20 is a mechanism that moves the stage 10 in the scanning direction (Y-axis direction), the sub-scanning direction (X-axis direction), and the rotation direction (rotation direction (θ-axis direction) about the Z-axis). The platform moving mechanism 20 includes a bottom plate 24 for supporting the support plate 22 that rotatably supports the platform 10, a sub-scanning mechanism 23 for moving the support plate 22 in the sub-scanning direction, and a main scanning mechanism 25 The bottom plate 24 is moved in the main scanning direction. The sub-scanning mechanism 23 and the main scanning mechanism 25 move the stage 10 in accordance with an instruction from the control unit 90.

The sub-scanning mechanism 23 includes a linear motor 23a which is constituted by a moving member (not shown) attached to the lower surface of the support plate 22, and a fixing member which is laid on the upper surface of the bottom plate 24 and which is not shown. Further, between the support plate 22 and the bottom plate 24, one pair of guide portions 23b extending in the sub-scanning direction is provided. Therefore, when the linear motor 23a operates, the support plate 22 moves along the guide portion 23b on the bottom plate 24 in the sub-scanning direction X.

The main scanning mechanism 25 includes a linear motor 25a which is constituted by a moving member attached to the lower surface of the bottom plate 24 and a fixing member laid on the base 106 of the pattern drawing device 100. Further, between the bottom plate 24 and the base 106, a pair of guide portions 25b extending in the main scanning direction is provided. Therefore, when the linear motor 25a is operated, the bottom plate 24 moves along the guide portion 25b on the base 106 in the main scanning direction Y.

The platform position measuring unit 30 is a mechanism for measuring the position of the platform 10. The platform position measuring unit 30 is electrically connected to the control unit 90, and measures the position of the platform 10 based on an instruction from the control unit 90. Although the platform position measuring unit 30 borrows For example, the laser beam is irradiated onto the stage 10, and the position of the stage 10 is measured by the interference between the reflected light and the emitted light. However, the configuration is not limited thereto. In the present embodiment, the stage position measuring unit 30 includes an emitting unit 31 that emits laser light, a beam splitter 32, a bending machine 33, a first interferometer 34, and a second interferometer 35. The emission units 31 and the interferometers 34 and 35 are electrically connected to the control unit 90, and the position of the stage 10 is measured based on an instruction from the control unit 90.

The laser light emitted from the emitting portion 31 is first incident on the spectroscope 32, and is divided into a first divergent light toward the bending machine 33 and a second divergent light toward the second interferometer 35. The first divergent light is reflected by the bending machine 33, enters the first interferometer 34, and is irradiated from the first interferometer 34 to the first portion of the stage 10. Then, the first divergent light reflected at the first portion is incident on the first interferometer 34 again. The first interferometer 34 measures the positional parameter corresponding to the position of the first part based on the interference between the first divergent light that is directed toward the first portion of the stage 10 and the first divergent light that is reflected by the first portion.

On the other hand, the second divergent light is incident on the second interferometer 35, and is irradiated from the second interferometer 35 to the second portion of the stage 10 (however, the second portion is at a position different from the first portion). Then, the second divergent light reflected at the second portion is incident on the second interferometer 35 again. The second interferometer 35 measures the positional parameter corresponding to the position of the second portion based on the interference between the second divergent light toward the second portion of the stage 10 and the second divergent light reflected at the second portion of the stage 10.

The control unit 90 acquires positional parameters corresponding to the position of the first portion of the platform 10 and positional parameters corresponding to the position of the second portion of the platform 10 from the first interferometer 34 and the second interferometer 35, respectively. Then, based on the positions obtained The parameter calculates the position of the platform 10.

The calibration unit 60 images the calibration marks formed on the upper surface of the substrate W and not shown. The calibration unit 60 includes a calibration camera 601 having a lens barrel, a counter lens, and a CCD image sensor. The CCD image sensor included in the calibration camera 601 is constituted by, for example, an area image sensor (two-dimensional image sensor). Further, the calibration unit 60 is supported by a lifting mechanism (not shown) that can be lifted and lowered within a specific range.

The illumination unit 61 is connected to the optical fiber 611 via a lens barrel for supplying illumination light to the calibration unit 60. The light guided by the optical fiber 611 extending from the illumination unit 61 is guided to the upper surface of the substrate W via the lens barrel of the calibration camera 601, and the reflected light is received by the CCD image sensor via the objective lens. Thereby, the upper surface of the substrate W is imaged and image data is acquired. The calibration camera 601 is electrically connected to the image processing unit of the control unit 90, acquires imaging data based on an instruction from the control unit 90, and transmits the acquired imaging data to the control unit 90.

Based on the imaging data supplied from the calibration camera 601, the control unit 90 detects the reference mark (calibration mark) provided at the reference position of the substrate W, and performs calibration processing of the relative positional positioning of the optical unit 40 and the substrate W. Next, pattern drawing is performed by irradiating a light beam modulated from the optical unit 40 corresponding to the drawing pattern to a specific position of the substrate W.

In the present embodiment, the optical unit 40 includes two optical heads 40a and 40b. The optical heads 40a and 40b have the same configuration, and the laser light supplied from the light irradiation unit is modulated based on the strip-shaped material corresponding to the drawing pattern. Here, the configuration associated with the optical head 40a will be described with reference to FIG. 40b also has the same composition. Further, the number of the optical heads may be any number, and is not limited thereto.

The light irradiation unit 41 includes a laser driving unit 411, a laser oscillator 412, and an illumination optical system 413. In the light irradiation unit 41, laser light is emitted from the laser oscillator 412 by the operation of the laser driving unit 411, and is guided to the optical head 40a via the illumination optical system 413. A light modulation element is disposed on the optical head 40a to modulate the laser light based on the strip data. Next, the optical head 40a projects the substrate W that has been moved to the position directly under the optical head 40a by the modulated laser light, and exposes the substrate W held by the stage 10 to draw a pattern. Thereby, the upper layer pattern (drawing pattern) is formed by superimposing the lower layer pattern formed on the unprocessed substrate W.

Fig. 3 is a view showing the configuration of the optical head 40a in more detail. Further, the configuration of the other optical head 40b is also the same. The optical head 40a includes a light modulation unit 421 having a diffractive lattice type spatial light modulator. The laser light L from the laser oscillator 412 is guided by the illumination optical system 413 and the mirror surface 422 to the light modulation unit 421 whose normal line of the reflection surface is inclined with respect to the optical axis.

At this time, the incident light from the laser oscillator 412 is a linear light having a uniform intensity distribution (light having a linear beam profile) by the illumination optical system 413, and is irradiated onto the spatial light modulator 421. The effective area of the change action. In the spatial light modulator 421, the light from the mirror surface 422 is spatially modulated based on a control command from the control unit 90, and the modulated light is incident on the lens of the projection optical system 430 along the optical axis thereof.

The light passing through the lens of the projection optical system 430 is guided to the zoom lens, and guided to the surface S of the substrate W at a specific magnification via the focus lens 431. Focus The lens 431 is attached to the focus drive mechanism 432. The focus drive mechanism 432 raises and lowers the focus lens 431 along the vertical axis (Z axis) according to the control command from the focus control unit 901 of the control unit 90, and converges the light beam emitted from the focus lens 431 on the surface S of the substrate W.

Further, the lower portion of the housing of the optical head 40a is provided with an illuminating portion 441 as an autofocus portion, for example, a laser diode (LD) as a light source, and a control signal based on the LD driving portion 902 from the control portion 90. And irradiating light to the surface S of the substrate W; and the image sensor 442, which receives the reflected light from the substrate surface S of the illumination light, for example, includes a CMOS sensor or a one-dimensional CCD image sensor.

Here, a case where the distance between the optical head 40a and the substrate surface S fluctuates is considered. As shown by an arrow A1 in FIG. 3, when the substrate surface S is away from the optical head 40a, or as indicated by an arrow A2, when the substrate surface S approaches the optical head 40a, the optical path of the reflected light from the substrate surface S changes to an arrow, respectively. The direction indicated by A3 and arrow A4, and the amount of light received by each of the light receiving positions of the image sensor 442 also varies. That is, the peak positions of the received light amounts of the image sensor 442 are changed as indicated by the arrows A5 and A6, respectively. The autofocus section thereby detects the distance between the optical head 40a and the substrate surface S.

Specifically, the distance detecting unit 903 of the control unit 90 receives the signal output from the image sensor 442 and uses it as focus control as information corresponding to the distance between the optical head 40a and the substrate surface S. Further, the information is memorized in the memory unit 904 as needed. In addition, the information corresponding to the distance between the optical head 40a and the substrate surface S may be the result of calculating the distance from the output signal of the image sensor 442, or may be the image sensor 442. The peak position of the amount of light itself. This is because the systems are in a one-to-one correspondence.

When the distance between the optical head 40a and the substrate surface S fluctuates, the focus position of the light beam emitted from the focusing lens 431 is deviated from the substrate surface S, and the resolution of the drawn pattern is lowered. In order to prevent this from happening, the focus control unit 901 controls the focus drive mechanism 432 to move the focus lens 431 up and down (in the direction of the arrow A7 or the direction of the arrow A8) to prevent the focus position from deviating. By performing feedback control using the output signal of the image sensor 442, the focus position of the focus lens 431 can be moved up and down following the positional change of the substrate surface S in the vertical direction, and the light beam can be stably converged on the substrate surface S.

In order for the above-described autofocus operation to function effectively, it is necessary to grasp in advance the distance between the optical head 40a and the substrate surface S when the focus of the focus lens 431 is aligned with the substrate surface S. Although the distance is almost unchanged in the short term, it will change with time as the device is used for a long time. The composition of the calibration used to correct this change is explained below.

Fig. 4(a) is a view showing the configuration for performing calibration. 4(b) is a view showing an example of a reference mask pattern. As shown in Fig. 4(a), an observation optical system 80 is provided on the side of the stage 10 for receiving the light beams emitted from the optical heads 40a, 40b and observing the optical image thereof. The observation optical system 80 is provided with a substantially transparent dummy substrate 801 formed of, for example, quartz glass in a flat shape. The surface (upper surface 801a) of the dummy substrate 801 is formed with a reference mask pattern 802 as shown in FIG. 4(b), and is used for focus adjustment of the calibration unit 60 as described below.

Under the dummy substrate 801, that is, the optical substrate is interposed between the dummy substrate 801 On the opposite side of 40a and 40b, an observation camera 803 having an imaging unit including, for example, a two-dimensional CCD image sensor and an optical system for converging incident light is provided. The dummy substrate 801 and the observation camera 803 are attached to the casing 804 and integrated, and the focus position of the optical system of the observation camera 803 is adjusted so as to be aligned with the upper surface 801a of the dummy substrate 801.

The outer casing 804 is supported by the support frame 805 which is erected on the support plate 22, and is vertically supported by the observation system control unit 920 of the control unit 90 and the observation system elevating mechanism 806 having an appropriate drive mechanism. The direction position is controlled. In other words, the dummy substrate 801 of the observation optical system 80 is integrally formed with the observation camera 803, and moves integrally with the stage 10 in the horizontal direction. On the other hand, the stage 10 can be moved up and down independently of the vertical direction.

The observation optical system 80 is positioned directly below the optical head 40a (or 40b), and the upper surface 801a of the dummy substrate 801 is positioned to be positioned substantially at the same position as the upper surface S of the substrate W placed on the stage 10, The optical image that is incident on the dummy substrate upper surface 801a from the optical head 40a is imaged by the observation camera 803. This output signal is processed by the image processing unit 910 of the control unit 90. When the focus control unit 901 changes the position of the focus lens 431 in the vertical direction, the focus is made by the observation camera 803, and the optical image is minimized (the contrast of the image is maximized). The vertical position. Thereby, the focus of the focus lens 431 is aligned with the dummy substrate upper surface 801a. At this time, the distance between the optical head 40a and the dummy substrate upper surface 801a is referred to as a "reference distance", and the distance detecting unit 903 memorizes the information corresponding to the reference distance. Recalling part 904.

In the subsequent drawing operation, by controlling the position of the focus lens 431 based on the distance between the optical head 40a and the opposing substrate surface S and the above reference distance, the focus position can be stabilized and aligned on the substrate surface S. . Further, by performing the calibration operation periodically at a specific timing, the stable focus position adjustment can be performed for a long period of time in accordance with the temporal change of the projection optical system 430.

Fig. 5 is a view showing a detailed configuration of the calibration unit. In the figure, in comparison with the calibration unit 60, the autofocus portion of the optical head 40a is also recorded. The calibration unit 60 detects the reference mark on the surface of the substrate, grasps the position of the optical head 40a and the stage 10 or the substrate W in the horizontal direction, and detects the reference mask pattern 802 of the observation optical system 80, and performs focus adjustment by the calibration unit 60.

As shown in FIG. 5, the calibration unit 60 includes a calibration camera 601 that images the substrate surface S, and includes an automatic focusing unit: an illuminating unit 641 having the same function as the illuminating unit 441 provided in the optical head 40a; The light receiving unit 642 has the same function as the light receiving unit 442 provided in the optical head 40a. Similarly to the autofocus portion of the optical head 40a, the distance detecting unit 906 provided on the control unit 90 detects the distance between the calibration camera 601 and the substrate surface S based on the output of the light receiving unit 642, and the focus control unit 930 is used. The focus position of the calibration camera 601 is made coincident with the substrate surface S, and the vertical direction position of the calibration unit 60 is controlled.

In this case, it is also necessary to use the distance information of the focus alignment reference of the calibration camera 601, and the distance has a possibility of changing with time. In this regard, the reference to the dummy substrate upper surface 801a formed on the observation optical system 80 is used. Mask pattern 802. That is, the observation optical system 80 is positioned directly below the calibration unit 60, and the image processing unit 910 performs data processing on the image of the reference mask pattern 802 imaged by the calibration camera 601, and detects the camera with the most vivid calibration pattern. The distance between the 601 and the dummy substrate upper surface 801a is previously stored as a reference. Using this distance as a reference, the calibration camera 601 can be made to perform an autofocus operation. Further, by performing the above-described operations periodically, it is also possible to stably perform the autofocus operation for a long period of time in accordance with the temporal change of the characteristics of the calibration camera 601.

So far, the principle of the control action of each unit has been described separately. Next, the calibration operation of the entire pattern drawing device 100 will be described based on the above principle. If the calibration process as described below is performed, the focus position adjustment of the optical heads 40a, 40b and the calibration unit 60 can be performed separately, and the vertical direction of the optical heads 40a, 40b and the calibration unit 60 can be based on the same reference (Z). The focus position on the axis direction is relatively adjusted, and the pattern drawing device 100 can be operated in an optimum state.

Figure 6 is a flow chart showing the corrective action of the device. 7(a) to 7(c) are diagrams schematically showing a part of the steps in the operation of FIG. 6. This correction operation is performed, for example, immediately after the device is started or at a periodic sequence (for example, once a day) before the substrate W is carried into the device.

Initially, the initial position of the calibration camera 601 is set. Specifically, the position of the upper and lower directions of the calibration camera 601 is set so that the focus position is aligned with the position of the virtual substrate surface S on the platform 10 in accordance with the thickness of the predetermined substrate W to be loaded (step S101). As shown in Fig. 7(a), since the substrate W is not loaded at this time, it is preferable that the alignment is satisfactory.

Then, the moving platform 10 moves the observation optical system 80 directly under the calibration unit 60 (step S102), and causes the virtual substrate upper surface 801a of the observation optical system 80 to coincide with the focus position of the calibration camera 601 (step S103). Specifically, as shown in FIG. 7(b), the reference mask pattern 802 formed on the upper surface 801a of the dummy substrate is imaged by the calibration camera 601, and the outer casing of the observation optical system 80 is viewed by the observation system elevating mechanism 806. The 804 is raised and lowered and the outer casing 804 is positioned at the most sharp position of the image of the reference reticle pattern 802.

Thereby, the position of the dummy substrate upper surface 801a in the vertical direction substantially coincides with the position of the substrate surface S to be carried in later, and at this position, the focus of the calibration camera 601 is aligned. Therefore, the distance-related information is obtained from the output of the light receiving unit 642 of the autofocus unit (AF unit) based on the distance between the calibration camera 601 and the dummy substrate upper surface 801a at this time, and is stored in the memory unit 904 ( Step S104). Thereafter, the focus of the calibration camera 601 at the time of drawing is adjusted based on the distance. This specific method is as described above.

In addition, in the correction operation, the position setting of the dummy substrate upper surface 801a is not limited to the position of the substrate surface S on which the stage 10 is placed. However, since the above-described action associates the information about the focus position of the calibration camera 601 with the distance of the corresponding autofocus portion, actually, even the position of the substrate surface S placed on the stage 10 and the dummy substrate are The position of the upper surface 801a is somewhat offset, and the focus can be aligned toward this position. However, if the position of the upper surface 801a of the dummy substrate is largely deviated from the position of the substrate surface S at the time of drawing, Correction, the substrate surface S has a deviation from the focus adjustment range when drawing. This means that it is effective to align the position of the dummy substrate upper surface 801a in the vertical direction to the position of the virtual substrate surface S. This point is also the same in the correction of the optical head described below.

Next, focus adjustment of the optical heads 40a, 40b is performed. Here, the operation of the optical head 40a will be exemplified, and the operation of the optical head 40b will be the same. First, the observation optical system 80 is moved and positioned directly below the optical head 40a (step S105). Next, as shown in FIG. 7(c), the optical lens of the laser light incident on the upper surface 801a of the dummy substrate by the focusing lens 431 of the projection optical system 430 is observed by the observation camera 803, and the focus lens 431 is placed. The position in the vertical direction changes. The position of the focus lens 431 is set to a position at which the spot size of the optical image becomes the smallest (step S106).

Thereby, the focus of the projection optical system 430 is aligned to the dummy substrate upper surface 801a. Then, the distance between the optical head 40a and the dummy substrate upper surface 801a at this time is used as the reference distance, and the information on the reference distance is obtained from the output of the light receiving unit 422, and is stored in the memory unit 904 (step S107). Thereafter, the focus adjustment of the projection optical system 430 at the time of drawing is performed based on the reference distance. The specific method is described in the prior art, but the present embodiment will be described in more detail.

Fig. 8 is a flow chart showing the focus adjustment operation at the time of drawing. As shown in FIG. 3, the optical head 40a is opposed to the substrate surface S at the time of drawing. In this state, based on the output of the light receiving unit 422 of the autofocus unit (AF unit), information on the distance between the optical head 40a and the substrate surface S is obtained (step S201), and the reference to the memory unit 904 is obtained. The difference between the distances (step S202). Here, if There is no difference between the distance from the optical head 40a to the substrate surface S and the reference distance, and since the focus is on the substrate surface S, there is no need to change it. In the case of a difference, since the focus position is deviated from the substrate surface S, the difference is corrected. Specifically, the focus lens 431 is moved to a direction in which the above-described distance difference is eliminated, and the amount of driving (for example, the moving distance of the focus lens 431 in the vertical direction and the number of pulses of the drive motor) is calculated (step S203), and The focus lens 431 is moved upward or downward only by the calculated driving amount (step S204). The above operation continues until the drawing ends (step S205).

9(a) and 9(b) are diagrams schematically showing the focus adjustment operation at the time of drawing. As shown in Fig. 9(a), the distance between the appropriate reference position (lower end in this example) of the optical head 40a and the substrate surface S is indicated by the symbol D1. Further, the driving amount of the focus lens 431 for focus adjustment (the moving distance in the vertical direction in this example) is indicated by a symbol D2. The distance D1 is a direction from the lower end of the optical head 40a toward the substrate surface S as a positive direction. The driving amount D2 is such that the focus lens 431 is upward, that is, the direction away from the substrate surface S is a positive direction.

As a result of the previous calibration operation, if the distance D1 coincides with the reference distance, the focus of the projection optical system 430 can be said to be aligned with the substrate surface S. Therefore, as shown in FIG. 9(b), the driving amount D2 at this time is zero, that is, the position in the vertical direction of the focus lens 431 is maintained at the set position by the correcting operation. On the other hand, when the distance D1 is larger than the reference distance, the driving amount D2 is set to a negative value, that is, the focus lens 431 is moved downward to eliminate the focus deviation. On the contrary, when the distance D1 is smaller than the reference distance, the driving amount D2 is set to a positive value, and the focus lens 431 is moved upward to eliminate the focus deviation. If the amount of deviation from the reference distance of the distance D1 is larger, the driving of the focus lens 431 The amount D2 also becomes larger. Thereby, the focus position of the projection optical system 430 is stably maintained on the substrate surface S.

As described above, in the observation optical system 80 including the dummy substrate 801 and the observation camera 803, the dummy substrate 801 and the observation camera 803 can be integrally moved in the vertical direction. In the correction operation, the light beam from the optical head 40a is incident on the dummy substrate upper surface 801a while the upper surface 801a of the dummy substrate 801 is positioned at the virtual position of the surface S of the substrate W placed on the stage 10. The observation lens 803 is used to observe the position of the focus lens 431 in the vertical direction so that the optical image is minimized. Further, information relating to the reference distance obtained from the output of the autofocus unit at this time is stored in advance, and the distance between the optical head 40a and the substrate surface S obtained from the output of the autofocus unit is calculated based on the reference distance at the time of drawing. Make focus adjustments. In such a configuration, even when the autofocus unit and the projection optical system 430 change the reference distance due to the change over time, the reference distance at the time is set by the correction, and the focus adjustment is performed based on this, so that it is possible to correspond The device changes over time to perform long-term stable and high-precision focus adjustment.

Further, the focus adjustment of the calibration unit 60 can be performed by using the reference mask pattern 802 formed on the upper surface 801a of the dummy substrate 801 set at the same position as described above. Thereby, the relative positional relationship between the focus position of the optical head 40a and the vertical direction of the focus position of the calibration unit 60 is associated via the dummy substrate upper surface 801a which is a common position reference. Therefore, it is possible to combine two units that are originally independently controlled. Thereby, the pattern drawing device 100 can be operated in an optimum state.

Therefore, the dummy substrate upper surface 801a, which is the position reference of the optical head 40a and the calibration unit 60 in the vertical direction, can be raised and lowered according to the surface position of the substrate W placed on the stage 10. Therefore, it is possible to perform high-precision and stable focus adjustment for the substrate W having various thicknesses.

In other words, after the correction operation and the drawing operation corresponding to the first substrate having the specific thickness, if the subsequent substrates have the same thickness, the new correction operation is not performed, and the drawing operation can be performed using the result of the correction operation of the previous substrate. The new correction operation may be performed periodically at a specific interval, for example, when the number of processed substrates or the operation time reaches a specific value.

On the other hand, when the second substrate having a different thickness from the previous substrate is subjected to the drawing operation, the second substrate can be accurately and stably obtained in the same manner by performing a new correction operation corresponding to the thickness of the substrate and resetting the reference distance. Focus adjustment when drawing.

As described above, in the present embodiment, the optical heads 40a and 40b and the light-irradiating portion 41 are integrated to function as the "drawing mechanism" of the present invention. The laser oscillator 412 functions as a "light source" of the present invention, and the projection optical system 430 functions as a "convergence optical system".

Further, in the present embodiment, the platform moving mechanism 20 functions as a "moving mechanism" of the present invention. In the present embodiment, the observation optical system 80 functions as the "observation means" of the present invention, and the upper surface 801a of the dummy substrate 801 corresponds to the "observation optical surface" of the present invention. Further, the reference mask pattern 802 corresponds to the "reference pattern" of the present invention. In addition, the observation system lifting mechanism 806 and the observation system control unit 920 are integrated and used as the present The "observation height change mechanism" of the invention functions.

Further, in the present embodiment, the focus control unit 901 and the focus drive mechanism 432 are integrated to function as the "focus adjustment mechanism" of the present invention. Further, the illuminating unit 441 and the light receiving unit 442 constituting the autofocus unit are integrated to function as the "distance detecting means" of the present invention. Further, in the present embodiment, the calibration unit 60 functions as the "position detecting means" of the present invention.

Further, in the correcting operation of the present embodiment as shown in FIG. 6, step S103 corresponds to the "reference setting step" of the present invention, and step S106 corresponds to "pre-focus adjustment step". Further, step S107 corresponds to the "memory step" of the present invention. Further, steps S201 to S204 of Fig. 8 correspond to the "focus adjustment step at the time of drawing" of the present invention.

The present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit and scope of the invention. For example, in the correction operation of the above-described embodiment, the correction of the optical head 40a (40b) is matched with the correction by the calibration unit 60, but the present invention is not limited thereto, and only the focus adjustment operation is performed on the convergence optical system for drawing. The invention can also be applied.

Further, in the correcting operation of the above-described embodiment, the focus position of the calibration camera 601 is set to the vertical position of the substrate surface S so as to be in the vertical direction of the substrate surface S, and is matched with the upper surface of the dummy substrate by setting At the position of 801a, the approximate position of the dummy substrate upper surface 801a is set to the position of the substrate surface S. However, the present invention is not limited thereto, and for example, the position of the upper surface 801a of the dummy substrate may be set first, and then the position of the calibration unit 60 may be adjusted so that the focus is aligned with it.

Further, in the autofocusing unit of the calibration unit 60 and the optical heads 40a and 40b of the above-described embodiment, the substrate surface S is irradiated with light, and the reflected light is received, and the distance is detected by the position of the reflected image. However, the distance detecting mechanism is not limited. Here, any mechanism can also be applied.

Further, the pattern drawing device 100 of the above-described embodiment is a device for modulating a light beam and patterning it by using a spatial modulator 421 of a diffraction lattice, but the modulation method of the light beam is not limited thereto, and any modulation is used. The present invention can also be applied to a drawing device of a variable mode.

The present invention is applicable to all drawing devices that draw light beams to the surface of a substrate for drawing. As the substrate to be processed, various substrates such as a semiconductor substrate, a printed substrate, a color filter substrate, a glass substrate for a flat panel display provided in a liquid crystal display device or a plasma display device, and a substrate for a disk can be used.

10‧‧‧ platform

20‧‧‧ Platform Mobile Agency (Mobile Agency)

22‧‧‧Support board

23‧‧‧Sub Scanning Mechanism

23a‧‧‧Linear motor

23b‧‧‧Guidance

24‧‧‧floor

25‧‧‧Main scanning mechanism

25a‧‧‧linear motor

25b‧‧‧Guidance

30‧‧‧ Platform Positioning Department

31‧‧‧Exporting Department

32‧‧‧Distributor

33‧‧‧Bending Machine

34‧‧‧1st interferometer

35‧‧‧2nd interferometer

40a‧‧‧Optical head (drawing agency)

40b‧‧‧ Optical head (drawing agency)

41‧‧‧Lighting Department (drawing agency)

60‧‧‧ Calibration unit (position detection mechanism)

70‧‧‧Transporting device

80‧‧‧Observation optical system (observation mechanism)

90‧‧‧Control Department

100‧‧‧pattern drawing device

101‧‧‧ ontology framework

102‧‧‧Processing area

103‧‧‧ handover area

104‧‧‧Substrate loader

106‧‧‧Abutment

411‧‧‧ Laser Drive Department

412‧‧‧Laser oscillator (light source, drawing mechanism)

413‧‧‧Lighting optical system

421‧‧‧Light Modulation Unit

422‧‧‧Mirror

430‧‧‧Projection optical system (convergence optical system, drawing mechanism)

431‧‧‧focus lens

432‧‧‧Focus-driven mechanism (focus adjustment mechanism)

441‧‧‧Irradiation Department (distance detection agency)

442‧‧‧Lighting Department (distance detection agency)

601‧‧‧ Calibration camera

611‧‧‧ fiber optic

641‧‧‧ Department of Irradiation

642‧‧‧Receiving Department

801‧‧‧Dummy substrate

801a‧‧‧ (virtual substrate 801) upper surface (observation optical surface)

802‧‧‧ reference mask pattern

803‧‧‧ observation camera

804‧‧‧ Shell

805‧‧‧Support frame

806‧‧‧ observation system lifting mechanism

901‧‧‧Focus Control Department

902‧‧‧LD drive department

903‧‧‧Distance Detection Department

904‧‧‧Memory Department

906‧‧‧Distance Detection Department

910‧‧‧Image Processing Department

920‧‧‧Observation System Control Department

930‧‧‧Focus Control Department

S‧‧‧ substrate surface

S103‧‧‧ benchmark setting procedure

S106‧‧ prior focus adjustment steps

S107‧‧‧ memory steps

S201‧‧‧ Focus adjustment steps during drawing

S202‧‧‧ Focus adjustment steps during drawing

S203‧‧‧ Focus adjustment steps during drawing

S204‧‧‧ Focus adjustment steps during drawing

W‧‧‧Substrate

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a front elevational view showing an embodiment of a pattern drawing device of the present invention.

2 is a top plan view of the pattern drawing device of FIG. 1.

Fig. 3 is a view showing the configuration of the optical head in more detail.

Fig. 4(a) is a diagram showing the configuration for performing correction.

Fig. 4(b) is a view showing an example of a reference mask pattern.

Fig. 5 is a view showing the detailed configuration of the calibration unit.

Figure 6 is a flow chart schematically showing the correcting action of the device.

7(a) to 7(c) are diagrams schematically showing a part of the steps in the operation of Fig. 6.

Fig. 8 is a flow chart showing the focus adjustment operation at the time of drawing.

9(a) and 9(b) are diagrams schematically showing the focus adjustment operation at the time of drawing.

10‧‧‧ platform

22‧‧‧Support board

40a‧‧‧ optical head

40b‧‧‧ optical head

80‧‧‧Observation optical system

90‧‧‧Control Department

431‧‧‧focus lens

441‧‧‧Auto Focus (Irradiation Department)

442‧‧‧Auto Focus (light receiving department)

801‧‧‧Dummy substrate

801a‧‧‧Dummy substrate upper surface

802‧‧‧ reference mask pattern

803‧‧‧ observation camera

804‧‧‧ Shell

805‧‧‧Support frame

806‧‧‧ observation system lifting mechanism

901‧‧‧Focus Control Department

903‧‧‧Distance Detection Department

904‧‧‧Memory Department

910‧‧‧Image Processing Department

920‧‧‧Observation System Control Department

S‧‧‧ substrate surface

W‧‧‧Substrate

Claims (12)

A drawing device, comprising: a platform capable of placing a substrate in a horizontal state; and a drawing mechanism comprising a convergent optical system that converges light from the light source from the vertical direction to the surface of the substrate, and the beam is converged by the convergence And drawing on the surface of the substrate; the moving mechanism is configured to move the irradiation position of the light beam from the drawing mechanism relative to the substrate placed on the platform in a horizontal direction; and the observation mechanism has a different surface from the substrate Positioning the observation light receiving surface of the light beam and observing the optical image incident on the observation light receiving surface; and observing the height changing mechanism for changing the position of the observation light receiving surface in the vertical direction; and the focus adjustment mechanism based on the observation mechanism The optical image adjusts a focus position of the convergence optical system in the vertical direction; and the distance detecting mechanism detects a vertical distance between the convergence optical system and the observation light receiving surface, and the convergence optical system and the substrate surface Vertical direction distance; and the above-mentioned observation height changing mechanism The position of the observation light receiving surface in the vertical direction is set to be equal to the vertical direction of the substrate surface, and the focus adjustment mechanism adjusts the light image based on the optical image in a state in which the light beam is irradiated onto the observation light receiving surface from the drawing means. The focus position of the convergence optical system; The distance detecting means detects a distance between the convergence optical system whose focus position is adjusted and the vertical direction of the observation light receiving surface as a reference distance, and the distance detecting means detects the convergence optics when drawing the surface of the substrate by the drawing means. The distance between the system and the surface of the substrate irradiated by the light beam is a distance at the time of drawing, and the focus adjustment means adjusts a focus position in the vertical direction of the convergence optical system based on the distance between the drawing and the reference distance. The drawing device according to claim 1, wherein the observation light receiving surface is formed of a material having transparency to the light beam, and the observation mechanism observes the optical image of the observation light receiving surface from a side opposite to a direction in which the light beam is incident. The drawing device of claim 1, wherein the distance detecting unit includes: an illuminating unit that illuminates light from a direction different from a direction in which the light beam is incident on the surface of the substrate on which the light beam is irradiated; and a light receiving unit that receives the light a reflective optical image reflected from the surface of the substrate; and detecting a distance between the convergence optical system and the surface of the substrate based on the position of the reflected optical image of the light received by the light receiving portion. The drawing device of claim 1, comprising: a position detecting mechanism that images a reference portion provided on a surface of the substrate placed on the platform to detect a relative position of the substrate and the irradiation position of the light beam in a horizontal direction The focus position of the position detecting means in the vertical direction coincides with the position of the observed light receiving surface in the vertical direction when the reference distance is detected. The drawing device of claim 4, wherein a reference pattern for adjusting a focus position of the position detecting mechanism is provided on the observation light receiving surface. The drawing device according to any one of claims 1 to 5, wherein the convergence optical system includes a focus lens movable in a vertical direction; and the focus adjustment mechanism controls a vertical direction position of the focus lens. A focus adjustment method, which is a focus adjustment method of a drawing device, the drawing device includes: a platform that can mount a substrate in a horizontal state; and a drawing mechanism that converges light from the light source from a substantially vertical direction to the surface of the substrate Converging the optical system and drawing on the surface of the substrate by the converged light beam; and moving the mechanism to move the irradiation position of the light beam from the drawing mechanism relative to the substrate placed on the platform in a horizontal direction; The focus adjustment method is characterized by comprising: a reference setting step of setting the observation light receiving surface at a horizontal position different from the substrate placed on the platform, and vertically positioning the surface of the substrate placed on the platform a position in which the positions in the vertical direction are substantially equal; a focus adjustment step is performed to observe an optical image of the light beam incident on the light receiving surface to adjust a focus position in the vertical direction of the convergence optical system in a manner to minimize the optical image a memory step of adjusting the focus position to the above convergent optical system Receiving the observation of the surface from the vertical direction from the memory as a reference; and when a focus adjusting step drawing, is placed on the irradiated surface of the substrate of the light flux of said platform and plotted, and detecting the light beam irradiated The distance between the surface of the substrate and the vertical direction of the convergence optical system is such that the focus position of the convergence optical system is aligned with the surface of the substrate based on the detection result and the reference distance. The focus adjustment method of claim 7, wherein in the focus adjustment step of the drawing, the focus position of the convergence optical system is adjusted to only the displacement from the focus position set in the advance adjustment step, and the detection result and the reference The distance from the distance corresponds to the location of the distance. The focus adjustment method of claim 7 or 8, wherein the drawing device includes a position detecting mechanism for detecting a reference portion disposed on a surface of the substrate to be placed on the platform, and detecting the substrate and the light beam The relative position in the horizontal direction of the irradiation position, and the focus position in the vertical direction of the position detecting means coincides with the vertical direction position of the observation light receiving surface set in the reference setting step. The focus adjustment method of claim 9, wherein the reference light receiving surface is provided with a reference pattern, the position detecting means images the reference pattern, and the focus position of the position detecting means is adjusted based on the result. The focus adjustment method of claim 9, wherein the position detecting means is configured such that a focus position in the vertical direction of the position detecting means coincides with a vertical direction position of the observation light receiving surface set in the reference setting step Observe the distance of the light receiving surface as described above. The focus adjustment method of claim 7, wherein after the first substrate is drawn by the drawing mechanism, the drawing mechanism is different from When drawing the second substrate of the first substrate, for example, when the first substrate and the second substrate have the same thickness, the reference setting step, the preceding focus adjustment step, and the memory step of the second substrate are omitted. And performing the above-described drawing focus adjustment step using the reference distance of the first substrate, and when the first substrate and the second substrate have different thicknesses, performing the reference setting step on the second substrate, The focus adjustment step beforehand, the above-mentioned memory step, and the focus adjustment step in the above drawing.