KR101906770B1 - Polishing device for wafer - Google Patents

Abstract

The present invention relates to a polishing device for a semiconductor wafer, comprising: a wafer stage provided with a vacuum adsorption portion for adsorbing and fixing a lower portion surface of a wafer, and supporting the wafer; a drum rotating with respect to the wafer; a pad attached to the drum and directly contacting an edge portion of the wafer; a slurry supplying portion supplying slurry toward an upper portion surface of the wafer; and a chamber provided with a space for accommodating the wafer stage, the drum, the pad, and the slurry supplying portion.

Description

TECHNICAL FIELD [0001] The present invention relates to a polishing apparatus for polishing a semiconductor wafer,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer polishing apparatus, and more particularly, to a semiconductor wafer polishing apparatus in which process efficiency is improved while uniformly polishing semiconductor wafers without defects.

After the grinding, cleaning and etching steps, according to the prior art, the surface (s) of the semiconductor wafer is planarized by abrasive polishing.

In the case of single-side polishing (SSP), the semiconductor wafer is fixed during processing to the back surface on a support plate using cement, either by vacuum or by gluing.

In the case of double-side polishing (DSP), semiconductor wafers are loosely introduced into a thin carrier and simultaneously polished against the front and back surfaces in a "free floating" manner between the top and bottom polishing plates covered with a polishing pad . This polishing method is usually carried out with the supply of abrasive slurry containing an abrasive, usually based on silica sol. Related double-side grinding machines are disclosed in DE 100 07 390 A1.

On the other hand, chemical-mechanical polishing (polishing), including final polishing of only the front side ("component side") using a softer polishing pad as so-called haze-free polishing (CMP), the abrasive is likewise supplied in the form of an abrasive slurry.

The semiconductor wafer to be polished is usually a silicon wafer or a substrate having a hierarchical structure (e.g., silicon-germanium) derived from silicon. The silicon wafer is used in particular to produce semiconductor components such as memory chips (DRAM), microprocessors, sensors, light emitting diodes, and the like.

In particular, the requirements for manufacturing silicon wafers for manufacturing memory chips and microprocessors have become more stringent. This relates primarily to the crystallinity itself, but also to the geometry and flatness of the wafer, in particular to the defect density, to the internal getter for impregnating metallic impurities. It would be desirable to have a silicon wafer with two perfectly parallel planar surfaces, a particularly good flatness on the surface on which the part of the silicon wafer is to be fabricated, and a low surface roughness. Also, although it is currently not possible due to the reduction in thickness at the wafer edge and the poor geometry in the edge region, it would be desirable to be able to utilize the total area of the component surfaces.

Conventional methods for polishing semiconductor wafers are known to handle this edge roll-off.

The edge geometry is typically quantified by designating one or more edge roll-off parameters that are typically associated with the total thickness of the silicon wafer or with its front and / or back edge geometry, and the edge roll- Or the customarily observed reduction in the flatness of the front and / or back of the silicon wafer in its edge region. Methods for measuring the edge roll-off of silicon wafers are described in Jpn. J. Appl. Phys. Vol. 38 (1999), pp. 38-39.

The polishing of semiconductor wafers by "Fixed Abrasive Polishing (FAP)" is further known and the semiconductor wafers are polished against a polishing pad containing an abrasive material bonded to a polishing pad ("fixed abrasive pad").

The polishing step in which such a FAP polishing pad is used is referred to below as the FAP step.

DSP and CMP differ from FAP in that DSP and CMP in particular do not include any abrasive pads in the polishing pad and that abrasives are always supplied in the form of abrasive slurries.

As described above, various researches have been made on an apparatus and a process for polishing a semiconductor wafer more finely.

An object of the present invention is to provide a polishing apparatus for a semiconductor wafer with improved process efficiency.

Another object of the present invention is to provide a semiconductor wafer polishing apparatus capable of homogeneously polishing the wafer by uniformly and efficiently supplying slurry on a semiconductor wafer.

It is still another object of the present invention to provide a semiconductor wafer polishing apparatus capable of cleanly polishing a wafer by blocking inflow of impurities such as dust into a chamber for providing a space for polishing the wafer.

It is still another object of the present invention to provide a semiconductor wafer polishing apparatus capable of polishing wafers of various sizes by variously controlling the size of a wafer stage for holding a wafer.

According to an aspect of the present invention, there is provided an apparatus for polishing a semiconductor wafer, comprising: a wafer stage having a vacuum adsorption unit for adsorbing and fixing a lower surface of the wafer, the wafer stage supporting the wafer; A drum rotating with respect to the wafer; A pad attached to the drum and in direct contact with an edge of the wafer; A slurry supply unit for supplying a slurry toward an upper surface of the wafer; And a chamber having a space for receiving the wafer stage, the drum, the pad and the slurry supply portion, wherein the slurry supply portion includes an inner nozzle having a first space therein for supplying slurry, And a second space for enclosing the outer surface of the inner nozzle and having a second space through which the inert gas flows, and a plurality of air nozzles provided at the distal end of the inner nozzle and the outer nozzle, for dispersing the slurry on the wafer, A chamber shutter for opening and closing the wafer in a slidable manner such that the wafer flows into the chamber, an air ejecting unit for ejecting air adjacent to the chamber shutter, and a sub-nozzle for detecting the proximity of the wafer, Wherein the chamber sensor is configured to allow the wafer to contact the chamber shutter side And when the root is sensed, the chamber shutter is opened to form an opening, and the air injecting unit injects air so as to be parallel to the opening.

The chamber shutter is provided inside the chamber to move from the upper portion to the lower portion to close the opening portion of the chamber. A plate extending perpendicularly to the outer surface of the chamber at the lower side of the opening portion is formed on the outer surface of the chamber The air injecting unit injects air vertically toward the plate from the upper side of the opening, and the plate is provided with a plurality of holes through which the air injected from the air injecting unit passes.

Wherein the air injecting portion includes a plurality of nozzles arranged in parallel at equal intervals from each other, the nozzles having air holes extending vertically from an outer surface of the chamber and having a plurality of air injected in a direction toward the plate, The air hole provided at the outermost side in the air ejecting part injects air moving by 0.5 mm to 0.7 mm away from the end of the plate, and the chamber sensor may be provided at the end of the air ejecting part.

The wafer stage includes a base plate having a vacuum adsorption unit at a central portion thereof, and a pair of sliding members provided on the base plate and sandwiching the vacuum adsorption unit. One end of the pair of sliding members is connected to the base plate And the other end of the pair of sliding members is slid on the base plate so that the other ends of the pair of sliding members are spaced apart from each other so as to support wafers of various sizes by the movement of the pair of sliding members on the wafer stage .

Wherein the inner nozzle has a circular cross section and a cross section of the outer nozzle has a larger diameter than a cross section of the inner nozzle and the inner nozzle is provided at a central portion of the outer nozzle, And the inner nozzle has a coating part made of carbon nanotube (CNT), and the air flowing through the outer nozzle is heated or cooled in the inner part of the outer nozzle, Wherein the coating part forms a plurality of flow paths extending in a direction in which the slurry flows, the flow path is formed in a semicircular shape in cross section, and the coating part is provided with a heat exchange member A plurality of ribs protruding toward the central portion to disintegrate the aggregation of the slurry, It may be each formed of a different height with cone.

Wherein the sub nozzle comprises a plurality of pipe portions extending corresponding to the first space to discharge the slurry and a funnel portion extending in a manner corresponding to the second space and discharging air, And at least one inclined pipe extending in an inclined relation with respect to the vertical pipe in the first space, wherein the inclined pipe is provided close to an upper side of the vertical pipe, And the funnel portion extends to be inclined in the second space and extends to cover the outer side of the inclined pipe, and the vertical pipe has a larger cross-sectional area than the inclined pipe And the slurry is directed toward the center of the wafer And the slant pipe discharges the slurry toward the outer periphery of the wafer, and the slurry pipe can be controlled so that the flow is guided by the air discharged by the funnel portion and does not flow out to the outside.

The upper portion of the pipe portion may have a first fastening portion formed of threads and an upper inner surface of the funnel portion may have a second fastening portion fastened to the first fastening portion by screwing.

As described above, according to the present invention, it is possible to provide a polishing apparatus for a semiconductor wafer with improved process efficiency.

Further, according to the present invention, it is possible to provide a semiconductor wafer polishing apparatus capable of homogeneously polishing the wafer by uniformly and efficiently supplying the slurry onto the semiconductor wafer.

Further, according to the present invention, it is possible to provide a semiconductor wafer polishing apparatus capable of cleanly polishing a wafer by blocking inflow of impurities such as dust into a chamber for providing a space for polishing the wafer.

Furthermore, according to the present invention, it is possible to provide a semiconductor wafer polishing apparatus capable of polishing wafers of various sizes by variously controlling the size of a wafer stage for holding wafers.

1 is a schematic view of a semiconductor wafer polishing apparatus according to an embodiment of the present invention.
FIG. 2 is a perspective view showing the rotary drum of FIG. 1;
3 is a schematic view showing a state in which a wafer is polished by a pad.
Fig. 4 is a view showing the chamber shutter side of the chamber of Fig. 1;
5 is a side view of Fig. 4. Fig.
6 is a front view of the slurry supply unit of FIG.
7A is a cross-sectional view of the inner nozzle and the outer nozzle of FIG.
Fig. 7B is a cross-sectional view taken along line AA of Fig. 7A.
7C is a schematic view of the inner surface of the inner nozzle of Fig. 7A.
8 is an exploded perspective view of the sub-nozzle of FIG.
9 is a view schematically showing the flow of slurry and air according to FIG.
Figs. 10 and 11 schematically illustrate the movement of the sliding member in the wafer stage of Fig. 1. Fig.

The details of other embodiments are included in the detailed description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments described below, but may be embodied in various forms. In the following description, it is assumed that a part is connected to another part, But also includes a case in which other media are connected to each other in the middle. In the drawings, parts not relating to the present invention are omitted for clarity of description, and like parts are denoted by the same reference numerals throughout the specification.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic view of a semiconductor wafer polishing apparatus according to an embodiment of the present invention, and FIG. 2 is a perspective view showing the rotary drum of FIG. 3 is a schematic view showing a state in which a wafer is polished by a pad. FIG. 4 is a view showing the chamber shutter side of the chamber of FIG. 1, and FIG. 5 is a side view of FIG. FIG. 6 is a front view of the slurry supply unit of FIG. 1, and FIG. 7A is a cross-sectional view of the inner nozzle and the outer nozzle of FIG. FIG. 7B is a cross-sectional view taken along line A-A of FIG. 7A, and FIG. 7C is a schematic view of an inner surface of the inner nozzle of FIG. 7A. 8 is an exploded perspective view of the sub-nozzle of FIG. 9 is a view schematically showing the flow of slurry and air according to FIG. Figs. 10 and 11 schematically illustrate the movement of the sliding member in the wafer stage of Fig. 1. Fig.

One embodiment of the present invention is an apparatus for polishing a semiconductor wafer, comprising: a wafer stage 400 having a vacuum adsorption unit 430 for adsorbing and fixing a lower surface of the wafer, the wafer stage 400 supporting the wafer; A drum (30) rotating with respect to the wafer; A pad 50 attached to the drum 30 and in direct contact with the edge of the wafer; A slurry supply unit 200 for supplying a slurry toward the upper surface of the wafer; And a chamber 100 having a space 100a for accommodating the wafer stage 300, the drum 30, the pad 50 and the slurry supply unit 200. The semiconductor wafer polishing apparatus 10 includes: .

The slurry supply unit 200 includes an inner nozzle 210 having a first space 210a therein to supply slurry and a second inner space 210 surrounding the outer surface of the inner nozzle 210 so as to surround the outer surface of the inner nozzle 210. [ An outer nozzle 220 having a second space 220a through which an inert gas flows and a second outer nozzle 220 disposed at a distal end of the inner nozzle 210 and the outer nozzle 220 to disperse the slurry on the wafer. And a sub nozzle 300 having a plurality of flow paths.

The chamber 100 is provided with a chamber shutter 110 opened and closed in a slidable manner to allow the wafer to flow into the chamber 100, an air injector 120 for injecting air adjacent to the chamber shutter 110, And a chamber sensor 130 for sensing the proximity of the chamber. The chamber sensor 130 senses the approach of the wafer to the chamber shutter 110 and the chamber sensor 130 transmits the sensed information to a control unit (not shown) 110 and the wafer stage 300 can be controlled. The chamber shutter 110 may be opened by the control unit to form an opening, and the air injecting unit 120 may inject air to be aligned with the opening.

4 and 5, the chamber 100 of the wafer polishing apparatus according to the present embodiment may include a chamber shutter 110 for accommodating the wafer in a space 100a inside the chamber 100 .

The chamber shutter 110 may be provided inside the chamber 100 to move from the upper part to the lower part to close the opening 110a of the chamber 100. [ The chamber 100 may have a plate 140 extending from the lower side of the opening 110a to the outer surface of the chamber 100.

The air injecting unit 120 injects air vertically toward the plate 140 from the upper side of the opening 110a and the plate 140 has a plurality of holes 141, So that the air injected from the air inlet 120 passes.

The air injecting unit 120 includes a plurality of nozzles 121 aligned at equal intervals and the nozzles 121 extend vertically from the outer surface of the chamber and extend in a direction toward the plate 140 And an air hole 122 through which a plurality of air is injected. The air hole 122 provided at the outermost portion of the air injection portion 120 and spaced apart from the chamber 100 is separated from the end of the plate 150 by 1 mm to 0.5 mm, As shown in FIG. In addition, the chamber sensor 130 may be provided at the end of the nozzle 121 in the air injection unit 120.

The inside of the chamber 100 of the wafer polishing apparatus 10 may be provided so as to block external air while the polishing process is performed. Therefore, unnecessary dust or the like other than the slurry is prevented from flowing into the chamber 100 during the polishing process, so that the wafer can be precisely polished in a clean environment without defects by the dust or the like.

The chamber sensor 130 senses the wafer adjacent to the wafer, and transmits the wafer to a controller (not shown). The control unit primarily activates the air injecting unit 120 to cause air to be injected through the air hole 122 and secondarily to operate the chamber shutter 110 to move the chamber shutter 100 And the opening 110a through which the wafer flows can be formed.

The air injected by the air injecting unit 120 may be injected perpendicularly toward the plate 140. The vertically injected air is provided in parallel with the opening 110a and the chamber shutter 110 is provided before the opening 110a is formed so that external dust or the like is introduced into the chamber 100 together with the wafer Can be prevented.

The air injected from the outermost side of the air injecting unit 120 may be injected vertically with a distance of 0.5 mm to 0.7 mm with respect to the end of the plate 140. Since the outermost air is jetted away from the end of the plate 140 in the above-described range, the air can block the outside air more efficiently without forming a vortex caused by the plate 140 .

6 to 9, a slurry supply unit 200 is provided on the wafer, and the slurry injected through the slurry supply unit 200 can be uniformly sprayed onto the upper surface of the wafer. The slurry supply unit 200 includes an inner nozzle 210 to which a slurry is supplied, an outer nozzle 220 to which air is supplied to guide a moving path of the slurry, and a lower part of the inner nozzle 210 and the outer nozzle 220 And a sub nozzle 300 for deforming the flow of the slurry and the air.

The outer nozzle 220 may include a heat exchange member 221 and the heat exchange member 221 may heat or cool the air flowing through the outer nozzle 220.

The slurry flowing through the inner nozzle 210 may be sprayed onto the wafer to polish the wafer, and the air supplied through the outer nozzle 220 guides the direction of the slurry, Can be controlled. The air supplied through the external nozzle 220 may be argon (Ar) or nitrogen (N ₂ ) and is cooled or heated by the heat exchange member 221, By controlling the temperature, the slurry can be delivered into the wafer at the optimum temperature, solvent amount, and concentration. A temperature sensor (not shown) is provided inside the outer nozzle 220 and the temperature measured by the temperature sensor is transmitted through the control unit to check the temperature of the slurry. The temperature of the slurry is measured through the heat exchanging member 221 By controlling the temperature, the temperature of the slurry can be kept within a predetermined temperature range.

The cross section of the inner nozzle 210 may have a circular shape and the cross section of the outer nozzle 220 may have a circular shape having a larger diameter than the cross section of the inner nozzle 210. The inner nozzle 210 may be provided at a central portion of the outer nozzle, and a cross section of the second space 220 between the inner nozzle and the outer nozzle may be formed in a hoop shape.

A coating part 221 made of carbon nanotubes (CNT) is formed on the inner surface of the inner nozzle 210. The coating part 221 forms a plurality of channels extending in parallel to the slurry flow direction, The flow path may have a semicircular cross section. It is possible to reduce the friction between the slurry and the inner nozzle 210 by the coating portion 211 and to change the composition of the slurry due to the friction generated with the inner nozzle 210 due to the flow of the slurry The inner nozzle 210 can be prevented from being worn.

The coating part 211 is provided with a plurality of ribs 212 protruding toward the central part of the first space 210a of the inner nozzle 210 to dissolve the aggregation of the slurry, As shown in FIG. Preferably, the ribs 212 may protrude from the portion 211a where the semicircles of the coating portion 211 are in contact with each other at the highest portion, for example, the adjacent flow paths. The ribs 212 can prevent the wafers from being unnecessarily worn out by agglomeration of the slurry by disassembling the agglomerated portions of the slurry passing through the inner nozzle 210.

The sub nozzle 300 may be provided at the ends of the inner nozzle 210 and the outer nozzle 220 so as to deform the flow of slurry and air to uniformly spray the slurry on the wafer.

The sub nozzle 300 includes a plurality of pipes 310 extending in correspondence to the first space 210a and discharging the slurry and a funnel-shaped And a funnel part 320.

The pipe unit 310 includes a vertical pipe 311 vertically extending in the first space 210a and at least one inclined pipe 311 extending in an inclined relation with respect to the vertical pipe 311 in the first space 210a. And the inclined pipe 312 is provided close to the upper side of the vertical pipe 311 so as to be inclined with respect to the vertical pipe 311 so as to be further away from the lower side of the vertical pipe 311 .

The funnel portion may extend so as to be inclined in the second space and to surround the sloping pipe.

The vertical pipe (311) has a cross-sectional area wider than the slant pipe (312) to discharge the slurry toward the center of the wafer, and the slant pipe (312) discharges the slurry toward the outer periphery of the wafer, So that the flow is guided by the air discharged by the unit 320 so as to be prevented from flowing out to the outside.

The upper part of the upper part of the pipe part 310 is provided with a first fastening part 313 made of thread and the upper part of the upper part of the funnel part 320 is fastened to the second fastening part 313 A fastening portion 321 may be provided. The funnel part 320 can be fastened by the first and second fastening parts 313 and 321 by screwing.

10 and 11, a ball screw 25 is provided below the wafer stage 400 and a driving rod 21 is provided on the wafer stage 400 to vertically move the wafer stage 400 Direction.

The chamber sensor 130 senses the proximity of the wafer and can transmit the sensed information to the control unit. The control unit controls the driving rod 21 and the driving rod 21 moves the chamber shutter The wafer stage 400 can be moved so as to accommodate the wafer introduced through the wafer stage 110.

The wafer stage 400 includes a base plate 410 having a vacuum adsorption unit 430 at a central portion thereof and a pair of vacuum chucks 430 disposed at upper portions of the base plate 410, And may include a sliding member 420.

One end of the pair of sliding members 420 may be fixed to the base plate 410 and the other ends of the pair of sliding members 420 may be slid in a direction away from the base plate 410. And may be provided to support wafers of various sizes by the movement of the pair of sliding members 420 in the wafer stage 400.

The wafer stage 400 is provided with the other ends of the sliding members 420 spaced apart from each other to receive wafers introduced through the chamber shutters 110. The wafers are provided on the sliding members 420, The other end of the member 420 may move so as to be close to each other to fix the wafer.

The semiconductor wafer polishing apparatus 10 includes a wafer pivoting portion 10, a drum 30, and a polishing pad 50.

The wafer pivoting unit 10 is provided on the lower side of the chamber 100 to suck and rotate the wafer. The wafer rotating unit 10 includes a wafer stage 400 for holding and supporting a wafer and a vacuum adsorption unit for applying a vacuum pressure to the wafer to fix the wafer to the wafer stage 400 is provided at the center of the wafer stage 400 can do.

The lower side of the wafer stage 400 is fixed by the rotary shaft 12 and the rotary shaft 12 is rotatably supported by pedestals 14 fixed to the support stand 13. A vacuum path 15 for applying a vacuum pressure to the wafer stage 400 is formed on the rotary shaft 12. An electric motor 16 is mounted under the support table 13 to drive the rotary shaft 12 and is provided as means for rotating the wafer. The gear 18 fixed to the main shaft 17 of the electric motor 16 meshes with the gear 19 fixed to the rotary shaft 12. [ Accordingly, the wafer stage 400 rotates the wafer about the rotary shaft 10a by the electric motor 16 via the rotary shaft 12. [0064]

A plurality of drive rods 21 are mounted on the support 13 and each of the drive rods 21 protrudes downward from the support 13. The lower end of the driving rod 21 is fixed to the driving plate 22. [ And the nut 23 provided on the drive plate 22 is screwed to the ball screw 25. [ The ball screw 25 is rotationally driven by the main shaft of the electric motor 24 which is the reciprocating transporting means in the axial direction. By the ball screw 25, the driving rod 21 reciprocally moves the wafer stage 400 in the vertical direction. That is, the driving rod 21 can reciprocate the wafer in the vertical direction.

The drum (30) is disposed on the wafer turning part (10). The rotary drum 30 rotates relative to the wafer W. The drum 30 includes a main assembly 31 disposed on the upper side and a sub-assembly 32 disposed on the lower side.

The main assembly 31 and the sub assembly 32 are arranged parallel to each other and are connected by a plurality of connecting rods 33. A space 34 for polishing the wafer W is formed between the main body 31 and the sub-body 32. In addition, the main assembly 31 may have a disk shape, and the sub-assembly 32 may have a ring shape.

The main shaft 31 is mounted on a hollow shaft 38 rotatably supported by a support tube 37. The hollow shaft 38 is rotatably supported by a rotating shaft 10b As shown in FIG. A pulley 27 fixed to the main shaft of the electric motor 26 and a pulley 28 fixed to the hollow shaft 38 are mounted on the belt 38 to rotate the electric motor 26 to the hollow shaft 38, Lt; / RTI >

A slurry supply unit 200 for supplying a slurry is formed in the hollow shaft 38 and a slurry is supplied to the upper surface of the wafer provided on the wafer stage 400 through the slurry supply unit 200 .

A first abrading arm 41 is provided on the main assembly 31. The first polishing arm 41 urges the polishing pad 50 to the inside of the drum 30 by a centrifugal force when the drum 30 rotates. A scale is additionally mounted on one end of the first polishing arm 41 and the polishing pad 50 is mounted on the other end. In addition, an intermediate portion of the first polishing arm 41 may be fixed to the main assembly 31 so that the first polishing arm 41 is hinged. As the drum 30 rotates, the weight is subjected to a centrifugal force to the outside, and the first polishing arm 41 performs a hinge rotation. Accordingly, the polishing pad 50 can apply pressure to the edge portion E of the wafer W.

A second polishing arm (42) is provided on the sub-assembly (32). The second polishing arm 42 urges the polishing pad 50 to the inside of the drum 30 by the centrifugal force when the drum 30 rotates. More specifically, a scale is additionally mounted on one end of the second polishing arm 42, and the polishing pad 50 is mounted on the other end. Further, an intermediate portion of the second abrading arm 42 may be fixed to the main assembly 31 so that the second abrading arm 42 is hinged. As the rotary drum 30 rotates, the weight is subjected to a centrifugal force to the outside, and the second polishing arm 42 performs a hinge rotation. Accordingly, the polishing pad 50 can apply pressure to the edge portion E of the wafer W.

The polishing pad 50 is installed in the first polishing arm 41 and the second polishing arm 42. The polishing pad 50 is attached to the rotary drum 30 through the first polishing arm 41 and the second polishing arm 42. The polishing pad 50 is rotated together with the rotation of the rotary drum 30 and the wafer W is rotated by the hinge rotation of the first and second polishing arms 41 and 42, .

The polishing pad 50 may be directly attached to the first polishing arm 41 and the second polishing arm 42 but may be coupled to the supporting pad so that the first polishing arm 41 and the second polishing arm 42, (Not shown). That is, the polishing pad 50 is coupled to the support pad, and the support pad can be installed directly on the first and second polishing arms 41 and 42. The support pad may have sufficient rigidity to support the polishing pad 50.

The polishing pad 50 is in contact with the edge E of the wafer W. The polishing pad 50 is in direct contact with the outer circumferential surface of the wafer W. That is, the first polishing arm 41 and the second polishing arm 42 are hingedly rotated by the centrifugal force generated by the rotation of the rotary drum 30, and the polishing pad 50 is rotated on the wafer W, And the pressure is applied.

The polishing pad 50 includes a plurality of grooves 51. The grooves 51 are formed on a surface where the wafer W and the polishing pad 50 are in contact with each other. For example, the pads including the nonwoven fabric and the urethane can be cut by a diamond wheel or the like, so that the grooves 51 can be formed. The polishing pad 50 is formed. The grooves 51 may have a shape extending in one direction. The grooves 51 may be formed side by side. The grooves 51 may extend in the same direction as the rotation axis 10a of the wafer W. [ The grooves 51 may extend in a direction intersecting the upper surface of the wafer W and the lower surface of the wafer W. [

The polishing pad 50 has elasticity. That is, the polishing pad 50 may be made of polyurethane having pores therein and may be flexible. Therefore, when the edge portion E of the wafer W is polished, the inner surface 52 of the grooves 51 and the edge portion E of the wafer W can directly contact each other. The grooves 51 may be formed in a square shape and may have a bottom surface which is the deepest portion of the grooves 51 and a pair of inner surfaces vertically provided on both sides of the bottom surface. The bottom surface of the grooves 51 can directly contact the edge portion E of the wafer W. [ The upper surface of the polishing pad 50, the inner surface of the grooves 51 and the bottom surface of the grooves 51 may have different polishing rates at the edge E of the wafer W. [ That is, since the upper surface of the polishing pad 50 extends in a direction different from the inner surface of the grooves 51 and forms a step with the bottom surface of the grooves 51, the upper surface of the polishing pad 50, The inner surface of the grooves 51 and the bottom surface of the grooves 51 rotate at different speeds. The relative speed between the edge portion E of the wafer W and the upper surface of the polishing pad 50, the inner surface of the grooves 51 and the bottom surface of the grooves 51 are different from each other, Speeds can also be different.

The grooves 51 extend in a direction intersecting the direction in which the wafer W extends, that is, in a direction intersecting the upper surface of the wafer W. The slurry injected onto the wafer W can flow easily through the grooves 51 and beyond the edge portion E of the wafer W and below the wafer W. [ That is, the slurry can be easily supplied to the edge portion E of the wafer W through the grooves 51. Thus, the wafer polishing apparatus according to the present embodiment can easily polish the edge portion of the wafer by the grooves 51.

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the foregoing detailed description, and all changes or modifications derived from the meaning and scope of the claims and the equivalents thereof are included in the scope of the present invention Should be interpreted.

10: wafer polishing apparatus
100: chamber
110: chamber shutter
120:
200: Slurry supply part
210: inner nozzle
220: External nozzle
300: sub nozzle
400: Wafer stage

Claims (7)

An apparatus for polishing a semiconductor wafer,
A wafer stage having a vacuum adsorption portion for adsorbing and fixing the lower surface of the wafer, the wafer stage supporting the wafer;
A drum rotating with respect to the wafer;
A pad attached to the drum and in direct contact with an edge of the wafer;
A slurry supply unit for supplying a slurry toward an upper surface of the wafer; And
A chamber having a space to receive the wafer stage, the drum, the pad, and the slurry supply,
Wherein the slurry supply unit includes an inner nozzle having a first space therein for supplying slurry and an outer nozzle having a second space spaced apart from the outer surface of the inner nozzle to surround the outer surface of the inner nozzle, And a sub nozzle provided at the distal end of the inner nozzle and the outer nozzle and having a plurality of flow paths for dispersing the slurry on the wafer,
Wherein the chamber includes a chamber shutter that is slidably opened and closed to allow the wafer to flow into the chamber, an air ejection portion that ejects air adjacent the chamber shutter, and a chamber sensor that senses proximity of the wafer, When the wafer is sensed to approach the chamber shutter side, the chamber shutter is opened to form an opening, and the air injection unit injects air so as to be aligned with the opening,
The chamber shutter is provided inside the chamber to move from the upper part to the lower part to close the opening of the chamber,
And a plate extending perpendicularly to an outer surface of the chamber at a lower side of the opening, wherein the air injection unit vertically blows air from the upper side of the opening toward the plate,
Wherein the plate is provided with a plurality of holes so that the air injected from the air injecting portion passes through the plate. delete The method according to claim 1,
Wherein the air injecting part includes a plurality of nozzles arranged in parallel at equal intervals from each other, the nozzle having an air hole extending vertically from the outer surface of the chamber and having a plurality of air injected in a direction toward the plate,
Wherein the air holes provided at the outermost side in the air ejecting part eject air moving at a distance of 0.5 mm to 0.7 mm from the end of the plate,
Wherein the chamber sensor is provided at an end of the air injection unit. The method of claim 3,
Wherein the wafer stage includes a base plate having a vacuum adsorption unit at a central portion thereof, and a pair of sliding members provided on the base plate and sandwiching the vacuum adsorption unit,
Wherein one end of the pair of sliding members is fixed to the base plate and the other ends of the pair of sliding members slide on the base plate so that the other ends of the pair of sliding members are spaced apart from each other,
And to support the wafers of various sizes by the movement of the pair of sliding members on the wafer stage. The method according to claim 1,
Wherein the inner nozzle has a circular cross section and a cross section of the outer nozzle has a larger diameter than a cross section of the inner nozzle and the inner nozzle is provided at a central portion of the outer nozzle, A cross section of the second space is provided in a hoop shape,
A coating part made of carbon nanotube (CNT) is provided on the inner surface of the inner nozzle,
A heat exchange member for heating or cooling the air flowing through the outer nozzle is provided in the outer nozzle,
Wherein the coating portion forms a plurality of flow paths extending in parallel to the direction in which the slurry flows, the flow paths having a semicircular cross section,
Wherein the coating portion is provided with a plurality of ribs protruding toward the central portion of the first space of the inner nozzle to dissolve the agglomeration of the slurry, wherein the ribs are formed in a conical shape at different heights. 6. The method of claim 5,
Wherein the sub nozzle comprises a plurality of pipe portions extending corresponding to the first space to discharge the slurry and a funnel-shaped funnel-shaped portion extending to correspond to the second space and discharging air,
Wherein the pipe section includes a vertical pipe vertically extending in the first space and at least one inclined pipe extending in an inclined relation with respect to the vertical pipe in the first space, The vertical pipe is inclined with respect to the vertical pipe so as to be further away from the vertical pipe,
Wherein the funnel portion extends to be inclined in the second space and to surround the slope pipe,
Wherein the vertical pipe is provided with a cross-sectional area wider than the slant pipe to discharge the slurry toward the center of the wafer, and the slant pipe discharges the slurry toward the outer periphery of the wafer, Is controlled so as not to flow out to the outside. The method according to claim 6,
Wherein the upper portion of the pipe portion has a first fastening portion formed of a thread, and an upper inner surface of the funnel portion has a second fastening portion fastened to the first fastening portion by screwing.

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