JP3649531B2 - Semiconductor wafer chamfered surface polishing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor wafer chamfering method and apparatus for polishing a chamfered surface formed on the periphery of a semiconductor wafer.
[0002]
[Prior art]
As a technique for etching (etching) a chamfered surface formed on the periphery of a semiconductor wafer such as a silicon wafer, CCR (Chemical Corner Rounding) processing is known. When this CCR processing is performed, Protrusions are formed at the boundaries between the front and back surfaces of the semiconductor wafer. Although this protrusion is minute, when the semiconductor wafer is accommodated in a resin cassette, it contacts the cassette and scrapes the cassette, producing minute shavings. Needless to say, the shavings cause deterioration of the performance of the semiconductor wafer.
[0003]
Therefore, it is known to perform CMP (Chemical Mechanical Polishing) processing on the chamfered surface of the semiconductor wafer separately from CCR processing. This CMP processing is a technique of polishing with a polishing cloth while supplying a polishing liquid toward the chamfered surface of a semiconductor wafer. Conventionally, as an apparatus for performing this CMP processing, a polishing drum around which a polishing cloth is wound is used. The wafer is polished by pressing the chamfered surface of the semiconductor wafer while rotating the polishing drum while rotating the polishing drum.
[0004]
In a conventional chamfered surface polishing apparatus for a semiconductor wafer, the chamfered surface is polished as follows.
First, the semiconductor wafer transported by the transport mechanism is attached to the front surface side holder, and the chamfered surface on the front surface side is polished. After polishing the front surface side, the semiconductor wafer is removed and the semiconductor wafer is attached to the rear surface side holder. In this state, the chamfered surface on the back surface side is polished, and after polishing the back surface side, the semiconductor wafer is removed from the holder and conveyed to the next process.
[0005]
[Problems to be solved by the invention]
However, the following problems remain in the conventional semiconductor wafer chamfered surface polishing apparatus. That is, after polishing the chamfered surface on the front surface side, the semiconductor wafer is changed from the holder for the front surface side to the holder for the back surface side while the polishing liquid is adhered, and the chamfered surface on the back surface side is further polished. Therefore, there is a disadvantage that the polishing liquid is interposed between the holder for the back surface side and the semiconductor wafer, and the contact portion of the semiconductor wafer with the holder, that is, the front surface or the back surface is slightly polished and the contact mark of the holder remains. It was.
[0006]
The present invention has been made in view of the above problems, and provides a chamfered surface polishing apparatus for a semiconductor wafer that prevents the front and back surfaces other than the chamfered surface of the semiconductor wafer from being polished by the attached polishing liquid. Objective.
[0007]
[Means for Solving the Problems]
The present invention employs the following configuration in order to solve the above problems.
That is, a chamfered surface polishing apparatus for a semiconductor wafer that polishes the chamfered surface by supplying a polishing liquid to a chamfered surface formed on the periphery of the semiconductor wafer and sliding a polishing cloth in a pressed state,
A wafer transfer mechanism for transferring the semiconductor wafer;
A front surface polishing chamber and a back surface polishing chamber for polishing the chamfered surfaces on the front surface side and the back surface side of the semiconductor wafer, respectively;
A front surface polishing chamber transfer mechanism and a back surface polishing chamber transfer mechanism that transfer the semiconductor wafer transferred by the wafer transfer mechanism to the front surface polishing chamber and the back surface polishing chamber and return to the wafer transfer mechanism after polishing, respectively.
The surface polishing chamber transfer mechanism is provided with a wafer suction disk that supports a semiconductor wafer at the time of polishing and transfer and is positioned in the surface polishing chamber at the time of surface chamfering polishing of the semiconductor wafer,
The backside polishing chamber transfer mechanism is provided with a wafer suction disk that is supported during polishing and transfer of the semiconductor wafer and is positioned in the backside polishing chamber during backside chamfering polishing of the semiconductor wafer,
In the wafer transfer mechanism, a surface-polished semiconductor wafer held by the wafer suction disk by the surface polishing chamber transfer mechanism and transferred from the surface polishing chamber and a water tank filled with the wafer suction disk with cleaning water A wafer-side surface cleaning unit for cleaning the semiconductor wafer and the polishing liquid adhering to the wafer suction disk by rotating the wafer suction disk and washing the wafer suction disk.
The back-polished semiconductor wafer transferred by the back surface polishing chamber held by the back surface polishing chamber transfer mechanism and transferred from the back surface polishing chamber and the wafer suction plate are positioned in a submerged state in a water tank filled with cleaning water. The above problem has been solved by providing a backside wafer cleaning section for rotating the wafer suction disk to wash off the semiconductor wafer and the polishing liquid adhering to the wafer suction disk.
Further, in the semiconductor wafer chamfered surface polishing apparatus of the present invention, a semiconductor wafer for polishing the chamfered surface by supplying a polishing liquid to a chamfered surface formed on the periphery of the semiconductor wafer and sliding a polishing cloth in a pressed state. A chamfered surface polishing apparatus, comprising: a wafer transfer mechanism for transferring the semiconductor wafer; a surface polishing chamber and a backside polishing chamber for polishing the chamfered surfaces on the front side and the back side of the semiconductor wafer; and the wafer transfer mechanism. A front surface polishing chamber transfer mechanism and a back surface polishing chamber transfer mechanism for transferring a semiconductor wafer to be transferred to the front surface polishing chamber and the back surface polishing chamber and returning them to the wafer transfer mechanism after polishing, respectively. The polishing chamber transfer mechanism and the back surface polishing chamber transfer mechanism transfer the surface polishing chamber and the back surface polishing chamber from the surface polishing chamber. Technical surface side wafer cleaning unit for cleaning each conductor wafers with wash water and which has a back side wafer cleaning unit Ru be employed.
[0008]
In this semiconductor wafer chamfered surface polishing apparatus, a front surface side wafer cleaning unit and a rear surface side wafer cleaning unit are provided separately from the front surface polishing chamber and the rear surface polishing chamber, so the front surface side chamfered surface is polished in the front surface polishing chamber. By transferring the semiconductor wafer to the surface side wafer cleaning section by the surface polishing chamber transfer mechanism, the polishing liquid adhering during the surface side polishing is cleaned. Furthermore, the polishing liquid adhering at the time of backside polishing is cleaned by transferring the semiconductor wafer whose backside chamfered surface is polished in the backside polishing chamber to the backside wafer cleaning unit by the backside polishing chamber transfer mechanism. Therefore, each time the polishing of the chamfered surface on the front surface side and the back surface side is completed, the semiconductor wafer is immediately cleaned in the front surface side wafer cleaning unit and the back surface side wafer cleaning unit separately from the front surface polishing chamber and the back surface polishing chamber, The adhering polishing liquid remains so that unnecessary portions are not polished.
In addition, since the front surface polishing chamber and the back surface polishing chamber are provided separately, the polishing process is individually processed in parallel, and other semiconductor wafers are parallel in the front surface side wafer cleaning unit and the back surface side wafer cleaning unit. Washed.
Furthermore, since the front surface polishing chamber, the back surface polishing chamber, the front surface side wafer cleaning unit, and the back surface side wafer cleaning unit are provided separately, there is little mutual mixing of the polishing liquid and the cleaning water, and each can be easily reused. .
[0009]
In chamfer polishing apparatus of a semiconductor wafer of the present invention, the chamfer polishing apparatus of the semiconductor wafer, the wafer transport mechanism receives the semiconductor wafer to be transferred from the surface polishing chamber by the surface polishing chamber transfer mechanism inversion technology was provided with a wafer reversal unit to pass to the back surface polishing chamber transport mechanism is the Ru can be employed.
[0010]
In this semiconductor wafer chamfered surface polishing apparatus, since the wafer transfer mechanism includes a wafer reversing unit, the front side and the back side of the semiconductor wafer polished in the front surface polishing chamber and the rear surface polishing chamber by the wafer reversing unit are the same. Since it is directed in the direction, the polishing process on the front surface side and the back surface side can be performed by the polishing mechanism having the same configuration.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a chamfered surface polishing apparatus for a semiconductor wafer according to the present invention will be described with reference to FIGS.
In these drawings, reference numeral 1 denotes a wafer take-out mechanism, 2 denotes a wafer positioning unit, 3 denotes a wafer transfer mechanism, 4 denotes a surface polishing chamber, 5 denotes a surface polishing chamber transfer mechanism, 6 denotes a surface polishing mechanism, and 7 denotes a back surface polishing. Reference numeral 8 denotes a backside polishing chamber transfer mechanism, 9 denotes a backside polishing mechanism, and 10 denotes a wafer storage mechanism.
[0012]
As shown in FIGS. 1 and 2, the semiconductor wafer chamfered surface polishing apparatus of this embodiment includes a wafer take-out mechanism 1 that takes out a semiconductor wafer W from a cassette C 1, and positioning of the semiconductor wafer W taken out from the wafer take-out mechanism 1. A wafer positioning unit 2 that performs the above, a wafer transfer mechanism 3 that transfers the semiconductor wafer W positioned by the wafer positioning unit 2 and sends it to the polishing process on the front surface side and the back surface side of the semiconductor wafer W, and the wafer transfer mechanism 3 A surface polishing chamber transfer mechanism 5 that transfers the semiconductor wafer W to be transferred to the surface polishing chamber 4 where the surface side polishing is performed and returns to the wafer transfer mechanism 3 after polishing, and the surface side of the semiconductor wafer W in the surface polishing chamber 4 A surface polishing mechanism 6 for polishing the semiconductor, and a semiconductor which is polished on the surface side and transported again by the wafer transport mechanism 3 A backside polishing chamber transfer mechanism 8 for transferring the wafer W to the backside polishing chamber 7 where the backside polishing is performed and returning the wafer W to the wafer transfer mechanism 3 after polishing, and a backside for polishing the backside of the semiconductor wafer W in the backside polishing chamber 7. A polishing mechanism 9, a wafer storage mechanism 10 for transferring the semiconductor wafer W whose back side is polished and transferred again by the wafer transfer mechanism 3 to the storage cassette C 2, and electrically connected to and controlled by the respective mechanisms. And an operation control unit 12.
[0013]
As shown in FIGS. 1 to 3, the wafer take-out mechanism 1 includes a cassette mounting table 13, and four cassettes C1 mounted on the upper surface of the cassette mounting table 13 so as to surround the central portion. And a loader unit 15 provided at the center of the cassette mounting table 13 for picking up semiconductor wafers W from a predetermined cassette C1 with a picking hand 14 and picking them up one by one and transferring them to the wafer transfer mechanism 3. Yes.
[0014]
Each of the cassettes C1 is placed such that a plurality of stored semiconductor wafers W are in a horizontal state, and the direction in which each semiconductor wafer W is taken out is directed toward the center of the cassette placement table 13. .
The loader unit 15 is installed in the cassette mounting table 13 in a state in which a take-out hand 14 extending in the horizontal direction is arranged at the center of the upper surface of the cassette mounting table 13. The take-out hand 14 can be rotated about the vertical axis of the loader unit 15 and can be advanced and retracted in the extending direction, and is supported so as to move up and down.
[0015]
The wafer positioning unit 2 is installed at the cassette mounting table 13 side end on the base 16 installed adjacent to the cassette mounting table 13 and mounts the semiconductor wafer W taken out from the cassette C1. The centering (centering) and orientation flat (orientation flat) directions are determined on the mounting table 2a.
[0016]
As shown in FIGS. 4 and 5, the wafer transfer mechanism 3 receives the semiconductor wafer W positioned by the wafer positioning unit 2 by the first polishing section (surface-side wafer cleaning section) 20 by the surface polishing chamber transfer mechanism 5. The first transfer unit 21 to be transferred and the semiconductor wafer W whose surface is polished by the surface polishing mechanism 6 are received and transferred from the surface polishing chamber transfer mechanism 5 by the first transfer unit 20, and the semiconductor wafer W is inverted by the second transfer unit 22. The second transfer unit 23 (wafer reversing means) to be received, and the semiconductor wafer W inverted by the second transfer unit 23 is received and received by the back surface polishing chamber transfer mechanism 8 by the third transfer unit (back surface side wafer cleaning unit) 24. The third transfer unit 25 to be transferred and the semiconductor wafer W whose back side is polished by the back side polishing mechanism 9 are received from the back side polishing chamber transfer mechanism 8 and the fourth is transferred. Only and a fourth conveying unit 27. pass the wafer housing mechanism 10 passes section 26.
[0017]
The first to fourth transfer portions 20, 22, 24, and 26 are arranged in the longitudinal direction in order from the end on the cassette mounting table 13 side on the base 16, and the first to fourth transport portions 21, Reference numerals 23, 25, and 27 are provided in order from the end on the cassette mounting table 13 side along one side surface of the first to fourth transfer portions 20, 22, 24, and 26.
[0018]
The first transport unit 21 includes a first hand 28 that sucks and supports the semiconductor wafer W by an arc-shaped suction groove 28a formed at a tip portion, and the first hand 28 and a loader unit 15 and a first transfer unit. 20, a first rodless cylinder 29 that is supported so as to be horizontally movable, a first vertically moving cylinder 30 that supports the first hand 28 so as to be movable up and down, a suction groove 28a of the first hand 28, a first And a first pipe portion 31 bundled with compressed air supply pipes individually connected to the rodless cylinder 29 and the first vertical cylinder 30.
[0019]
Both ends of the first rodless cylinder 29 are fixed horizontally to one side surface of the first delivery portion 20, and the first movable portion 32 of the first rodless cylinder 29 has a proximal end of the first hand 28. The part is supported so as to be movable up and down, and the first vertical movement cylinder 30 is installed. The first movable portion 32 is supported by a first guide portion 33 disposed above and parallel to the first rodless cylinder 29 so as to be horizontally movable.
The first hand 28 extends in a horizontal state in a direction perpendicular to the longitudinal direction of the base 16, and a base end portion of the first hand 28 is connected to a front end portion of the piston portion 30 a of the first vertical cylinder 30 and a connecting member 34. Connected.
[0020]
The second transfer unit 23 includes a second hand 35 that sucks and supports the semiconductor wafer W through two suction holes 35a formed at the tip, and the second hand 35 and the second delivery unit 20 and the second delivery unit 20. A second rodless cylinder 36 that supports the second hand 35 so as to be horizontally movable, a second vertical movement cylinder 37 that supports the second hand 35 so as to be movable up and down, a suction hole 35 a of the second hand 35, And a second pipe portion 38 that bundles pipes for supplying compressed air that are individually connected to the two-rodless cylinder 36 and the second vertically moving cylinder 37, respectively.
[0021]
Both ends of the second rodless cylinder 36 are fixed horizontally to one side of each of the first delivery portion 20 and the second delivery portion 22, and the second movable portion 39 of the second rodless cylinder 36 has a second movable portion 39. The base end portion of the second hand 35 is supported so as to move up and down and rotate, and the second up and down motion cylinder 37 is installed. Further, the second movable portion 39 is supported by a second guide portion 40 disposed above and parallel to the second rodless cylinder 36 so as to be horizontally movable.
[0022]
The second hand 35 extends in a horizontal state in a direction perpendicular to the longitudinal direction of the base 16, and a base end portion of the second hand 35 is interposed between a front end portion of a piston portion 37 a of the second vertical cylinder 37 and a connecting member 41. Connected. A reversing actuator 42 that rotatably supports the second hand 35 is provided at the base end portion of the second hand 35 with the extending direction of the second hand 35 as an axis.
[0023]
The third transfer unit 25 includes a third hand 43 that sucks and supports the semiconductor wafer W through two suction holes 43a formed at the tip, and the third hand 43 and the second delivery unit 22 and the third delivery unit. A third rodless cylinder 44 that is supported so as to be horizontally movable with respect to the portion 24, a third vertical movement cylinder 45 that supports the third hand 43 so as to be movable up and down, a suction hole 35a of the third hand 43, a second And a third pipe section 46 that bundles compressed air supply pipes individually connected to the three rodless cylinder 44 and the third vertical cylinder 45.
[0024]
Both ends of the third rodless cylinder 44 are fixed horizontally to one side of each of the second delivery portion 22 and the third delivery portion 24, and the third movable portion 47 of the third rodless cylinder 44 includes The base end of the third hand 43 is supported so as to be movable up and down, and the third vertical movement cylinder 45 is installed. The third movable portion 47 is supported by a third guide portion 48 disposed above and parallel to the third rodless cylinder 44 so as to be horizontally movable.
Similarly to the second hand 35, the third hand 43 extends in a horizontal state in a direction perpendicular to the longitudinal direction of the base 16, and its base end portion moves in a third vertical direction via a connecting member 49. The piston 45 is connected to the tip of the piston 45 a of the cylinder 45.
[0025]
The fourth transport unit 27 supports a fourth hand 50 on which the semiconductor wafer W is placed, and a fourth hand 50 movably supported between the third delivery unit 24 and the fourth delivery unit 26. A rodless cylinder 51 is provided.
Both ends of the fourth rodless cylinder 51 are fixed horizontally to one side surface of each of the third delivery portion 24 and the fourth delivery portion 26, and the fourth movable portion 52 of the fourth rodless cylinder 51 includes The base end portion of the fourth hand 50 is supported so as to be movable up and down.
[0026]
The fourth hand 50 extends in a direction perpendicular to the longitudinal direction of the base 16, and is disposed in a horizontal state at a position where the tip end is lower than the base end.
The tip of the fourth hand 50 is set to have the same width as the diameter of the semiconductor wafer W to be placed, and four protrusions 50a are provided that contact and position the outer edge of the semiconductor wafer W.
[0027]
The fourth delivery section 26 is provided with a hand lifting air cylinder 53 that supports the fourth hand 50 moved to the fourth delivery section 26 at the longitudinal end of the base 16 so as to be movable up and down. The air cylinder 53 for raising and lowering the hand is arranged to extend in the vertical direction, and a fourth hand support member 53b into which a side portion of the fourth hand 50 is fitted is attached to the tip of the cylinder rod 53a. .
[0028]
As shown in FIG. 6, the first delivery unit 20 is a rectangular water tank provided adjacent to the loader unit 15, and is filled with pure water as cleaning water. The second delivery part 22 is a rectangular water tank adjacent to the first delivery part 20 and set deeper than the first delivery part 20, so that the pure water overflowing from the first delivery part 20 and the like flows into the tank. The washing water drain hole 54 through which the pure water is drained is formed at the bottom.
The third delivery unit 24 and the fourth delivery unit 26 are rectangular water tanks adjacent to the second delivery unit 22 and set to the same depth as the first delivery unit 20, and are in communication with each other. The interior is filled with pure water as cleaning water.
[0029]
As shown in FIG. 7, the surface polishing chamber transfer mechanism 5 includes a pair of wafer suction disks 54 that support the semiconductor wafer W in the suction state from above in the first transfer unit 20 and the surface polishing chamber 4, and the wafer suction A pair of suction disk support portions 55 that respectively support the disk 54 so as to move up and down and rotate, and the rotation of the suction disk support portions 55 erected between the first transfer section 20 and the surface polishing chamber 4. A turning mechanism 57 that is supported by the shaft member 56 and turns around the turning shaft member 56 is provided. In other words, the pair of wafer suction disks 54 are arranged at symmetrical positions around the pivot shaft member 56.
[0030]
On the other hand, the back surface polishing chamber transfer mechanism 8 includes a pair of wafer suction plates 54 that support the semiconductor wafer W in the suction state from above in the third delivery unit 24 and the back surface polishing chamber 7, and moves the wafer suction plates 54 up and down. Centered on a pair of suction disk support portions 55 that are rotatably supported, and a rotatable swivel shaft member 56 erected between the third delivery portion 24 and the back surface polishing chamber 7. And a turning mechanism 57 for turning the head.
[0031]
The turning mechanism 57 includes a turning rotary actuator 58 that rotates the turning shaft member 56 and a cylindrical support member 59 that rotatably supports the turning shaft member 56 in the inserted state.
The rotary rotary actuator 58 is installed below the front surface polishing chamber 4 or the back surface polishing chamber 7, and a connecting gear 61 fixed to the rotary drive shaft 60 is fixed to the lower portion of the rotary shaft member 56. Is engaged.
The cylindrical support member 59 is in a state of penetrating the center portion of the base 16, and a lower flange portion 63 provided on the outer periphery of the lower portion is fixed and supported on the upper surface of the base 16.
[0032]
A rod-like turning stopper 64 extending radially outward is fixed to the lower end of the turning shaft member 56, and a turning positioning portion 65 is provided at two predetermined positions (1) on the upper rear surface of the base 16. (Not shown). The swivel positioning unit 65 is a position where the tip of the swivel stopper 64 is swung and locked by a predetermined amount, that is, when the wafer suction plate 54 swivels to the upper part of the first delivery part 20 or the upper part of the surface polishing chamber 4. And it is provided at a position corresponding to the case where the upper part of the third delivery part 24 or the upper part of the back surface polishing chamber 7 is swung.
Further, the turning positioning portion 65 includes a shock absorber 66 that absorbs an impact when the tip end portion of the turning stopper 64 comes in contact and a positioning bolt 67 that finely adjusts the locking position on the lower side surface.
[0033]
An upper flange portion 68 is provided at the upper end of the pivot shaft member 56, and a cylindrical member 69 is fixed to the upper portion of the upper flange portion 68 with the same axis. On the outer peripheral surface of the cylindrical member 69, a pair of suction plate lifting / lowering air cylinders 70 extending in the vertical direction are provided at positions symmetrical to the axis of the cylindrical member 69. These suction plate lifting / lowering air cylinders 70 are provided with a cylinder part 70a fixed to the upper part and a cylinder rod part 70b that can be moved forward and backward in the cylinder part 70a. The suction disk support 55 is fixed to the tip of the cylinder rod 70b.
[0034]
The suction disk support portion 55 is connected to a frame portion 71 fixed to the tip portion of the cylinder rod portion 70b, a rotation motor 72 fixed to the upper portion of the frame portion 71, and a rotation drive shaft of the rotation motor 72. A reduction gear 73a that reduces the number of rotations, a rotation angle detection sensor 73b that detects the rotation angle of the wafer suction disk 54 decelerated by the reduction gear 73a, and a vertical axis connected to the rotation shaft of the reduction gear 73a. A support rod 74 supported at the lower end of the frame portion 71 so as to be rotatable is provided as a center. The support rod 74 is connected to a suction means (not shown) and has a connection hole 74a penetrating vertically.
[0035]
The wafer suction plate 54 has an upper surface fixed to the lower end of the support rod 74 and can be rotated by the rotation of the rotary motor 72 with the same axis. The wafer suction disk 54 is formed in a disk shape having a diameter smaller than the semiconductor wafer W to be sucked by a predetermined amount and partially cut away corresponding to the orientation flat. It is made into a shape. Further, a suction hole (not shown) connected to the connection hole 74a is formed on the lower surface of the wafer suction disk 54.
That is, the wafer suction disk 54 and the suction disk support part 55 function as a wafer rotation mechanism that holds the semiconductor wafer W and supports the semiconductor wafer W so as to be rotatable in the circumferential direction.
[0036]
As shown in FIGS. 7 and 8, the front surface polishing chamber 4 and the back surface polishing chamber 7 are disposed on the opposite sides of the first transfer portion 20 and the third transfer portion 24 with respect to the pivot shaft member 56, respectively. The chamber side plate 75, the polishing chamber top plate 76, the polishing chamber shutter 77, and the polishing chamber bottom plate 78 are configured. The polishing chamber bottom plate 78 is set in an inclined state toward the outside of the central portion, and a polishing liquid drain hole 79 for draining the polishing liquid used at the time of polishing is formed in the lowermost part. The polishing liquid drain hole 79 is connected to a drainage reservoir (not shown) for reusing the used polishing liquid. A mist extraction port 75a for removing mist is provided at the lower portion of the polishing chamber side plate 75.
[0037]
The polishing chamber top plate 76 is disposed so as to cover the upper surfaces of the front surface polishing chamber 4 and the rear surface polishing chamber 7, and is set slightly larger than the outer diameter of the semiconductor wafer W adsorbed by the wafer suction plate 54 at the center. A circular top plate opening 76a having an inner diameter is formed.
Further, the polishing chamber top plate 76 includes a pair of shutter air cylinders 80 supported on the portion directly above the outer polishing chamber side plate 75 so as to extend and contract in the longitudinal direction of the base 16, and the cylinders of these shutter air cylinders 80. A pair of plate-shaped polishing chamber shutters 77 are fixed to the distal end portion of the rod 80a via a connecting member 81, respectively.
[0038]
A through hole 81a is formed in the connecting member 81, and a guide rod 82 provided on the polishing chamber top plate 76 is inserted into the through hole 81a. That is, it is supported by the connecting member 81 and the guide rod 82 so as to be horizontally movable in the longitudinal direction of the base 16.
These polishing chamber shutters 77 are arranged along the polishing chamber top plate 76 so as to cover the front surface polishing chamber 4 and the back surface polishing chamber 7, respectively, and in the longitudinal direction of the base 16 by the expansion and contraction of the shutter air cylinder 80. The polishing chamber top plate 76 is supported to be openable and closable. Further, the pair of polishing chamber shutters 77 are formed with semicircular cutouts 77a at inner edges facing each other, and a circular opening having an inner diameter slightly larger than the diameter of the support rod 74 at the center when closed. It is formed.
[0039]
The polishing chamber top plate 76 is provided with a polishing chamber top plate peripheral wall portion 83 that protrudes upward at the peripheral portion and is disposed so as to surround the upper surface of the polishing chamber top plate 76.
An intermediate top plate 84 is provided between the front surface polishing chamber 4 and the first transfer portion 20 and between the back surface polishing chamber 7 and the third transfer portion 24. An intermediate top plate peripheral wall 85 is provided at the peripheral edge so as to protrude upward and surround the upper surface of the intermediate top plate 84.
[0040]
The intermediate top plate 84 has one side edge disposed on the side plates 20a, 24a of the first transfer portion 20 and the third transfer portion 24 on the pivot shaft member 56 side, and the other side edges are the surface polishing chamber 4 and the back surface. The polishing chamber 7 is disposed on the outer surface of the polishing chamber side plate 75. That is, the intermediate section top plate 84 is arranged at a position lower than the polishing chamber top board 76 and is arranged at a position higher than the first delivery section 20 and the third delivery section 24.
[0041]
The polishing chamber top plate peripheral wall portion 83 is formed with a first low wall portion 83a whose protrusion amount is smaller than that of other portions on the intermediate portion top plate 84 side, and the intermediate portion top plate peripheral wall portion 85 is a protrusion amount. The second low wall portion 85a, which is smaller than the other portions, is formed on the first delivery portion 20 side and the third delivery portion 24 side, respectively.
Further, cleaning water is supplied onto the polishing chamber top plate 76 and the intermediate top plate 84 and is stored shallowly by the polishing chamber top plate peripheral wall portion 83 and the intermediate top plate peripheral wall portion 85.
[0042]
As shown in FIGS. 8 to 10, the front surface polishing mechanism 6 and the rear surface polishing mechanism 9 are centered on the semiconductor wafer W held by the wafer suction disk 54 in the front surface polishing chamber 4 and the back surface polishing chamber 7, respectively. A pair of polishing drums 90 that are arranged on both sides in the longitudinal direction of the base 16 and that are rotatably supported with axes parallel to the front and back surfaces of the semiconductor wafer W, that is, axes in a direction perpendicular to the longitudinal direction; A pair of drum driving means 91 for rotating and moving each of the polishing drums 90, and a polishing liquid supply means 92 for supplying the polishing liquid onto the polishing drum 90 and supplying the chamfered surface of the semiconductor wafer W during polishing. Each has.
[0043]
The drum driving means 91 is configured to move the polishing drum 90 forward and backward in a direction perpendicular to the longitudinal direction of the base 16, and to be supported by the drum linear movement unit portion 93 so as to be swingable. And a drum support portion 94 that contacts the chamfered surface of the semiconductor wafer W in a pressed state and supports the polishing drum 90 so as to be slidable in the direction toward the axis of the semiconductor wafer W. .
[0044]
The drum linear motion unit 93 is disposed between the first delivery unit 20 and the front surface polishing chamber 4 and between the third delivery unit 24 and the rear surface polishing chamber 7 and is fixed on the base 16 and is not shown. A unit main body 94 incorporating a ball screw and a motor for rotating the ball screw is provided, and a linear motion portion 95 that is screwed to the ball screw and movable along the ball screw.
[0045]
The drum support portion 94 includes a swing arm portion 96 whose upper end portion is supported by a pivot bearing portion 95 a provided on the upper portion of the linear motion portion 95 so as to be swingable, and a lower end portion of the swing arm portion 96. A drum support shaft portion 97 that is fixed and extends in a direction orthogonal to the longitudinal direction of the base 16 and that rotatably supports the polishing drum 90 is provided at the tip portion.
The swing arm portion 96 has a through hole 96a formed at an upper end portion thereof, and includes a swing rod 96b that is inserted into the through hole 96a and is rotatably supported at both ends by the pivot bearing portion 95a. .
[0046]
The drum support shaft portion 97 is fixed to the lower end portion of the swing arm portion 96 and penetrates the polishing chamber side plate 75 inside the surface polishing chamber 4, and the drum cylindrical member 98 inside the drum cylindrical member 98. And a drum rotating shaft member 99 that is rotatably inserted through a bearing portion 98a.
The drum rotation shaft member 99 has a polishing drum 90 fixed at the front end with the same axis, and a rotation drive source (not shown) connected to the rear end.
[0047]
The upper end portion of the swing arm portion 96 and the lower portion of the linear motion portion 95 are connected by a balance spring 100, and the lower end portion of the swing arm portion 96 and the lower portion of the direct motion portion 95 are a pressure air cylinder. 101.
The balance spring 100 holds the drum support shaft portion 97 supported by the swing arm portion 96 at a constant height, and sets the height position of the polishing drum 90 attached to the drum support shaft portion 97. It is to set.
[0048]
In addition, the pressing air cylinder 101 is fixed at a diagonally upward position so that the drum support shaft portion 97 held at a constant height by the balance spring 100 is directed toward the semiconductor wafer W in the suction state on the wafer suction plate 54 during polishing. The outer peripheral surface of the rotating polishing drum 90 that is pushed by the pressing force and is attached to the drum support shaft 97 is a chamfered surface on the front surface side of the semiconductor wafer W in the surface polishing mechanism 6, and the semiconductor wafer W in the back surface polishing mechanism 9. Are pressed against the chamfered surface on the back side.
[0049]
A drum cover 102 covering the outer peripheral surface half of the polishing drum 90 is attached to the tip of the drum cylindrical member 98.
The drum cover 102 is fixed to the drum cylindrical member 98 and is disposed in close proximity to the inner surface of the polishing drum 90, and the inner surface of the surface polishing chamber 4 and the rear surface polishing of the outer peripheral surface of the polishing drum 90. And an arcuate plate portion 102b that covers the other half of the semiconductor wafer W arranged in the chamber 7 on the opposite side.
[0050]
In addition, between the disk portion 102a and the polishing chamber side plate 95 inside the front surface polishing chamber 4 and between the disk portion 102a and the polishing chamber side plate 95 inside the back surface polishing chamber 7, the inside of the front surface polishing chamber 4 and the back surface polishing are performed. A bellows member 103 that covers the drum tubular member 98 in the chamber 7 is attached. These bellows members 103 prevent the polishing liquid from entering the drum cylindrical member 98 during polishing.
[0051]
The polishing liquid supply means 92 includes a plurality of supply nozzles 104 attached to the upper part of the arc-shaped plate portion 102 b of the drum cover 102, and the semiconductor wafer W fixed to the supply nozzles 104 and held on the wafer suction plate 54. A polishing liquid brush 105 disposed on the side and a polishing liquid introducing means 106 connected to the supply nozzle 104 and supplying the polishing liquid are provided.
The polishing liquid brush 105 is formed of an elastic body such as nylon, and its tip is arranged in contact with the outer peripheral surface along the axial direction of the polishing drum 90.
[0052]
As shown in FIG. 3, the polishing liquid introducing means 106 includes a slurry tank 107 that stores the polishing liquid, and a slurry pump 108 that sucks the polishing liquid from the slurry tank 107 and guides it to the supply nozzle 104. Reference numeral 109 denotes a cyclone for removing discharged mist used for reusing a used polishing liquid.
[0053]
As shown in FIG. 11, the polishing drum 90 includes a wheel body 110 made of an aluminum alloy that is fixed to the mounting flange 99a provided at the tip of the drum rotating shaft member 99 with the bolt 109 with the same axis. A polishing cloth 111 provided to cover the outer peripheral surface of the wheel main body 110 is provided.
On the outer peripheral surface of the wheel body 110, a ridge-shaped key 110a that extends parallel to the axis and protrudes radially outward is provided, and is inserted into the polishing cloth 111 from the inside to prevent the polishing cloth 111 from rotating. It is said that.
[0054]
The polishing cloth 111 is formed by laminating a plurality of unit polishing cloths 111a formed in an annular shape with a non-woven fabric having a non-constant fiber orientation, and is formed into a cylindrical shape. It is attached in the inserted state.
An annular reinforcing plate 112 made of vinyl chloride and set to the same outer diameter as that of the polishing cloth 111 is arranged on both end faces of the polishing cloth 111, and the outer side surfaces of these reinforcing boards 112 are made of stainless steel. An annular presser plate 113 having an outer diameter smaller than that of the polishing pad 111 is provided.
[0055]
The polishing cloth 111 has a compression rate set to 6 to 10%, and is set to a compression rate of 8% in this embodiment. Further, the thickness of the polishing pad 111 in the radial direction is set to about four times that of the semiconductor wafer W. For example, when the thickness of the semiconductor wafer W is 0.75 mm, the thickness is 3.0 mm.
The compression rate is based on JIS L-1096, and the thickness T ₁ after 1 minute when the initial load W ₀ is applied to the unit polishing cloth 111a is read, and simultaneously the load W ₁ is increased to 1 minute. It is calculated by the following equation from a reading of the thickness T ₂ of the post.
Compression rate (%) = (T ₁ −T ₂ ) / T ₁ × 100
(W ₀ = 300 g / cm ² , W ₁ = 1800 g / cm ² )
[0056]
The holding plate 113 on the base end side of the polishing drum 90 is locked to the enlarged diameter portion 110b formed on the outer peripheral surface of the base end portion of the wheel main body 110, and the press plate 113 on the front end side of the polishing drum 90 is the tip end of the wheel main body 110. It is supported in a pressed state toward the base end side by an annular polishing cloth pressing plate 115 fixed to the surface by bolts 114. Therefore, the polishing pad 111 is held between the reinforcing plate 112 and the holding plate 113 and is compressed in the axial direction by a constant pressing force.
[0057]
As shown in FIG. 12, the wafer storage mechanism 10 includes an unloader unit 15 for taking out and transferring the semiconductor wafer W, which is arranged above the third transfer unit 24 and transferred to the third transfer unit 24, with a storage hand 116. And a storage cassette mounting portion 117 for mounting the storage cassette C2 in which the semiconductor wafer W transferred by the unloader unit 15 is stored at a predetermined position.
[0058]
The unloader unit 15 is supported in a suspended state by a beam member 119 installed on top of two column members 118 erected on the base 16, and is moved in the horizontal direction attached to the beam member 119. The device 120 is movable along the extending direction of the beam member 119, that is, the direction orthogonal to the longitudinal direction of the base 16.
On the side surface of the horizontal movement device 120, a storage air cylinder 121 that can be expanded and contracted in the vertical direction is fixed with its upper portion suspended, and a lower portion of the storage air cylinder 121 has a storage hand at the tip. A hand rocking / rotating part 122 having 116 is supported.
[0059]
The hand rocking / rotating portion 122 includes a rocking rotary actuator 123 that rocks the storage hand 116 around a horizontal axis perpendicular to the longitudinal direction of the base 16 and an extension direction of the storage hand 116 as an axis. And a rotary actuator 124 for rotation.
The storage hand 116 has a plurality of suction holes (not shown) connected to suction means (not shown) at the tip, and sucks the semiconductor wafer W transferred to the fourth delivery section 26 by these suction holes. Support.
[0060]
The storage cassette mounting portion 117 is provided on the side surface on the end side of the base 16 and is disposed at a lower position than the fourth delivery portion 26. The storage cassette mounting section 117 includes a water tank section 125 in which four storage cassettes C2 can be arranged in a direction orthogonal to the longitudinal direction of the base 16 and supplied with pure water, and the water tank section 125. The cassette cassette 126 is placed between the water tank portion 125 and the base 16 and can be moved up and down individually. And four cassette raising / lowering air cylinders 127 to be supported.
[0061]
The storage cassette C2 is set such that the mounting position of the semiconductor wafer W is such that the front and back surfaces thereof are parallel to the longitudinal direction of the base 16 and the axis of the semiconductor wafer W is horizontal.
The cassette hand 126 is formed in an L-shaped longitudinal section, and the upper part thereof is fixed to the tip of the corresponding cylinder rod 127a of the cassette lifting / lowering air cylinder 127.
[0062]
Next, a semiconductor wafer chamfered surface polishing method in an embodiment of a semiconductor wafer chamfered surface polishing apparatus according to the present invention will be described with respect to a [wafer removal step], a [wafer positioning step], a [surface polishing step], and a [wafer reversal step] ], [Backside polishing step] and [Wafer storage step].
[0063]
[Wafer removal process]
First, the cassette C1 containing the semiconductor wafer W before the polishing process is set at a predetermined position on the cassette mounting table 13 so that the surface of the semiconductor wafer W faces downward.
[0064]
The loader unit 15 is driven to move the take-out hand 14 up and down and move it from the central part of the cassette mounting table 13 to the upper part of the semiconductor wafer W at a predetermined position to hold the semiconductor wafer W by suction. After the suction, the take-out hand 14 is returned to the central portion of the cassette mounting table 13 and rotated around the vertical axis so that the front end holding the semiconductor wafer W faces the wafer positioning unit 2.
[0065]
[Wafer positioning process]
After the loading hand 14 holding the semiconductor wafer W is moved upward by the loader unit 15 and set to a height corresponding to the mounting table 2 a of the wafer positioning unit 2, the extracting hand 14 is set to the mounting table of the wafer positioning unit 2. Move horizontally up 2a. At this time, the first hand 28 is arranged in advance under the mounting table 2a.
[0066]
Then, the suction is released while the semiconductor wafer W is placed on the mounting table 2 a, and the semiconductor wafer W is opened and transferred to the wafer positioning unit 2.
Next, the wafer positioning unit 2 is driven to center the semiconductor wafer W on the mounting table 2a and determine the orientation flat, thereby positioning the semiconductor wafer W in a predetermined direction.
[0067]
[Surface polishing process]
Next, the first hand 28 is raised by the first vertical movement cylinder 30 and the semiconductor wafer W positioned is placed on the upper surface, and is sucked and held by the suction groove 28a.
Then, the first hand 28 is moved horizontally above the first delivery unit 20 by the first rodless cylinder 29 to transfer the semiconductor wafer W to the first delivery unit 20.
[0068]
In this state, the wafer suction disk 54 previously positioned above the first delivery part 20 is lowered together with the suction disk support part 55 by the suction disk lifting / lowering air cylinder 70 and brought into contact with the semiconductor wafer W. At this time, the suction of the first hand 28 is released to release the semiconductor wafer W, and the semiconductor wafer W is sucked and held by the wafer suction disk 54 with the same axis.
[0069]
With the wafer suction plate 54 holding the semiconductor wafer W, the turning rotary actuator 58 is driven to turn the turning shaft member 56 by 180 ° and the wafer suction plate 54 to turn 180 °, and above the surface polishing chamber 4. Position.
Then, the polishing chamber shutter 77 of the surface polishing chamber 4 is slid by the operation of the shutter air cylinder 80 to open the top plate opening 76 a of the polishing chamber top plate 76.
[0070]
In a state where the top plate opening 76a is opened, the wafer suction plate 54 is lowered by the suction plate lifting / lowering air cylinder 70 and disposed at a predetermined position in the surface polishing chamber 4. At this time, the orientation of the semiconductor wafer W held on the wafer suction disk 54 is arranged along a direction perpendicular to the longitudinal direction of the base 16.
Further, in this state, the polishing chamber shutter 77 is slid again by the operation of the shutter air cylinder 80 to close the top plate opening 76 a of the polishing chamber top plate 76. At this time, the support rod 74 is disposed in a circular opening formed by the notch 77a of the polishing chamber shutter 77 in contact with each other.
[0071]
Next, the pair of polishing drums 90 in the surface polishing chamber 4 are moved from the base 16 side to both sides of the held semiconductor wafer W by driving the drum linear motion unit portion 93.
Further, by operating the pressing air cylinder 101 and pushing up the swing arm 96, the polishing cloth 111 of the pair of polishing drums 90 is pressed from the both sides of the semiconductor wafer W to the chamfered surface on the surface side with a predetermined pressing force. Abut. At this time, the orientation flat of the semiconductor wafer W is brought into contact with the vicinity of the lower part of the polishing liquid brush 105 on the polishing pad 111 of one polishing drum 90.
[0072]
In this state, the slurry pump 108 is driven to supply the polishing liquid sucked up from the slurry tank 107 onto the polishing cloth 111 from one supply nozzle 104. Then, a rotation driving source (not shown) is driven to rotate the polishing drum 90 in contact with the chamfered surface of the orientation flat so that the polishing cloth 111 slides along the chamfered surface of the orientation flat toward the axis of the semiconductor wafer W. Polishing is performed.
[0073]
At this time, the polishing liquid supplied from the supply nozzle 104 onto the polishing cloth 111 moves toward the semiconductor wafer W due to its own weight and the rotation of the polishing drum 90 and contacts the tip of the polishing liquid brush 105 to polish the polishing liquid. The drum 90 is spread in the axial direction. That is, since the polishing liquid is uniformly supplied in the axial direction of the polishing drum 90 and is made accustomed to the polishing cloth 111, good polishing performance can be obtained in the polishing cloth 111 at any position in the axial direction.
[0074]
After finishing the polishing of the chamfered surface of the orientation flat, the other polishing drum 90 is rotated in the same manner and the polishing liquid is supplied from the other supply nozzle 104 to the polishing pad 111. At the same time, the rotation motor 72 is driven to rotate the semiconductor wafer W together with the wafer suction disk 54 by 180 ° (half circumference). At this time, the rotation of the rotation motor 72 is decelerated to a predetermined rotation speed by the speed reducer 73a, the rotation angle of the wafer suction plate 54 is detected by the rotation angle detection sensor 73b, and the semiconductor wafer W is accurately rotated by 180 °. .
In other words, since the pair of polishing drums 90 are symmetrically arranged around the axis of the semiconductor wafer W on both sides of the semiconductor wafer W in a rotating state, the semiconductor wafer W is made to wrap around the entire circumference by making a half turn. The chamfered surface on the front side is polished.
[0075]
At this time, since the polishing pad 111 is slid along the chamfered surface in the direction toward the axis of the semiconductor wafer W, polishing is performed at the contact point between the polishing pad 111 and the chamfered surface M of the semiconductor wafer W as shown in FIG. Since the direction in which the cloth 111 moves (the direction of arrow A in the figure) and the direction in which the chamfered surface M of the semiconductor wafer W moves are orthogonal, the occurrence of circumferential streaks due to polishing is prevented.
[0076]
Furthermore, since the polishing cloth 111 is pressed against the chamfered surface M to be elastically deformed and slid, a raised portion 111b of the polishing cloth 111 that contacts the outer surface S of the semiconductor wafer W is formed, and the raised portion 111b is formed. Contacts the outer surface S in a pressed state and slides from the outer surface S toward the chamfered surface M. That is, the chamfered surface M is polished by the polishing cloth 111, and the outer surface S is also simultaneously polished without causing streaks in the circumferential direction.
[0077]
Also, the polishing liquid used during the above-described polishing flows down directly from the polishing drum 90 onto the polishing chamber bottom plate 78, or is guided downward by the arc-shaped plate portion 102b of the drum cover 102 and onto the polishing chamber bottom plate 78. run down. The disk portion 102 a of the drum cover 102 prevents the polishing liquid from scattering around the drum cylindrical member 98, and the arc-shaped plate portion 102 b prevents the polishing liquid from scattering to the polishing chamber side plate 75. .
[0078]
The polishing liquid that has flowed down on the polishing chamber bottom plate 78 flows to the polishing liquid drain hole 79 according to the inclination, and is discharged to a drainage reservoir (not shown). Note that the used polishing liquid in the drainage reservoir is subjected to mist removal processing by the cyclone 109 for reuse.
The polishing drum 90 is moved by a predetermined amount in the axial direction by the drum linear motion unit 93 for each semiconductor wafer W to be polished, and polished over a wide range on the outer peripheral surface of the polishing pad 111, whereby the length of the polishing drum 90 is increased. Life expectancy has been achieved.
[0079]
After the chamfered surface M on the front side is polished, the polishing chamber shutter 77 is slid to open the top plate opening 76a of the polishing chamber top plate 76. Then, the wafer suction plate 54 holding the semiconductor wafer W is raised to above the polishing chamber top plate 76 by the suction plate elevating air cylinder 70.
[0080]
While the chamfered surface M on the surface side of the semiconductor wafer W held by one wafer suction plate 54 is being polished in the surface polishing chamber 4, the other wafer suction plate 54 is used for the wafer take-out step and the wafer. Another semiconductor wafer W transferred to the first delivery unit 20 through the positioning process is sucked and held in the same manner as the one wafer suction disk 54.
[0081]
In this state, the turning rotary actuator 58 is driven to rotate the turning shaft member 56, and the one and the other wafer suction disks 54 are turned 180 degrees. That is, the semiconductor wafer W held on one wafer suction plate 54 is transferred again above the first delivery unit 20, and the semiconductor wafer W held on the other wafer suction plate 54 is transferred to the surface polishing chamber 4. The chamfered surface M on the front surface side is polished in the same manner as the semiconductor wafer W transferred to the upper side of the wafer and held on one wafer suction plate 54.
[0082]
At the time of turning, the polishing liquid may fall on the polishing chamber top plate 76 and the intermediate top plate 84 from one of the wafer suction plates 54 that are turning and the held semiconductor wafer W. However, the polishing chamber top plate 76 and the intermediate portion top plate 84 have their peripheral portions raised by the polishing chamber top plate peripheral wall portion 83 and the intermediate portion top plate peripheral wall portion 85 and store cleaning water. Does not flow down from the polishing chamber top plate peripheral wall portion 83 and the intermediate portion top plate peripheral wall portion 85 to other portions and does not dry out and adhere.
[0083]
The intermediate top plate 84 is set lower than the polishing chamber top plate 76 and higher than the first delivery unit 20 and the third delivery unit 24, and the polishing chamber top plate peripheral wall portion 83 and the intermediate top plate peripheral wall portion 85 are set. Since the first low wall portion 83a and the second low wall portion 85a are respectively formed in the polishing chamber, the polishing liquid that has dropped on the polishing chamber top plate 76 passes through the first low wall portion 83a together with the cleaning water. It flows down from the top plate 76 to the intermediate top plate 84, and further flows down from the intermediate top plate 84 to the first transfer portion 20 and the third transfer portion 24 via the second low wall portion 85a.
[0084]
[Wafer reversal process]
After the surface-polished semiconductor wafer W is transferred above the first delivery unit 20, the held wafer suction plate 54 is lowered and placed in the pure water of the first delivery unit 20 in a submerged state, The wafer suction disk 54 is rotated by a predetermined amount. At this time, the polishing liquid adhering to the semiconductor wafer W and the wafer suction disk 54 is washed away with pure water.
[0085]
After washing off the polishing liquid, the wafer suction plate 54 is raised again and positioned above the first delivery unit 20, and the second hand 35 is set at a position lower than the wafer suction plate 54 by the second vertical movement cylinder 37. The first rod 20 is horizontally moved by the second rodless cylinder 36 below the wafer suction plate 54 of the first delivery unit 20.
In this state, the wafer suction disk 54 is lowered and the semiconductor wafer W is placed on the second hand 35. At this time, the suction of the wafer suction disk 54 is released to open the semiconductor wafer W, and the lower surface, that is, the front side of the semiconductor wafer W is sucked and held by the suction holes 35a of the second hand 35.
[0086]
Next, the second hand 35 holding the semiconductor wafer W is moved horizontally to the second delivery unit 22 by the second rodless cylinder 36. The second hand 35 transferred to the second delivery unit 22 is set at a position higher than the radius of the semiconductor wafer W with respect to the bottom of the second delivery unit 22.
In this state, the reversing actuator 42 is driven to rotate the second hand 35 by 180 ° with the extending direction as the axis.
Then, the third hand 43 is moved below the semiconductor wafer W held by the second hand 35 by the third vertical movement cylinder 45 and the third rodless cylinder 44.
[0087]
After the third hand 43 is positioned below the second hand 35, the second hand 35 is lowered to place the semiconductor wafer W on the third hand 43. At this time, the suction of the second hand 35 is released to open the semiconductor wafer W, and the lower surface, that is, the back surface side of the semiconductor wafer W is sucked by the suction hole 35a of the third hand 43 to hold the semiconductor wafer W.
After adsorbing the semiconductor wafer W, the third hand 43 is moved horizontally by the third rodless cylinder 44 to the third delivery unit 24.
[0088]
[Back polishing process]
After the third hand 43 is arranged on the third delivery unit 24, the wafer suction plate 54 of the back surface polishing chamber transfer mechanism 8, which has been previously positioned above the third delivery unit 24, is lowered and on the third hand 43. It is brought into contact with the upper surface of the semiconductor wafer W. At this time, the suction of the third hand 43 is released to release the semiconductor wafer W, and the upper surface, that is, the front surface side of the semiconductor wafer W is sucked by the wafer suction disk 54 of the back surface polishing chamber transfer mechanism 8 to remove the semiconductor wafer W. Hold.
[0089]
Thereafter, similarly to the front surface polishing step, the back surface polishing chamber transfer mechanism 8 transfers the semiconductor wafer W held with the back surface facing downward into the back surface polishing chamber 7, and the orientation flat on the back surface side and the entire circumference of the outer edge portion are transferred. Polish the chamfered surface. At this time, similarly to the front surface side polishing, the outer side surface polishing is also performed on the back side.
Then, after the polishing of the chamfered surface on the back surface side is completed, the semiconductor wafer W held on the wafer suction plate 54 of the back surface polishing chamber transfer mechanism 8 is again placed above the third delivery portion 24 in the same manner as the front surface polishing step. Be transported.
[0090]
As in the surface polishing step, while the chamfered surface M on the back surface side of the semiconductor wafer W held on one wafer suction plate 54 in the back surface polishing chamber 7 is being polished, the other wafer suction plate 54 Another semiconductor wafer W transferred to the third delivery unit 24 through the surface polishing step and the wafer reversing step is sucked and held in the same manner as the one wafer suction disk 54.
[0091]
In this state, the turning rotary actuator 58 is driven to rotate the turning shaft member 56, and the one and the other wafer suction disks 54 are turned 180 degrees. That is, the semiconductor wafer W held on one wafer suction plate 54 is transferred again above the third delivery unit 24, and the semiconductor wafer W held on the other wafer suction plate 54 is transferred to the backside polishing chamber 7. The chamfered surface M on the back surface side is polished in the same manner as the semiconductor wafer W transferred to the upper side of the wafer and held on one of the wafer suction plates 54.
[0092]
[Wafer storage process]
After transferring the back-polished semiconductor wafer W to above the third delivery unit 24, the held wafer suction plate 54 is lowered and placed in the pure water of the third delivery unit 24 in a submerged state. The wafer suction disk 54 is rotated by a predetermined amount. At this time, the polishing liquid adhering to the semiconductor wafer W and the wafer suction disk 54 is washed away with pure water.
[0093]
After washing off the polishing liquid, the wafer suction disk 54 is further lowered, and the semiconductor wafer W is placed on the fourth hand 50 previously disposed near the bottom of the third delivery section 24. At this time, the suction of the wafer suction disk 54 is released to release the semiconductor wafer W, and the semiconductor wafer W is positioned and held on the fourth hand 50 by the protrusion 50a.
[0094]
Next, the fourth hand 50 holding the semiconductor wafer W is moved horizontally to the fourth delivery section 26 in a submerged state by the fourth rodless cylinder 51. At this time, the moving direction side portion of the fourth hand 50 moved to the fourth delivery portion 26 is fitted into the fourth hand support member 53 b of the hand lifting air cylinder 53.
Thereafter, the fourth hand 50 is raised above the fourth delivery section 26 by the hand lifting air cylinder 53 with the semiconductor wafer W placed thereon.
[0095]
At this time, the unloader unit 15 is driven in advance, and the tip of the storage hand 116 is arranged above the fourth delivery section 26 with the suction hole facing downward, and the fourth hand 50 is connected to the semiconductor wafer W. Is stopped at a position where it comes into contact with the storage hand 116.
In this state, the upper surface of the semiconductor wafer W is sucked by the suction holes of the storage hand 116 and the semiconductor wafer W is held.
Thereafter, the fourth hand 50 is lowered and retracted again to the vicinity of the bottom of the fourth delivery section 26 by the hand lifting air cylinder 53 again.
[0096]
Next, the storage hand 116 holding the semiconductor wafer W in a horizontal state is rotated 90 degrees about the extending direction as an axis by operating the rotary rotary actuator 124 to bring the semiconductor wafer W into a vertical state.
In this state, the storage hand 116 is lifted together with the hand swinging rotary part 122 by operating the storage air cylinder 121, and then the swinging rotary actuator 123 is operated to be orthogonal to the longitudinal direction of the base 16. The semiconductor wafer W is swung by rotating by 105 ° downward (in the direction of the arrow in the figure) around the horizontal axis, and the semiconductor wafer W is positioned above the water tank portion 125 of the storage cassette mounting portion 117.
[0097]
Further, the horizontal movement device 120 is driven, the storage hand 116 is moved in the extending direction of the beam member 119, and the semiconductor wafer W is positioned immediately above the storage position of the predetermined storage cassette C2.
Thereafter, the storage air cylinder 121 is extended, and the semiconductor wafer W held in the storage hand 116 is lowered to the storage position of the storage cassette C2. Then, the suction of the storage hand 116 is released, and the semiconductor wafer W is released and stored in the storage cassette C2.
[0098]
After a predetermined number of semiconductor wafers W are stored in the storage cassette C2 by the above steps, the cassette hand 126 on which the storage cassette C2 is placed is raised by the cassette lifting / lowering air cylinder 127, and the storage cassette C2 The handle part is taken out from the water tank part 125 upward. Thereafter, the semiconductor wafer W is taken out from the water tank unit 125 together with the storage cassette C2 and transferred to the next process.
[0099]
Since the semiconductor wafer chamfered surface polishing apparatus includes the first transfer unit 20 and the third transfer unit 24 for cleaning the semiconductor wafer W in addition to the front surface polishing chamber 4 and the back surface polishing chamber 7, the front surface polishing chamber The semiconductor wafer W whose surface side chamfered surface M is polished in step 4 is transferred to the first delivery unit 20 by the surface polishing chamber transfer mechanism 5, whereby the polishing liquid adhering during the surface side polishing is cleaned.
[0100]
Further, by transferring the semiconductor wafer W whose chamfered surface M on the back surface side is polished in the back surface polishing chamber 7 to the third delivery section 24 by the back surface polishing chamber transfer mechanism 8, the polishing liquid adhering during the back surface polishing is cleaned. The Therefore, each time the polishing of the chamfered surface M on the front surface side and the back surface side is completed, the semiconductor wafer W is respectively transferred to the first transfer portion 20 and the third transfer portion 24 provided separately from the front surface polishing chamber 4 and the back surface polishing chamber 7. Since it is cleaned immediately, the adhering polishing liquid remains so that unnecessary portions are not polished.
[0101]
Further, since the front surface polishing chamber 4 and the back surface polishing chamber 7 are separately provided, the polishing process is individually processed in parallel, and other semiconductor wafers W are formed in the first transfer unit 20 and the third transfer unit 24. It is cleaned in parallel.
Further, since the front surface polishing chamber 4 and the back surface polishing chamber 7, and the first transfer unit 20 and the third transfer unit 24 are provided separately, the mutual mixing of the polishing liquid and the cleaning water is small, and each reuse is possible. Easy to do.
[0102]
Furthermore, since the wafer transfer mechanism 3 includes a wafer reversing unit, the front side and the back side of the semiconductor wafer to be polished in the front surface polishing chamber and the rear surface polishing chamber are directed in the same direction by the wafer reversing unit. The polishing process on the front surface side and the back surface side can be performed by a polishing mechanism having the same configuration.
[0103]
【The invention's effect】
The present invention has the following effects.
(1) According to the semiconductor wafer chamfered surface polishing apparatus of the present invention, since the front surface side cleaning chamber and the rear surface polishing chamber are provided separately from the front surface polishing chamber and the rear surface polishing chamber, the front surface side and the back surface side are provided. Each time the polishing of the chamfered surface is finished, the semiconductor wafer and the wafer suction disk are immediately cleaned in the front side wafer cleaning unit and the back side wafer cleaning unit, respectively. A trace is not left and high flatness can be maintained and a high-quality semiconductor wafer can be manufactured. In addition, since the front surface polishing chamber and the back surface polishing chamber are provided separately, each of the polishing processes is processed in parallel, and other semiconductor wafers are cleaned in parallel in the front surface side wafer cleaning section and the back surface side wafer cleaning section. By processing, a large amount of semiconductor wafers can be polished continuously and efficiently in a short time. Further, since the front surface polishing chamber and the back surface polishing chamber are separately provided from the front surface side wafer cleaning unit and the back surface side wafer cleaning unit, the reuse of each can be reduced by reducing the mutual mixing of the polishing liquid and the cleaning water. It is easy to reduce the running cost and the like.
[0104]
(2) According to the semiconductor wafer chamfered surface polishing apparatus of the present invention , since the wafer transport mechanism includes the wafer reversing means, the front surface side of the semiconductor wafer polished by the wafer reversing means in the front surface polishing chamber and the back surface polishing chamber. Since the front surface and the back surface are directed in the same direction, the polishing process on the front surface side and the back surface side can be performed by a polishing mechanism having the same configuration. Therefore, it is possible to reduce the cost of the polishing apparatus and improve the maintainability.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of a chamfered surface polishing apparatus for a semiconductor wafer according to the present invention.
FIG. 2 is a plan view showing an embodiment of a chamfered surface polishing apparatus for a semiconductor wafer according to the present invention.
FIG. 3 is a left side view showing an embodiment of a chamfered surface polishing apparatus for a semiconductor wafer according to the present invention.
FIG. 4 is a plan view showing a wafer transfer mechanism in an embodiment of a semiconductor wafer chamfered surface polishing apparatus according to the present invention.
FIG. 5 is a front view showing a wafer transfer mechanism in an embodiment of a chamfered surface polishing apparatus for a semiconductor wafer according to the present invention.
FIG. 6 is a longitudinal sectional view showing first to fourth transfer units in an embodiment of a chamfered surface polishing apparatus for a semiconductor wafer according to the present invention.
7 is a cross-sectional view taken along line XX in FIG.
FIG. 8 is a longitudinal sectional view showing a surface polishing chamber and a surface polishing mechanism in an embodiment of a chamfered surface polishing apparatus for a semiconductor wafer according to the present invention.
FIG. 9 is a partially cutaway plan view showing a surface polishing chamber and a surface polishing mechanism in an embodiment of a chamfered surface polishing apparatus for a semiconductor wafer according to the present invention.
FIG. 10 is a longitudinal sectional view showing a main part of a surface polishing mechanism in an embodiment of a chamfered surface polishing apparatus for a semiconductor wafer according to the present invention.
FIG. 11 is a cross-sectional view showing a polishing drum in one embodiment of a chamfered surface polishing apparatus for a semiconductor wafer according to the present invention.
FIG. 12 is a longitudinal sectional view showing a wafer storage mechanism in an embodiment of a chamfered surface polishing apparatus for a semiconductor wafer according to the present invention.
FIG. 13 is an enlarged longitudinal sectional view of a main part for explaining polishing of a chamfered surface in an embodiment of a chamfered surface polishing apparatus for a semiconductor wafer according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 3 Wafer conveyance mechanism 4 Surface polishing chamber 5 Surface polishing chamber transfer mechanism 6 Surface polishing mechanism 7 Back surface polishing chamber 8 Back surface polishing chamber transfer mechanism 9 Back surface polishing mechanism 20 1st delivery part (surface side wafer cleaning part)
23 Second transfer unit (wafer reversing means)
24 Third delivery section (backside wafer cleaning section)
42 Reverse actuator M Chamfered surface W Semiconductor wafer

Claims (2)

A semiconductor wafer chamfered surface polishing apparatus for supplying a polishing liquid to a chamfered surface formed on a peripheral edge of a semiconductor wafer and sliding the polishing cloth in a pressed state to polish the chamfered surface,
A wafer transfer mechanism for transferring the semiconductor wafer;
A front surface polishing chamber and a back surface polishing chamber for polishing the chamfered surfaces on the front surface side and the back surface side of the semiconductor wafer, respectively;
A front surface polishing chamber transfer mechanism and a back surface polishing chamber transfer mechanism that transfer the semiconductor wafer transferred by the wafer transfer mechanism to the front surface polishing chamber and the back surface polishing chamber and return to the wafer transfer mechanism after polishing, respectively.
The surface polishing chamber transfer mechanism is provided with a wafer suction disk that supports a semiconductor wafer at the time of polishing and transfer and is positioned in the surface polishing chamber at the time of surface chamfering polishing of the semiconductor wafer,
The backside polishing chamber transfer mechanism is provided with a wafer suction disk that is supported during polishing and transfer of the semiconductor wafer and is positioned in the backside polishing chamber during backside chamfering polishing of the semiconductor wafer,
The said wafer transport mechanism, filled the surface polishing chamber transferor up of the wafer the surface polishing chamber or al transfer surface being polished of the semiconductor wafer and the wafer suction plate and held by a suction disc with wash water together are positioned in a submerged state in a water bath, and the wafer suction disc is rotated, the surface-side wafer cleaning unit for washing washed off the polishing solution adhering to the semiconductor wafer and the wafer suction disc,
It is positioned in a submerged state in a water bath filled with cleaning water back surface polished of the semiconductor wafer and the wafer suction cups that are transported to the front Symbol backside polishing chamber held by the wafer suction disc at the back grinding chamber transport mechanism In addition, a chamfered surface polishing of a semiconductor wafer is provided , wherein the wafer suction disk is rotated, and a semiconductor wafer and a back-side wafer cleaning unit for cleaning the semiconductor wafer and the polishing liquid adhering to the wafer suction disk are washed away. apparatus. The chamfered surface polishing apparatus for a semiconductor wafer according to claim 1,
The wafer transfer mechanism includes a wafer reversing unit that receives and inverts the semiconductor wafer transferred from the front surface polishing chamber by the front surface polishing chamber transfer mechanism and passes it to the back surface polishing chamber transfer mechanism. Chamfered surface polishing equipment.

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