JP2009070932A - Wafer-cleaning apparatus and wafer-cleaning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning apparatus and a cleaning method for removing diamond powder and a solvent, such as, oil remaining on the periphery of a wafer on a ceramics block side and on the front surface of a ceramics block with the wafer. <P>SOLUTION: A cleaning apparatus has a cleaner body in which a rotation electric portion is built, a rotation brush portion attached to the cleaner body so that the rotation of the rotating electric portion is transmitted, and a brush set in a circular shape, in such a manner that it faces the periphery from the center of the rotation brush portion, in such a manner that a plurality of aligned objects are formed in the rotation brush portion. The cleaning method removes the remaining diamond powder and the remaining solvent, by placing the cleaning apparatus against a wafer immersed in a cleaning liquid. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a ceramic block and a cleaning apparatus and a cleaning method for a wafer attached to the surface thereof. More specifically, the ceramic block with a wafer is submerged in an alkaline cleaning liquid, and the ceramic block with a wafer is submerged in a liquid using a brush motor. The present invention relates to a wafer cleaning apparatus and a wafer cleaning method for cleaning a surface. The role of the brush is to scrape the diamond powder remaining on the outer periphery of the ceramic block side wafer and to clean the outer periphery of the wafer.

  The block surface after polishing using an oily diamond slurry (particle size 1 to 6 μm) has a solvent such as oil attached thereto. As a method for removing these, scrubbing with a sponge or the like using an alkaline cleaning solution. Specifically, a ceramic block with a wafer after diamond wrap is placed in a mixed solution of 30 liters of water and an alkaline cleaning solution (No. 200: manufactured by Castrol) in a sink of a commercial sink. Then, use a sponge in the liquid to wash away the solvent such as oil and diamond powder adhering to the surface of the ceramic block with the wafer.

  In particular, the outer periphery of the ceramic block side wafer is attached with a lot of solvent such as oil and diamond powder. In order to remove the solvent such as oil and diamond powder adhering to this portion, the removal is performed using the edge portion of the sponge. In the combination of alkaline cleaning liquid and sponge, the solvent such as oil to be removed and diamond powder are not completely removed, so after removing the ceramic block with wafer from the alkaline cleaning liquid, wash the alkaline cleaning liquid with running water and dry it with dry air. .

  After drying, place the ceramic block with a wafer on a stable table, and apply a thin (around 1mm) plate-like object to the outer periphery of the ceramic block side wafer with oil-soaked cotton (Bencot). Remove the solvent and diamond powder.

  In these methods, a solvent such as oil and diamond powder cannot be completely removed. In particular, when diamond powder remains on the outer periphery of the ceramic block side wafer, the mirror finish in the next process is affected. In the next step, the wafer surface is mirror-finished using a slurry containing colloidal silica with a particle size of several tens of nm. If the remaining diamond powder is mixed in the slurry, scratches with a depth of several μm are formed on the wafer surface. Will be generated. For example, when a scratch having a depth of 6 μm is generated, it takes 2 to 3 hours to process the wafer surface into a mirror surface.

  Currently, WAX having a wafer attached to a ceramic block has a property of dissolving in ethanol, and there is a possibility that WAX is dissolved when a solvent such as oil and diamond powder are removed after drying. At this time, if a gap occurs between the ceramic block and the wafer, diamond powder may enter the gap. When diamond powder enters, it is the same as above, and scratches having a depth of 1 to 6 μm are generated during mirror finishing.

  The surface of the contaminated ceramic block with a wafer and the outer periphery of the ceramic block side wafer after polishing with an oily diamond slurry can be removed with an alkaline cleaning solution and a sponge, and a certain amount of solvent such as oil and diamond powder can be removed. However, there is a limit in cleaning with a sponge. For this reason, if even a single diamond enters during mirror processing in the next process, the wafer surface may be damaged.

  Therefore, the object of the present invention is to remove the solvent such as oil and diamond powder remaining on the surface of the ceramic block with the wafer and the outer peripheral portion of the wafer on the ceramic block and the diamond powder, and in particular, remain on the outer peripheral portion of the wafer on the ceramic block side. An object of the present invention is to provide a cleaning device and a cleaning method capable of removing diamond powder with a rotary electric motor with a brush.

In order to achieve the above-described object, the cleaning apparatus of the present invention is a cleaning apparatus that is immersed in a cleaning solution to clean a wafer, so that a cleaning machine main body including a rotary electric unit and rotation of the rotary electric unit are transmitted. A rotating brush part attached to the main body of the washing machine, a brush planted in an arc shape so as to face the outer periphery from the center so as to form a plurality of alignment bodies in the rotating brush part,
It is characterized by having.

  Further, the cleaning method of the present invention is a cleaning method in which a wafer is cleaned by submerging in a cleaning solution, and the wafer is submerged in the cleaning solution, so that a plurality of alignment bodies are formed on the rotating brush portion so as to face the outer circumference from the center. The cleaning device with the brush implanted in the surface is applied to the surface of the ceramic block with the wafer and the outer peripheral portion of the wafer on the ceramic block side, with the rotating brush portion rotated in the direction in which the tip of the brush arc alignment body faces. It is characterized by scraping out the remaining diamond powder.

  The cleaning device of the present invention has a rotating electric part and a brush part in which a brush is implanted, and includes an attaching / detaching part that can be easily attached to and detached from the rotating electric part and a drive part that controls the rotation of the brush.

  The brush alignment method that is suitable for removing diamond powder is a circular arc from the center to the outer periphery so that the scraped diamond powder moves away from the center of the wafer or away from the outer periphery of the wafer. The alignment direction is configured to be opposite to the rotation direction.

  In order to scrape out the diamond powder on the outer peripheral part of the wafer on the ceramic block side, the tip should have a fineness of φ5 μm to φ10 μm, and the length of the brush is preferably 20 mm to 30 mm from the force of scraping the diamond powder and the efficiency of scraping. However, 20 mm to 30 mm is a length that is not embedded in the brush portion.

  The number of flocks per bundle of brushes to be flocked to the brush part consists of 100 to 150. Moreover, the hair | bristle bundle | flux comprised by 100-150 is comprised by two or more bundles according to a to-be-cleaned object and its magnitude | size.

  The best brush material is vinyl, nylon, and high-strength polyethylene, which are easy to process and elastic.

  The brush part is fixed with screws so that it can be attached to and detached from the rotating electric part. By using the screwing method, the brush part can be easily replaced.

  The number of rotations of the brush unit controlled by the rotating electric unit is variable according to the object to be cleaned, and is composed of two types of high-speed rotation mode and low-speed rotation mode.

  Water resistance is required because diamond powder and the like are removed and washed in the liquid. Therefore, it is an absolute condition that the wiring welded part and the electric part are shielded. The required water resistance (waterproofing) is required to be equivalent to JISIPX7.

  What is cleaned is, for example, a wafer with a thickness of several hundred μm attached on the ceramic block, and the outer diameter thereof is smaller than that of the ceramic block. Therefore, the cross-sectional shape of the pasted object is a convex shape.

  According to the present invention, the solvent such as oil remaining on the outer peripheral portion of the wafer on the ceramic block side and the diamond powder, which could not be removed until now, are almost removed by performing the rotation at a low speed. Further, most of the diamond powder on the wafer surface is removed by high-speed rotation. Thus, by using the rotating brush, cleaning becomes easy and the diamond powder on the wafer surface is removed. In addition, since it is possible to remove oil and other solvents and diamond powder remaining on the outer periphery of the wafer on the ceramic block side, diamond remaining on the wafer substrate or ceramic block due to insufficient cleaning during the mirror finish of the next process Mixing of powder can be prevented, and a stable polishing time can be secured during mirror finishing. In addition, the cleaning time is greatly shortened by the electric drive.

  Next, a cleaning device comprising the brushed rotary motor of the present invention will be described. 1-5 is a figure for demonstrating schematic structure of the rotary electric motor with a brush, Among these, FIG. 1 is a top view of a washing | cleaning apparatus, FIG. 2 is a side view of a washing | cleaning apparatus, FIG. FIG. 4 is a sectional view of the brush portion of the cleaning device, FIG. 4 is a bottom view of the brush portion, and FIG. 5 is an enlarged side view of the brush.

  A cleaning device, that is, a rotary electric motor with a brush, is roughly divided into an apparatus including a rotary electric unit and a brush unit. The rotary electric unit includes an electric motor (not shown) that controls the rotation of the brush, and has a function of changing the rotation speed in accordance with the residual amount of diamond powder. Moreover, in order to be able to cope with the wafer shape when the shape of the wafer is different, the brush must be easily detachable.

  Specifically, referring to FIG. 1 to FIG. 5, the cleaning apparatus has a cleaning machine body 1, and a rotary electric unit (not shown) is provided in the cleaning machine body 1, and the upper surface thereof is provided on the upper surface. A rotation speed changeover switch 2 that switches the rotation speed of the rotating electric part is provided. The rotation speed changeover switch 2 is provided with a switch for turning on / off rotation and a switch for changing the rotation speed between high speed (Hi) and low speed (Lo). The washing machine body 1 is formed with a grip portion 3 as a groove having a semicircular cross section so that it can be easily gripped by hand.

  A rotating brush portion 4 is detachably attached to the lower end of the cleaning machine main body 1 by screws 7. As shown in FIG. 4, a large number of brushes 5 extend in the radial direction from the center of the rotating brush 4 to the outer periphery on the bottom surface of the rotating brush portion 4 (hereinafter also simply referred to as the brush portion) 4. It is planted in line. The rotating brush portion is rotated in the direction opposite to the alignment direction (in the direction in which the tip of the alignment body of the arcs of the brush faces), that is, counterclockwise in FIG.

Furthermore, the structure of the brush part 4, the brush 5, and the rotary electric part is explained in full detail.
The shape of the brush part 4 is circular according to the shape of the wafer. Further, the brush portion 4 is fixed with a screw to enable the brush portion 4 to be attached to and detached from the washing machine body 1. The screws must be buried so as not to damage the wafer surface. Therefore, it is necessary to set the plate thickness to be planted to 10 mm in order to provide the counterbore 6.

  The size of the brush portion 4 needs to be larger than the wafer size of 3 inches in order to remove the residue on the outer peripheral portion of the wafer on the ceramic side, and the size of the brush portion 4 is desirably 80 mm to 85 mm.

  The bundle of brushes 5 implanted in the brush part 4 is composed of 100 to 150 flocks per bundle from the efficiency of scraping the residue on the outer periphery of the wafer on the ceramic side. The bundle of brushes 5 constituted by 150 pieces / bundle is constituted by a plurality of pieces. The length of each brush 5 (brush) is preferably 20 mm to 30 mm in view of the force for scraping diamond powder and the scraping efficiency.

  In addition, when the tip of each brush 5 comes into contact with the outer periphery of the wafer on the ceramic block side, it must be possible to reach the boundary with the ceramic block. is there. Therefore, the shape of the brush 5 is preferably a toothpick type, the size of the tip a is φ5 μm to φ10 μm, the distance from the tip a to the shoulder b is ½ of the total length, and the shoulder b to the root part The diameter up to c is preferably φ50 μm. The thinness of the tip of the brush 5 implanted in the brush part should not reach the boundary with the ceramic block when the tip of the brush 5 is in contact with the outer peripheral part of the wafer on the ceramic block side. Therefore, the thinner the tip of the brush 5, the more effective.

  Since the surface of the ceramic block and the wafer is cleaned while rotating the brush portion 4, the material of the brush 5 is one or more selected from vinyl, nylon, and high strength polyethylene having a large elastic coefficient. Depending on the material, it is formed by integral molding, multi-color molding of different materials, insert molding of other materials, or the like.

  The method for aligning the implanted brushes 5 is a circular arc having a radius of 50 mm to 60 mm from the center to the outer periphery, and the number of rows is 50 to 60 rows. In this case, since the hair is radially planted, the interval between the outer peripheral portions is about 10 mm, and the density of the brush is different from the vicinity of the center. In order to make the density of the central portion and the outer peripheral portion as uniform as possible, the flocking is added in an arc shape having a radius of 50 mm to 60 mm from the center of the brush portion to the outer periphery. In addition, the arc shape must be aligned with an arc opposite to the rotation direction in consideration of the rotation direction and the diamond powder away from the center to the outer periphery or away from the wafer outer periphery. In this case, the number of brush bundles in which the hair is implanted is preferably 100 at the central portion, and the number of brush bundles is increased toward the outer peripheral portion to be 150 at the outer peripheral portion.

  The rotating electric part in the main body of the washing machine is equipped with a high-torque small DC motor, a circuit attached to the DC motor, and a rotation transmission mechanism that transmits rotation from the DC motor to the brush part and shifts the number of rotations. is there.

  In addition, a battery (Ni-MH battery × 4 pcs) is built in the rotating electric part. The brush part is attached and detached using a screw 7 at the center of the brush part 4. The screw 7 is provided with a counterbore 6 in the center of the brush portion 4 so that the surface of the wafer base is not damaged during cleaning, and the screw 7 is made to be buried. The number of rotations of the brush unit 4 transmitted from the rotary electric unit needs to be determined according to the size of the object to be cleaned.

  Next, a cleaning apparatus according to an embodiment of the present invention will be described.

  In this embodiment, the brush unit 4 is attached to the cleaning machine main body 1 having a built-in rotary electric unit, and the brush unit 4 is rotated so that the brush 5 adheres to the ceramic block and the wafer outer periphery. The diamond powder at the boundary between the ceramic block and the ceramic block is cleaned.

  The drive unit (rotary electric unit) that controls the rotation is cylindrical, and the center part thereof is provided with a recess on the inside in order to facilitate handling, that is, the grip part 3 is provided. ing. Further, a rubber-based anti-slip is attached to the circumferential recess (gripping part). A rotation start / stop switch and a rotation speed control switch Hi / Lo are provided on the upper surface.

  As the material of the drive unit for controlling the rotation, a material having durability and chemical resistance was used.

  The brush portion 4 in which the brush 5 is implanted has a disk shape, and an attachment hole for the purpose of attachment / detachment from the rotation drive portion is formed in the center portion thereof. Screws 7 were used for attaching and detaching. The mounting holes for attachment and detachment have a structure in which a counterbore 6 is applied so that the head of the screw is within the bottom surface of the brush portion 4 so that the surface of the wafer or the like is not damaged when the wafer is cleaned. . The diameter of the brush part was 10 mm larger than the diameter of the wafer.

  Next, wafer cleaning by the wafer cleaning apparatus configured as described above will be described.

  Pure water or water 9 is mixed with the alkaline cleaning liquid (No. 200 Castrol) 1 in a washing tank or sink sink and stirred well.

  The ceramic block with the wafer to be cleaned is submerged in the cleaning tank or sink sink. The height of the cleaning liquid surface at this time was adjusted to a height of 5 mm to 10 mm from the surface of the ceramic block.

  Here, the wafer cleaning apparatus of the present invention is pressed onto the wafer and the ceramic block.

  A switch on the upper surface of the drive unit for controlling the rotation was turned on to activate the drive mechanism, and the brush 5 was rotated on the wafer and the ceramic block. The rotation speed of the brush part 4 at this time was 120 rpm for high speed rotation and 60 rpm for low speed rotation. This operation is repeated a predetermined number of times to complete the cleaning. After completion, the oil system and diamond adhering to the brush part are washed away.

  Thus, in the wafer cleaning apparatus of the present invention, since the brush member having durability and chemical resistance is used, the wafer and the ceramic block are cleaned several times without replacing the brush member. I was able to. Therefore, the work efficiency in the wafer cleaning operation could be improved. Further, it was possible to remove the solvent such as oil remaining on the outer peripheral portion of the wafer on the cleaned ceramic block side. The diamond powder was confirmed to have been removed by the fact that the wafer surface was not damaged at the time of mirror finishing in the next step.

  If the brush member is worn due to the cleaning work of several wafers and ceramic blocks, it is necessary to replace the brush member. However, since the brush member is attached with screws, the replacement can be easily performed. . The same applies when the wafer size is different.

It is a top view of the cleaning apparatus of the present invention. It is a side view of a washing | cleaning apparatus. It is sectional drawing of the brush part of a washing | cleaning apparatus. It is a bottom view of the brush part of a cleaning device. It is an enlarged side view which shows the detail of the brush of a washing | cleaning apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Washing machine main body 2 Rotation speed changeover switch 3 Grip part 4 Rotating brush part 5 Brush 6 Counterbore 7 Screw (screw)

Claims (10)

In a cleaning device that is immersed in a cleaning solution to clean the wafer,
A washing machine main body with a built-in rotary motor,
A rotating brush part attached to the washing machine main body so that rotation of the rotating electric part is transmitted;
A brush planted in an arc shape from the center to the outer periphery so as to form a plurality of alignment bodies in the rotating brush portion;
A cleaning apparatus comprising:   2. The cleaning apparatus according to claim 1, wherein the rotating brush portion is rotated in a direction in which the tip of the arcuate alignment body of the brush faces.   The cleaning apparatus according to claim 1, wherein the brush has a very thin tip shape and a length of 20 to 30 mm.   2. The cleaning device according to claim 1, wherein the brush is made of an elastic material having low rigidity.   The cleaning apparatus according to claim 1, wherein the number of flocks per bundle of brushes is plural, and the bundle of brushes composed of plural is composed of plural.   The cleaning apparatus according to claim 1, wherein the rotating brush portion is detachable from the main body of the cleaning machine.   2. The cleaning apparatus according to claim 1, wherein the rotational speed of the rotary electric unit is switchable.   The cleaning apparatus according to claim 1, wherein the rotary electric unit is water resistant.   In a cleaning method in which a wafer is cleaned by immersing it in a cleaning solution, the wafer is submerged in the cleaning solution, and cleaning is performed with a brush planted in an arc from the center to the outer periphery so as to form a plurality of alignment bodies on the rotating brush part. Remaining solvent and diamond by applying the device to the surface of the ceramic block with a wafer and the outer peripheral part of the wafer on the ceramic block side while rotating the rotating brush part in the direction in which the tip of the arcuate alignment of the brush arcs faces A cleaning method comprising removing powder.   10. The cleaning method according to claim 9, wherein the solvent and diamond powder remaining on the outer peripheral portion of the wafer on the ceramic block side are removed by rotating the cleaning device at a low speed, and the solvent and diamond powder on the wafer surface are removed from the cleaning device at high speed. A cleaning method comprising removing by rotating.