KR20130035318A - Polishing apparatus and polishing method using the same - Google Patents

Abstract

PURPOSE: A polishing device and a polishing method using the same are provided to improve the surface flatness of an object's surface and to reduce the work time for polishing. CONSTITUTION: A polishing device comprises a polishing unit(400) and a polishing position control module(900). The polishing unit comprises a polishing pad and enables to rotate, to horizontally move, and to ascend and descend. The polishing position control module is connected to the polishing unit, sets up the polishing work area which is higher than the average height value of the object's surface, and moves the polishing unit to a predetermined polishing work area. [Reference numerals] (910) Surface height measuring device; (920) Average height calculating part; (930) Polishing height setting part; (940) Polishing unit position adjusting part;

Description

Polishing apparatus and polishing method using the same {POLISHING APPARATUS AND POLISHING METHOD USING THE SAME}

The present invention relates to a polishing apparatus and a polishing method using the same, and more particularly to a polishing apparatus that can improve the flatness of the surface of the workpiece to be polished.

As liquid crystal display devices (LCDs), plasma display panels (PDPs), organic light emitting display devices (OLEDs), etc. are gradually miniaturized and highly integrated, the importance of surface flatness of photomasks used in photolithography is increasing. .

On the other hand, even if the photomask is manufactured, it is difficult to control the difference between the highest height and the lowest height of the surface to less than about 50 nm. And a photo mask having a flatness in which the difference between the highest height and the lowest height exceeds about 50 nm is not easy to form a fine pattern, and thus cannot be used for a photolithography process.

Thus, in the related art, the operation of regrinding the surface of the photomask, which has been manufactured by a separate polishing apparatus, was performed. The conventional polishing apparatus includes a lower plate on which the photo mask is seated, and a polishing unit positioned above the lower plate to polish the photo mask seated on the lower plate. Here, the polishing unit includes a lifting pad and a rotatable body, and a polishing pad connected to the lower portion of the body and in contact with the upper surface of the photo mask for polishing. Since such a conventional polishing apparatus polishes the entire upper surface of the photo mask, precise planarization work is difficult. In addition, the center region or the edge region of the photo mask may be excessively polished, or conversely, the center region or the edge region of the photo mask may not be polished. In this way, the entire surface of the photomask surface becomes convex or concave.

Therefore, even after performing the post-process polishing operation of the photomask in which the fabrication is completed by using a conventional polishing apparatus, the flatness of the photomask is still poor. In addition, since the entire surface of the photo mask must be unnecessarily polished, there is a disadvantage that the polishing operation time becomes long and the equipment becomes large.

Korea Patent Publication 2010-0130956 Korean Patent Publication 2002-0084143

An object of the present invention is to provide a polishing apparatus and a polishing method using the same that can improve the flatness of the surface of the workpiece.

Another technical problem of the present invention is to provide a polishing apparatus capable of locally polishing a surface of a workpiece and a polishing method using the same.

Another technical problem of the present invention is to provide a polishing apparatus and a polishing method using the same, which automatically detects a surface area having a height higher than the average surface height, sets the polishing work position, and polishes the set polishing work position. .

The present invention provides a polishing apparatus for polishing a surface of a workpiece, comprising a polishing pad for polishing the surface of the workpiece, the polishing unit capable of raising, lowering, horizontally moving and rotating, and an average of the surface of the workpiece in connection with the polishing unit. And a polishing position control module for setting the region having a height higher than the height value as the polishing work region and moving the polishing unit to the set polishing work region.

It is disposed below the polishing unit, the stage on which the workpiece is seated, installed in one direction extending from the upper side of the stage, the gantry on which the polishing unit is supported, coupled to the gantry lower and horizontally moved The first movable block is spaced apart from at least one side of the stage and is installed extending in a direction crossing the gantry, the first guide rail is engaged with the first movable block to guide the horizontal movement of the first moving block The first moving block is controlled to be moved by the polishing position control module.

The second guide rail extends in a direction intersecting with the first guide rail on one side of the gantry and is engaged with the polishing unit to guide horizontal movement of the polishing unit.

The polishing unit is coupled to a rear surface of the first support member and the first support member spaced to one side of the gantry extending in the vertical direction, and is horizontally along the second guide rail provided in the gantry. A second moving block which slides in a direction; a third guide rail installed to extend in a vertical direction from a front surface of the first support member; and a second extending block extending in a vertical direction from a front of the third guide rail. A support member, an elevating power unit provided on an upper portion of the first supporting member to provide an elevating force, and an elevating shaft having one end connected to the elevating power unit, and another portion thereof coupled with the second supporting member; It is coupled to the rear surface of the second support member, and is connected to the third moving block and the second support member and the lifting shaft which slides up and down along the third guide rail, It includes parts of polishing comprising a polishing pad for polishing the group treated.

The movement of the second and third moving blocks is controlled by the polishing position control module.

One end of the abrasive portion is connected to the elevating shaft, the rotating shaft is provided with an internal space for moving the abrasive therein, a rotating power unit for rotating the rotating shaft, is connected to the other end of the rotating shaft to rotate, the abrasive moves inside A rotating disk provided with a first outlet hole, and a polishing pad provided at a lower portion of the rotating disk to polish the surface of the workpiece, and having a second outlet hole communicating with the first outlet hole therein, and one end thereof connected to the lifting shaft. The other end is connected to the rotary shaft, and includes a joint provided therein an internal space for moving the abrasive, the internal space of the joint is in communication with the internal space of the rotary shaft.

The polishing position control module may include an average height calculator configured to calculate an average height value of the surface of the workpiece, a region having a height higher than the average height value by comparing the average height value with the height of each region of the workpiece surface. And a polishing position setting unit for setting the polishing work position to a polishing work position, and a polishing unit position adjusting unit for adjusting the polishing unit to be positioned at a set polishing work position.

And a surface height meter for acquiring the treatment surface image and measuring the surface height of each region of the surface of the treatment using the image.

The polishing work position set by the polishing position setting unit is set to (X, Y) coordinates in the coordinate plane of the image, and the coordinate plane of the stage corresponds to the coordinate plane of the workpiece image.

The polishing unit position adjusting unit adjusts the polishing unit to correspond to the (X, Y) coordinate which is the set polishing work position above the coordinate plane of the stage.

The polishing unit position adjusting unit controls the movement of the first to third moving blocks so that the polishing unit is positioned corresponding to the set polishing work position.

A polishing operation connected to the polishing unit to detect a change in the surface height of the region being polished in real time, and to determine whether to proceed with the polishing operation by comparing the surface height of the region being polished with the average height value of the workpiece surface A control unit.

The polishing operation control unit may include a surface height measuring device configured to measure, in real time, the surface height of the region being polished according to the moving distance of the second support member which is moved up and down during the polishing operation, and the surface height measuring instrument. Comparing unit for comparing the surface height of the surface and the average height of the workpiece surface and the polishing operation is stopped when the surface height of the area being polished reaches the average height of the workpiece surface or is within the average height tolerance range And a polishing operation determining unit.

The surface height measuring device is installed such that a main body coupled to the upper part of the first support member, one end thereof is connected to the main body, and the other end is in contact with the upper part of the second support member, is moved up and down together according to the lifting and lowering of the second support member. The lowering includes a tip and a calculation unit for converting the elevating distance of the tip into the elevating distance of the second supporting member, and converting the elevating distance of the second supporting member to the surface height of the workpiece region being polished. .

In the polishing method according to the present invention, a process of acquiring an object surface image to be polished, measuring a height for each region of the surface of the treatment, calculating an average height of the surface of the treatment, the average height and a height for each region Comparing the steps, setting a region having a height higher than the average height to the polishing operation position, and moving the polishing unit to the set polishing operation position, and then starting the polishing.

The polishing work position is the (X, Y) coordinate of the coordinate plane of the image of the workpiece surface, and the stage on which the workpiece is placed corresponds to the coordinate plane of the workpiece image.

After the polishing unit is moved in the X-axis and Y-axis directions, the polishing unit is moved in the Z-axis such that the lower portion of the polishing unit is in contact with the surface of the workpiece.

During the polishing operation of the workpiece using the polishing unit, the surface height of the working area is compared with the average height of the workpiece surface to determine whether the polishing operation is to proceed.

The polishing operation is stopped when the surface height of the working area reaches the average height or falls within the average height tolerance range.

The treatment is a photo mask used for a photolithography process.

The polishing apparatus according to the embodiment of the present invention locally polishes the workpiece surface to planarize the workpiece surface. That is, instead of grinding the entire surface of the workpiece as in the prior art, it is locally polished to planarize the surface of the workpiece. As a result, the center region or the edge region may be excessively polished as in the related art, or the center region or the edge region may not be polished, thereby preventing the processing surface from being convex or concave. Therefore, the flatness of a processed material can be improved compared with the past. In addition, since the polishing operation is carried out locally, the polishing operation time can be reduced, and the polishing can be performed in various ways regardless of the area of the processed material. In addition, there is an advantage in that the size of the polishing apparatus can be reduced as compared with the polishing of the entire processed material as in the prior art.

1 illustrates a polishing apparatus according to an embodiment of the present invention.
2 shows a stage according to an embodiment of the invention.
3 and 4 show a polishing unit according to an embodiment of the invention.
5 is a view showing an image taken for measuring the height of the surface of the workpiece
6 is a flow chart sequentially illustrating a method of polishing a workpiece using a polishing apparatus according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It will be apparent to those skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know. Wherein like reference numerals refer to like elements throughout.

1 is a view showing a polishing apparatus according to an embodiment of the present invention. 2 is a diagram illustrating a stage according to an embodiment of the present invention. 3 and 4 show a polishing unit according to an embodiment of the present invention. FIG. 5 is a diagram illustrating an image photographed for measuring a height of a treatment surface. FIG.

The polishing apparatus according to the embodiment of the present invention is installed on the table 100, the stage 200 is placed on the table 100 is placed on the stage (200), the processing object (S) that is to be polished on the upper part is placed on the stage (200) The polishing module 700 having the polishing unit 400 for polishing the processing S, the polishing position control module 900 for controlling the position of the polishing unit 400, and extending in the X-axis direction on the table 100. It is installed includes a first guide rail 800 for horizontally moving the polishing module 700 in the X-axis direction. The processed material S according to the embodiment may be a photo mask having a rectangular shape, and the photo mask is used during a photolithography process for forming a pattern on a wafer. However, the processed material S is not limited to the photo mask, and objects of various shapes to be polished for the flatness of the surface may be applied.

The stage 200 is a means for seating and fixing the treatment S on the upper portion thereof, and a mounting groove 210 into which the treatment S may be inserted is provided inside the stage 200. The stage 200 according to the embodiment may be manufactured in a rectangular plate shape, but is not limited thereto and may be manufactured in various shapes. And the mounting groove 210 has a rectangular cross-section so that the rectangular treatment (S) can be easily inserted, it is preferable that the size is larger than or equal to the treatment (S). Of course, the shape of the mounting groove 210 may be variously modified according to the shape of the treatment (S). In such a stage 200, it is necessary to set an 'zero' point to adjust the position of the polishing unit 400. In the embodiment, as shown in FIG. 2, one corner of the seating groove 210, that is, a vertex is designated as a '0' point. Of course, the present invention is not limited thereto, and any one point may be stored as a '0' point. In addition, although not shown, the stage 200 may be provided with a separate seating means for seating and fixing the treatment (S). The seating means may be, for example, an electrostatic chuck using an electrostatic force or a vacuum hole using a vacuum suction force. Of course, the present invention is not limited to the above-described mounting means, and various means capable of mounting and fixing the treatment S on the stage 200 may be used.

The first guide rail 800 guides the gantry 300 in a direction crossing the direction in which the polishing unit 400 horizontally moves, for example, in the X-axis direction. In an embodiment, a pair of first guide rails 800 spaced apart from each other is provided. Here, the pair of first guide rails 800 are spaced side by side in parallel to the table 100 is installed in parallel, spaced apart one side and the other side of the stage 200 is installed. The pair of first guide rails 800 according to the embodiment may be, for example, an LM guide. However, the pair of first guide rails 800 may use various means for horizontally moving the first moving block 600 to be described later.

As shown in FIGS. 1 and 2, the polishing module 700 extends in a direction intersecting the first guide rail 800 on the stage 200 and on the gantry 300. Is installed in the horizontal movement and can be moved up and down, the polishing unit 400 for polishing the processing (S), extending in the direction crossing the first guide rail 800 on the gantry 300 is installed in the polishing unit ( A pair of agents that slide along the first guide rail 800 are installed to connect between the second guide rail 500, the gantry 300 and the first guide rail 800 to guide the movement of the 400 One moving block 600 is included.

The gantry 300 extends in a direction crossing the first guide rail 800, for example, in the Y-axis direction, and has a lower end connected to the first moving block 600. For example, the gantry 300 may include, for example, a first extension member extending in the Y-axis direction, one end of which is connected to a lower portion of the first extension member, and the other end of which is connected to a pair of first guide rails 800, respectively. It consists of a pair of 2nd extension member. That is, the gantry 300 according to the embodiment may be manufactured in a shape in which 'c' of the Korean consonants is inverted, but is not limited thereto. The gantry 300 may support the polishing unit 400 and may be manufactured in various shapes capable of horizontal movement. have. In addition, a second guide rail 500 for moving the polishing unit 400 in the horizontal direction, that is, the Y-axis direction, is installed at one side surface of the gantry 300. The second guide rail 500 extends in a direction crossing the first guide rail 800, that is, the Y-axis direction, and the second guide rail 500 may be an LM guide.

Each of the pair of first moving blocks 600 has an upper portion connected to a lower portion of the gantry 300 and a lower portion thereof connected to a pair of first guide rails 800, and thus, the pair of first guide rails 800. Slide along). As the first moving block 600 slides along the first guide rail 800, the gantry 300 coupled to the upper portion of the first moving block 600 moves horizontally in the X-axis direction. The first moving block 600 according to the embodiment may be, for example, a combination of a linear motor capable of linear motion and a motor for rotating the ball screw and the ball screw. The first moving block 600 calculates the operation amount of the motor, that is, the distance that the first moving block 600 and the polishing unit 400 move per unit pulse. Then, the X-axis position of the polishing unit 400 is detected from the '0' point, and the movement operation is controlled. That is, when the first moving block 600 slides along the first guide rail 800, the distance that the polishing unit 400 moves by using the unit pulse value of the motor is calculated, and thus the current polishing unit ( A position in the X-axis direction of 400 is detected in real time. When the polishing unit 400 reaches the target point in the X-axis direction, the movement operation is terminated.

The polishing unit 400 locally polishes the surface of the workpiece S to planarize the surface of the workpiece S. FIG. As shown in FIG. 3, the polishing unit 400 is installed above the first support member 410, the first support member 410, and the elevating power unit 420 and the gantry that provide the lifting force. The third moving block 430 provided on the rear surface of the first support member 410 facing the 300, the third guide coupled to the front surface of the first support member 410 extending in the vertical direction The second support member 450 spaced apart from one side of the rail 440 and the third guide rail 440 facing the stage 200 and installed in an upward and downward direction, one end thereof is connected to the rear surface of the second support member 450. A third moving block 460 whose other end is connected to the third guide rail 440, a lifting shaft 470 having one end connected to the lifting power unit 420, and at least a part of which is connected to the second supporting member 450; A joint 480 connected to the second supporting member 450 to connect the polishing unit 480, the lifting shaft 470, and the polishing unit 480 to connect the second support member 450. 480-1, the first support member 410 and the second support member 450 are connected to the polishing operation to control the progress of the polishing operation by measuring the change in the surface height of the workpiece S during the polishing operation in real time. Control unit 490.

The first support member 410 according to the embodiment is, for example, the first member 411 extending in the vertical direction, the second member 412 connected to the upper portion of the first member 411 to be perpendicular to the first member 411. ) And a third member 413 connected to the lower portion of the first member 411 so as to be perpendicular to the first member 411. Of course, the shape of the first support member 410 is not limited thereto and may be modified in various shapes. The first support member 410 is provided with a third guide rail 440, the lifting power unit 420 and the second moving block 430. The third guide rail 440 may extend in an up and down direction from one side of the first member 411, and the third guide rail 440 may be an LM guide. The second moving block 430 is installed on the rear surface of the first member 411, and the lifting power unit 420 is installed on the upper portion of the second member 412. Here, the second moving block 430 is installed to connect between the first member 411 of the first support member 410 and the second guide rail 500, and the polishing unit through the first support member 410 (400) The entire horizontal movement in the Y-axis direction. The second moving block 430 may be, for example, a combination of a linear motor capable of linear movement and a motor for rotating the ball screw and the ball screw. Of course, the present invention is not limited thereto, and the second moving block 430 may be applied in any manner that can slide on the second guide rail 500. Therefore, when the second moving block 430 slides along the second guide rail 500, the entire polishing unit 400 is horizontally moved in the Y-axis direction by the first support member 410. At this time, the second moving block 430 detects the Y-axis position in the same manner as in the first moving block 600. That is, when the second moving block 430 slides along the second guide rail 500, the distance traveled by the second moving block 430 and the polishing unit 400 is calculated using the unit pulse value of the motor. In this way, the position in the Y-axis direction of the current polishing unit 400 is detected in real time. When the polishing unit 400 reaches the target point in the Y-axis direction, the movement operation is terminated. In addition, although the hydraulic power or pneumatic cylinder is used as the elevating power unit 420 in the embodiment, various means for providing the elevating power to the elevating shaft may be used.

The second support member 450 extends in the vertical direction and is installed in front of the first support member 410 and is connected to the first support member 410. For example, the second support member 450 may include, for example, a third member 413 extending in the vertical direction, and a fifth member connected to an upper portion of the fourth member 451 to be perpendicular to the third member 413. 452). That is, the second support member 450 according to the embodiment may be manufactured in a 'a' shape of the Hangul consonant, but is not limited thereto. The second support member 450 may be changed into various shapes that can support the polishing unit 400. . A third moving block 460 for raising and lowering the second support member 450 is installed on the rear surface of the second support member 450. That is, the third moving block 460 is installed to connect the third member 413 and the third guide rail 440. In the embodiment, a plurality of third moving blocks 460 are provided to be installed in the vertical direction. . In the exemplary embodiment, a combination of a linear motor capable of linear movement with the third moving block 460 and a motor for rotating the ball screw and the ball screw may be used. However, various means may be used. On the other hand, the second support member 450 and the second moving block 430 is raised or lowered according to the contact state between the polishing unit 480 and the processing (S) to be described later, a detailed description thereof will be described below. Shall be.

The elevating shaft 470 transmits the elevating force of the elevating power unit 420 to the second supporting member 450, and one end thereof passes through the first supporting member 410 and is connected to the elevating power unit 420. The other end penetrates through the second support member 450 and is connected to the joint 480-1. The lifting shaft 470 according to the embodiment may be, for example, a cylinder rod extending or contracting by the operation of the lifting power unit 420. Accordingly, when the lifting shaft 470 contracts by the lifting power unit 420, the second supporting member 450 and the third moving block 460 move upward. On the contrary, when the lifting shaft 470 extends, the second supporting member 450 and the third moving block 460 move downward. In the above description, for example, the lifting shaft 470 is a cylinder rod, the present invention is not limited thereto. Various means for providing the lifting force to the second support member 450 may be used.

The polishing unit 480 is installed at the lower end of the rotating shaft 481 connected to the joint 480-1, the rotating disk 482 connected to the lower portion of the rotating shaft 481, and the rotating disk 482 to polish the workpiece. A rotary power unit 484 installed between the polishing pad 483, the joint 480-1, and the rotating disk 482 to rotate the rotating shaft 484, and the sides and the upper portion of the rotating disk 482. It includes a cover 485 installed to cover the. It also includes a connecting member for connecting between the rotary power unit 484 and the second support member. In this case, the joint 480-1 connects the elevating shaft 470 and the rotary shaft 481, and is detachable from at least the elevating shaft 470. In addition, the joint 480-1 may be manufactured to have an empty shape, and when the joint 480-1 is separated from the lifting shaft 470, abrasives may be introduced into the joint 480-1.

The rotating shaft 481 is installed to extend in the vertical direction to penetrate the rotating power unit 484, one end of which is connected to the lower portion of the joint 480-1, and the other end of which is connected to the rotating disk 482. Thus, when the rotary shaft 481 rotates by the operation of the rotary power unit 484, the rotary disk 482 connected to the other end of the rotary shaft 481 rotates. In addition, the rotating shaft 481 has a hollow pipe shape, and the inner space of the rotating shaft 481 communicates with the inner space of the joint 480-1. Therefore, when the abrasive is introduced into the joint 480-1 by separating the joint 480-1 and the lifting shaft, the abrasive moves into the rotation shaft 481.

The rotating disk 482 is connected to the other end of the rotating shaft 481 and rotates together with the rotating shaft 481, and a first outlet hole 482a communicating with the inner space of the rotating shaft 481 is provided therein. Thus, the abrasive moved to the inner space of the rotation shaft 481 moves to the first outlet hole 482a. Rotating disk 482 according to the embodiment is made of a cross-sectional shape of the letter 'T', but is not limited to this can be made of a variety of shapes that can be rotated and the polishing pad 483 can be installed below. .

The polishing pad 483 is installed at the lower portion of the rotating disk 482 to rotate together with the rotating disk 482, and the second discharge hole 483a communicating with the first outlet hole 482a is provided therein. . Thus, the abrasive introduced into the first outlet hole 482a of the rotating disk 482 through the rotating shaft 481 is discharged to the upper portion of the processing object S to be polished through the second outlet hole 483a.

The polishing operation control unit 490 measures the height of the surface of the workpiece S in operation from the surface height measuring unit 491 and the surface height measuring unit 491 to measure the surface height of the processing object S in real time during the polishing operation. And a polishing operation determiner 493 which receives and compares the average value with the comparison unit 492 and the polishing unit 439 for continuing or stopping the polishing operation according to the result of the comparison unit 492.

The surface height measuring unit 491 is installed to have a main body 491c coupled to an upper portion of the first support member, one end of which is connected to the main body 491c, and the other end of which is in contact with an upper portion of the second support member 450. 2 Ascending and descending distances of the tip 491a and the tip 491a which are raised and lowered together with the lifting and lowering of the supporting member 450 are converted into the lifting and lowering distance of the second supporting member 450, and the second supporting member And a computing unit 491b for converting the elevating distance of the 450 into a change in the surface height of the area of the workpiece S being polished. The operation of the tip 491a according to the raising and lowering of the second supporting member 450 will be described below.

In the comparator 492, the average height calculator 920 receives the average value of the workpiece S and the surface height value of the workpiece S being polished from the surface height meter, and the average value and the surface height of the polishing work are received. Compare the values in real time. The polishing operation determiner 493 continues the polishing operation when the surface height of the region being polished is larger than the average value. On the contrary, the polishing operation determining unit 493 stops the operation of the rotary power unit 484 when the surface height of the area under polishing reaches an average value or falls within a ± error range from the average value, thereby terminating the polishing operation. In this case, an error range from the average value may be, for example, +10 μm to 20 μm.

In the following, with reference to Figures 2 and 3, the lifting operation of the polishing unit and the operation of the polishing position control module will be briefly described.

When the elevating shaft 470 is extended using the elevating power unit 420, as shown in FIG. 3, the second supporting member 450 connected to the elevating shaft 470 is connected to the second moving block 430. Descend by When the lower surface of the polishing pad 483 of the polishing unit 480 connected to the second support member 450 contacts the surface of the workpiece S during the lowering, the lowering operation of the second support member 450 is stopped or The predetermined distance rises. When the polishing operation is performed, as the height of the surface of the workpiece S is lowered, the polishing pad 483 and the second support member 450 are in contact with the surface of the workpiece S. ) Descends. As such, during the polishing operation, the second support member 450, the second moving block 430, and the polishing unit 480 are lowered by load or gravity as the height of the surface of the workpiece S decreases. In addition, as the second supporting member 450 descends, the tip 491a of the surface height measuring unit 491 which is in contact with the upper surface of the second supporting member 450 descends by gravity. As described above, the calculation unit 491b calculates the distance at which the tip 491a is lowered to the distance at which the second support member 450 is lowered, and the polishing operation is performed from the lowered distance of the second support member 450. It converts into the surface height change of the water S area | region.

The polishing position control module 900 provides the height data of each surface of the processing material S from the surface height measuring device 910 and the surface height measuring device 910 for measuring the height of each area of the surface of the processing material S. And a polishing position (coordinate value) set by the average height calculator 920 for calculating the average height, the polishing position setting unit 930 for setting the position to be polished using the average height, and the polishing position setting unit 930. And a polishing unit position adjusting unit 940 for moving the polishing unit 400.

Hereinafter, for the convenience of description, the average height value of the surface of the processed material S will be referred to as an 'average value'.

For example, the surface height measuring instrument 910 acquires an image of the surface of the workpiece S, as shown in FIG. 5, and measures the height of each area of the surface of the workpiece. The location of each region of the image acquired through the surface height measuring instrument 910 is represented by (X, Y) coordinates, and may be represented by different colors according to the height of each region as shown in FIG. 5. In the embodiment, the surface height measuring instrument 910 uses AFM (Atomic Force Microscopy), but the present invention is not limited thereto. Various means for measuring the height of each region of the surface of the processed material S may be used. The height for each region (by coordinates) measured by the surface height measuring instrument 910 is transmitted to the average height calculator 920, and the average height calculator 920 calculates an average value.

The polishing position setting unit 930 compares the average value calculated by the average height calculating unit 920 with the height for each region, and sets the region having the surface height higher than the average value to be polished. The set polishing position is transmitted to the polishing unit position adjusting unit 940 in the form of (X, Y) coordinates. The polishing position to be set may be one or plural.

The polishing unit position adjusting unit 940 receives the position to be polished from the polishing position setting unit 930 as data in the form of (X, Y) coordinates, and adjusts the polishing unit 400 to move to the set polishing position. To this end, the polishing unit position adjusting unit 940 is connected to the first moving block 600 for moving the polishing unit 400 in the X-axis direction, and the second moving block 430 and the Z-axis for moving in the Y-axis direction. It is connected to the third moving block 460 to move in the direction.

6 is a flowchart sequentially showing a method of polishing a processed material using a polishing apparatus according to an embodiment of the present invention. Hereinafter, a method of polishing a processed material using a polishing apparatus according to an embodiment will be described with reference to FIGS. 1 to 6. In this case, the content overlapping with the above description will be omitted or briefly described.

First, the processed material S to be polished is prepared, for example, a photomask having been manufactured, and the surface height of each area of the processed material S is measured using the surface height measuring instrument 910 (S100). The photo mask according to the embodiment is provided for patterning the wafer and may be quartz glass in which a pattern is formed. However, the present invention is not limited thereto, and various objects to be polished may be applied. In the embodiment, although the AFM is used as the surface height measuring instrument 910, various means for measuring the height of the surface of the workpiece S may be used. The areas of the workpiece S surface image measured from the surface height meter 910 are represented by (X, Y) coordinates. At this time, one corner of the surface of the processing S surface, that is, one vertex is expressed as a '0' point, and is represented by (X, Y) coordinates based on the '0' point. The height data for each (X, Y) coordinate is transmitted to the average height calculator 920.

Thus, while measuring the surface height of the processed material S, it is preferable to separate the joint 480-1 from the lifting shaft 470, and to supply an abrasive into the joint 480-1. The abrasive moves to the second outlet hole 483a of the polishing pad 483 through the inner space of the rotating shaft 481 and the first outlet hole 482a of the rotating disk 482. When the abrasive is added, the joint 480-1 and the lifting shaft 470 are combined.

The average height calculating unit 920 calculates an average height of the processed material S, that is, an average value, by using height values for each (X, Y) coordinate (S200). The polishing position setting unit 930 compares the average value calculated by the average height calculating unit 920 with the height for each region (S300), and sets an area having a higher surface height than the average value as the polishing work position (S400). The polishing operation position may be one or a plurality, and the set polishing position is transmitted to the polishing unit position adjusting unit 940 in the form of (X, Y) coordinates.

Thereafter, the treatment S is seated and fixed on the stage 200. The coordinate plane of the stage 200 corresponds to the coordinate plane of the workpiece surface image, and the point of the actual workpiece S corresponding to the '0' point of the workpiece surface image corresponds to the coordinate plane of the workpiece surface image. Settle at the '0' point. In addition, the polishing unit position adjusting unit 940 controls the movement of the first and second moving blocks 430 to move the polishing unit 400 to be positioned at the polishing position set above (S500). That is, the polishing unit position adjusting unit 940 transmits the X coordinate value to the first moving block 600 and the Y coordinate value to the second moving block 430. Accordingly, the first moving block 600 moves along the first guide rail 800 in the X axis direction, and the second moving block 430 moves along the second guide rail 500 in the Y axis direction. Here, by calculating the moving distance of the polishing unit 400 in motion by using the unit pulse values of the first and second moving blocks 430, the real time position of the polishing unit 400 can be known. Thus, when the polishing unit 400 reaches the set X, Y coordinate position, the movement is stopped. In addition, when the elevating shaft 470 is extended using the elevating power unit 420, as shown in FIG. 3, the second support member 450 connected to the elevating shaft 470 is the second moving block 430. Descend by). The downward force of the second supporting member 450 is transmitted to the third moving block 460 installed on the rear surface of the second supporting member 450, whereby the third moving block 460 moves to the third guide rail ( 440) down. When the lower surface of the polishing pad 483 of the polishing unit 480 connected to the second support member 450 contacts the surface of the workpiece S during the lowering, the lowering operation of the second support member 450 is stopped or The predetermined distance rises. In addition, as the second supporting member 450 descends, the tip 491a of the surface height measuring unit 491 which is in contact with the upper surface of the second supporting member 450 descends by gravity. At this time, the calculation unit 491b of the polishing operation control unit 490 adjusts the positions of the tip 491a and the second support member 450 when the polishing pad 483 contacts the surface of the workpiece S before the polishing operation. Set as a reference.

When the polishing unit 400 is positioned at a set polishing position, that is, (X, Y) coordinates, and the lower surface of the polishing pad 483 contacts the surface of the workpiece S, polishing is started (S600). To this end, when the rotary shaft 481 is rotated using the rotary power unit 484, the rotary disk 482 connected to the lower portion of the rotary shaft 481 and the polishing pad 483 provided at the lower portion of the rotary disk 482 are provided. Rotate At this time, since the lower surface of the polishing pad 483 is in contact with the upper surface of the treatment S, the upper surface of the treatment S is polished by the rotation of the polishing pad 483. In addition, the abrasive is discharged to the surface of the workpiece S to be polished through the second outlet hole 483a, and the polishing operation is performed using the abrasive.

During the polishing operation, the surface height measuring unit 491 of the polishing operation control unit 490 measures the surface height of the area in the polishing operation in real time (S700).

That is, in the calculation unit 491b, as described above, when the polishing pad 483 is in contact with the surface of the workpiece S before the polishing operation, it is set based on the positions of the tip 491a and the second support member 450. . Thereafter, when the polishing operation is started, the second support member 450, the polishing unit 480, and the second moving block 430 are lowered by load or gravity as the surface height of the processing material S gradually decreases. As the second supporting member 450 descends, the tip 491a of the surface height measuring unit 491 which contacts the upper surface of the second supporting member 450 descends. At this time, the calculation unit 491b calculates the distance that the tip 491a is lowered to the distance that the second support member 450 is lowered, and the reference position (pre-polishing position) and the lowering distance of the second support member 450. It is converted into the surface height of the workpiece | work area | region S in grinding | polishing operation | work using.

The comparator 492 receives the average value of the processed material S from the average height calculator 920 and the surface height value of the processed material S, which is being polished from the surface height measuring device, and the average value and the surface being polished. The height value is compared in real time (800). The polishing operation determination unit 493 stops the polishing operation when the surface height of the region in the polishing operation reaches an average value or falls within a tolerance range of the average value (S900). That is, when the surface height of the area under polishing reaches an average value or falls within the tolerance range of the average value, the polishing operation determiner 493 stops the operation of the rotary power unit 484. On the contrary, if the surface height of the region being polished is larger than the average value or is outside the tolerance range, the polishing operation is continued (S600).

In the above, the polishing of one (X, Y) coordinate region has been described, but a plurality of regions may be polished.

As described above, in the polishing apparatus according to the embodiment of the present invention, the surface of the workpiece S is locally polished to planarize the surface of the workpiece S. That is, the surface of the processed material S is planarized by locally polishing it, without polishing the entire surface of the processed material S as in the prior art. Thus, as described above, the center region or the edge region is excessively polished or, conversely, the center region or the edge region is not polished, thereby preventing the problem that the surface of the processed material S becomes convex or concave as a whole. Therefore, the flatness of the processed material S can be improved compared with the past. In addition, since the polishing operation is performed locally, the polishing operation time can be reduced, and the polishing can be performed in various ways regardless of the area of the processed material S. FIG. In addition, there is an advantage in that the size of the polishing apparatus can be reduced as compared with the polishing of the whole processed material S as in the related art.

S: stage 200: stage
300: gantry 400: polishing unit
500: second guide rail 600: first moving block
800: first guide rail 900: polishing position control module

Claims (20)

A polishing apparatus for polishing the surface of a workpiece,
A polishing unit having a polishing pad for polishing the surface of the workpiece and capable of raising, lowering, horizontally moving and rotating;
And a polishing position control module connected to the polishing unit to set a region having a height higher than an average height value of the workpiece surface as the polishing work region, and move the polishing unit to the set polishing work region. The method according to claim 1,
A stage disposed below the polishing unit, on which the treatment is placed;
A gantry extending in one direction from an upper side of the stage and supporting the polishing unit;
A first moving block coupled to a lower portion of the gantry and capable of horizontal movement;
A first guide rail spaced apart from at least one side of the stage to extend in a direction crossing the gantry and engaged with the first moving block to guide horizontal movement of the first moving block;
And the first moving block is controlled to be moved by the polishing position control module. The method according to claim 2,
And a second guide rail extending in a direction crossing the first guide rail on one side of the gantry and fastened to the polishing unit to guide horizontal movement of the polishing unit. The method according to any one of claims 1 to 3,
The polishing unit,
A first support member spaced apart from one side of the gantry and installed in an up and down direction;
A second moving block coupled to a rear surface of the first support member and sliding in a horizontal direction along a second guide rail provided in the gantry;
A third guide rail installed to extend in a vertical direction from a front surface of the first support member;
A second support member extending in a vertical direction from the front of the third guide rail;
A lifting power unit installed on an upper portion of the first supporting member to provide lifting force;
An elevating shaft having one end connected to the elevating power unit, and another portion thereof coupled with the second supporting member;
A third moving block coupled to a rear surface of the second supporting member and sliding upward and downward along the third guide rail; And
And a polishing unit connected to the second supporting member and the lifting shaft, the polishing unit including a polishing pad for polishing the processing object. The method of claim 4,
And the second and third moving blocks are controlled to be moved by the polishing position control module. The method of claim 4,
The polishing unit has one end connected to the elevating shaft, the rotating shaft provided with an inner space to move the abrasive therein;
A rotary power unit for rotating the rotary shaft;
A rotating disk connected to the other end of the rotating shaft and provided with a first outlet hole through which the abrasive may move;
A polishing pad disposed below the rotating disk to polish the surface of the workpiece and having a second outlet hole communicating with the first outlet hole therein; And
One end is connected to the lifting shaft, the other end is connected to the rotating shaft, and includes a joint provided therein the inner space for moving the abrasive,
The inner space of the joint is in communication with the inner space of the rotating shaft. The method according to claim 2 or 5,
The polishing position control module,
An average height calculator configured to calculate an average height value of the surface of the workpiece;
A polishing position setting unit which compares the average height value with the height of each region of the workpiece surface to set a region having a height higher than the average height value as a polishing work position;
And a polishing unit position adjusting portion for adjusting the polishing unit to be positioned at a predetermined polishing work position. The method of claim 7,
And a surface height measuring device for acquiring the treatment surface image and measuring a surface height of each surface of the surface of the treatment object using the image. The method of claim 7,
The polishing work position set by the polishing position setting unit is set to (X, Y) coordinates in the coordinate plane of the image,
And a coordinate plane of the stage corresponds to a coordinate plane of the workpiece image. The method of claim 7,
And the polishing unit position adjusting unit adjusts the polishing unit to correspond to the (X, Y) coordinate which is the set polishing work position above the coordinate plane of the stage. The method of claim 10,
And the polishing unit position adjusting unit controls the movement of the first to third moving blocks so that the polishing unit is positioned corresponding to the set polishing work position. The method of claim 4,
Connected with the polishing unit to detect a change in the surface height of the area under polishing in real time,
And a polishing operation control unit which compares the surface height of the region during the polishing operation with the average height value of the workpiece surface to determine whether the polishing operation is in progress. The method of claim 12,
The polishing operation control unit,
A surface height measuring device that measures, in real time, the surface height of the area being polished according to the moving distance of the second supporting member which is moved up and down during the polishing operation;
A comparison unit connected to the surface height measuring unit to compare the surface height of the area during the polishing operation with the average height of the surface of the workpiece; And
And a polishing operation determiner configured to stop the polishing operation when the surface height of the region being polished reaches the average height of the workpiece surface or is included in the average height tolerance. The method according to claim 13,
The surface height measuring device may be coupled to an upper portion of the first support member;
A tip, one end of which is connected to the main body and the other end of which is in contact with an upper portion of the second supporting member, which is lifted up and down along with the lifting of the second supporting member; And
And a calculating unit for converting the elevating distance of the tip to the elevating distance of the second supporting member, and converting the elevating distance of the second supporting member to the surface height of the workpiece region being polished. Obtaining an image of the surface of the workpiece to be polished and measuring a height of each region of the surface of the workpiece;
Calculating an average height of the surface of the workpiece;
Comparing the average height with the height of each region;
Setting a region having a height higher than the average height as a polishing work position;
And starting the polishing after moving the polishing unit to the set polishing work position. The method according to claim 15,
The polishing working position is the (X, Y) coordinate of the coordinate plane of the image of the workpiece surface,
And a stage in which the workpiece is placed corresponds to a coordinate plane of the workpiece image. 18. The method of claim 16,
And moving the polishing unit in the X-axis and Y-axis directions, and then moving the polishing unit in the Z-axis such that the lower portion of the polishing unit is in contact with the workpiece surface. The method according to claim 15,
During the polishing operation of the workpiece using the polishing unit, determining whether or not to proceed with the polishing operation by comparing the surface height of the working area with the average height of the workpiece surface. 18. The method of claim 17,
And a polishing operation is stopped when the surface height of the working area reaches the average height or falls within an average height tolerance range. The method according to any one of claims 15 to 19,
And the treated material is a photo mask used for a photolithography process.

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