JP2000077379A - Brush washing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brush washing apparatus where washing irregularity is hard to occur within the wafer face in a wafer brush-washing process and besides is equipped with relatively simple structure. SOLUTION: A wafer 1 is supported at its periphery by a support roller 3, and roller brushes 2 having rotary shafts in the direction of an X axis are arranged at the top and bottom. The support roller 3 is supported by a gear box 4, and they are coupled with each other through a toothed belt 10, and are rotated by a motor 12. The gear box 4 is supported through a linear motion bearing 7 or the like on a base plate 6. The rotation of a motor 2 is transmitted to an SE shaft, too, through gears 15, 16, and 17. A cam follower 18 is attached eccentrically to the SE shaft, and the roller part 18a of the cam follower 18 is accommodated in the cam groove 19a made on the side of the base plate 6. Rotating the motor 12 will make the wafer 1 reciprocate in the direction of a Y axis simultaneously with rotating within the horizontal plane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brush cleaning apparatus used for cleaning a brush after polishing a semiconductor wafer.

[0002]

2. Description of the Related Art When flattening a wafer using a CMP apparatus, a brush cleaning step of cleaning the upper and lower surfaces of the wafer using a brush is performed after a polishing step. In the brush cleaning process, a brush cleaning device of a so-called horizontal scrubber type is widely used. In this type of brush cleaning apparatus, a pair of rotating roller brushes are brought into contact with the upper and lower surfaces of the wafer while the wafer is rotated in a horizontal plane, and particles or the like attached to the surface are scraped off, thereby cleaning the wafer surface. It is carried out.

(Problems of conventional brush cleaning) a. A specific location on the wafer surface is always in contact with a specific location on the outer periphery of the roller brush, and the relationship is fixed. In other words, the center of the wafer is always in contact with the axial center of the roller brush, and the peripheral edge of the wafer is always in contact with both ends of the roller brush. Therefore, it is difficult to uniformly clean the entire surface of the wafer.

B. There is also a difference between the center and the periphery of the wafer with respect to the contact travel distance of the roller brush to the wafer surface, which causes an axial difference in the roller brush damage speed (i.e., when both ends of the roller brush As a result, the life of the roller brush is shortened.

C. There is also a difference in the state of contamination of the roller brush in the axial direction (that is, both ends are more easily contaminated than the central part), and as a result, the cleaning degree of the wafer surface becomes uneven. JP-A-3-88330 discloses that a pair of rotating roller brushes are brought into contact with the upper and lower surfaces of a wafer while the wafer is rotated in a horizontal plane, and at the same time, the roller brushes are moved along the upper and lower surfaces of the wafer. A brush cleaning device that reciprocates in a horizontal direction is described. In the case of this device, it is necessary to provide a dedicated drive mechanism in order to reciprocate the roller brush in a horizontal plane. As a result, the structure of the device becomes complicated, the manufacturing cost of the device increases, and the downtime of the device increases. And other factors.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the conventional brush cleaning apparatus, and
An object of the present invention is to provide a brush cleaning process for a wafer,
An object of the present invention is to provide a brush cleaning apparatus which is less likely to cause cleaning unevenness in a wafer surface and has a relatively simple structure.

[0007]

According to the brush cleaning apparatus of the present invention, the outer peripheral portion of a wafer is supported by a plurality of support rollers, and the wafer is rotated in a horizontal direction while rotating the wafer in a horizontal plane using these support rollers. In a brush cleaning device for cleaning a wafer surface by bringing a roller brush rotating around an axis into contact with a wafer surface, the shafts of the plurality of support rollers, together with the supporting portions thereof, are connected to the rotation shaft of the roller brush in a horizontal plane. A reciprocating mechanism is provided in a direction orthogonal to the direction.

[0008] Preferably, the brush cleaning apparatus of the present invention comprises:
A plurality of support rollers for supporting the wafer at its outer peripheral portion and rotating in a horizontal plane, having a horizontal rotation axis, and a roller brush for cleaning the wafer surface by rotating in contact with the wafer surface; A fixed base provided with a support mechanism for the rotating shaft of the roller brush, a moving table provided on the fixed base and provided with a support mechanism for the shaft of each of the support rollers, and provided on the moving table. A drive motor, a rotation transmission mechanism provided on the moving table, for transmitting rotation of the drive motor to the shaft of each of the support rollers, and a rotation transmitting mechanism provided between the fixed base and the moving table; A guide mechanism for supporting the movable table in a state in which the movable table can be moved in a direction perpendicular to a rotation axis of the roller brush in a horizontal plane; A motion conversion mechanism provided between the base and the moving table, for converting the rotation of the driving motor into reciprocating motion of the moving table along the guide mechanism; and And simultaneously reciprocating the wafer in a direction perpendicular to the rotation axis of the roller brush in a horizontal plane.

The motion conversion mechanism is provided on the moving table, for example, a transmission shaft penetrating the moving table in a vertical direction and having a rotation axis parallel to the rotation axis of the wafer. A gear train for transmitting the rotation of a motor to the transmission shaft, a cam follower having a shaft mounted eccentrically to the transmission shaft at a lower end of the transmission shaft, and a cam follower formed on an upper surface of the fixed base; A cam groove for accommodating the roller portion in a state of restricting movement in a direction perpendicular to the rotation axis of the roller brush,
Can be composed of

According to the brush cleaning apparatus of the present invention, since the wafer can be rotated in the horizontal plane and the wafer can be reciprocated in the horizontal plane, the wafer surface and the roller brush always contact each other at a specific location. The problem is solved. As a result, in-plane uniformity of brush cleaning is improved. In addition, the life of the roller brush is increased as a result of averaging the damage speed of the roller brush.

Further, according to the brush cleaning device of the present invention,
Since a common drive source is used for the rotation and reciprocation of the wafer, and the rotation is converted to the rotation and reciprocation via the gear mechanism, the apparatus is not complicated. Therefore, without significantly increasing the production cost of the device,
Further, there is no possibility that the reliability of the device is reduced.

[0012]

1 to 6 show a brush cleaning apparatus according to the present invention. 1 is a top view of the brush cleaning device, FIGS. 2 and 3 are vertical cross-sectional views of AA section and BB section of FIG. 1, respectively, and FIGS.
FIG. 4 is a lateral cross-sectional view of a CC section, a DD section, and an EE section of FIG. 3, respectively. In the figure, 1 is a wafer, 2 is a roller brush, 3 is a support roller, 4 is a gear box (moving table), 7 is a linear motion bearing, 9 is a belt pulley, 10 is a toothed belt, 12 is a variable speed motor, 13
17 to 17 indicate gears, 18 indicates a cam follower, and 19 indicates a cam plate.

In each of the above figures, an XY axis is set on a plane parallel to the surface of the wafer 1, a Z axis is set in a direction perpendicular to the XY axis, and a direction parallel to the axis of the roller brush 2 is set as X. An axial direction is defined, and a direction perpendicular to the axial direction is defined as a Y-axis direction.
In these figures, parts related to the present invention are mainly shown, and a rotation drive mechanism of a roller brush and a shaft support mechanism thereof, an opening / closing mechanism for transferring a wafer, a cleaning liquid supply mechanism, an entire housing, and wiring・ Piping is omitted.

As shown in FIGS. 1 and 3, the wafer 1
Six support rollers 3 arranged along the outer periphery
And provide rotation in a horizontal plane. A pair of roller brushes 2 having a horizontal (X-axis) rotation axis are arranged so as to sandwich the wafer 1 from the upper and lower surfaces thereof. In this example, the outer circumference of the roller brush 2 is made of a polyvinyl alcohol sponge material.

As shown in FIGS. 3 and 4, belt pulleys 9 are fixed near the lower ends of the shafts of the six support rollers 3, respectively. Each belt pulley 9 is
It is connected via a toothed belt 10. Toothed belt 1
0 is given a tension by a tension pulley 11 (FIGS. 2 and 4) disposed between the shafts of the two support rollers 3. The rotation of the variable speed motor 12 (drive source) is performed by a gear 14 fixed to the shaft (SM axis) of the variable speed motor 12 via a gear 13 fixed to one of the support rollers 3. It is transmitted to the support roller 3. The rotation of the support roller 3 is further transmitted to the other five support rollers 3 via the belt pulley 9 and the toothed belt 10. With the above configuration, the six support rollers 3 are driven by the rotation of the variable speed motor 12,
It rotates in the same direction at the same speed.

As shown in FIG. 3, the variable speed motor 12, the gears 13, 14 and the like, and the lower end portions of the shafts of the support rollers 3 are accommodated in a gear box 4. The upper end of the shaft of each support roller 3 protrudes upward from the upper surface of the gear box 4. This gearbox 4
On a base plate 6 fixed to a fixed base 5,
Two linear motion bearings 7 (FIGS. 3 and 5) and 2
It is supported via a plurality of cam followers 8 (FIGS. 2 and 5) and can move relative to the base plate 6 in a direction (Y-axis direction) perpendicular to the rotation axis of the roller brush 2 in a horizontal plane. Although not shown, the support mechanism for the rotating shaft of the roller brush 2 is directly supported by the fixed base 5.

As shown in FIG. 3 and FIG.
2 (drive source) rotates the shaft (SM) of the variable speed motor 12.
From the gear 14 fixed to the shaft, the light is transmitted to the shaft of the support roller 3 as described above, and simultaneously transmitted to the Si shaft via the gear 15 fixed to the upper end of the Si shaft. The rotation of the Si shaft is further performed by the gear 1 fixed to the lower end of the Si shaft.
6, and a gear 17 fixed to the lower end of the SE shaft is transmitted to the SE shaft in order.

As shown in FIGS. 3 and 5, the shaft of the cam follower 18 is attached to the lower end of the SE shaft at a position eccentric with respect to the rotation center of the SE shaft (eccentricity e). On the other hand, the roller portion 18a of the cam follower 18 is housed in a groove 19a formed in a cam plate 19 fixed to the base plate 6 side.

As shown in FIG. 6, the groove 19a formed in the cam plate 19 has a substantially oblong shape narrow in the Y-axis direction and long in the X-axis direction, and has a width (Y-axis direction). The dimension (dimension) corresponds to the diameter of the roller portion 18a of the cam follower 18, and its length (dimension in the X-axis direction) is set to a value slightly more than twice the eccentricity (e). As a result, the roller portion 18a of the cam follower 18 is accommodated in the groove 19a in a state where relative movement in the Y-axis direction is restricted with respect to the base plate 6 (fixed side) and only relative movement in the X-axis direction is possible. Have been.

The variable speed motor 12 is driven, and the gears 14-1
When the SE axis is rotated via 7, the cam follower 18 makes a swiveling motion about the rotation axis of the SE axis. The roller 18a of the cam follower 18 is provided with the groove 1 of the cam plate 19 as described above.
The gear box 4 is actually moved relative to the base plate 6 (fixed side) because the gear box 4 is accommodated in the 9a in a state where the movement in the Y-axis direction is restricted. That is, the gear box 4 is guided by the linear motion bearing 7 (FIGS. 3 and 5) and the cam follower 8 (FIGS. 2 and 5), and has an amplitude 2e in the Y-axis direction with respect to the base plate 6 (fixed side). Perform reciprocating motion.

By driving the variable speed motor 12 as described above, the wafer 1 rotates in the horizontal plane and simultaneously reciprocates in the Y-axis direction (amplitude 2e) in the horizontal plane.
I do.

When the wafer 1 is loaded or unloaded, the roller brush 2 is opened up and down, and the robot hand is brought closer. At this time, the support roller 3 (therefore, the gear box 4) moves at the origin position of the horizontal reciprocating motion. I need to wait. If the rotary position sensor 20 (FIG. 2) is provided for the detection disk attached to the SE axis for stopping at the origin position and confirming the stop position, standby at the origin position can be easily realized. Can be.

In the above example, both surfaces of the wafer 1 are simultaneously cleaned using a pair of roller brushes 2.
One roller brush may be used to clean only one side of the wafer.

[0024]

Effect of the Invention a. According to the brush cleaning device of the present invention,
Since the wafer is rotated in the horizontal plane and reciprocated in the direction perpendicular to the rotation axis of the roller brush in the horizontal plane, the entire surface of the wafer can be uniformly cleaned.

B. With respect to the contact travel distance of the roller brush to the wafer surface, the difference between the center and the peripheral edge of the wafer is reduced, so that the damage speed of the roller brush is averaged in the axial direction and the life of the roller brush is extended.

C. A difference in the axial direction also hardly occurs in the contamination state of the roller brush, and therefore, the cleaning degree of the wafer surface is hardly uneven. d. As a motor for rotating the wafer is also used as a driving source for reciprocating the wafer, and a relatively simple structure is provided, the increase in the size and manufacturing cost of the apparatus is suppressed, and the downtime of the apparatus is reduced. It is not a factor such as an increase in

[Brief description of the drawings]

FIG. 1 is a top view of a brush cleaning device of the present invention.

FIG. 2 is a longitudinal sectional view of an AA section of the brush cleaning device shown in FIG.

FIG. 3 is a longitudinal sectional view of a BB section of the brush cleaning device shown in FIG. 1;

FIG. 4 is a transverse cross-sectional view taken along the line CC of FIG. 3;

FIG. 5 is a cross-sectional view of a DD section of FIG. 3;

FIG. 6 is a transverse cross-sectional view taken along the line EE of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Wafer, 2 ... Roller brush, 3 ... Support roller, 4 ... Gear box (moving table), 5 ... Fixed base, 6 ... Base plate, 7 ... Linear motion Bearings 8 Cam followers 9 Belt pulleys 10 Synchronous belts 11 Tension pulleys 12 Variable speed motors 13-17 Gears 18 Cam follower, 18a: roller portion, 19: cam plate, 19a: groove (cam groove), 20: position sensor.

Claims (3)

[Claims] 1. A roller brush rotating around a horizontal rotation axis is supported on a wafer surface while supporting the outer peripheral portion of the wafer with a plurality of support rollers, and rotating the wafer in a horizontal plane using the support rollers. Let me touch
In a brush cleaning apparatus for cleaning a wafer surface, a mechanism for reciprocating the axes of the plurality of support rollers in a direction perpendicular to the rotation axis of the roller brush in a horizontal plane together with the support portions thereof is provided. Characterized brush cleaning device. 2. A wafer surface is cleaned by supporting a wafer at its outer peripheral portion and rotating it in a horizontal plane, and having a plurality of support rollers for rotating the wafer in a horizontal direction and rotating in contact with the wafer surface. A roller brush; a fixed base provided with a support mechanism for a rotating shaft of the roller brush; a moving table disposed on the fixed base and provided with a support mechanism for the shaft of each of the support rollers; and the moving table. A driving motor provided on the moving table, a rotation transmitting mechanism provided on the moving table and transmitting the rotation of the driving motor to the shaft of each of the support rollers, and provided between the fixed base and the moving table;
A guide mechanism for supporting the movable table on the fixed base in a state in which the movable table can be moved in a direction perpendicular to a rotation axis of the roller brush in a horizontal plane; and a guide mechanism provided between the fixed base and the movable table. And
A motion converting mechanism for converting the rotation of the drive motor into a reciprocating motion of the moving table along the guide mechanism, using the drive motor to rotate the wafer in a horizontal plane, and at the same time, the roller brush in the horizontal plane. A brush cleaning apparatus for reciprocating a wafer in a direction orthogonal to a rotation axis of the brush. 3. The movement conversion mechanism, wherein: a transmission shaft penetrating the moving table in a vertical direction and having a rotation axis parallel to a rotation axis of a wafer; and a transmission shaft provided on the movement table; A gear train for transmitting rotation to the transmission shaft; a cam follower having a shaft attached to a lower end of the transmission shaft so as to be eccentric with respect to the transmission shaft; and a roller of the cam follower formed on an upper surface of the fixed base. A cam groove for accommodating the portion in a state of restricting the movement of the roller brush in the direction perpendicular to the rotation axis, using the drive motor to rotate the wafer in a horizontal plane and at the same time in the horizontal plane The brush cleaning apparatus according to claim 2, wherein the wafer is reciprocated in a direction orthogonal to a rotation axis of the roller brush.