KR20070044083A - Apparatus for cleaning a wafer - Google Patents

Abstract

A wafer cleaning apparatus for improving the cleaning uniformity of a wafer has an upper portion and a container for receiving a plurality of wafers in a vertical direction. The wafer transfer portion includes a pair of chucks for supporting the side portions of the wafers and loads or unloads the wafers into or out of the container while driving up and down. The nozzle pipe is provided with a pair so as to extend in a direction crossing the wafers received in the vertical direction inside the container, and each has a nozzle for supplying a cleaning liquid for cleaning the wafers. Racks are provided in the chucks, respectively, and move linearly as the chucks move up and down. The pinion is mounted to each nozzle pipe and engages the racks as the chucks loaded with the wafers are spaced apart from the side portions of the wafers, extending the nozzle pipes by changing the linear motion of the rack to rotational motion to change the nozzle's ejection direction. Rotate around the central axis of the direction.

Description

Wafer cleaning apparatus {Apparatus for cleaning a wafer}

1 is a schematic cross-sectional view for explaining a wafer cleaning apparatus according to the prior art.

2 is a cross-sectional view illustrating a wafer cleaning apparatus according to an embodiment of the present invention.

3 is a cross-sectional view taken along line III-III ′ of FIG. 2.

4 and 5 are cross-sectional views for explaining the operation of the wafer cleaning apparatus of FIG.

Explanation of symbols on the main parts of the drawings

110: container 120: guide

130: wafer transfer part 131: vertical drive shaft

132: horizontal support 133: chuck arm

134: Chuck 140: cleaning liquid supply unit

141: nozzle pipe 142: nozzle

143: fixed shaft 144: bearing

145 connection pipe 150 rack

160: Pinion 170: Torsion Spring

W: Wafer

The present invention relates to a semiconductor device manufacturing apparatus, and more particularly to a wafer cleaning apparatus for removing foreign matter adhered to the wafer.

In general, a semiconductor device includes a Fab process for forming an electrical circuit including electrical elements on a silicon wafer used as a semiconductor wafer, and an EDS (electrical) for inspecting electrical characteristics of the semiconductor devices formed in the fab process. die sorting) and a package assembly process for encapsulating and individualizing the semiconductor devices with an epoxy resin.

The fab process includes a deposition process for forming a film on a wafer, a chemical mechanical polishing process for planarizing the film, a photolithography process for forming a photoresist pattern on the film, and the photoresist pattern using the photoresist pattern. An etching process for forming the film into a pattern having electrical characteristics, an ion implantation process for implanting specific ions into a predetermined region of the wafer, a cleaning process for removing impurities on the wafer, and a process for forming the film or pattern Inspection process for inspecting the surface;

As semiconductor devices are highly integrated, the cleaning process in the process is more diversified in technology, and its importance is increasing. In particular, in the manufacturing process of a semiconductor device having a microstructure, electrostatic, watermark, pipe-like particles, etc., as well as particles attached to the substrate after the cleaning process of the wafer have a great influence on subsequent processes. Therefore, the necessity of the wafer cleaning and drying process is further increased.

In general, the wafer cleaning apparatus removes particles, organic matter, metal contaminants, or oxide films attached to the substrate, and at the same time, a drying process is performed.

In the wafer cleaning process, a processing liquid (chemical liquid) and a cleaning liquid (rinse liquid) are sequentially supplied to the substrates to remove particles, organic substances, metal contaminants, or oxide films attached to the substrate, and at the same time, drying and the like are performed.

1 is a schematic cross-sectional view for explaining a wafer cleaning apparatus according to the prior art.

Referring to FIG. 1, a wafer cleaning apparatus 1 includes a container 10 for accommodating a plurality of wafers W, and a guide 30 for supporting the wafers W accommodated in the container 10. And a plurality of nozzle pipe parts 20 provided on the bottom surface of the container 10 to supply pure water as a cleaning liquid.

The wafer W cleaning process using the wafer cleaning apparatus 1 will be briefly described. First, a processing liquid is supplied from the processing liquid supply unit (not shown) to the container 10 to chemically clean the wafer W. Next, pure water that is a cleaning liquid is supplied from the nozzle pipe portion 20. As the cleaning liquid overflows, the processing liquid in the container 10 is replaced with the cleaning liquid, and the wafer W is cleaned by the cleaning liquid. Thereafter, the wafer W is dried.

However, in the wafer cleaning apparatus 1, the nozzle pipe portion 20 is fixed. The cleaning liquid is supplied from the nozzle pipe portion 20 only in one direction. Therefore, when the processing liquid is replaced with the cleaning liquid through the overflow method, vortex is generated in the container 10. The vortex causes the treatment liquid concentration in the container 10 to be partially changed. Therefore, the degree of cleaning varies depending on the site of the wafer, or the degree of cleaning for each wafer varies. That is, there is a problem that the cleaning uniformity of the wafer becomes poor.

An object of the present invention for solving the above problems is to provide a wafer cleaning apparatus that can improve the cleaning uniformity of the wafer.

According to a preferred embodiment of the present invention for achieving the object of the present invention, the wafer cleaning apparatus has an open top, and has a container for receiving a plurality of wafers in the vertical direction. The wafer transfer part includes a pair of chucks for supporting the side portions of the wafers, and loads or unloads the wafers into or from the container while driving up and down. The nozzle pipe is provided with a pair so as to extend in a direction crossing the wafers accommodated in the vertical direction inside the container, and each has a nozzle for supplying a cleaning liquid for cleaning the wafers. Racks are respectively provided on the chucks, and linearly move according to the vertical movement of the chucks. A pinion is mounted on each nozzle pipe, and engages the racks respectively when the chucks loaded with the wafers are spaced apart from the side portions of the wafers, and rotates the linear motion of the rack to change the spraying direction of the nozzles. To rotate the nozzle pipes about the central axis in the extending direction.

The wafer cleaning apparatus further includes a torsion spring, one end of which is fixed to the nozzle pipe and the other end of which is fixed to the container, to provide a restoring force so that the nozzle of the nozzle pipe faces a certain direction when the rack and the pinion are separated. can do.

In the wafer cleaning apparatus according to the present invention configured as described above, the nozzle pipe rotates while the cleaning liquid is injected from the nozzle pipe. Therefore, it is possible to prevent the vortex inside the container. Therefore, since the wafer is uniformly cleaned, the cleaning uniformity of the wafer can be improved.

Hereinafter, a wafer cleaning apparatus according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a cross-sectional view illustrating a wafer cleaning apparatus according to an exemplary embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along line III-III ′ of FIG. 2.

2 and 3, the wafer cleaning apparatus 100 includes a container 110, a guide 120, a wafer transfer unit 130, a cleaning liquid supply unit 140, a rack 150, a pinion 160, and a torsion spring. And 170.

The container 110 is a hollow rectangular parallelepiped with an open top. The container 110 stores a processing liquid for chemically cleaning the wafer W, or stores a cleaning liquid for cleaning the processing liquid remaining on the wafer W.

The treatment liquid is for removing foreign substances, for example, polymers, etc. present on the surface of the wafer W. Examples of the treatment liquid include APM (NH ₄ OH / H ₂ O ₂ / H ₂ O), SPM (H ₂ SO ₄ / H ₂ O ₂ ), DHF (HF / DIW), a mixture of ozone water and hydrofluoric acid (O ₃ / HF) and the like.

The cleaning liquid is for cleaning the processing liquid remaining on the surface of the wafer W after chemical cleaning of the wafer W. Pure water (Deionized Water, DIW) is used as the cleaning liquid.

In addition, the container 110 accommodates a plurality of wafers (W) for cleaning. The wafers W are disposed in the container 110 in the vertical direction, respectively.

The guide 120 supports the received wafers W in the container 110. The guide 120 extends along the longitudinal direction of the cuboid-shaped container 110. That is, the guide 120 extends in a direction crossing the wafers W disposed in the vertical direction. The guide 120 has a plurality of first slots for receiving the wafers W, respectively.

The wafer transfer unit 130 loads the wafers W into the guide 120 for cleaning, or unloads the wafers W, which have been cleaned, from the guide 120. The wafer transfer unit 130 includes a vertical drive shaft 131, a first driver 132, a chuck arm 133, and a chuck 134.

The vertical drive shaft 131 is connected to a second drive unit (not shown) and receives a driving force of the second drive unit to move in the vertical direction. The first driving unit 132, the chuck arm 133 and the chuck 134 are moved in the vertical direction by the movement of the vertical drive shaft 131.

The first driving unit 132 is provided at an upper end of the vertical driving shaft 131, and provides a rotational driving force for rotating the chuck arm 133.

The chuck arm 133 has a bar shape, and a pair extends in a horizontal direction from the first driver 132. The pair of chuck arms 133 are parallel to each other and spaced apart from each other by a predetermined interval. Specifically, the pair of chuck arms 133 may be spaced apart by the diameter of the wafer (W). The chuck arms 133 rotate with the rotation axis as the center of the chuck arms 133 by the driving force of the first driver 132. At this time, each chuck arm 133 rotates in the opposite direction. The rotation speed of each chuck arm 133 is the same.

The chuck 134 is provided with a pair to support a plurality of wafers (W). The chucks 134 are respectively connected to the chuck arms 133 and are respectively connected to be perpendicular to the chuck arms 133. The chuck 134 is fixed to the chuck arm 133 so as not to move, and the chuck 134 and the chuck arm 133 may be integrally formed.

The chuck 134 simultaneously drives both sides of the wafer W by the rotation of the chuck arm 133, and is driven in a clamping manner to grip the wafer W in a vertical direction.

In this case, an end portion of the chuck 134 which is not connected to the chuck arm 133 has a flat plate shape to simultaneously support the wafers W. A second slot is formed at the end of the chuck 134 in direct contact with both sides of the wafer W so that the wafers W may be individually inserted.

The nozzle pipe unit 140 is for injecting pure water, which is a cleaning liquid for cleaning the wafers W, into the container 110. The nozzle pipe 141, the nozzle 142, and the fixed shaft 143 ), Bearing 144 and connecting pipe 145.

The nozzle pipe 141 has a tubular shape in which both ends are closed, and is disposed to extend along the longitudinal direction of the container 110. The nozzle pipe 141 is provided with a pair. When the pair of chucks 134 are lowered into the vessel 110 to load the wafer W into the guide 120, the nozzle pipes 141 are respectively the chuck 134 and the vessel. Disposed between the sidewalls of 110.

The material of the nozzle pipe 141 is generally chemically stable quartz. Meanwhile, the material of the nozzle pipe 141 may be Teflon having chemical resistance and easy processing.

The nozzle 142 has a knife-edge type extending along the length of the nozzle pipe 141. On the other hand, a plurality of the nozzle 142 may be formed in a line in the longitudinal direction of the nozzle pipe 141. However, in the case of the plurality of nozzles 142 formed in a row, the cleaning liquids injected from the nozzles 142 may interfere with each other to form a vortex. Therefore, the nozzle 142 is preferably formed in the shape of a blade. In the drawing, the blade-shaped nozzle 142 is illustrated as being provided with one, but the plurality of nozzles 142 may be provided.

In the pair of nozzle pipes 141, the nozzles 142 may be positioned to correspond to each other. Specifically, the nozzles 142 in the pair of nozzle pipes 141 may be positioned to face each other at an initial position before rotation.

The fixed shaft 143 is provided on the inner side of both side walls perpendicular to the longitudinal direction of the container 110, respectively. The fixed shaft 143 fixes both ends of the nozzle pipe 141. The fixed shaft 143 extends to the inside of the nozzle pipe 141, respectively.

The bearing 144 is provided between the outer surface of the fixed shaft 143 extending to the inside of the nozzle pipe 141 and the inner surface of the nozzle pipe 141. One bearing 144 is provided at each end of one nozzle pipe 141. The bearing 144 easily rotates the nozzle pipe 141 around the fixed shaft 143.

The bearing 144 is formed of a material that can withstand the acid or alkaline treatment liquid, it is preferably installed and processed so as not to generate particles.

The connecting pipe 145 is connected to the inside of the nozzle pipe 141 through the side wall and the fixed shaft 143 of the container 110. The connection pipe 145 supplies a cleaning liquid to the nozzle pipe 145.

The rack 150 is provided on second surfaces opposite to the first surface of the chuck 134. Specifically, the rack 150 is provided with one pair in each of the chuck 134, each provided in the vertical direction at both ends of the longitudinal direction on the second surface of the chuck 134. The rack 150 moves up and down according to the vertical direction of the vertical drive shaft 132. That is, the rack 150 linearly moves.

Although the rack 150 is illustrated as being provided separately from the chuck 134, in some cases, the rack 150 may be formed integrally with the chuck 134.

The pinions 160 are provided along the circumferences of the nozzle pipes 141, respectively.

 Specifically, the pinion 160 is provided with a pair of one nozzle pipe 141, respectively, and are located at both ends of the nozzle pipe 141, respectively. The position of the pinion 160 corresponds to the position of the rack 150.

The rack 150 and the pinion 160 are preferably provided at both ends of the chuck 134 and the nozzle pipe 141 so as not to disturb the flow of the cleaning liquid injected from the nozzle 142.

Meanwhile, the rack 150 and the pinion 160 may be formed of quartz or Teflon material similarly to the nozzle pipe 141.

After the wafer transfer unit 130 loads the wafers W into the guide 120, the chucks 134 move in a direction away from the wafers W so that side surfaces of the wafers W are moved. When spaced apart from the site, the rack 150 and pinion 160 are engaged with each other. In the above state, when the vertical movement of the vertical drive shaft 132 moves up and down, the rack 150 also linearly moves up and down. The pinion 160 is rotated by the linear motion of the rack 150. Accordingly, the nozzle pipe 141 rotates, and the position of the nozzle 142 is changed. Therefore, the injection direction of the cleaning liquid is changed.

On the other hand, the rotation angle of the nozzle 142 is changed according to the driving range of the vertical drive shaft 132 in the vertical direction. In addition, the rotation speed of the nozzle 142 is changed according to the driving speed of the vertical drive shaft 132. Therefore, the rotation angle and rotation speed of the nozzle 142 may be adjusted by adjusting the driving range and the speed of the vertical drive shaft 132.

Since the spraying direction of the cleaning liquid is continuously changed, it is possible to minimize the vortex generated when the processing liquid for chemically cleaning the wafers W in the container 110 is replaced with the cleaning liquid through an overflow method. That is, when the treatment liquid is replaced with the washing liquid, the treatment liquid and the washing liquid are evenly mixed. Therefore, the process liquid is evenly performed without the portion where the chemical cleaning of the wafer W is relatively performed or the portion where the chemical cleaning of the wafer W is relatively small. Therefore, it is possible to minimize the generation of the vortex to improve the uniformity of the cleaning of the wafer (W).

The torsion spring 170 has one end fixed to the nozzle pipe 141 and the other end fixed to the container 110. The torsion spring 170 provides a restoring force so that the nozzle 142 faces an initial position in a predetermined direction when the rack 150 and the pinion 160 are separated. Although the torsion spring 170 is illustrated as being provided in one nozzle pipe 141 in the above, in some cases, the torsion spring 170 may be provided at both ends of one nozzle pipe 141. have. The material of the torsion spring 170 is preferably Teflon.

4 and 5 are cross-sectional views for explaining the operation of the wafer cleaning apparatus of FIG.

A wafer cleaning method using the wafer cleaning apparatus 100 will be described with reference to FIGS. 2, 4, and 5.

First, the processing liquid is supplied into the container 110 from the processing liquid supply unit. When the processing liquid is filled in the container 110, as shown in FIG. 2, the chuck 134 of the wafer transfer arm 130 supports the plurality of wafers W, and the wafer W Are lowered to be sufficiently immersed in the processing liquid to load the wafers W into the guide 120.

When the loading of the wafers W is completed, the chuck 134 moves in a direction spaced apart from the side surfaces of the wafers W. FIG. As shown in FIG. 4, the rack 150 and the pinion 160 are engaged with each other by the movement of the chuck 134.

The wafers W are chemically cleaned while being immersed in the processing liquid. That is, the processing liquid removes foreign matter present in the wafers W.

When the chemical cleaning by the processing liquid is completed, the cleaning liquid is injected into the container 110 through the nozzle 142 of the nozzle pipe 141. As the cleaning liquid and the processing liquid overflow, the processing liquid in the container 110 is replaced with the cleaning liquid.

The vertical drive shaft 131 of the wafer transfer unit 130 moves up and down while the cleaning liquid is injected. The rack 150 also moves up and down as shown in FIGS. 4 and 5 by vertical movement of the vertical drive shaft 131. Therefore, the pinion 160 engaged with the rack 150 rotates, and the direction of the nozzle 142 is changed by the rotation of the pinion 160. Therefore, the spraying direction of the cleaning liquid is continuously changed.

Therefore, it is possible to prevent the generation of vortex due to the cleaning liquid injection. Therefore, when the treatment liquid is replaced with the cleaning liquid, the treatment liquid and the cleaning liquid are evenly mixed. By minimizing the generation of the vortex, it is possible to improve the cleaning uniformity of the wafer (W).

When the cleaning of the wafer W by the cleaning liquid is completed, the supply of the cleaning liquid is stopped, and the operation of the vertical drive shaft 131 of the wafer transfer unit 130 is stopped. Thereafter, the chuck 134 moves in a direction approaching the side surfaces of the wafers W to support the wafers W on which the cleaning is completed. As shown in FIG. 4, the rack 150 and the pinion 160 are separated from each other by the movement of the chuck 134. When the rack 150 and the pinion 160 are separated from each other, the nozzle pipe 141 is rotated by the restoring force of the torsion spring 170 so that the nozzle 142 faces the initial position.

The wafer transfer unit 130 ascends while the chuck 134 supports the wafers W to unload the wafers W from the guide 120. The wafers W raised to the outside of the container 110 are exposed to the outside. Gas is supplied from the gas supply unit to the exposed wafers W to dry the wafers W. FIG.

Thereafter, the cleaning solution of the container 110 is discharged to complete the cleaning process. The above processes are repeated to proceed with the wafer cleaning process.

As described above, the wafer cleaning apparatus according to the preferred embodiment of the present invention can adjust the cleaning liquid injection direction of the nozzle pipe by driving the wafer transfer unit up and down using the rack and pinion. Therefore, it is possible to minimize the generation of vortex during the substitution of the treatment liquid and the cleaning liquid. Therefore, the cleaning uniformity of the wafer can be improved.

While the foregoing has been described with reference to preferred embodiments of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

Claims (3)

A container having a top open, for receiving a plurality of wafers in a vertical direction; A wafer transfer part including a pair of chucks for supporting the side portions of the wafers, the wafer transfer part for loading or unloading the wafers into the container while driving up and down; A pair of nozzle pipes provided to extend in a direction crossing the wafers accommodated in the vertical direction in the container, the nozzle pipes each having a nozzle for supplying a cleaning liquid to clean the wafers; Racks each provided on the chucks and linearly moving according to vertical movements of the chucks; And Mounted in each nozzle pipe and engaged with the racks respectively when the chucks loaded with the wafers are spaced apart from the lateral portions of the wafers, changing the linear motion of the rack to rotational motion to change the spraying direction of the nozzles. And a pinion for rotating the nozzle pipes about the central axis in the extending direction. The torsion spring of claim 1, wherein one end is fixed to the nozzle pipe and the other end is fixed to the container, and a torsion spring is further provided to provide a restoring force so that the nozzle of the nozzle pipe faces a certain direction when the rack and the pinion are separated. Wafer cleaning apparatus comprising a. The wafer cleaning apparatus of claim 1, wherein the nozzle has a knife-edge type extending along the length direction.

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