JP2003086545A - Device for removing processing strain - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for removing processing strain of a compact constitution, which can remove processing strain by polishing a treated surface having processing strain of a workpiece such as a ground rear of a semiconductor wafer by means of a polishing tool, with high efficiency and at high quality. SOLUTION: The device has a cassette receiving means 10 for mounting a cassette 8 storing a plurality of workpieces, a carrying means 12, a temporarily receiving/cleaning means 14, a carrying-in/out means 16, a chuck means which can be positioned selectively in a carrying-in/out region 18 and a polishing region, and a polishing means 94. A cassette receiving means, a carrying means, a temporarily receiving/cleaning means, a carrying-in/out means, a carrying-in/out region and a polishing region are arranged in this order practically linearly. A polishing means includes a rotary shaft and a polishing tool attached to the rotary shaft. A processing surface is polished by pressing the rotating polishing tool to the treated surface of a workpiece on a chuck means positioned in the polishing region.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing strain removing apparatus for removing a processing strain by polishing a surface of a workpiece to be processed having a processing strain, and particularly, although not limited thereto, A semiconductor wafer with a large number of circuits on its surface,
The present invention relates to a processing strain removing apparatus suitable for polishing a back surface on which a processing strain is generated by performing a grinding process and removing the processing strain therefrom.

[0002]

2. Description of the Related Art In the process of manufacturing a semiconductor chip, a large number of rectangular regions are divided by streets arranged in a lattice on the surface of a semiconductor wafer, and a semiconductor circuit is arranged in each of the rectangular regions. Then, by separating the semiconductor wafer along each of the streets, each of the rectangular regions is made to be a semiconductor chip. In order to reduce the size and weight of the semiconductor chip, the thickness of the semiconductor wafer is usually ground by grinding the back surface of the semiconductor wafer before cutting the semiconductor wafer along each street to separate the rectangular areas. Is reduced. Alternatively, in the so-called dicing method, a groove is formed from the front surface of the semiconductor wafer along the streets to form a groove having a predetermined depth, and then the back surface of the semiconductor wafer is deeper than the bottom surface of the groove. Then, grinding is applied to reduce the thickness of the semiconductor wafer and separate the rectangular regions. The grinding process is generally performed by causing a rotary grinding tool having a grinding member or a grinding wheel formed by bonding diamond abrasive grains with an appropriate bond such as a resin bond to act on the back surface of the semiconductor wafer.

When the back surface of the semiconductor wafer is ground, a processing strain is generated on the back surface of the semiconductor wafer.
The bending strength is considerably reduced by such processing strain. Therefore, in order to remove the processing strain from the back surface of the semiconductor wafer and avoid the reduction of bending strength, the ground back surface of the semiconductor wafer is polished using free abrasive grains, and the ground back surface of the semiconductor wafer is ground. It has been proposed to chemically etch the semiconductor wafer using an etching solution containing nitric acid and hydrofluoric acid, or to physically etch the ground back surface of the semiconductor wafer with plasma.

[0004]

However, polishing using free abrasive grains requires a complicated operation such as supply and recovery of the free abrasive grains, and the polishing efficiency is low. There is a problem that waste must be treated as industrial waste. Further, the chemical etching and the physical etching have problems that they require considerably expensive equipment and it is difficult to perform sufficiently uniform etching.

On the other hand, Japanese Patent Application No. 200 related to the applicant's application
1-93397 (invention title "Abrasive tool"), the use of an abrasive tool, in particular an abrasive tool having an abrasive member composed of felt and abrasive grains dispersed in the felt. It has been found that polishing the back surface of a semiconductor wafer can effectively remove processing strain. Polishing using such polishing tools does not produce large amounts of waste that must be treated as industrial waste.

The present invention has been made in view of the above facts, and its main technical problem is to use a polishing tool to polish a surface of a workpiece having a processing strain, for example, a ground back surface of a semiconductor wafer. It is an object of the present invention to provide a compact processing strain removing device capable of polishing with high efficiency and high quality to remove processing strain.

[0007]

According to the present invention, as a processing strain removing apparatus which achieves the above-mentioned main technical problems, a processing surface having a processing strain of a workpiece is polished to remove the processing strain. As a machining strain removing device for carrying out, a cassette receiving means on which a cassette containing a plurality of workpieces is placed, a conveying means, a temporary receiving / cleaning means, a loading / unloading means, a loading / unloading A chuck means that is selectively positioned in the polishing area and the polishing area, and a polishing means, and the cassette receiving means, the transporting means, the temporary receiving / cleaning means, the loading / unloading means, and the loading / unloading area. The polishing areas are arranged substantially in a straight line in this order, and the chuck means is linearly reciprocally movable between the loading / unloading area and the polishing area and mounted on the cassette receiving means. Workpiece accommodated in the placed cassette The transport means transports the workpiece onto the temporary receiving / cleaning means, and then the loading / unloading means transports the workpiece from the temporary receiving / washing means onto the chuck means positioned in the loading / unloading area. And held on the chucking means, after which the chucking means is moved to the polishing zone, and the work piece on the chucking means positioned in the polishing zone is polished by the polishing means, Thereafter, the chuck means is moved to the carry-in / carry-out area, then the workpiece on the chuck means is carried out by the carry-in / carry-out means onto the temporary receiving / cleaning means, and then the temporary receiving / cleaning means. The workpiece is cleaned by the means, and thereafter, the workpiece on the temporary receiving / cleaning means is transported into the cassette on the cassette receiving means by the transporting means, and the polishing means rotates. A polishing tool mounted on the shaft and the rotating shaft, the rotating polishing tool being pressed against the work surface of the workpiece on the chuck means located in the polishing zone. There is provided a processing strain removing device characterized in that a treated surface is polished.

In the preferred embodiment, the work piece is a semiconductor wafer having a large number of circuits on the front surface, and the work surface is the back surface subjected to grinding. The polishing tool has a polishing member composed of felt and abrasive grains dispersed in the felt, the polishing tool having a support member having a circular support surface, and the polishing member having the support member of the support member. It has a disc shape joined to a circular support surface. The chuck means is rotatable about a center axis of rotation that extends parallel to the rotation axis of the polishing means. When the polishing means polishes a surface to be processed of the workpiece, the chuck means rotates. It is rotated about the central axis and is linearly reciprocated over a predetermined range. A dust-proof cover surrounding the chuck means positioned in the polishing area, the workpiece held on the chuck means, and the polishing tool pressed against the surface to be processed of the workpiece is provided. The dust collecting cover is provided with the chucking means.
An opening is formed through which the chuck means and the workpiece held on the chuck means can pass when moving from the unloading area to the polishing area and from the polishing area to the loading / unloading area. In addition, an exhaust duct for exhausting the inside of the dustproof cover is connected. The rotating shaft of the polishing means is movable in the central axis direction, and the dustproof cover holds the polishing tool on the chuck means by moving the rotating shaft in the central axis direction. An opening is formed through which the polishing tool can pass when it is moved toward and away from the work piece. The chuck means includes a chuck plate formed of a porous material and having a substantially flat surface, and a workpiece is adsorbed onto the chuck plate, and a chuck plate cleaning means for cleaning the chuck plate. Is provided. The chuck plate cleaning means includes a cleaning brush and an oil stone, and the cleaning brush and the oil stone are rotated against the surface of the chuck plate and extend substantially perpendicularly to the surface of the chuck plate. It is preferably rotated about a central axis and reciprocated in a direction substantially parallel to the surface of the chuck plate. Preferably, a common housing is provided, and the common housing includes a first cassette receiving means, a first transporting means, a first temporary receiving / cleaning means, a first loading / unloading means, a first chucking means, and A first machining strain removing means including a first polishing means, a second cassette receiving means, a second transporting means, a second temporary receiving / cleaning means, a second loading / unloading means, a second The chucking means and the second processing strain removing means including the second polishing means are arranged in parallel.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a more detailed description will be given with reference to the accompanying drawings illustrating a preferred embodiment of a machining strain removing device constructed according to the present invention.

1 and 2 show a preferred embodiment of a machining strain removing device constructed according to the present invention.
The processing strain removing device shown in the drawing is provided with a housing generally designated by reference numeral 2. The housing 2 has a rectangular parallelepiped-shaped main portion 4 that extends in an elongated shape. An upright wall 6 that extends substantially vertically upward is disposed at the rear end of the main portion 4. As will be understood by referring to FIG. 1 as well as FIG. 2 on the main portion 4 of the housing 2, cassette receiving means 10 on which a cassette 8 containing a plurality of workpieces is placed, and conveying means 12 , Temporary receiving / cleaning means 14, loading / unloading means 1
6, and chuck means 22 selectively positioned in the loading / unloading area 18 and the polishing area 20 are provided. The cassette receiving means 10, the conveying means 12, the temporary receiving / cleaning means 14, the loading / unloading means 16, the loading / unloading area 18, and the polishing area 20 are substantially arranged in this order from the front end to the rear end of the main portion 4. They are arranged in a straight line.

The work piece housed in the cassette 8 is shown in FIG.
The semiconductor wafer 28 mounted on the frame 24 via the mounting tape 26 as shown in FIG. 4 or the semiconductor wafer 28 mounted on the supporting substrate (substrate) 30 as shown in FIG. In FIG. 3, a frame 24 that can be formed from a suitable metal plate or a suitable synthetic resin.
Has a mounting opening 32 formed in the center thereof, and the semiconductor wafer 28 is positioned inside the mounting opening 32 of the frame 24 with the front and back reversed, that is, with the back surface facing upward. A mounting tape 26 is adhered across the lower surface of the frame 24 and the surface of the semiconductor wafer 28, that is, the lower surface, so that the semiconductor wafer 28 is attached to the frame 24.
Is installed. In FIG. 4, the semiconductor wafer 28 is turned upside down on a support substrate 30 which can be formed of glass, ceramics, or a synthetic resin such as PET.
That is, it is adhered with its back surface facing upward. The outer shape of the support substrate 30 may be substantially the same as the outer shape of the semiconductor wafer 28. Adhesion between the mounting tape 26 and the semiconductor wafer 28 and adhesion between the support substrate 30 and the semiconductor wafer 28 are performed through a well-known adhesive whose adhesive action is canceled by heating or irradiation of ultraviolet rays during later peeling. It is convenient to have A large number of rectangular areas are defined on the surface of the semiconductor wafer 28 by streets (not shown) arranged in a grid pattern, and a semiconductor circuit (not shown) is formed in each of the rectangular areas. . In order to reduce the thickness of the semiconductor wafer 28,
The back surface of the semiconductor wafer 28 facing upward is subjected to a grinding process, and due to the grinding process, a processing strain remains on the back surface of the semiconductor wafer 28.

Continuing the description with reference to FIGS. 1 and 2,
The transfer means 12 transfers the semiconductor wafer 28 from the cassette 8
Each sheet is carried out onto the temporary receiving / cleaning means 14. Next, the semiconductor wafer 28 is carried in by the carrying-in / carrying-out means 16 from the temporary receiving / cleaning means 14 onto the chuck plate 38 of the chucking means 22 positioned in the carrying-in / carrying-out area 18, and held on the chucking means 22. To be done. After that, the chuck means 22 moves from the loading / unloading area 18 to the polishing area 2
The semiconductor wafer 28, which has been moved to 0 and held on the chuck means 22, has its back surface polished to remove processing strain as described later in detail. Thereafter, the chuck means 22 is returned from the polishing area 20 to the carry-in / out area 18, and the semiconductor wafer 28 is carried out from the chuck means 22 onto the temporary receiving / cleaning means 14 by the carrying means 16. In the temporary receiving / cleaning means 14, cleaning water, which may be pure water, is jetted to the back surface of the semiconductor wafer 28 while rotating the semiconductor wafer 28 at a high speed, and the semiconductor wafer 28 is cleaned.
The back side of the is washed and dried. After that, the transport means 1
Semiconductor wafer 2 on the temporary receiving / cleaning means 14
8 is conveyed into the cassette 8 on the cassette receiving means 10. When all of the semiconductor wafers 28 accommodated in the cassette 8 on the cassette receiving means 10 are sequentially carried out and the machining strains are removed by polishing and then returned to the cassette 8, the cassette 8 is manually carried out, Then, a new cassette 8 containing a plurality of semiconductor wafers 28 is manually placed on the cassette receiving means 10.

Thus, the above-described structure of the processing distortion removing device shown in the figure, that is, the cassette receiving means 10 and the conveying means 1
2. Each of the temporary receiving / cleaning means 14 itself may have substantially the same configuration as that used in a grinder sold under the trade name “DFG841” by Disco Corporation, for example, and is well known to those skilled in the art. Therefore, detailed description thereof will be omitted in the present specification.

Continuing the description with reference to FIGS. 1 and 2,
A substantially rectangular recess 34 is formed on the rear half of the main portion 4 of the housing 2, and the chuck means 22 is mounted on the recess 34. The chuck means 22 includes a support member 36 and a disc-shaped chuck plate 38 rotatably mounted on the support member 36 about a rotation center axis extending substantially vertically. An electric motor (not shown) for rotating the chuck plate 38 is provided in the support member 36. The chuck plate 38 is conveniently constructed of a suitable porous material such as porous ceramics. Arrows 40 and 42 on the recessed portion 34 are substantially horizontal in the extending direction of the housing 4 (thus, substantially perpendicular to the rotation axis of the polishing means described later).
A pair of guide rails (not shown) extending in the direction shown by are provided, and the support member 36 of the chuck means 22 is slidably mounted on the pair of guide rails. Further, a screw shaft (not shown) extending in the directions indicated by arrows 40 and 42 is rotatably mounted on the recess 34. On the other hand, the support member 36 of the chuck means 22.
Has a penetrating female screw hole (not shown) extending in the directions shown by arrows 40 and 42, and the screw shaft is screwed into the female screw hole. An output shaft of an electric motor (not shown), which may be a pulse motor, is connected to the screw shaft. When the electric motor is normally rotated, the chuck means 22 is moved in the direction indicated by the arrow 40, and when the electric motor is reversely rotated, the chuck means 22 is moved in the direction indicated by the arrow 42. On both sides of the chuck means 22 in the moving direction, bellows means 44 and 46 having an inverse channel cross-section and covering the screw shaft and the like are provided. Bellows means 44 and 4
6 can be formed from an appropriate material such as campus cloth. The front end of the bellows means 44 is fixed to the front wall of the recess 34, and the rear end is fixed to the front end surface of the support member 36 of the chuck means 22. The front end of the bellows means 46 is fixed to the rear end surface of the support member 36 of the chuck means 22, and the rear end is fixed to the front surface of the upright wall 6 of the housing 2. When the chuck means 22 is moved in the direction indicated by the arrow 40, the bellows means 44 is expanded and the bellows means 46 is contracted,
When the chuck means 22 is moved in the direction indicated by the arrow 42, the bellows means 44 is contracted and the bellows means 46 is expanded. The chuck means 22 which is moved along a linear path extending in the directions indicated by arrows 40 and 42,
As described above, the loading / unloading area 18 and the polishing area 20 which are positioned at intervals in the directions indicated by the arrows 40 and 42 are selectively positioned (the chuck means 22 further includes , Chuck means cleaning area 1
8 and the polishing area 20, the arrow 4 extends over a predetermined range.
It is reciprocated in the directions indicated by 0 and 42). The chuck plate 38 of the chuck means 22 is selectively brought into communication with a vacuum source via a communication passage (not shown) provided in the support member 36 and the housing 4, and should be polished as described later. The workpiece, that is, the semiconductor wafer 28 is vacuum-sucked.

The loading / unloading means 16 disposed in the middle of the main portion 4 of the housing 2 has a vertical portion 48 extending substantially vertically and a horizontal portion extending substantially horizontally from the vertical portion 48. It is composed of a movable arm 50 and a suction tool 52 attached to the tip of the movable arm 50. Carry-in
The vertical portion 48 of the carry-out means 16 is mounted so as to be movable up and down and rotatable about a central axis extending substantially vertically. A porous member is arranged on the lower surface of the suction tool 52. The suction tool 52 is passed through a communication passage (not shown) provided in the movable arm 50 and the main portion 4 of the housing 2.
Is selectively communicated with a vacuum source (not shown), so that the semiconductor wafer 28 is adsorbed to the lower surface of the adsorption tool 52, and the semiconductor wafer 28 is conveyed to a required position by moving and rotating the movable arm 50.

The suction tool 52 of the loading / unloading means 16 is disposed on the lower surface of the suction tool 52 when the semiconductor wafer 28 is sucked by being brought into contact with the back surface of the semiconductor wafer 28 before being polished. Although the porous member is not contaminated, when the semiconductor wafer 28 is adsorbed by being brought into contact with the back surface of the semiconductor wafer 28 after being polished, the porosity provided on the lower surface of the adsorbing tool 52 is used. The parts are contaminated with abrasive debris. Therefore, housing 2
In the middle part of the main part 4 of the
Suction tool cleaning means 54 is provided for cleaning the lower surface of No. 2 as required. The suction tool cleaning means 54 includes a support frame 56 fixed on the recessed portion 34 formed in the main portion 4 of the housing 2, and a brush member 58 and an oil stone 60 arranged in parallel with the support frame 56. It consists of and. The cylindrical brush member 58 extending substantially horizontally is rotated about its central axis. A large number of fibers, which may be synthetic fibers, are arranged on the peripheral surface of the brush member 58. The oil stone 60, which may be plate-shaped, is reciprocated in a substantially horizontal direction. When the lower surface of the suction tool 52 is washed, the brush member 58 is rotated, the oil stone 60 is reciprocated, and the lower surface of the suction tool 52 is pressed against the brush member 58 and / or the oil stone 60. Then, the suction tool 52 is swung back and forth over a predetermined range. Brush member 5
8 sweeps away the polishing dust from the porous member, and oil stone 6
0 grinds the surface of the porous member to discharge the polishing dust that has entered the porous member and flatten the surface of the porous member.

Continuing the description with reference to FIG. 1, in the illustrated embodiment, the chuck plate 38 is selectively positioned slightly rearward of the intermediate portion on the main portion 4 of the housing 2. A chuck plate cleaning means 62 is provided in association with the loading / unloading area 18. More specifically, upright support members 64 extending upward are disposed on both side edges of the main portion 4 of the hoisting 2, and guide rods 66 extending substantially horizontally are fixed between the support members 64. .
A sliding block 68 is attached to the guide rod 66. The slide block 68 has a through hole through which the guide rod 66 is inserted, and the slide block 68 is slidable along the guide rod 66. The support member 6
A screw shaft 70 that extends substantially horizontally below the guide rod 66 is rotatably mounted between the four. The screw shaft 70 is screwed into a penetrating female screw hole formed in the sliding block 68. An electric motor 72 is mounted on one side of the support member 64, and the output shaft of the motor 72 is connected to the screw shaft 70. When the motor 72 is rotated in the normal direction and the screw shaft 70 is rotated in a predetermined direction, the sliding block 68 is moved in the direction indicated by the arrow 74, the motor 72 is rotated in the reverse direction, and the screw shaft 70 is rotated in the reverse direction. Then, the sliding block 68 is moved in the direction indicated by the arrow 76. Sliding block 68
Cases 78 and 80 are attached to the front surface of the. Guide rails 82 and 84 extending substantially vertically are formed on the front surface of the sliding block 68, and a guided groove extending substantially vertically is formed on the rear surface of each of the cases 78 and 80. By engaging the guided grooves of 80 with the guide rails 82 and 84, the cases 78 and 80 are mounted on the front surface of the sliding block 68 so as to be movable up and down. Sliding block 68 and cases 78 and 80
An ascending / descending means (not shown), which may be a pneumatic cylinder mechanism, is interposed between each of these cases, and the cases 78 and 80 are caused to ascend / descend by the ascending / descending means. An electric motor is installed in the case 78,
The output shaft 86 is extended downward beyond the case 78. The output shaft 86 extends substantially vertically (and thus substantially perpendicular to the surface of the chuck plate 38), and a brush member 88 is fixed to the lower end of the output shaft 86. Brush member 88
Consists of a disk-shaped base and a large number of fibers which may be synthetic fibers planted on the underside of this base. An electric motor is also mounted in the case 80, and its output shaft 90 extends downward beyond the case 80. The output shaft 90 extends substantially vertically (thus, substantially perpendicularly to the surface of the chuck plate 38), and a disc-shaped oil stone 92 is fixed to the lower end thereof.

As will be further referred to later, the loading / unloading area 18
When the work piece is carried in on the chuck means 22 located at the position and when the work piece is carried out from the chuck means 22, the cases 78 and 80 are raised to the non-acting position, and the sliding block 68 is moved. Is the main part 4 of the housing 2.
It is evacuated to one side of. On the other hand, when the workpiece that has been subjected to the polishing process is carried out from the chuck plate 38 of the chuck means 22, and when the chuck plate 38 of the chuck means 22 is washed as needed, the sliding block 68 of the housing 2 is used. It is moved to the central portion of the main portion 4 and positioned so as to face the chuck plate 38 of the chuck means 22. Then, the brush member 88 and the oil stone 92 are rotationally driven, the cases 78 and 80 are lowered to the operating position, and the brush member 88 is rotationally driven.
And the oil stone 92 is pressed against the surface of the chuck plate 38. At this time, the sliding block 68 is reciprocated over a predetermined range in the directions indicated by arrows 74 and 76 (and thus in the direction parallel to the surface of the chuck plate 38). The chuck plate 38 of the chuck means 22 is rotated and reciprocated over a predetermined range in the directions indicated by arrows 40 and 42. Thus, the brush member 88 acts on the chuck plate 38 made of a porous material to sweep the polishing debris therefrom, and the oil stone 92 grinds the surface of the chuck plate 38 to discharge the invading polishing debris and the chuck. The surface of the plate 38 is flattened.

Continuing the description with reference to FIGS. 1 and 2, and particularly to FIG. 2, polishing means 94 is provided on the upright wall 6 provided at the rear end of the housing 2. More specifically, a pair of guide rails 96 extending substantially vertically are fixed to the front surface of the upright wall 6. A slide block 98 is mounted on the pair of guide rails 96 so as to be vertically slidable. Leg portions 100 that extend substantially vertically are formed on both sides of the rear surface of the sliding block 98, and the guided groove formed in the leg portions 100 has a pair of guide rails 9.
6 is slidably engaged. Further, a screw shaft 102 extending substantially vertically is rotatably mounted on the front surface of the upright wall 6 by bearing members 104 and 106. An electric motor 108, which may be a pulse motor, is also mounted on the bearing member 104, and the output shaft of the motor 108 is connected to the screw shaft 102. On the rear surface of the sliding block 98, there is also formed a connecting portion (not shown) projecting rearward from the center portion in the width direction, and such a connecting portion is formed with a through female screw hole extending in the vertical direction. The screw shaft 102 is screwed into the female screw hole. Therefore, when the motor 108 is normally rotated, the sliding block 98 is lowered, and when the motor 108 is reversely rotated, the sliding block 98 is raised.

A supporting portion 110 protruding forward is formed on the front surface of the sliding block 98.
A case 112 is attached to the. A rotating shaft 114 extending substantially vertically is rotatably mounted on the case 112. An electric motor (not shown) is also disposed in the case 112, and the output shaft of the motor is connected to the rotating shaft 114. The lower end of the rotary shaft 114 is projected downward beyond the lower end of the case 112,
A polishing tool 116 is attached to the lower end of the rotary shaft 114. More specifically, a disc-shaped mounting member 118 is fixed to the lower end of the rotating shaft 114. The mounting member 118 has a plurality of through holes (not shown) formed at intervals in the circumferential direction. As shown in FIGS. 5 and 6, the polishing tool 116 is composed of a disk-shaped support member 120 and a disk-shaped polishing member 122.
The support member 120 is formed with a plurality of blind screw holes 124 that extend downward from the upper surface of the support member 120 at intervals in the circumferential direction. The lower surface of the support member 120 constitutes a circular support surface, and the polishing member 122 is joined to the circular support surface of the support member 120 by an appropriate adhesive such as an epoxy resin adhesive. The polishing member 122 is preferably composed of felt and a large number of abrasive grains dispersed in the felt. The detailed description of the structure of the polishing member 122 itself is described in detail in the specification and drawings of the above-mentioned Japanese Patent Application No. 2001-93397, and thus the description will be omitted and the description thereof will be omitted here. Rotating shaft 11
The polishing tool 116 is positioned on the lower surface of the mounting member 118 fixed to the lower end of the mounting member 118, and the supporting member 12 for the polishing tool 116 is passed through the through hole formed in the mounting member 118.
The fastening bolt 126 is inserted into the blind screw hole 124 formed in
The polishing tool 1 is attached to the mounting member 118 by screwing.
16 is attached.

In the polishing area 20, when polishing the surface of the workpiece held on the surface of the chuck plate 38 of the chuck means 22, that is, the back surface of the semiconductor wafer 28, the sliding block 98 is lowered. The polishing member 122 of the polishing tool 116 that is rotationally driven is pressed against the back surface of the semiconductor wafer 28. Then, the chuck plate 38 of the chuck means 22 is rotated about a rotation center axis line that extends substantially vertically (and thus extends parallel to the rotation axis 114 of the polishing means 94), and within a predetermined range in the directions indicated by arrows 40 and 42. You can move across.
Thus, the polishing member 122 is made to act on the back surface of the semiconductor wafer 28, and the back surface of the semiconductor wafer 28 is polished to remove the residual processing strain. When the polishing is completed, the sliding block 98 is raised to some extent and the polishing member 122 is separated from the back surface of the semiconductor wafer 28.

Continuing the description with reference to FIG. 7 in conjunction with FIGS. 1 and 2, in the illustrated embodiment, the chuck means 22 positioned in the polishing zone 20 as well as the workpiece held by the chuck means 22. Polishing tool 1 pressed against the surface of the workpiece to be processed, that is, the back surface of the semiconductor wafer 28.
A dustproof cover 128 that surrounds 16 is provided. The dustproof cover 128 has a box shape as a whole and has an upper wall 130, a front wall 132, and both side walls 134. The dustproof cover 128 is fixed at the position shown in FIG. 1 with its rear edge being in close contact with the upright wall 6. Both side walls 134 of the dustproof cover 128 have a shoulder surface 136 facing downward in the middle of the vertical direction. The upper surfaces of both side edges of the main portion 4 are closely attached.
A rectangular opening 138 for allowing passage of the chuck means 22 is formed in the front wall 132 of the dustproof cover 128. A circular opening 140 for allowing the support member 120 of the polishing means 94 and the polishing tool 116 to pass therethrough is formed in the upper wall 130 of the dustproof cover 128. Dust cover 12
A part of the upper wall 130 of 8 is defined by a door 142 that can be opened and closed. This door 142 has one edge at one side wall 13
Swiveling member 144 rotatably connected to the upper edge of No. 4
And a second turning member 146, one end of which is rotatably connected to the tip end edge of the first turning member 144. The circular opening 1 is formed on the free end edge of the second turning member 146.
A semicircular cutout defining half of 40 is formed. The outer surface of the second turning member 146 is also formed with a recess 148 in which a finger can be hung. The door 142 is normally located at the closed position shown by the solid line in FIGS. 1 and 7, but when the polishing tool 116 is repaired or replaced, the recess 1
48 can be hooked with a finger to move it to the open position shown by the alternate long and two short dashes line in FIG. On the upper wall 130 of the dustproof cover 128, the cylindrical member 15 extending upward from the peripheral edge of the circular opening 140 is provided.
0 is attached. The cylindrical member 150 is composed of two semi-cylindrical members, one of which is the upper wall 13.
0 is fixed to the main part, and the other is fixed to the second turning member 146 of the door 142 and can be opened and closed together with the second turning member 146. The upper wall 130 of the dustproof cover 128 is further provided with an exhaust duct 152 for exhausting the inside of the dustproof cover 128. Appropriate exhaust means (not shown) is attached to the exhaust duct 152, and when the back surface of the semiconductor wafer 28 is polished by the polishing tool 116, the polishing area 20 surrounded by the dustproof cover 128 is exhausted. To be done.

With reference to FIG. 1 and FIG. 2, an example of the polishing action in the illustrated processing strain removing apparatus will be summarized and described below.
When the chuck means 22 is positioned in the carry-in / carry-out area 18, the carry-in / carry-out means 16 removes the machining distortion by polishing the back surface having machining distortion from the temporary receiving / cleaning means 14 to the chuck means 22. Semiconductor wafer 28
Is loaded with its back surface facing upward, and the semiconductor wafer 28 is adsorbed on the chuck plate 38. Then, the chuck means 22 is moved to the polishing area 20 in the direction indicated by the arrow 40. Then, in the polishing area 20, the chuck plate 38 holding the semiconductor wafer 28 is rotated, and the polishing member 122 of the polishing tool 116 that is rotationally driven is pressed against the back surface of the semiconductor wafer 28 on the chuck plate 38. Then, the chuck means 22 is reciprocated in the directions indicated by the arrows 40 and 42 over a predetermined range, and thus the back surface of the semiconductor wafer 28 is dry-polished by the action of the polishing member 122 to remove the residual processing strain. At this time, the exhaust means attached to the exhaust duct 152 is operated to exhaust the dust inside the dustproof cover 128.

After the polishing is completed, the polishing tool 116 is separated upward from the back surface of the semiconductor wafer 28, and the chuck means 22 is moved to the loading / unloading area 18 in the direction indicated by the arrow 42. Thereafter, the semiconductor wafer 28 is unloaded from the chuck means 22 to the temporary receiving / cleaning means 14 by the loading / unloading means 16. Next, the chuck plate cleaning means 62 cleans the chuck plate 38 as needed. More specifically, the sliding block 68 is moved to the central portion of the main portion 4 of the housing 2 and positioned so as to face the chuck plate 38 of the chuck means 22. Then, the brush member 88 and the oil stone 92 are rotationally driven, the cases 78 and 80 are lowered to the operating position, and the brush member 88 is rotationally driven.
And the oil stone 92 is pressed against the surface of the chuck plate 38. Then, the sliding block 68 has arrows 74 and 76.
Is reciprocated over a predetermined range in the direction indicated by, and the chuck plate 38 of the chuck means 22 is rotated and reciprocated over a predetermined range in the directions indicated by arrows 40 and 42. When the cleaning of the chuck plate 38 is completed, the cases 78 and 80 are raised to the non-acting position, and the sliding block 68 is retracted to one side of the main portion 4 of the housing 2. After that, the next semiconductor wafer 28 located on the temporary receiving / cleaning means 14 is loaded onto the chuck means 22 by the loading / unloading means 16. While the chuck plate 38 is being cleaned in the chuck plate cleaning area 18, the suction tool 52 of the loading / unloading means 16 can be cleaned by the suction tool cleaning means 54 as needed.

FIG. 8 shows a modification of the processing strain removing device. In this modification, the common housing 202 is provided, and the first processing strain removing means 203 and the second processing strain removing means 205 are arranged in parallel in the common housing 202. The first processing strain removing means 203 includes a first cassette receiving means 207, a first transporting means 209, a first temporary receiving / cleaning means 211, and a first loading / unloading means 21.
3, first chuck means 215 and first polishing means 21
7, the second processing strain removing means 205 includes the second cassette receiving means 219, the second transporting means 221, the second temporary receiving / cleaning means 223, the second loading / unloading means 225,
The second chuck means 227 and the second polishing means 229 are provided. On the rear end side of the main part 204 of the common housing 202, which is slightly rearward of the middle part, the chuck plate 231 of the first chuck means 215 is selectively positioned and the loading / unloading area 233 of the second chuck means 227. Loading / unloading area 23 in which the chuck plate 235 is selectively positioned
7, a common chuck plate cleaning means 262 is provided. The sliding block 268 of the common chuck plate cleaning means 262 is the main portion 204 of the housing 202.
Of the first chuck means 215 and the chuck plate 231 of the first chuck means 215 is selectively positioned.
The chuck plate 235 of No. 7 can be positioned so as to oppose the loading / unloading area 237 that is selectively positioned, and the workpiece subjected to the polishing process is the first chuck means 2
After being unloaded from the chuck plate 231 of the No. 15 chuck plate 231, the chuck plate 231 of the first chuck unit 215 is washed as necessary, and the workpiece subjected to the polishing process is removed from the chuck plate 235 of the second chuck unit 227. After being carried out, the chuck plate 23 of the second chuck means 227 may be used as needed.
Wash 5. Further, in the modified example shown in FIG. 8, a common dustproof cover 239 is provided, and the common dustproof cover 239 and the chuck plate 231 of the first chuck means 215 located in the polishing area, The first polishing means 2 is pressed against the back surface of the semiconductor wafer 28 held by the first chuck means 215.
17 polishing tools, the chuck plate 235 of the second chuck means 227 positioned in the polishing area, and the semiconductor wafer 28 held by the second chuck means 227.
The second polishing means 229, which is pressed against the back surface of the
It is surrounded by polishing tools. Such a common dustproof cover 2
On the front wall 241 of 39, a rectangular opening 243 for allowing passage of the first chuck means 215 and a rectangular opening 245 for allowing passage of the second chuck means 227 are formed. On the upper wall 247 of the common dustproof cover 239, the circular opening 249 of the first polishing means 217 for allowing the support member and the polishing tool to pass, and the second polishing means 229 of the support member and the polishing tool. A circular opening 251 for allowing passage is formed. The upper wall 247 of the common dust cover 239 is further provided with a common dust cover 239.
A common exhaust duct 253 for exhausting the inside is provided, and the common exhaust duct 253 allows the chuck plate 231 of the first chuck means 215 to be selectively positioned and the second chuck means 227. And the polishing area in which the chuck plate 235 is selectively positioned is exhausted. Other configurations of the modification shown in FIG. 8 are substantially the same as those of the embodiment shown in FIGS. 1 to 7.

Although the modified example of the present invention has been described with reference to FIG. 8, the present invention is not limited to such modified example, and various changes and modifications can be made without departing from the scope of the present invention. is there. For example, in the above modification,
The common housing 202 has a first processing strain removing means 203.
Although the example in which the two and the second processing strain removing means 205 are arranged in parallel is shown, a plurality of processing strain removing means may be arranged in parallel in the common housing 202.

[0027]

In the processing strain removing apparatus of the present invention, the surface of the workpiece to be processed having the processing strain, for example, the ground back surface of the semiconductor wafer, is polished with a polishing tool with high efficiency and high quality. The processing strain can be removed by using the method, and the entire device is also compactly constructed.

[Brief description of drawings]

FIG. 1 is a perspective view showing a preferred embodiment of a machining strain removing device configured according to the present invention.

FIG. 2 is a partial perspective view showing a main part of the processing strain removing device shown in FIG. 1 in a state in which a dustproof cover and a chuck plate cleaning means are removed.

FIG. 3 is a perspective view showing a state in which a semiconductor wafer, which is a typical example of an object to be processed having a surface to be processed with residual processing strain, is mounted on a frame via a mounting tape. Processing strain remains

FIG. 4 is a perspective view showing a state in which a semiconductor wafer, which is a typical example of a workpiece having a surface to be processed, is mounted on a supporting substrate.

5 is a perspective view showing a polishing tool used in the processing strain removing device shown in FIG. 1. FIG.

6 is a perspective view showing the polishing tool shown in FIG. 5 as viewed from the lower surface side thereof.

FIG. 7 is a perspective view showing a dustproof cover used in the processing distortion removing device shown in FIG. 1.

FIG. 8 is a perspective view showing another preferred embodiment of the processing strain removing device configured according to the present invention.

[Explanation of symbols]

2: Housing 8: Cassette 10: cassette receiving means 12: Transporting means 14: Temporary receiving / cleaning means 16: Loading / unloading means 18: Loading / unloading area 20: Polishing area 28 22: Chuck means 28: Semiconductor wafer (workpiece) 38: Chuck plate 62: chuck plate cleaning means 88: Brush member 92: Oil stone 94: Polishing means 116: Polishing tool 120: Support member 122: Polishing member 128: Dust cover 138: Opening 140: Open 152: Exhaust duct 202: Common housing 203: First processing strain removing means 205: Second processing strain removing means 207: First cassette receiving means 209: First transport means 211: First temporary receiving / cleaning means 213: First loading / unloading means 215: First chuck means 217: First polishing means 219: Second cassette receiving means 221: Second transportation means 223: Second temporary receiving / cleaning means 225: Second loading / unloading means 227: Second chuck means 229: Second polishing means 239: Dust cover 243: opening 245: opening 251: opening 253: opening 262: Chuck plate cleaning means

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B24B 37/04 B24B 37/04 Z H01L 21/68 H01L 21/68 PF term (reference) 3C058 AA07 AA09 AB04 AC05 CA01 CB03 CB05 DA17 5F031 CA02 FA01 FA07 FA11 FA12 FA20 GA02 GA45 HA02 HA12 HA37 HA57 HA58 HA59 MA03 MA22 MA23 NA14 NA18 PA04 PA24

Claims (10)

[Claims] 1. A processing strain removing device for removing a processing strain by polishing a surface of a workpiece to be processed, which has a processing strain, and a cassette containing a plurality of workpieces is mounted. A cassette receiving means, a conveying means, a temporary receiving / cleaning means, a loading / unloading means, a chucking means selectively positioned in a loading / unloading area and a polishing area, and a polishing means, The cassette receiving means, the conveying means, the temporary receiving / cleaning means, the loading / unloading means, the loading / unloading area, and the polishing area are
The chuck means are arranged substantially linearly in this order, the chuck means is linearly reciprocally movable between the loading / unloading area and the polishing area, and the cassette mounted on the cassette receiving means. The workpiece accommodated in the
The workpiece is conveyed to the cleaning means, and then the work-in / out means transfers the workpiece from the temporary receiving / cleaning means to the chuck means positioned in the carry-in / out area and holds it on the chuck means. Then, the chuck means is moved to the polishing zone, and then the work piece on the chuck means positioned in the polishing zone is polished by the polishing means, and then the chuck means is carried in. · Moved to the carry-out area, then the work-in / carry-out means carries out the workpiece on the chuck means to the temporary receiving / cleaning means, and then the temporary receiving / cleaning means cleans the workpiece. After that, the workpiece on the temporary receiving / cleaning means is transported by the transporting means into the cassette on the cassette receiving means, and the polishing means is the rotary shaft and the polishing tool mounted on the rotary shaft. A surface to be processed is polished by pressing the rotating polishing tool, including a polishing tool, against the surface to be processed of the workpiece on the chuck means located in the polishing zone. Characteristic processing strain removal device. 2. The processing strain removing apparatus according to claim 1, wherein the object to be processed is a semiconductor wafer having a large number of circuits on its surface, and the surface to be processed is a back surface subjected to grinding. 3. The processing strain removing apparatus according to claim 1, wherein the polishing tool has a polishing member composed of felt and abrasive grains dispersed in the felt. 4. The machining strain removing device according to claim 3, wherein the polishing tool has a support member having a circular support surface, and the polishing member has a disc shape joined to the circular support surface of the support member. apparatus. 5. The chuck means is rotatable about a center axis of rotation extending parallel to the rotation axis of the polishing means, and when polishing the surface to be processed of the workpiece by the polishing means, The machining strain removing device according to any one of claims 1 to 4, wherein the chuck means is rotated about the rotation center axis and is linearly reciprocated over a predetermined range. 6. Surrounding the chuck means located in the polishing area, the workpiece held on the chuck means and the polishing tool being pressed against the surface of the workpiece to be processed. A dustproof cover is provided, and when the chuck means moves from the loading / unloading area to the polishing area and from the polishing area to the loading / unloading area, the dustproof cover is provided. Any of claims 1 to 5, wherein an opening through which a workpiece held on the chuck means can pass is formed, and an exhaust duct for exhausting the inside of the dustproof cover is connected. The processing strain removing device according to claim 1. 7. The rotating shaft of the polishing means is movable in the central axis direction thereof, and the polishing tool is mounted on the chuck means by moving the rotating shaft in the central axis direction of the dustproof cover. 7. The processing strain removing apparatus according to claim 6, wherein an opening through which the polishing tool can pass when being moved in a direction approaching and separating from a workpiece held by is formed. 8. The chuck means includes a chuck plate formed of a porous material and having a substantially flat surface for adhering a workpiece to the chuck plate for cleaning the chuck plate. 8. The processing strain removing device according to claim 1, wherein the chuck plate cleaning means is provided. 9. The chuck plate cleaning means includes a cleaning brush and an oil stone, and the cleaning brush and the oil stone are pressed against the surface of the chuck plate and are substantially against the surface of the chuck plate. 9. The processing strain removing device according to claim 8, wherein the device is rotated about an axis of rotation extending vertically upward and is reciprocated in a direction substantially parallel to the surface of the chuck plate. 10. A common housing comprising: a first cassette receiving means, a first conveying means;
First machining strain removing means having a first temporary receiving / cleaning means, a first loading / unloading means, a first chucking means and a first polishing means, a second cassette receiving means, and a second cassette receiving means. A second processing strain removing means including a transporting means, a second temporary receiving / cleaning means, a second loading / unloading means, a second chucking means and a second polishing means are arranged in parallel. Item 10. The processing strain removing device according to any one of items 1 to 9.