Wafer polishing equipment

Abstract

A wafer polishing apparatus includes a platen having a polishing pad attached to its upper surface and rotating together with the polishing pad, and a polishing unit disposed on an upper side of the platen and configured to perform polishing by pressurizing and rotating a wafer interposed between the polishing unit and a polishing pad, wherein the polishing unit includes a baseplate, a plurality of polishing parts, a plurality of rotation drive parts and a plurality of pressure drive parts.

Description

CROSS REFERENCE TO RELATED APPLICATIONS AND CLAIM OF PRIORITY

[0001] This application claims priority to Korean Patent Application No. 10-2024-0107975, filed in the Korean Intellectual Property Office on Aug. 13, 2024, and all the benefits accruing therefrom under 35 U.S.C. § 119, the content of which in its entirety is herein incorporated by reference.BACKGROUND1. Technical Field

[0002] The present disclosure relates to a polishing apparatus for semiconductor wafer.2. Background Art

[0003] In general, multiple polishing processes are performed during the manufacturing process of wafers used in semiconductor devices. Among them, CMP equipment based on Chemical and Mechanical Polishing is mainly used for the process of polishing the wafer surface.

[0004] CMP is a process that enables ultra-fine polishing by simultaneously polishing the surface of a wafer coated with materials such as tungsten or oxides through mechanical friction and chemical polishing agents. Mechanical polishing involves applying pressure to the wafer while rotating it against a rotating polishing pad, resulting in surface abrasion due to the friction between the polishing pad and the wafer surface. Chemical polishing, on the other hand, utilizes a slurry supplied between the polishing pad and the wafer. As the slurry is introduced, the wafer polishing is performed through the combined action of mechanical polishing and chemical agents.

[0005] Mechanical polishing is a method of polishing a wafer surface by applying pressure and rotating the wafer against a rotating polishing pad, thereby creating friction between the polishing pad and the wafer surface. Chemical polishing uses slurry supplied between the polishing pad and the wafer. The wafer polishing is performed by mechanical polishing while supplying slurry between the polishing pad and the wafer.

[0006] Since CMP is mostly performed under low-pressure conditions of 300 to 400 g / cm2, the overall process time is long and the consumables increase, which incurs high costs. In conventional low-pressure CMP equipment, when polishing under ultra-high-pressure conditions of 78.4 kPa (800 g / cm2) or more, there is a problem that the wax fixing the wafer melts due to high frictional heat and the wafer is detached, which causes problems of polishing imbalance and deterioration of wafer shape precision. Therefore, it is necessary to develop CMP equipment that can increase the polishing rate per unit time and reduce the process cost accordingly.

[0007] Korean Patent No. 10-1678992 discloses a CMP equipment having multi-heads, and Korean Patent Publication 10-2019-0073661 discloses a wafer polishing apparatus. Conventional CMP equipment is structured to control 1 to 4 polishing heads in batches with one motor, and due to this structural characteristic, it is not easy to meet appropriate conditions for wafer polishing. For example, in the actual wafer production process, there may be cases where the wafer states before the polishing process are different from each other, and a situation may arise where different polishing conditions must be applied to each wafer. In this case, since individual settings for each polishing head are not possible with the above-mentioned batch control method, there is no choice but to select wafers separately according to polishing conditions and polish them, or to batch-polish them under specific conditions and then re-polish them, which is a significant disadvantage in terms of time and cost.

[0008] Meanwhile, Japanese Patent No. 2011-519166 discloses a technology for independent driving of a polishing head in CMP equipment, but it is necessary to develop CMP equipment with further improved functions to increase driving efficiency and polishing flatness.SUMMARY

[0009] It is an object of the present disclosure to provide a wafer polishing apparatus capable of individually controlling multiple polishing heads.

[0010] It is another object of the present disclosure to provide a wafer polishing apparatus capable of improving the efficiency of a polishing process.

[0011] As a means to achieve the above-mentioned object, the present disclosure provide a wafer polishing apparatus including: a platen having a polishing pad attached to its upper surface and rotating together with the polishing pad; and a polishing unit disposed on an upper side of the platen and configured to perform polishing by pressurizing and rotating a wafer interposed between the polishing unit and a polishing pad, wherein the polishing unit includes: a baseplate; a plurality of polishing parts mounted on the baseplate to be spaced from each other at a predetermined interval, wherein each polishing part includes polishing rotation shafts rotatably coupled to the baseplate to penetrate the baseplate and a polishing head coupled to a lower part of the polishing rotation shaft to rotate together with the polishing rotation shaft, and that rotates around each polishing rotation shaft and are raised and lowered in each polishing rotation shaft direction; a plurality of rotation drive parts mounted on the baseplate to be adjacent to the polishing parts and configured to respectively, individually provide rotational power to the corresponding polishing part; and a plurality of pressure drive parts mounted on the baseplate to be adjacent to the polishing parts and configured to respectively, individually provide pressure to the corresponding polishing part.

[0012] According to one embodiment, each of the polishing parts includes a first rotary gear that surrounds and is coupled to the polishing rotation shaft on an upper side of the polishing head and rotates together with the polishing rotation shaft, and each of the rotation drive parts includes a turning motor mounted on the baseplate and having a motor rotation shaft penetrating downwardly through the baseplate; and a second rotary gear coupled to a motor rotation shaft of the turning motor, configured to rotate together with the turning motor and engaged with a first rotary gear.

[0013] According to another embodiment, each of the pressure drive parts includes: a pressure cylinder mounted on the baseplate and equipped with a piston rod that moves up and down and back and forth; and a pressure bracket having one end coupled to the piston rod of the pressure cylinder and coupled to the polishing rotation shaft of the polishing parts so that the polishing rotation shaft and polishing head descend and ascend as the piston rod is advanced and retracted.

[0014] According to another embodiment, each of the pressure drive parts further includes a first frame to which other end of the pressure bracket is nutatably coupled; a first bearing coupled to the pressure bracket, and rotatably coupled to the polishing rotation shaft such that the polishing rotation shaft penetrates the first bearing; and a joining bar configured to fixedly couple the pressure bracket and the first bearing.

[0015] According to another embodiment, each of the pressure drive parts further includes a base frame mounted on the baseplate and provided with the first frame protruding from one side thereof; and a second frame formed to protrude from other side of the base frame to a height higher than the first frame and provided with the pressure cylinder vertically mounted on an upper surface thereof.

[0016] According to another embodiment, the polishing unit, the polishing unit further includes an oscillation part configured to provide left-right oscillation to the baseplate to provide left-right oscillation to the polishing parts.

[0017] According to another embodiment, the oscillation part includes: an oscillation motor spaced apart from the baseplate and arranged so that a rotary shaft direction of the oscillation motor is orthogonal to a left-right vibration direction of the baseplate; and a connecting rod whose one end is rotatably coupled to the rotating shaft of the oscillation motor and whose other end is rotatably coupled to the baseplate so that the baseplate oscillates left and right according to rotation of the rotating shaft of the oscillation motor.

[0018] According to another embodiment, the oscillation part further includes: a rotary plate that is fixedly coupled to an end of the rotating shaft of the oscillation motor to rotate together with the oscillation motor and has a protrusion formed on one surface thereof at a position spaced from the rotating shaft of the oscillation motor, wherein the protrusion penetrates and is coupled to the first coupling hole formed at one end of the connecting rod such that one end of the connecting rod can rotate around the protrusion as an axis. In this case, the protrusion is fitted into the first coupling hole of the connecting rod and bolted into a threaded hole formed in the rotary plate. In addition, a plurality of threaded holes are provided, the threaded holes are spaced apart from the rotating shaft of the oscillation motor at different distances, and the protrusion is selectively fastened to one of the threaded holes.

[0019] According to another embodiment, the baseplate further includes a fixed bracket which is formed on one side of its upper surface and to which other end of the connecting rod is coupled, wherein the fixed bracket includes a pair of vertical members and a shaft member fixedly coupled between the vertical members, wherein the shaft member penetrates and is coupled into the second coupling hole formed at the other end of the connecting rod.

[0020] According to another embodiment, the oscillation part further includes a pair of rail-shaped linear motion guides coupled along a front end and rear end edges of the baseplate, and the baseplate oscillates between the linear motion guides while moving left and right.

[0021] According to another embodiment, each of the polishing parts further includes a wafer carrier mounted on the polishing head so as to be disposed on a lower side of the polishing head, and rotated and raised / lowered together with the polishing head. In this case, the wafer carrier has a template attached to its lower surface, wherein the template has at least one wafer mounting hole. In addition, an upper surface of the wafer carrier is formed in a truss structure.

[0022] According to another embodiment, the wafer polishing apparatus includes a housing configured to accommodate the platen and the polishing unit, wherein the housing includes a housing body on a top of which the platen is mounted; a housing lid which is configured to open / close the housing body and on which the polishing unit is mounted; a pair of lifting cylinders mounted on both sides of an upper end of the housing body to vertically raise and lower piston rods; and a pair of joining frames mounted on both sides of the housing lid and coupled to ends of the piston rods of the lifting cylinders, wherein, when the piston rods of the lifting cylinders are raised and lowered, the housing lid is raised and lowered.

[0023] According to another embodiment, the lifting cylinder is disposed at a front end of the housing body and an end of the piston rod is nutatably coupled to the joining frame so that a front end of the housing lid is opened and closed while being inclined at a predetermined angle as it ascends and descends.

[0024] According to another embodiment, the housing lid has a pair of rollers mounted on both sides of the rear end, the housing body has rails on which the rollers can move, and when the front end of the housing lid ascends and descends, the rear end of the housing lid moves forward and backward on the rails.

[0025] According to another embodiment, the polishing unit further includes a slurry supply tube mounted so as to protrude from a center of a lower surface of the baseplate.

[0026] According to another embodiment, the housing lid includes at least one exhaust line, and the exhaust line is connected to an exhaust pump outside the housing lid.BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and other features of the inventive concept will become more apparent by describing in detail exemplary embodiments thereof with reference to the accompanying drawings, in which:

[0028] FIG. 1 is a drawing substitute photo illustrating a wafer polishing apparatus according to an embodiment of the present invention, and FIGS. 2 and 3 are drawing substitute photos illustrating the open state of the wafer polishing apparatus of FIG. 1.

[0029] FIG. 4 is a plan view for explaining the polishing unit of the wafer polishing apparatus of FIG. 1, and FIG. 5 is a drawing substitute photo for explaining a polishing unit of the wafer polishing apparatus of FIG. 1.

[0030] FIG. 6 is a schematic diagram for explaining rotation drive parts of the polishing unit of FIGS. 4 and 5, FIG. 7 is a schematic diagram for explaining the operational relationship between the polishing parts and the rotation drive parts of FIGS. 4 and 5, FIGS. 8 and 9 are drawings for explaining pressure drive parts of the polishing unit of FIGS. 4 and 5, and FIGS. 10 and 11 are drawings for explaining oscillation parts of the polishing unit of FIGS. 4 and 5.

[0031] FIGS. 12 and 13 are drawings for explaining the opening / closing structure of the wafer polishing apparatus according to an embodiment of the present invention.

[0032] FIGS. 14 and 15 are drawings for explaining a manual input / output screen and Auto Recipe input / output screen provided in a controller of the wafer polishing apparatus according to an embodiment of the present invention.DETAILED DESCRIPTION

[0033] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, the embodiments described below are intended only to describe the disclosure in detail so that those having ordinary skill in the art to which the disclosure pertains can easily practice the invention, and are not intended to limit the scope of the disclosure. Throughout the description of various embodiments of the present disclosure, the same reference numerals are used to refer to components having the same technical features.

[0034] As shown in FIGS. 1 to 3, a wafer polishing apparatus (hereinafter referred to as “wafer polishing apparatus 100”) according to an embodiment of the present invention includes a platen 104 provided with a polishing pad 105 attached to an upper surface thereof and configured to rotate together with the polishing pad 105 in one or the other direction; and a polishing unit 106 disposed on an upper side of the platen 104, wherein the wafer polishing apparatus 100 performs polishing by pressing and rotating a wafer 10 interposed between the polishing unit 106 and the polishing pad 105.

[0035] The wafer polishing apparatus 100 may further include a housing 101 that accommodates the platen 104 and the polishing unit 106. Here, the housing 101 includes a housing body 102; and a housing lid 103 for opening / closing the top of the housing body 102. The platen 104 may be rotatably mounted on the top of the housing body 102, and the polishing unit 106 may be mounted on the housing lid 103. In this case, when the housing lid 103 is opened, the polishing unit 106 is spaced from the platen 104, and when the housing lid 103 is closed, the bottom of the polishing unit 106 may come into contact with the polishing pad 105 of the platen 104. Although not indicated as reference numerals in the drawings, various display parts are mounted on the exterior of the housing 101. FIGS. 2 and 3 show the housing 101 in an open state, and the opening / closing of the housing 101 is described below.

[0036] The polishing unit 106 includes a baseplate 108, a plurality of polishing parts 110, a plurality of pressure drive parts 120 and a plurality of rotation drive parts 130, and further includes an oscillation part 140.

[0037] The baseplate 108 is mounted in the housing lid 103. As described below, the baseplate 108 is coupled to a linear motion guide 146 to be linearly moved together with the polishing parts 110, the rotation drive parts 130 and the pressure drive parts 120. The baseplate 108 may include a fixed bracket 150 formed on one side of the upper surface thereof, which is described below. For reference, the baseplate 108 may be mounted inside the housing lid 103 or on the upper surface of the housing lid 103.

[0038] The plural polishing parts 110 are mounted on the baseplate 108 to be spaced from each other at a predetermined interval. Each of the polishing parts 110 includes a polishing rotation shaft 133 and a polishing head 136. The polishing rotation shaft 133 is rotatably coupled to the baseplate 108 to penetrate the baseplate 108, and the polishing head 136 is coupled to a lower part of the polishing rotation shaft 133 to rotate together. Accordingly, the polishing head 136 rotates as each polishing rotation shaft 133 in the plural polishing parts 110 rotates, and the polishing head 136 is raised and lowered as the polishing rotation shaft 133 is raised and lowered. Each of the polishing parts 110 receives rotational power and pressure from the corresponding rotation drive part 130 and pressure drive part 120, thereby being individually operated and controlled.

[0039] Each of the plural rotation drive parts 130 and the plural pressure drive parts 120 is mounted in the baseplate 108 to be adjacent to the polishing parts 110 to individually provide rotational power and pressure to the corresponding polishing parts 110, and the oscillation part 140 is provided to the polishing parts 110 so as to provide left-right oscillation thereto.

[0040] Hereinafter, the particulars of the polishing parts 110, the pressure drive parts 120, the rotation drive parts 130, the oscillation part 140 are described in detail with reference to the accompanying drawings.

[0041] Referring to FIGS. 1 to 5, the polishing parts 110 includes the polishing rotation shaft 133 and the polishing head 136, and may further include a first rotary gear 134 and a wafer carrier 138.

[0042] The polishing rotation shaft 133 is coupled to the baseplate 108 while penetrating it, so that a lower end of the polishing rotation shaft 133 extends toward a lower part of the baseplate 108, i.e. toward the inside of the housing lid 103. In this case, the polishing rotation shaft 133 is fixedly coupled to the baseplate 108, and the polishing head 136 and first rotary gear 134 coupled to the polishing rotation shaft 133 rotate around the polishing rotation shaft 133. In addition, the polishing rotation shaft 133 may be raised and lowered from the baseplate 108 by the pressure drive parts 120 as described below, so that the polishing head 136 coupled to the polishing rotation shaft 133 may be raised and lowered together.

[0043] The polishing head 136 is coupled to rotate around the polishing rotation shaft 133. For example, the polishing head 136 may be coupled to a lower end of the polishing rotation shaft 133. Accordingly, the polishing head 136 is disposed at the lower part of the baseplate 108, i.e., inside the housing lid 103, and comes into contact with the polishing pad 105 of the platen 104. The polishing head 136 is made of stainless steel that is suitable to withstand the high pressure, high temperature, and moisture generated during a polishing process, but other materials with similar rigidity and durability to stainless steel may also be used. The polishing head 136 may be raised and lowered together with the polishing rotation shaft 133, which is described below.

[0044] The first rotary gear 134 is coupled to and surrounds the polishing rotation shaft and is rotatable around the polishing rotation shaft. The first rotary gear 134 is disposed on an upper side of the polishing head 136 and connected to the polishing head 136. The first rotary gear 134 receives rotational power and rotates in a state of being engaged with a second rotary gear 132 of the rotation drive part 130 described below. At this time, the polishing head 136 rotates together with the first rotary gear 134.

[0045] The wafer carrier 138 is mounted on the polishing head 136 to be disposed on a lower side of the polishing head 136. For this, the polishing head 136 may include a carrier mounting part 137. The wafer carrier 138 may have a truss structure on its upper surface to withstand high pressure generated during polishing. For example, a plurality of frames may be formed on an upper surface of the wafer carrier 138 to form a truss structure. The wafer carrier 138 may include a template 139 attached to its lower surface. At least one wafer mounting hole (reference numeral not shown) is formed on a lower surface of the template 139. The wafer mounting hole has a shape corresponding to the wafer 10, and the wafer 10 is inserted into the wafer mounting holes and attached to the lower surface of the wafer carrier 138. The wafer carrier 138 is rotated and raised / lowered together with the polishing head 136, and the wafer 10 attached to the wafer carrier 138 comes into contact with the polishing pad 105 of the platen 104 and is polished. The template 139 is a consumable material and is polished by the polishing pad 105 when polishing the wafer 10, and the template 139 may be replaced after several polishing processes. Meanwhile, a mounting groove may be formed on a lower surface of the template and a wafer may be attached to the mounting groove.

[0046] Referring to FIGS. 8 and 9, the pressure drive parts 120 are mounted in the baseplate 108 to be adjacent to the polishing parts 110, thereby individually providing pressure to the corresponding polishing parts 110, include a pressure cylinder 122 and a pressure bracket 112, and may further include a base frame 123, a first frame 124, a second frame 125, a first bearing 135 and a joining bar 126.

[0047] The pressure cylinder 122 is vertically mounted on the baseplate 108 such that a piston rod 121 moves up and down and back and forth, and provides pressure downward. The pressure cylinder 122 may be a Bellofram cylinder to stably transmit the pressure required for wafer polishing. The Bellofram cylinder is completely sealed from the outside and has no air leakage, so it can transmit pressure stably even during long-term operation, can be adjusted and used even with small pressures, and can implement more sensitive and detailed operation settings due to fast response speed to pressure fluctuations.

[0048] The pressure bracket 112 serves to transmit pressure from the pressure cylinder 122 to the polishing head 136. For this, one end of the pressure bracket 112 is coupled to the piston rod 121 of the pressure cylinder 122 and coupled to the polishing rotation shaft 133 of the polishing parts 110. When the piston rod 121 is advanced and retracted, the pressure bracket 112 causes the polishing rotation shaft 133 and the polishing head 136 to be lowered and raised. Accordingly, when the piston rod 121 of the pressure cylinder 122 advances, the pressure bracket 112, the polishing rotation shaft 133 and the polishing head 136 are pressured to descend, so that the polishing head 136 presses the polishing pad 105 of the platen 104. When the piston rod 121 of the pressure cylinder 122 retreats, the pressure bracket 112, the polishing rotation shaft 133 and the polishing head 136 rise and are separated from the polishing pad 105. The pressure bracket 112 may be formed in a ‘⊏’ shape. In this case, the polishing rotation shaft 133 may be disposed in an opening (reference numeral not shown) of the pressure bracket 112 and coupled to the pressure bracket 112.

[0049] The base frame 123 is mounted on the baseplate 108, the first frame 124 is formed to protrude from one side of the base frame 123, and the second frame 125 is formed to protrude from another side of the base frame 123. The second frame 125 protrudes at a higher height than the first frame 124, and the pressure cylinder 122 is vertically mounted on an upper surface thereof.

[0050] The other end of the pressure bracket 112 may have a structure of being rotatably around the first frame 124 and coupled thereto. Accordingly, when the piston rod 121 of the pressure cylinder 122 is advanced and retracted downward, the pressure bracket 112 may rotate in a predetermined angle range based on the axis of the first frame 124.

[0051] The first bearing 135 is coupled to the pressure bracket 112 and has a penetration hole (reference numeral not shown) where the polishing rotation shaft 133 can be rotatably penetrated and coupled. When the pressure bracket 112 is formed in a ‘⊏’ shape, the first bearing 135 may be placed approximately in the center of the pressure bracket 112.

[0052] The joining bar 126 couples and fixes the first bearing 135 to the pressure bracket 112. For example, when the pressure bracket 112 is formed in a “⊏” shape, the joining bar 126 may penetrate the side of the pressure bracket 112 and be fixedly coupled to the first bearing 135, and the joining bars 126 may be applied in pairs. When the piston rod 121 of the pressure cylinder 122 presses one end of the pressure bracket 112 due to the coupling by the joining bar 126, the first bearing 135 descends, and the polishing rotation shaft 133 and polishing head 136 attached to the first bearing 135 descend to pressurize the polishing pad 105. Accordingly, the rotation and pressurization of the polishing rotation shaft 133 may both be implemented. Meanwhile, the pressure bracket 112 may be nutatably coupled to the joining bar 126 as an axis.

[0053] Meanwhile, the pressure drive parts 120 may be equipped with an EP regulator that adjusts the air pressure supplied to the Bellofram cylinder, and the pressure value of the Bellofram cylinder, i.e., the pressure intensity, is determined according to the air pressure that is output from the EP regulator.

[0054] The process of transmitting pressure from the pressure cylinder 122 to the polishing head 136 is as follows. First, when main air is supplied to the EP regulator, air adjusted to a specific pressure by the EP regulator is supplied to the pressure cylinder 122, so that the piston rod 121 descends vertically, a piston rod connection part 111 presses the pressure bracket 112 in a vertical direction, and the first bearing 135 and the polishing rotation shaft 133 descend to transmit pressure required for polishing to a polishing head.

[0055] Referring to FIGS. 6 and 7, the rotation drive parts 130 includes a turning motor 131 and a second rotary gear 132. The turning motor 131 is mounted on the baseplate 108 and a motor rotation shaft 131a penetrates downward through the baseplate 108. The second rotary gear 132 is coupled to the motor rotation shaft 131a of the turning motor 131 and rotates together with the turning motor 131, and is engaged with the first rotary gear 134 of the polishing parts 110. Accordingly, the rotational power by the turning motor 131 is transmitted to the polishing head 136 through the second rotary gear 132, the first rotary gear 134, and the polishing rotation shaft 133, thereby rotating. As described above, the polishing rotation shaft 133 is coupled to the first bearing 135 so that smooth rotation is possible. Meanwhile, the turning motor 131 may be controlled by an inverter (not shown), and, by adjusting an output voltage and frequency through an inverter operation, the speed and torque of the motor may be adjusted to required conditions and its rotational direction conversion may be controlled.

[0056] A process of transmitting rotational power from the turning motor 131 to the polishing head 136 is as follows. First, the inverter outputs a frequency and voltage required to drive the turning motor 131, and the turning motor 131 that receives the frequency and voltage output of the inverter rotates at a specific speed and direction. At this time, the first rotary gear 134 of the polishing rotation shaft 133, which is engaged with the second rotary gear 132 of the turning motor 131, rotates in the opposite direction to the second rotary gear 132, so that the polishing rotation shaft 133 and the polishing head 136 rotate in the same direction as the first rotary gear 134.

[0057] Referring to FIGS. 10 and 11, The oscillation part 140 provides left-right oscillation to the baseplate 108 so that the left-right oscillation is provided to the polishing parts 110. For this, the oscillation part 140 includes an oscillation motor 142 and a connecting rod 144, and the fixed bracket 150, to which the connecting rod 144 is to be coupled, is formed on the baseplate 108.

[0058] The oscillation motor 142 is mounted at a position spaced apart from the baseplate 108, and the direction of its rotary shaft 142a is arranged to be orthogonal to the left-right oscillation direction of the baseplate 108.

[0059] A rotary plate 143 may be fixedly coupled to an end of the rotary shaft 142a of the oscillation motor 142, and the rotary plate 143 rotates together with the rotary shaft 142a of the oscillation motor 142. A protrusion 148 may be formed on one surface of the rotary plate 143 for coupling with the connecting rod 144. In this case, the protrusion 148 may be formed at a position spaced apart from the rotary shaft 142a of the oscillation motor 142.

[0060] Meanwhile, the protrusion 148 may be detachably coupled to the rotary shaft 142a, and for example, a threaded hole 149 may be formed on one surface of the rotary plate 143, and an end of the protrusion 148 may be bolted. In this case, a plurality of threaded holes 149 may be formed at multiple different distances from the rotary shaft 142a of the oscillation motor 142, and the protrusion 148 may be selectively connected to one of the threaded holes 149, thereby adjusting the rotation radius of the protrusion 148, so that the left-right oscillation width of the baseplate 108 may be appropriately selected as needed. The oscillation amplitude of the baseplate 108 roughly corresponds to the rotational diameter of the protrusion 148. When the rotational radius of the protrusion 148 is small, the oscillation amplitude of the baseplate 108 is small, and when the rotational radius of the protrusion 148 increases, the oscillation amplitude of the baseplate 108 increases. Meanwhile, a nut groove may be applied instead of the threaded hole 149.

[0061] The connecting rod 144 is used to oscillate the baseplate 108 left and right according to the rotation of the rotary shaft 142a of the oscillation motor 142. One end of the connecting rod 144 is rotatably coupled to the rotary shaft 142a of the oscillation motor 142 and the other end thereof is rotatably coupled to the baseplate 108. When the oscillation motor 142 rotates, the baseplate 108 is repeatedly pulled and pushed. The repetition of this motion creates oscillation.

[0062] As described above, one end of the connecting rod 144 is coupled to the protrusion 148 of the rotary plate 143, thereby circularly rotating around the rotary shaft 142a with a predetermined radius together with the protrusion 148. The end of the connecting rod 144 may be rotatably coupled to the protrusion 148 used as a shaft of the connecting rod 144. For this, the connecting rod 144 may have a first coupling hole 145. In this case, the protrusion 148 may be bolted to the threaded hole 149 of the rotary plate 143 while being fitted into the first coupling hole 145 of the connecting rod 144.

[0063] The other end of the connecting rod 144 is coupled to the fixed bracket 150 of the baseplate 108 to provide power by the operation of the oscillation motor 142 to the baseplate 108. The fixed bracket 150 may include a pair of vertical members 151a and a shaft member 152 arranged between and fixedly coupled to the vertical members 151, and the other end of the connecting rod 144 may have a second coupling hole (reference numeral not shown) where the shaft member 152 penetrates and is coupled. As both the ends of the connecting rod 144 are nutatably connected to the protrusion 148 of the oscillation motor 142 and the shaft member 152 of the fixed bracket 150, respectively, the connecting rod 144 may smoothly provide power by the oscillation motor 142 in the horizontal direction of the baseplate 108.

[0064] Meanwhile, the oscillation part 140 may further include the linear motion guide 146. The linear motion guide 146 may be formed in the form of a pair of rails coupled along the front and rear edges of the baseplate, and the baseplate 108 may be moved left and right between the linear motion guide 146.

[0065] When the baseplate 108 oscillates left and right by the oscillation part 140, components mounted on the baseplate 108 also oscillate to the same width, so that the polishing head 136 eventually oscillates left and right.

[0066] Meanwhile, the oscillation part 140 is equipped with an inverter (not shown) to adjust a specific frequency and voltage, thereby controlling the rotation direction and speed of the oscillation motor 142. When the inverter outputs the frequency and voltage required to drive the oscillation motor 142, the rotary shaft 142a of the oscillation motor 142 rotates, so that the rotary plate 143 and the protrusion 148 rotate together and the end of the connecting rod 144 connected to the protrusion 148 also rotates together. Accordingly, the connecting rod 144 pushes or pulls the fixed bracket 150 connected to the other end of the connecting rod 144 while repeatedly moving left and right as a whole. Due to this movement, the baseplate 108 also repeats left-right oscillation to the same width.

[0067] As the oscillation function by the oscillation part 140 is added, a polishing plate, which was previously fixed, may be moved left and right, so that the area of the polishing pad 105 attached to the platen 104 may be used more widely, and as a result, damage to the polishing pad 105 which occurs during polishing may be distributed, so that the lifespan of the polishing pad 105, which is a consumable material, may be maximized.

[0068] As described above, the housing 101 is configured such that the housing lid 103 opens / closes the housing body 102. Referring to FIGS. 12 and 13, the housing 101 may include a pair of lifting cylinders 107 and joining frames 107b corresponding thereto. The pair of lifting cylinders 107 are respectively mounted on both sides of the top of the housing body 102 so that piston rods 107a are raised and lowered vertically. A pair of joining frames 107b are mounted on both sides of the housing lid 103, and ends of the piston rods 107a of the lifting cylinders 107 are coupled to the joining frames 107b. Accordingly, when the piston rods 107a of the lifting cylinders 107 are raised and lowered, the housing lid 103 is raised and lowered to open / close the housing body 102.

[0069] The lifting cylinders 107 may be disposed at the front end of the housing body 102, the ends of the piston rods 107a may be nutatably coupled to the joining frames 107b, and, as the front end of the housing lid 103 is tilted at a predetermined angle while rising, the housing lid 103 may open the housing body 102. In this case, the housing lid 103 may have a pair of rollers 109a mounted on both rear ends, and the housing body 102 may have rails 109b on which the rollers 109a can move. Accordingly, when the front end of the housing lid 103 ascends and descends as the lifting cylinders 107 are raised and lowered, the rear end of the housing lid 103 moves forward and backward on the rails 109b, and the opening / closing process of the housing lid 103 becomes smooth. Of course, a structure wherein the housing lid 103 is vertically raised and lowered by the lifting cylinders 107 may be applied, but considering the heavy weight of the housing lid 103, the former method is more efficient.

[0070] When a polishing process is performed in a completely sealed state by closing the housing body 102 with the housing lid 103, the inflow of external contaminants into the inside may be blocked. In addition, the housing lid 103 may include at least one exhaust line 160, and the exhaust line 160 may be connected to an exhaust pump (not shown) outside the housing lid 103. Through this, particles generated inside the housing 101 during the polishing process may be discharged to the outside, so that the generation of scratches on the wafer surface may be reduced, and harmful substances may be discharged to the outside, thereby protecting an operator.

[0071] Meanwhile, the polishing unit 106 may include a slurry supply tube 170 mounted to protrude from the center of a lower surface of the baseplate 108, and a slurry is supplied onto the polishing pad 105 through the slurry supply tube 170.

[0072] Although not shown, the wafer polishing apparatus 100 may further include a controller for controlling the operation of the pressure drive parts 120, the rotation drive parts 130 and the oscillation part 140.

[0073] The controller may have a manual input / output screen as shown in FIG. 14. It is intended for use in special situations such as equipment inspection or testing, and may be utilized to control the individual operation of a polishing head. For example, when a problem is suspected in a specific polishing part 110, the problem may be precisely inspected by changing the input value of only one polishing head and operating it, and, during testing, different input values may be set for each polishing head to operate the polishing head.

[0074] For reference, the description of the operation buttons shown in FIG. 14 is as follows: {circle around (1)} is the individual Up / Down button of the polishing head. {circle around (2)} is the individual rotation operation button of the polishing head to control forward or reverse rotation. For example, when the CW (forward) button of Head #1 is clicked, only Head #1 starts to rotate in the forward direction. {circle around (3)} is an integrated operation button which operates all of Head #1 to Head #4 at once, and rotates and up / downs the entire polishing head at once. {circle around (4)} is a pressure operation button which enables pressure operation control for the polishing head in the down operation, and if the polishing head is down, pressure operation is possible regardless of a single polishing head or a plurality of polishing heads. When a pressure value to be used is set, a Programmable Logic Controller (PLC) generates an output signal so that the EP regulator of the corresponding polishing head compresses the air to the corresponding pressure and transmits it to a pressure cylinder to provide a required pressure. {circle around (5)} is a rotation speed control button for each polishing head, and the rotation speed of each polishing head may be set through this. When a specific rotation speed is input, the output signal of the PLC is transmitted to an inverter of the polishing head, and the inverter outputs a voltage corresponding to the input speed to the turning motor 131 to rotate at a desired speed.

[0075] The controller may be equipped with an Auto Recipe input / output screen as shown in FIG. 15. Various types of recipes are saved in advance through the Auto Recipe input / output screen of the equipment applied in a mass production process, and a specific recipe is selected and used during actual wafer production. Since the polishing heads may be individually controlled, various complex settings, such as whether to use a specific polishing head for actual polishing by down-running it in the recipe or to use it by applying different rotation speeds for each process step, may be made. For example, in step 1, HD1 (Head #1) and HD2 may be set to rotate at 30 RPM and HD3, HD4 may be set to rotate at 15 RPM. If a specific polishing head has a problem and, accordingly, it is needed to be operated only on three polishing heads, only the problematic polishing head may be turned off.

[0076] The description of the main operation buttons shown in FIG. 15 is as follows: {circle around (1)} is an input field for setting the rotation speed of the polishing head by step, {circle around (2)} is an input field for setting the pressure condition of the polishing head by step, 3 is an input field for setting the rotation direction of the polishing head in the corresponding recipe, and {circle around (4)} is an input field for setting the up / down operation of the polishing head in the corresponding recipe.

[0077] The effects of the wafer polishing apparatus according to the embodiment of the present invention are as follows.

[0078] First, since the operation of multiple polishing heads can be individually controlled, polishing can be individually performed according to the conditions and environments required for each wafer, even when polishing wafers that are individually manufactured in the wafer manufacturing process and, accordingly, are in different states, so that, compared to existing CMP equipment, the process time can be reduced and the consumption of consumable materials can be reduced, thereby reducing the overall cost.

[0079] In addition, since a rotation drive part that provides rotational power to each polishing part; and a pressure drive part that provides pressure are equipped, the structure is simple and the energy loss rate can be reduced, compared to an existing method of controlling all heads with a single motor. Further, the polishing flatness can be improved, which can improve the wafer production quality, and the lifespan of a polishing pad consumed during a polishing process can be increased.

[0080] While the embodiments of the present disclosure have been described above, it will be appreciated by those skilled in the art that various modifications and changes can be made to the 10 present disclosure without departing from the spirit and scope of the claims of the present disclosure.

Examples

Embodiment Construction

[0033]Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, the embodiments described below are intended only to describe the disclosure in detail so that those having ordinary skill in the art to which the disclosure pertains can easily practice the invention, and are not intended to limit the scope of the disclosure. Throughout the description of various embodiments of the present disclosure, the same reference numerals are used to refer to components having the same technical features.

[0034]As shown in FIGS. 1 to 3, a wafer polishing apparatus (hereinafter referred to as “wafer polishing apparatus 100”) according to an embodiment of the present invention includes a platen 104 provided with a polishing pad 105 attached to an upper surface thereof and configured to rotate together with the polishing pad 105 in one or the other direction; and a polishing unit 106 disposed on an upper side of the platen 10...

CROSS REFERENCE TO RELATED APPLICATIONS AND CLAIM OF PRIORITY

[0001] This application claims priority to Korean Patent Application No. 10-2024-0107975, filed in the Korean Intellectual Property Office on Aug. 13, 2024, and all the benefits accruing therefrom under 35 U.S.C. § 119, the content of which in its entirety is herein incorporated by reference.BACKGROUND1. Technical Field

[0002] The present disclosure relates to a polishing apparatus for semiconductor wafer.2. Background Art

[0003] In general, multiple polishing processes are performed during the manufacturing process of wafers used in semiconductor devices. Among them, CMP equipment based on Chemical and Mechanical Polishing is mainly used for the process of polishing the wafer surface.

[0004] CMP is a process that enables ultra-fine polishing by simultaneously polishing the surface of a wafer coated with materials such as tungsten or oxides through mechanical friction and chemical polishing agents. Mechanical polishing involves applying pressure to the wafer while rotating it against a rotating polishing pad, resulting in surface abrasion due to the friction between the polishing pad and the wafer surface. Chemical polishing, on the other hand, utilizes a slurry supplied between the polishing pad and the wafer. As the slurry is introduced, the wafer polishing is performed through the combined action of mechanical polishing and chemical agents.

[0005] Mechanical polishing is a method of polishing a wafer surface by applying pressure and rotating the wafer against a rotating polishing pad, thereby creating friction between the polishing pad and the wafer surface. Chemical polishing uses slurry supplied between the polishing pad and the wafer. The wafer polishing is performed by mechanical polishing while supplying slurry between the polishing pad and the wafer.

[0006] Since CMP is mostly performed under low-pressure conditions of 300 to 400 g / cm2, the overall process time is long and the consumables increase, which incurs high costs. In conventional low-pressure CMP equipment, when polishing under ultra-high-pressure conditions of 78.4 kPa (800 g / cm2) or more, there is a problem that the wax fixing the wafer melts due to high frictional heat and the wafer is detached, which causes problems of polishing imbalance and deterioration of wafer shape precision. Therefore, it is necessary to develop CMP equipment that can increase the polishing rate per unit time and reduce the process cost accordingly.

[0007] Korean Patent No. 10-1678992 discloses a CMP equipment having multi-heads, and Korean Patent Publication 10-2019-0073661 discloses a wafer polishing apparatus. Conventional CMP equipment is structured to control 1 to 4 polishing heads in batches with one motor, and due to this structural characteristic, it is not easy to meet appropriate conditions for wafer polishing. For example, in the actual wafer production process, there may be cases where the wafer states before the polishing process are different from each other, and a situation may arise where different polishing conditions must be applied to each wafer. In this case, since individual settings for each polishing head are not possible with the above-mentioned batch control method, there is no choice but to select wafers separately according to polishing conditions and polish them, or to batch-polish them under specific conditions and then re-polish them, which is a significant disadvantage in terms of time and cost.

[0008] Meanwhile, Japanese Patent No. 2011-519166 discloses a technology for independent driving of a polishing head in CMP equipment, but it is necessary to develop CMP equipment with further improved functions to increase driving efficiency and polishing flatness.SUMMARY

[0009] It is an object of the present disclosure to provide a wafer polishing apparatus capable of individually controlling multiple polishing heads.

[0010] It is another object of the present disclosure to provide a wafer polishing apparatus capable of improving the efficiency of a polishing process.

[0011] As a means to achieve the above-mentioned object, the present disclosure provide a wafer polishing apparatus including: a platen having a polishing pad attached to its upper surface and rotating together with the polishing pad; and a polishing unit disposed on an upper side of the platen and configured to perform polishing by pressurizing and rotating a wafer interposed between the polishing unit and a polishing pad, wherein the polishing unit includes: a baseplate; a plurality of polishing parts mounted on the baseplate to be spaced from each other at a predetermined interval, wherein each polishing part includes polishing rotation shafts rotatably coupled to the baseplate to penetrate the baseplate and a polishing head coupled to a lower part of the polishing rotation shaft to rotate together with the polishing rotation shaft, and that rotates around each polishing rotation shaft and are raised and lowered in each polishing rotation shaft direction; a plurality of rotation drive parts mounted on the baseplate to be adjacent to the polishing parts and configured to respectively, individually provide rotational power to the corresponding polishing part; and a plurality of pressure drive parts mounted on the baseplate to be adjacent to the polishing parts and configured to respectively, individually provide pressure to the corresponding polishing part.

[0012] According to one embodiment, each of the polishing parts includes a first rotary gear that surrounds and is coupled to the polishing rotation shaft on an upper side of the polishing head and rotates together with the polishing rotation shaft, and each of the rotation drive parts includes a turning motor mounted on the baseplate and having a motor rotation shaft penetrating downwardly through the baseplate; and a second rotary gear coupled to a motor rotation shaft of the turning motor, configured to rotate together with the turning motor and engaged with a first rotary gear.

[0013] According to another embodiment, each of the pressure drive parts includes: a pressure cylinder mounted on the baseplate and equipped with a piston rod that moves up and down and back and forth; and a pressure bracket having one end coupled to the piston rod of the pressure cylinder and coupled to the polishing rotation shaft of the polishing parts so that the polishing rotation shaft and polishing head descend and ascend as the piston rod is advanced and retracted.

[0014] According to another embodiment, each of the pressure drive parts further includes a first frame to which other end of the pressure bracket is nutatably coupled; a first bearing coupled to the pressure bracket, and rotatably coupled to the polishing rotation shaft such that the polishing rotation shaft penetrates the first bearing; and a joining bar configured to fixedly couple the pressure bracket and the first bearing.

[0015] According to another embodiment, each of the pressure drive parts further includes a base frame mounted on the baseplate and provided with the first frame protruding from one side thereof; and a second frame formed to protrude from other side of the base frame to a height higher than the first frame and provided with the pressure cylinder vertically mounted on an upper surface thereof.

[0016] According to another embodiment, the polishing unit, the polishing unit further includes an oscillation part configured to provide left-right oscillation to the baseplate to provide left-right oscillation to the polishing parts.

[0017] According to another embodiment, the oscillation part includes: an oscillation motor spaced apart from the baseplate and arranged so that a rotary shaft direction of the oscillation motor is orthogonal to a left-right vibration direction of the baseplate; and a connecting rod whose one end is rotatably coupled to the rotating shaft of the oscillation motor and whose other end is rotatably coupled to the baseplate so that the baseplate oscillates left and right according to rotation of the rotating shaft of the oscillation motor.

[0018] According to another embodiment, the oscillation part further includes: a rotary plate that is fixedly coupled to an end of the rotating shaft of the oscillation motor to rotate together with the oscillation motor and has a protrusion formed on one surface thereof at a position spaced from the rotating shaft of the oscillation motor, wherein the protrusion penetrates and is coupled to the first coupling hole formed at one end of the connecting rod such that one end of the connecting rod can rotate around the protrusion as an axis. In this case, the protrusion is fitted into the first coupling hole of the connecting rod and bolted into a threaded hole formed in the rotary plate. In addition, a plurality of threaded holes are provided, the threaded holes are spaced apart from the rotating shaft of the oscillation motor at different distances, and the protrusion is selectively fastened to one of the threaded holes.

[0019] According to another embodiment, the baseplate further includes a fixed bracket which is formed on one side of its upper surface and to which other end of the connecting rod is coupled, wherein the fixed bracket includes a pair of vertical members and a shaft member fixedly coupled between the vertical members, wherein the shaft member penetrates and is coupled into the second coupling hole formed at the other end of the connecting rod.

[0020] According to another embodiment, the oscillation part further includes a pair of rail-shaped linear motion guides coupled along a front end and rear end edges of the baseplate, and the baseplate oscillates between the linear motion guides while moving left and right.

[0021] According to another embodiment, each of the polishing parts further includes a wafer carrier mounted on the polishing head so as to be disposed on a lower side of the polishing head, and rotated and raised / lowered together with the polishing head. In this case, the wafer carrier has a template attached to its lower surface, wherein the template has at least one wafer mounting hole. In addition, an upper surface of the wafer carrier is formed in a truss structure.

[0022] According to another embodiment, the wafer polishing apparatus includes a housing configured to accommodate the platen and the polishing unit, wherein the housing includes a housing body on a top of which the platen is mounted; a housing lid which is configured to open / close the housing body and on which the polishing unit is mounted; a pair of lifting cylinders mounted on both sides of an upper end of the housing body to vertically raise and lower piston rods; and a pair of joining frames mounted on both sides of the housing lid and coupled to ends of the piston rods of the lifting cylinders, wherein, when the piston rods of the lifting cylinders are raised and lowered, the housing lid is raised and lowered.

[0023] According to another embodiment, the lifting cylinder is disposed at a front end of the housing body and an end of the piston rod is nutatably coupled to the joining frame so that a front end of the housing lid is opened and closed while being inclined at a predetermined angle as it ascends and descends.

[0024] According to another embodiment, the housing lid has a pair of rollers mounted on both sides of the rear end, the housing body has rails on which the rollers can move, and when the front end of the housing lid ascends and descends, the rear end of the housing lid moves forward and backward on the rails.

[0025] According to another embodiment, the polishing unit further includes a slurry supply tube mounted so as to protrude from a center of a lower surface of the baseplate.

[0026] According to another embodiment, the housing lid includes at least one exhaust line, and the exhaust line is connected to an exhaust pump outside the housing lid.BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and other features of the inventive concept will become more apparent by describing in detail exemplary embodiments thereof with reference to the accompanying drawings, in which:

[0028] FIG. 1 is a drawing substitute photo illustrating a wafer polishing apparatus according to an embodiment of the present invention, and FIGS. 2 and 3 are drawing substitute photos illustrating the open state of the wafer polishing apparatus of FIG. 1.

[0029] FIG. 4 is a plan view for explaining the polishing unit of the wafer polishing apparatus of FIG. 1, and FIG. 5 is a drawing substitute photo for explaining a polishing unit of the wafer polishing apparatus of FIG. 1.

[0030] FIG. 6 is a schematic diagram for explaining rotation drive parts of the polishing unit of FIGS. 4 and 5, FIG. 7 is a schematic diagram for explaining the operational relationship between the polishing parts and the rotation drive parts of FIGS. 4 and 5, FIGS. 8 and 9 are drawings for explaining pressure drive parts of the polishing unit of FIGS. 4 and 5, and FIGS. 10 and 11 are drawings for explaining oscillation parts of the polishing unit of FIGS. 4 and 5.

[0031] FIGS. 12 and 13 are drawings for explaining the opening / closing structure of the wafer polishing apparatus according to an embodiment of the present invention.

[0032] FIGS. 14 and 15 are drawings for explaining a manual input / output screen and Auto Recipe input / output screen provided in a controller of the wafer polishing apparatus according to an embodiment of the present invention.DETAILED DESCRIPTION

[0033] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, the embodiments described below are intended only to describe the disclosure in detail so that those having ordinary skill in the art to which the disclosure pertains can easily practice the invention, and are not intended to limit the scope of the disclosure. Throughout the description of various embodiments of the present disclosure, the same reference numerals are used to refer to components having the same technical features.

[0034] As shown in FIGS. 1 to 3, a wafer polishing apparatus (hereinafter referred to as “wafer polishing apparatus 100”) according to an embodiment of the present invention includes a platen 104 provided with a polishing pad 105 attached to an upper surface thereof and configured to rotate together with the polishing pad 105 in one or the other direction; and a polishing unit 106 disposed on an upper side of the platen 104, wherein the wafer polishing apparatus 100 performs polishing by pressing and rotating a wafer 10 interposed between the polishing unit 106 and the polishing pad 105.

[0035] The wafer polishing apparatus 100 may further include a housing 101 that accommodates the platen 104 and the polishing unit 106. Here, the housing 101 includes a housing body 102; and a housing lid 103 for opening / closing the top of the housing body 102. The platen 104 may be rotatably mounted on the top of the housing body 102, and the polishing unit 106 may be mounted on the housing lid 103. In this case, when the housing lid 103 is opened, the polishing unit 106 is spaced from the platen 104, and when the housing lid 103 is closed, the bottom of the polishing unit 106 may come into contact with the polishing pad 105 of the platen 104. Although not indicated as reference numerals in the drawings, various display parts are mounted on the exterior of the housing 101. FIGS. 2 and 3 show the housing 101 in an open state, and the opening / closing of the housing 101 is described below.

[0036] The polishing unit 106 includes a baseplate 108, a plurality of polishing parts 110, a plurality of pressure drive parts 120 and a plurality of rotation drive parts 130, and further includes an oscillation part 140.

[0037] The baseplate 108 is mounted in the housing lid 103. As described below, the baseplate 108 is coupled to a linear motion guide 146 to be linearly moved together with the polishing parts 110, the rotation drive parts 130 and the pressure drive parts 120. The baseplate 108 may include a fixed bracket 150 formed on one side of the upper surface thereof, which is described below. For reference, the baseplate 108 may be mounted inside the housing lid 103 or on the upper surface of the housing lid 103.

[0038] The plural polishing parts 110 are mounted on the baseplate 108 to be spaced from each other at a predetermined interval. Each of the polishing parts 110 includes a polishing rotation shaft 133 and a polishing head 136. The polishing rotation shaft 133 is rotatably coupled to the baseplate 108 to penetrate the baseplate 108, and the polishing head 136 is coupled to a lower part of the polishing rotation shaft 133 to rotate together. Accordingly, the polishing head 136 rotates as each polishing rotation shaft 133 in the plural polishing parts 110 rotates, and the polishing head 136 is raised and lowered as the polishing rotation shaft 133 is raised and lowered. Each of the polishing parts 110 receives rotational power and pressure from the corresponding rotation drive part 130 and pressure drive part 120, thereby being individually operated and controlled.

[0039] Each of the plural rotation drive parts 130 and the plural pressure drive parts 120 is mounted in the baseplate 108 to be adjacent to the polishing parts 110 to individually provide rotational power and pressure to the corresponding polishing parts 110, and the oscillation part 140 is provided to the polishing parts 110 so as to provide left-right oscillation thereto.

[0040] Hereinafter, the particulars of the polishing parts 110, the pressure drive parts 120, the rotation drive parts 130, the oscillation part 140 are described in detail with reference to the accompanying drawings.

[0041] Referring to FIGS. 1 to 5, the polishing parts 110 includes the polishing rotation shaft 133 and the polishing head 136, and may further include a first rotary gear 134 and a wafer carrier 138.

[0042] The polishing rotation shaft 133 is coupled to the baseplate 108 while penetrating it, so that a lower end of the polishing rotation shaft 133 extends toward a lower part of the baseplate 108, i.e. toward the inside of the housing lid 103. In this case, the polishing rotation shaft 133 is fixedly coupled to the baseplate 108, and the polishing head 136 and first rotary gear 134 coupled to the polishing rotation shaft 133 rotate around the polishing rotation shaft 133. In addition, the polishing rotation shaft 133 may be raised and lowered from the baseplate 108 by the pressure drive parts 120 as described below, so that the polishing head 136 coupled to the polishing rotation shaft 133 may be raised and lowered together.

[0043] The polishing head 136 is coupled to rotate around the polishing rotation shaft 133. For example, the polishing head 136 may be coupled to a lower end of the polishing rotation shaft 133. Accordingly, the polishing head 136 is disposed at the lower part of the baseplate 108, i.e., inside the housing lid 103, and comes into contact with the polishing pad 105 of the platen 104. The polishing head 136 is made of stainless steel that is suitable to withstand the high pressure, high temperature, and moisture generated during a polishing process, but other materials with similar rigidity and durability to stainless steel may also be used. The polishing head 136 may be raised and lowered together with the polishing rotation shaft 133, which is described below.

[0044] The first rotary gear 134 is coupled to and surrounds the polishing rotation shaft and is rotatable around the polishing rotation shaft. The first rotary gear 134 is disposed on an upper side of the polishing head 136 and connected to the polishing head 136. The first rotary gear 134 receives rotational power and rotates in a state of being engaged with a second rotary gear 132 of the rotation drive part 130 described below. At this time, the polishing head 136 rotates together with the first rotary gear 134.

[0045] The wafer carrier 138 is mounted on the polishing head 136 to be disposed on a lower side of the polishing head 136. For this, the polishing head 136 may include a carrier mounting part 137. The wafer carrier 138 may have a truss structure on its upper surface to withstand high pressure generated during polishing. For example, a plurality of frames may be formed on an upper surface of the wafer carrier 138 to form a truss structure. The wafer carrier 138 may include a template 139 attached to its lower surface. At least one wafer mounting hole (reference numeral not shown) is formed on a lower surface of the template 139. The wafer mounting hole has a shape corresponding to the wafer 10, and the wafer 10 is inserted into the wafer mounting holes and attached to the lower surface of the wafer carrier 138. The wafer carrier 138 is rotated and raised / lowered together with the polishing head 136, and the wafer 10 attached to the wafer carrier 138 comes into contact with the polishing pad 105 of the platen 104 and is polished. The template 139 is a consumable material and is polished by the polishing pad 105 when polishing the wafer 10, and the template 139 may be replaced after several polishing processes. Meanwhile, a mounting groove may be formed on a lower surface of the template and a wafer may be attached to the mounting groove.

[0046] Referring to FIGS. 8 and 9, the pressure drive parts 120 are mounted in the baseplate 108 to be adjacent to the polishing parts 110, thereby individually providing pressure to the corresponding polishing parts 110, include a pressure cylinder 122 and a pressure bracket 112, and may further include a base frame 123, a first frame 124, a second frame 125, a first bearing 135 and a joining bar 126.

[0047] The pressure cylinder 122 is vertically mounted on the baseplate 108 such that a piston rod 121 moves up and down and back and forth, and provides pressure downward. The pressure cylinder 122 may be a Bellofram cylinder to stably transmit the pressure required for wafer polishing. The Bellofram cylinder is completely sealed from the outside and has no air leakage, so it can transmit pressure stably even during long-term operation, can be adjusted and used even with small pressures, and can implement more sensitive and detailed operation settings due to fast response speed to pressure fluctuations.

[0048] The pressure bracket 112 serves to transmit pressure from the pressure cylinder 122 to the polishing head 136. For this, one end of the pressure bracket 112 is coupled to the piston rod 121 of the pressure cylinder 122 and coupled to the polishing rotation shaft 133 of the polishing parts 110. When the piston rod 121 is advanced and retracted, the pressure bracket 112 causes the polishing rotation shaft 133 and the polishing head 136 to be lowered and raised. Accordingly, when the piston rod 121 of the pressure cylinder 122 advances, the pressure bracket 112, the polishing rotation shaft 133 and the polishing head 136 are pressured to descend, so that the polishing head 136 presses the polishing pad 105 of the platen 104. When the piston rod 121 of the pressure cylinder 122 retreats, the pressure bracket 112, the polishing rotation shaft 133 and the polishing head 136 rise and are separated from the polishing pad 105. The pressure bracket 112 may be formed in a ‘⊏’ shape. In this case, the polishing rotation shaft 133 may be disposed in an opening (reference numeral not shown) of the pressure bracket 112 and coupled to the pressure bracket 112.

[0049] The base frame 123 is mounted on the baseplate 108, the first frame 124 is formed to protrude from one side of the base frame 123, and the second frame 125 is formed to protrude from another side of the base frame 123. The second frame 125 protrudes at a higher height than the first frame 124, and the pressure cylinder 122 is vertically mounted on an upper surface thereof.

[0050] The other end of the pressure bracket 112 may have a structure of being rotatably around the first frame 124 and coupled thereto. Accordingly, when the piston rod 121 of the pressure cylinder 122 is advanced and retracted downward, the pressure bracket 112 may rotate in a predetermined angle range based on the axis of the first frame 124.

[0051] The first bearing 135 is coupled to the pressure bracket 112 and has a penetration hole (reference numeral not shown) where the polishing rotation shaft 133 can be rotatably penetrated and coupled. When the pressure bracket 112 is formed in a ‘⊏’ shape, the first bearing 135 may be placed approximately in the center of the pressure bracket 112.

[0052] The joining bar 126 couples and fixes the first bearing 135 to the pressure bracket 112. For example, when the pressure bracket 112 is formed in a “⊏” shape, the joining bar 126 may penetrate the side of the pressure bracket 112 and be fixedly coupled to the first bearing 135, and the joining bars 126 may be applied in pairs. When the piston rod 121 of the pressure cylinder 122 presses one end of the pressure bracket 112 due to the coupling by the joining bar 126, the first bearing 135 descends, and the polishing rotation shaft 133 and polishing head 136 attached to the first bearing 135 descend to pressurize the polishing pad 105. Accordingly, the rotation and pressurization of the polishing rotation shaft 133 may both be implemented. Meanwhile, the pressure bracket 112 may be nutatably coupled to the joining bar 126 as an axis.

[0053] Meanwhile, the pressure drive parts 120 may be equipped with an EP regulator that adjusts the air pressure supplied to the Bellofram cylinder, and the pressure value of the Bellofram cylinder, i.e., the pressure intensity, is determined according to the air pressure that is output from the EP regulator.

[0054] The process of transmitting pressure from the pressure cylinder 122 to the polishing head 136 is as follows. First, when main air is supplied to the EP regulator, air adjusted to a specific pressure by the EP regulator is supplied to the pressure cylinder 122, so that the piston rod 121 descends vertically, a piston rod connection part 111 presses the pressure bracket 112 in a vertical direction, and the first bearing 135 and the polishing rotation shaft 133 descend to transmit pressure required for polishing to a polishing head.

[0055] Referring to FIGS. 6 and 7, the rotation drive parts 130 includes a turning motor 131 and a second rotary gear 132. The turning motor 131 is mounted on the baseplate 108 and a motor rotation shaft 131a penetrates downward through the baseplate 108. The second rotary gear 132 is coupled to the motor rotation shaft 131a of the turning motor 131 and rotates together with the turning motor 131, and is engaged with the first rotary gear 134 of the polishing parts 110. Accordingly, the rotational power by the turning motor 131 is transmitted to the polishing head 136 through the second rotary gear 132, the first rotary gear 134, and the polishing rotation shaft 133, thereby rotating. As described above, the polishing rotation shaft 133 is coupled to the first bearing 135 so that smooth rotation is possible. Meanwhile, the turning motor 131 may be controlled by an inverter (not shown), and, by adjusting an output voltage and frequency through an inverter operation, the speed and torque of the motor may be adjusted to required conditions and its rotational direction conversion may be controlled.

[0056] A process of transmitting rotational power from the turning motor 131 to the polishing head 136 is as follows. First, the inverter outputs a frequency and voltage required to drive the turning motor 131, and the turning motor 131 that receives the frequency and voltage output of the inverter rotates at a specific speed and direction. At this time, the first rotary gear 134 of the polishing rotation shaft 133, which is engaged with the second rotary gear 132 of the turning motor 131, rotates in the opposite direction to the second rotary gear 132, so that the polishing rotation shaft 133 and the polishing head 136 rotate in the same direction as the first rotary gear 134.

[0057] Referring to FIGS. 10 and 11, The oscillation part 140 provides left-right oscillation to the baseplate 108 so that the left-right oscillation is provided to the polishing parts 110. For this, the oscillation part 140 includes an oscillation motor 142 and a connecting rod 144, and the fixed bracket 150, to which the connecting rod 144 is to be coupled, is formed on the baseplate 108.

[0058] The oscillation motor 142 is mounted at a position spaced apart from the baseplate 108, and the direction of its rotary shaft 142a is arranged to be orthogonal to the left-right oscillation direction of the baseplate 108.

[0059] A rotary plate 143 may be fixedly coupled to an end of the rotary shaft 142a of the oscillation motor 142, and the rotary plate 143 rotates together with the rotary shaft 142a of the oscillation motor 142. A protrusion 148 may be formed on one surface of the rotary plate 143 for coupling with the connecting rod 144. In this case, the protrusion 148 may be formed at a position spaced apart from the rotary shaft 142a of the oscillation motor 142.

[0060] Meanwhile, the protrusion 148 may be detachably coupled to the rotary shaft 142a, and for example, a threaded hole 149 may be formed on one surface of the rotary plate 143, and an end of the protrusion 148 may be bolted. In this case, a plurality of threaded holes 149 may be formed at multiple different distances from the rotary shaft 142a of the oscillation motor 142, and the protrusion 148 may be selectively connected to one of the threaded holes 149, thereby adjusting the rotation radius of the protrusion 148, so that the left-right oscillation width of the baseplate 108 may be appropriately selected as needed. The oscillation amplitude of the baseplate 108 roughly corresponds to the rotational diameter of the protrusion 148. When the rotational radius of the protrusion 148 is small, the oscillation amplitude of the baseplate 108 is small, and when the rotational radius of the protrusion 148 increases, the oscillation amplitude of the baseplate 108 increases. Meanwhile, a nut groove may be applied instead of the threaded hole 149.

[0061] The connecting rod 144 is used to oscillate the baseplate 108 left and right according to the rotation of the rotary shaft 142a of the oscillation motor 142. One end of the connecting rod 144 is rotatably coupled to the rotary shaft 142a of the oscillation motor 142 and the other end thereof is rotatably coupled to the baseplate 108. When the oscillation motor 142 rotates, the baseplate 108 is repeatedly pulled and pushed. The repetition of this motion creates oscillation.

[0062] As described above, one end of the connecting rod 144 is coupled to the protrusion 148 of the rotary plate 143, thereby circularly rotating around the rotary shaft 142a with a predetermined radius together with the protrusion 148. The end of the connecting rod 144 may be rotatably coupled to the protrusion 148 used as a shaft of the connecting rod 144. For this, the connecting rod 144 may have a first coupling hole 145. In this case, the protrusion 148 may be bolted to the threaded hole 149 of the rotary plate 143 while being fitted into the first coupling hole 145 of the connecting rod 144.

[0063] The other end of the connecting rod 144 is coupled to the fixed bracket 150 of the baseplate 108 to provide power by the operation of the oscillation motor 142 to the baseplate 108. The fixed bracket 150 may include a pair of vertical members 151a and a shaft member 152 arranged between and fixedly coupled to the vertical members 151, and the other end of the connecting rod 144 may have a second coupling hole (reference numeral not shown) where the shaft member 152 penetrates and is coupled. As both the ends of the connecting rod 144 are nutatably connected to the protrusion 148 of the oscillation motor 142 and the shaft member 152 of the fixed bracket 150, respectively, the connecting rod 144 may smoothly provide power by the oscillation motor 142 in the horizontal direction of the baseplate 108.

[0064] Meanwhile, the oscillation part 140 may further include the linear motion guide 146. The linear motion guide 146 may be formed in the form of a pair of rails coupled along the front and rear edges of the baseplate, and the baseplate 108 may be moved left and right between the linear motion guide 146.

[0065] When the baseplate 108 oscillates left and right by the oscillation part 140, components mounted on the baseplate 108 also oscillate to the same width, so that the polishing head 136 eventually oscillates left and right.

[0066] Meanwhile, the oscillation part 140 is equipped with an inverter (not shown) to adjust a specific frequency and voltage, thereby controlling the rotation direction and speed of the oscillation motor 142. When the inverter outputs the frequency and voltage required to drive the oscillation motor 142, the rotary shaft 142a of the oscillation motor 142 rotates, so that the rotary plate 143 and the protrusion 148 rotate together and the end of the connecting rod 144 connected to the protrusion 148 also rotates together. Accordingly, the connecting rod 144 pushes or pulls the fixed bracket 150 connected to the other end of the connecting rod 144 while repeatedly moving left and right as a whole. Due to this movement, the baseplate 108 also repeats left-right oscillation to the same width.

[0067] As the oscillation function by the oscillation part 140 is added, a polishing plate, which was previously fixed, may be moved left and right, so that the area of the polishing pad 105 attached to the platen 104 may be used more widely, and as a result, damage to the polishing pad 105 which occurs during polishing may be distributed, so that the lifespan of the polishing pad 105, which is a consumable material, may be maximized.

[0068] As described above, the housing 101 is configured such that the housing lid 103 opens / closes the housing body 102. Referring to FIGS. 12 and 13, the housing 101 may include a pair of lifting cylinders 107 and joining frames 107b corresponding thereto. The pair of lifting cylinders 107 are respectively mounted on both sides of the top of the housing body 102 so that piston rods 107a are raised and lowered vertically. A pair of joining frames 107b are mounted on both sides of the housing lid 103, and ends of the piston rods 107a of the lifting cylinders 107 are coupled to the joining frames 107b. Accordingly, when the piston rods 107a of the lifting cylinders 107 are raised and lowered, the housing lid 103 is raised and lowered to open / close the housing body 102.

[0069] The lifting cylinders 107 may be disposed at the front end of the housing body 102, the ends of the piston rods 107a may be nutatably coupled to the joining frames 107b, and, as the front end of the housing lid 103 is tilted at a predetermined angle while rising, the housing lid 103 may open the housing body 102. In this case, the housing lid 103 may have a pair of rollers 109a mounted on both rear ends, and the housing body 102 may have rails 109b on which the rollers 109a can move. Accordingly, when the front end of the housing lid 103 ascends and descends as the lifting cylinders 107 are raised and lowered, the rear end of the housing lid 103 moves forward and backward on the rails 109b, and the opening / closing process of the housing lid 103 becomes smooth. Of course, a structure wherein the housing lid 103 is vertically raised and lowered by the lifting cylinders 107 may be applied, but considering the heavy weight of the housing lid 103, the former method is more efficient.

[0070] When a polishing process is performed in a completely sealed state by closing the housing body 102 with the housing lid 103, the inflow of external contaminants into the inside may be blocked. In addition, the housing lid 103 may include at least one exhaust line 160, and the exhaust line 160 may be connected to an exhaust pump (not shown) outside the housing lid 103. Through this, particles generated inside the housing 101 during the polishing process may be discharged to the outside, so that the generation of scratches on the wafer surface may be reduced, and harmful substances may be discharged to the outside, thereby protecting an operator.

[0071] Meanwhile, the polishing unit 106 may include a slurry supply tube 170 mounted to protrude from the center of a lower surface of the baseplate 108, and a slurry is supplied onto the polishing pad 105 through the slurry supply tube 170.

[0072] Although not shown, the wafer polishing apparatus 100 may further include a controller for controlling the operation of the pressure drive parts 120, the rotation drive parts 130 and the oscillation part 140.

[0073] The controller may have a manual input / output screen as shown in FIG. 14. It is intended for use in special situations such as equipment inspection or testing, and may be utilized to control the individual operation of a polishing head. For example, when a problem is suspected in a specific polishing part 110, the problem may be precisely inspected by changing the input value of only one polishing head and operating it, and, during testing, different input values may be set for each polishing head to operate the polishing head.

[0074] For reference, the description of the operation buttons shown in FIG. 14 is as follows: {circle around (1)} is the individual Up / Down button of the polishing head. {circle around (2)} is the individual rotation operation button of the polishing head to control forward or reverse rotation. For example, when the CW (forward) button of Head #1 is clicked, only Head #1 starts to rotate in the forward direction. {circle around (3)} is an integrated operation button which operates all of Head #1 to Head #4 at once, and rotates and up / downs the entire polishing head at once. {circle around (4)} is a pressure operation button which enables pressure operation control for the polishing head in the down operation, and if the polishing head is down, pressure operation is possible regardless of a single polishing head or a plurality of polishing heads. When a pressure value to be used is set, a Programmable Logic Controller (PLC) generates an output signal so that the EP regulator of the corresponding polishing head compresses the air to the corresponding pressure and transmits it to a pressure cylinder to provide a required pressure. {circle around (5)} is a rotation speed control button for each polishing head, and the rotation speed of each polishing head may be set through this. When a specific rotation speed is input, the output signal of the PLC is transmitted to an inverter of the polishing head, and the inverter outputs a voltage corresponding to the input speed to the turning motor 131 to rotate at a desired speed.

[0075] The controller may be equipped with an Auto Recipe input / output screen as shown in FIG. 15. Various types of recipes are saved in advance through the Auto Recipe input / output screen of the equipment applied in a mass production process, and a specific recipe is selected and used during actual wafer production. Since the polishing heads may be individually controlled, various complex settings, such as whether to use a specific polishing head for actual polishing by down-running it in the recipe or to use it by applying different rotation speeds for each process step, may be made. For example, in step 1, HD1 (Head #1) and HD2 may be set to rotate at 30 RPM and HD3, HD4 may be set to rotate at 15 RPM. If a specific polishing head has a problem and, accordingly, it is needed to be operated only on three polishing heads, only the problematic polishing head may be turned off.

[0076] The description of the main operation buttons shown in FIG. 15 is as follows: {circle around (1)} is an input field for setting the rotation speed of the polishing head by step, {circle around (2)} is an input field for setting the pressure condition of the polishing head by step, 3 is an input field for setting the rotation direction of the polishing head in the corresponding recipe, and {circle around (4)} is an input field for setting the up / down operation of the polishing head in the corresponding recipe.

[0077] The effects of the wafer polishing apparatus according to the embodiment of the present invention are as follows.

[0078] First, since the operation of multiple polishing heads can be individually controlled, polishing can be individually performed according to the conditions and environments required for each wafer, even when polishing wafers that are individually manufactured in the wafer manufacturing process and, accordingly, are in different states, so that, compared to existing CMP equipment, the process time can be reduced and the consumption of consumable materials can be reduced, thereby reducing the overall cost.

[0079] In addition, since a rotation drive part that provides rotational power to each polishing part; and a pressure drive part that provides pressure are equipped, the structure is simple and the energy loss rate can be reduced, compared to an existing method of controlling all heads with a single motor. Further, the polishing flatness can be improved, which can improve the wafer production quality, and the lifespan of a polishing pad consumed during a polishing process can be increased.

[0080] While the embodiments of the present disclosure have been described above, it will be appreciated by those skilled in the art that various modifications and changes can be made to the 10 present disclosure without departing from the spirit and scope of the claims of the present disclosure.

Examples

Embodiment Construction

[0033]Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, the embodiments described below are intended only to describe the disclosure in detail so that those having ordinary skill in the art to which the disclosure pertains can easily practice the invention, and are not intended to limit the scope of the disclosure. Throughout the description of various embodiments of the present disclosure, the same reference numerals are used to refer to components having the same technical features.

[0034]As shown in FIGS. 1 to 3, a wafer polishing apparatus (hereinafter referred to as “wafer polishing apparatus 100”) according to an embodiment of the present invention includes a platen 104 provided with a polishing pad 105 attached to an upper surface thereof and configured to rotate together with the polishing pad 105 in one or the other direction; and a polishing unit 106 disposed on an upper side of the platen 10...

Claims

1. A wafer polishing apparatus, comprising:a platen having a polishing pad attached to its upper surface and rotating together with the polishing pad; anda polishing unit disposed on an upper side of the platen and configured to perform polishing by pressurizing and rotating a wafer interposed between the polishing unit and a polishing pad,wherein the polishing unit comprises:a baseplate;a plurality of polishing parts mounted on the baseplate to be spaced from each other at a predetermined interval, wherein each polishing part comprises polishing rotation shafts rotatably coupled to the baseplate to penetrate the baseplate and a polishing head coupled to a lower part of the polishing rotation shaft to rotate together with the polishing rotation shaft, and that rotates around each polishing rotation shaft and are raised and lowered in each polishing rotation shaft direction;a plurality of rotation drive parts mounted on the baseplate to be adjacent to the polishing parts and configured to respectively, individually provide rotational power to the corresponding polishing part; anda plurality of pressure drive parts mounted on the baseplate to be adjacent to the polishing parts and configured to respectively, individually provide pressure to the corresponding polishing part.

2. The wafer polishing apparatus according to claim 1, wherein each of the polishing parts comprises a first rotary gear that surrounds and is coupled to the polishing rotation shaft on an upper side of the polishing head and rotates together with the polishing rotation shaft, andeach of the rotation drive parts comprises a turning motor mounted on the baseplate and having a motor rotation shaft penetrating downwardly through the baseplate; and a second rotary gear coupled to a motor rotation shaft of the turning motor, configured to rotate together with the turning motor and engaged with a first rotary gear.

3. The wafer polishing apparatus according to claim 1, wherein each of the pressure drive parts comprises:a pressure cylinder mounted on the baseplate and equipped with a piston rod that moves up and down and back and forth; anda pressure bracket having one end coupled to the piston rod of the pressure cylinder and coupled to the polishing rotation shaft of the polishing parts so that the polishing rotation shaft and polishing head descend and ascend as the piston rod is advanced and retracted.

4. The wafer polishing apparatus according to claim 3, wherein each of the pressure drive parts further comprises a first frame to which other end of the pressure bracket is nutatably coupled; a first bearing coupled to the pressure bracket, and rotatably coupled to the polishing rotation shaft such that the polishing rotation shaft penetrates the first bearing; and a joining bar configured to fixedly couple the pressure bracket and the first bearing.

5. The wafer polishing apparatus according to claim 4, wherein each of the pressure drive parts further comprises a base frame mounted on the baseplate and provided with the first frame protruding from one side thereof; and a second frame formed to protrude from other side of the base frame to a height higher than the first frame and provided with the pressure cylinder vertically mounted on an upper surface thereof.

6. The wafer polishing apparatus according to claim 1, wherein the polishing unit further comprises an oscillation part configured to provide left-right oscillation to the baseplate to provide left-right oscillation to the polishing parts.

7. The wafer polishing apparatus according to claim 6, wherein the oscillation part comprises: an oscillation motor spaced apart from the baseplate and arranged so that a rotary shaft direction of the oscillation motor is orthogonal to a left-right vibration direction of the baseplate; and a connecting rod whose one end is rotatably coupled to the rotating shaft of the oscillation motor and whose other end is rotatably coupled to the baseplate so that the baseplate oscillates left and right according to rotation of the rotating shaft of the oscillation motor.

8. The wafer polishing apparatus according to claim 7, wherein the oscillation part further comprises: a rotary plate that is fixedly coupled to an end of the rotating shaft of the oscillation motor to rotate together with the oscillation motor and has a protrusion formed on one surface thereof at a position spaced from the rotating shaft of the oscillation motor, wherein the protrusion penetrates and is coupled to the first coupling hole formed at one end of the connecting rod such that one end of the connecting rod can rotate around the protrusion as an axis.

9. The wafer polishing apparatus according to claim 8, wherein the protrusion is fitted into the first coupling hole of the connecting rod and bolted into a threaded hole formed in the rotary plate.

10. The wafer polishing apparatus according to claim 9, wherein a plurality of threaded holes are provided, the threaded holes are spaced apart from the rotating shaft of the oscillation motor at different distances, and the protrusion is selectively fastened to one of the threaded holes.

11. The wafer polishing apparatus according to claim 8, wherein the baseplate further comprises a fixed bracket which is formed on one side of its upper surface and to which other end of the connecting rod is coupled, wherein the fixed bracket comprises a pair of vertical members and a shaft member fixedly coupled between the vertical members, wherein the shaft member penetrates and is coupled into the second coupling hole formed at the other end of the connecting rod.

12. The wafer polishing apparatus according to claim 7, wherein the oscillation part further comprises a pair of rail-shaped linear motion guides coupled along a front end and rear end edges of the baseplate, and the baseplate oscillates between the linear motion guides while moving left and right.

13. The wafer polishing apparatus according to claim 1, wherein each of the polishing parts further comprises a wafer carrier mounted on the polishing head so as to be disposed on a lower side of the polishing head, and rotated and raised / lowered together with the polishing head.

14. The wafer polishing apparatus according to claim 13, wherein the wafer carrier has a template attached to its lower surface, wherein the template has at least one wafer mounting hole.

15. The wafer polishing apparatus according to claim 13, wherein an upper surface of the wafer carrier is formed in a truss structure.

16. The wafer polishing apparatus according to claim 1, further comprising a housing configured to accommodate the platen and the polishing unit,wherein the housing comprises a housing body on a top of which the platen is mounted; a housing lid which is configured to open / close the housing body and on which the polishing unit is mounted; a pair of lifting cylinders mounted on both sides of an upper end of the housing body to vertically raise and lower piston rods; and a pair of joining frames mounted on both sides of the housing lid and coupled to ends of the piston rods of the lifting cylinders, wherein, when the piston rods of the lifting cylinders are raised and lowered, the housing lid is raised and lowered.

17. The wafer polishing apparatus according to claim 16, wherein the lifting cylinder is disposed at a front end of the housing body and an end of the piston rod is nutatably coupled to the joining frame so that a front end of the housing lid is opened and closed while being inclined at a predetermined angle as it ascends and descends.

18. The wafer polishing apparatus according to claim 17, wherein the housing lid has a pair of rollers mounted on both sides of the rear end, the housing body has rails on which the rollers can move, and when the front end of the housing lid ascends and descends, the rear end of the housing lid moves forward and backward on the rails.

19. The wafer polishing apparatus according to claim 1, wherein the polishing unit further comprises a slurry supply tube mounted so as to protrude from a center of a lower surface of the baseplate.

20. The wafer polishing apparatus according to claim 1, wherein the housing lid comprises at least one exhaust line, and the exhaust line is connected to an exhaust pump outside the housing lid.

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