Wafer transfer apparatus, wafer gripper, and wafer gripper guide used in such wafer transfer apparatus
In a wafer transfer apparatus for transferring a semiconductor wafer, a wafer gripper is composed of a pair of gripper arms, and a gripper guide is attached to each of the gripper arms. A driving unit operates the gripper arms such that the semiconductor wafer is releasably gripped with the gripper guides of the gripper arms. Each of the gripper guides is formed with a groove for receiving a peripheral edge of the semiconductor wafer, and the groove is configured as a generally V-shaped groove featuring a ridge element protruded from an outer side edge thereof.
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1. Field of the Invention
The present invention relates to a wafer transfer apparatus which may be used to transfer a semiconductor wafer from one apparatus to another apparatus in a semiconductor device manufacturing field, and more particularly relates to a wafer transfer apparatus which may be incorporated in an ion implantation equipment to load and unload semiconductor wafers into and from the ion implantation equipment.
Also, the present invention relates to a wafer gripper and a wafer gripper guide which are used in such a wafer transfer apparatus to grip the semiconductor wafer.
2. Description of the Related Art
In a manufactory for producing semiconductor devices, an ion implantation equipment is used to implant ions into semiconductor wafers. The ion implantation equipment includes a processing chamber housing in which a vacuum state is created, an ion beam generator provided in the processing chamber housing, a rotary disk rotatably provided in the processing chamber housing, and a plurality of circular pedestals arranged at regular intervals along a periphery of the rotary disk. Each of the circular pedestals is formed as a metal (e.g. aluminum) plate coated with silicone rubber, and a semiconductor wafer to be processed is placed and clamped on each of the circular pedestals.
In an ion implantation operation, an ion beam is emitted from the ion beam generator, while the rotary disk is rotated at a high rotational speed, e.g. 1200 rpm, and is swung at a speed, e.g. 46 mm/sec, in a direction perpendicular to the rotational axis of the rotary disk, so that all the wafers can be uniformly and completely scanned with the ion beam.
In the ion implantation equipment, the processing chamber housing is provided with a wafer loading/unloading chamber housing which is integrally and outwardly extended therefrom, and the wafer loading/unloading chamber housing is associated with a wafer loading/unloading unit. A wafer transfer apparatus is incorporated in the wafer loading/unloading chamber housing such that semiconductor wafers are transferred one by one from the wafer loading/unloading unit to the processing chamber housing, and the transferred wafer is placed and clamped on one of the circular pedestals.
When the wafers are placed and clamped on all circular pedestals, i.e., when the loading of the wafers in the processing chamber housing is completed, the wafers are processed with the ion beam in the above-mentioned manner, the processed wafers are transferred one by one from the processing chamber housing to the wafer loading/unloading unit by the wafer transfer apparatus. Namely, the unloading of the wafers from the processing chamber housing to the wafer loading/unloading unit is carried out by the wafer transfer apparatus.
The wafer transfer apparatus includes a wafer gripper composed of first and second gripper arms which are pivotally joined to each other by a pivot joint. The first gripper arm terminates with a curved end portion having a gripper guide securely attached thereto, and the second gripper arm terminates with a semi-circularly curved end portion having two gripper guides. Each of the gripper guides is formed with a generally V-shaped groove for receiving a peripheral edge of the wafer, and the first and second gripper arms are operated so that the peripheral edge of the wafer is engaged in and disengaged from the generally V-shaped grooves of the gripper guides. Namely, by operating the gripper arms, it is possible to releasably grip the wafer with the gripper guides.
When the processed wafer is removed from the pedestal, first, the wafer is gripped with the gripper guides by operating the gripper arms, and the processed wafer is unclamped on the pedestal. Thereafter, the gripper arms are moved so that the gripper guides carrying the processed wafer are moved from the pedestal.
Incidentally, while the wafers are processed in the processing chamber housing, some of the wafers may be stuck on the silicone rubber surfaces of the pedestals. As causes of the sticking of the wafer on the pedestal, there are a centrifugal force to which the wafers is subjected, moisture contents included in the processing chamber housing, a formation of a silicon dioxide layer on a surface of the wafer, (in this case, the wafer is made of silicon), and so on.
When the wafer is strongly stuck on the silicone rubber surface of the pedestal, the gripper arms may fail in the removal of the processed wafer from the pedestal, because the peripheral edge of the processed wafer is disengaged from the generally V-shaped grooves of the gripper guides without removing the wafer from the pedestal.
Also, when the processed wafers are relatively weakly stuck on the silicone rubber surface of the pedestal, it is possible to remove the processed wafers from the pedestal, but one or two of the gripper guides may be disengaged from the processed wafers, so that the processed wafers may fall off from the gripper arms.
Although the silicone rubber surface of the pedestal is treated as a rough surface in order to prevent the sticking of the wafer on the pedestal, although the silicone rubber surface of the pedestal is treated as a rough surface, the rough surface easily deteriorates to become a smooth surface. The pedestals carrying no semiconductor wafers are periodically irradiated with an argon ion beam by using the ion beam generator, to thereby improve the deterioration of the silicone rubber surface, but it is very costly to periodically repeat this process.
SUMMARY OF THE INVENTIONTherefore, an object of the present invention is to provide a wafer transfer apparatus including a wafer gripper composed of a pair of gripper arms which are constituted such that a safe removal of a processed semiconductor wafer from a pedestal can be ensured when the processed semiconductor wafer is stuck on the pedestal.
Another object of the present invention is to provide a wafer gripper and a wafer gripper guide which are used in such a wafer transfer apparatus.
In accordance with a first aspect of the present invention, there is provided a wafer transfer apparatus for transferring a semiconductor wafer, which comprises a wafer gripper composed of first and second gripper arms which are pivotally joined to each other, a first gripper guide attached to the first gripper arms, a second gripper guide attached to the second gripper arms, and a driving unit that operates the first and second grippers such that the semiconductor wafer is releasably gripped with the first and second gripper guides of the first and second gripper arms. Each of the first and second gripper guides is formed with a groove for receiving a peripheral edge of the semiconductor wafer, and the groove is configured as a generally V-shaped groove featuring a ridge element protruded from an outer side edge thereof.
In accordance with a second aspect of the present invention, there is provided a wafer gripper for gripping a semiconductor wafer, which comprises first and second gripper arms which are pivotally joined to each other, a first gripper guide attached to the first gripper arms, and a second gripper guide attached to the second gripper arm. Each of the first and second gripper guides is formed with a groove for receiving a peripheral edge of the semiconductor wafer, and the groove is configured as a generally V-shaped groove featuring a ridge element protruded from an outer side edge thereof.
Preferably, an end portion of the first gripper arm is formed as a curved end portion to which the first gripper guide is attached, and an end portion of the second gripper arm is formed as a semi-circularly curved end portion to which the second gripper guide is attached. More preferably, the semi-circularly curved end portion terminates with an arch extension which is detachably connected thereto, and the second gripper guide is attached to the arch extension. The arch extension may have a third gripper guide attached thereto.
In accordance with a third aspect of the present invention, there is provided a wafer gripper guide comprising a body portion which is formed with a groove for receiving a peripheral edge of a semiconductor wafer, with the groove being configured as a generally V-shaped groove featuring a ridge element protruded from an outer side edge thereof, and an attachment portion extended from the body portion.
Preferably, the generally V-shaped groove is defined by a bottom wall face, and a pair of tapered side wall faces extending from the lateral sides of the bottom wall face, and the ridge element is protruded from an outer side edge defining one of the tapered side wall faces. More preferably, the bottom wall face is configured as an arch bottom wall face having substantially the same curvature as that of a peripheral edge of the semiconductor wafer. The arch bottom wall face may have a width which is substantially equivalent to a thickness of the semiconductor wafer. The ridge element may have a height of at most 0.5 mm.
BRIEF DESCRIPTION OF THE DRAWINGSThe above object and other objects will be more clearly understood from the description set forth below, with reference to the accompanying drawings, wherein:
FIG 11B is a cross-sectional view taken along the XI-XI line of
First, referring to
Referring to
The processing chamber housing 12 includes a rotary disk 16 for carrying semiconductor wafers to be processed. Namely, the rotary disk 16 has a plurality of circular pedestals 18 arranged at regular intervals along a periphery thereof, and the wafers to be processed are placed and clamped on the respective circular pedestals 18. Although each of the circular pedestals 18 is securely attached to the rotary disk 16, they can be removed from the rotary disk 16, for example, when being exchanged with a fresh pedestal. Note, each of the circular pedestals 18 is formed as a metal (e.g. aluminum) plate coated with silicone rubber, and has a diameter which is somewhat smaller than that of the wafer to be processed. Note, the rotary disk 16 may have a diameter of 1,200 mm.
In order to clamp the wafers to be processed on the respective circular pedestals 18, each of the circular pedestals 18 is provided with a clamp unit including a centering stopper 20, a pair of wafer pusher pins 22, and a hydraulic cylinder (not shown) associated with the wafer pusher pins 22. After the wafer to be processed is placed on the circular pedestal 18, when the wafer pusher pins 22 are moved toward the centering stopper 20 by actuating the hydraulic cylinder, the wafer to be processed is centered with respect to the circular pedestal 18, and is clamped thereon by the wafer pusher pins 22 in conjunction with the centering stopper 20. When the wafer pusher pins 22 are moved apart from the centering stopper 20 by actuating the hydraulic cylinder, the wafer is released from the clamped state based on the conjunction of the wafer pusher pins 22 with the centering stopper 20.
Returning to
The wafer loading/unloading unit 26 includes a base stand 28 securely installed on a floor FL, a gutter-like frame 30 rotatably attached to a top of the base stand 28 at a pivot shaft 32, and a movable wafer cassette 34 movably received in the gutter-like frame 30. Note, although not shown in
In
Returning to
Note, as stated in detail hereinafter, the wafers W are loaded one by one from the wafer cassette 34 in the ion implantation equipment 10 so that each of the wafers W is placed and clamped on a corresponding pedestal 18 by the wafer pusher pins 22 in conjunction with the centering stopper 20, and are unloaded from the ion implantation equipment 10 in the wafer cassette 34 after the wafers-W are processed in the ion implantation equipment 10.
In
With reference to
In
As shown in
Then, as shown in
Next, as shown in
Thereafter, the wafer cassette 34 is moved to the position shown in
Returning to
Referring to
Again referring to
As shown in
Note, the gripper arms 42A and 42B may be formed of a suitable metal material, such as aluminum, stainless steel or the like.
Note, in
In
As shown in
As shown in
The arch extension 51 is fine or thin, and thus is susceptible to damage. This is the reason why the arch extension 51 is detachably connected to the semi-circularly curved end portion 48B. Namely, when the arch extension 51 is damaged, only the damaged arch extension 51 can be exchanged with a fresh arch extension without exchanging the entirety of the gripper arm 42B. Nevertheless, the arch extension 51 may be integrally formed as a part of the semi-circularly curved end portion 48B, if necessary.
In
According to the present invention, the gripper guide 50A features a ridge element 50A6 protruded from an outer side edge defining the tapered side wall face 50A5.
Also, the gripper guide 50A includes a plate element 50A7 defined as an attachment portion, which is integrally extended from the elongated rectangular head 50A1, and which has a pair of screw bores 50A8 for attaching the plate element 50A7 to the curved end portion 48A of the gripper arm 42A by screws, as shown in
In
According to the present invention, the gripper guide 50B features a ridge element 50B6 protruded from an outer side edge defining the tapered side wall face 50B5.
Also, the gripper guide 50B includes a block element 50B7 defined as an attachment portion, which is integrally extended from the trapezoid head 50B1, and which has a pair of screw bores 50B8 for attaching the block element 50B7 to the arch extension 51 of the gripper arm 42B by screws, as shown in
In
According to the present invention, the gripper guide 50C features a ridge element 50C3 protruded from an outer side edge defining the tapered side wall face 50C5.
Also, the gripper guide 50C includes a plate element 50C7 defined as an attachment portion, which is integrally extended from the trapezoid head 50C1, and which has a pair of screw bores 50C8 for attaching the plate element 50C7 to the arch extension 51 of the gripper arm 42B by screws as shown in
Note, a function of the ridge elements 50A3, 50B3 and 50C3 of the gripper guides 50A, 50B and 50C is stated in detail hereinafter.
Preferably, each of the gripper guides 50A, 50B and 50C is formed as a block piece composed of a suitable synthetic resin material. For example, each of the gripper guides 50A, 50B and 50C may be formed as a molded product. Otherwise, each of the gripper guides 50A, 50B and 50C may be shaped from a resin blank by a numerical control (NC) lathe machine.
In
The driving unit 44 also includes a hydraulic cylinder 54 securely supported by the bracket 52B, and a support plate member 56 securely suspended from a plunger 65A of the hydraulic cylinder 54. The support plate member 56 has a shoe portion 56A slidably engaged with the guide rail 52A, and thus the support plate 56 can be moved along the guide rail 52A by actuating the hydraulic cylinder 54. The support plate member 56 also has a pair of guide rails (only one of which is visible and indicated by reference 56B in
The driving unit 44 further includes a hydraulic cylinder 58 securely attached to a side wall of the support plate member 56, and a bearing drum 60 suspended from the guide rails 56B of the support plate member 56 through a pair of suspension arm members, only one of which is visible and indicated by reference 60A in
As shown in
In order to maintain a vacuum state created in the wafer loading/unloading chamber housing 24, a flexible bellows 60C is provided between the opened end face wall of the bearing drum 60 and the side wall of the chamber housing. 24. Namely, an end of the flexible bellows 60C is air-tightly attached to the opened end face wall 60F of the bearing drum 60, and the other end of the flexible bellows 60C is air-tightly attached to the side wall of the chamber housing 24 so as to surround the opening 62.
The bearing drum 60 has a shaft 60D rotatably supported therein, and the shaft 60D outwardly extends from the opened end face wall 60F of the bearing drum 60, and passes through the flexible bellows 60C and the opening 62. Then, the shaft 60S is securely connected to the lower end of the gripper arm 42A.
The driving unit 44 further includes a hydraulic cylinder 64 which is supported by a bracket member 60E securely attached to a side of the bearing drum 60 at the closed end face wall 60G thereof. The hydraulic cylinder 64 is used to slightly rotate the gripper arm 42B at the pivot joint 46 of
To this end, the bearing dram 60 contains a linkage acting between an lower end of the gripper arm 42B and a plunger of the hydraulic cylinder 64. Although not shown in
The driving unit 44 further includes a reduction gear drum 66 supported by a bracket member 60H suspended from the bearing drum 60, and an electric motor 68 operationally connected to the reduction gear drum 66. The reduction gear drum 66 contains a reduction gear train, an input shaft of which is connected to the electric motor 68. An output shaft of the reduction gear train is covered with an air-tight housing 66A, which is in communication with an interior of the bearing drum 60. Although is not shown in
With the above-mentioned arrangement of the driving unit 44, when the hydraulic cylinder 54 is actuated, the pair of gripper arms 42A and 42B are moved together upward and downward along the length of the guide rail 52A. When the hydraulic cylinder 58 is actuated, the pair of gripper arms 42A and 42B are laterally moved together along the length of the guide rails 56B. When the electric motor 68 is driven, the pair of gripper arms 42A and 42B are rotated together around an axis of the shaft 60D of the bearing drum 60. When the hydraulic cylinder 64 is actuated, only the gripper arm 42B is slightly rotated at the pivot joint 46 with respect to the gripper arm 42A.
In the above-mentioned ion implantation equipment of
As shown in
The wafer catcher unit 70 includes a hydraulic cylinder (not shown) securely attached to the processing chamber housing 12, and a movable casing 72 connected to a plunger of the hydraulic cylinder. By actuating the hydraulic cylinder, the movable casing 72 is moved in one of two directions indicated by a double-headed arrow AR.
In
Also, each of the wafer receivers 74 has an L-shaped rod element 74D integrally extended from the base portion 74A, and the L-shaped rod element 74D passes through the hole 12C of the lid member 12B of
In
The respective lower end portions of the L-shaped rod elements 74D of
The wedge-shaped cam 78 has a pair of cam faces 78A and 78B which cooperate with the respective cam followers 76A and 76B. Also, the wedge-shaped cam 78 is connected to a plunger of a hydraulic cylinder, indicated by reference 80.
Usually, as shown in
As shown in
Again, referring to
The operation of the wafer catcher unit 70 of
Note, during the unloading of the processed wafers W from the processing chamber housing 12 into the wafer cassette 34 and the loading of the not processed wafers W from the wafer cassette 34 into the processing chamber housing 12, the rotary disk 16 is intermittently rotated by a driving unit (not shown) such that the pedestals 18 are aligned with the wafer catchers 74 one after another.
With reference to
First, referring to
Then, by actuating the hydraulic cylinder 64 (see:
Subsequently, by actuating the hydraulic cylinder 54 (see:
Next, by driving the electric motor 68 (see:
Note, referring to
After the movement of the not processed W to the pedestal-aligned position is completed, the wafer catchers 74, which are in the opened state (see: FIG 11B), are moved from the initial position (see:
After the not processed wafer W has been securely caught by the claw elements 74C of the wafer catchers 74, by actuating the hydraulic cylinder 64 (see:
After the disengagement of the gripper guides 50A, 50B and 50C from the not processed wafer W is completed, the wafer receivers 74 are once returned from the intermediate position (see:
Referring to
After the processed wafer W′ is gripped by the gripper guides 50A, 50B and 50C of the gripper arms 42A and 42B at the aforesaid wafer-gripping position, as shown in
Next, by actuating the hydraulic cylinder 58 (see:
Then, by driving the electric motor 68 (see:
Subsequently, by actuating the hydraulic cylinder 54 (see:
Thereafter, the upper end portions 48A and 48B of the gripper arms 42A and 42B are operated in substantially the manner as explained with reference to
On the other hand, after both the upper end portions 48A and 48B of the gripper arms 42A and 42B are rotated in the clockwise direction to transfer the processed wafer W′ from the processing chamber housing 12 to the wafer loading/unloading chamber housing 24, the wafer catchers 74, by which the not processed wafer W is caught, are moved from the initial position (see:
Then, the wafer pusher pins 22 are moved toward the centering stopper 20 by actuating the hydraulic cylinder (not shown), and thus the not processed wafer W is clamped on the pedestal 18 by the wafer pusher pins 22 in conjunction with the centering stopper 20, as shown in
After the clamping of the not processed wafer W on the pedestal 18 by the centering stopper 20 and the wafer pusher pins 22 is completed, the wedge-shaped cam 78 is thrust from the retracted position (see:
After the wafer catchers 74 are returned to the initial position (see:
The above-mentioned operation is repeated until all the not processed wafers W are loaded from the wafer cassette 34 into the processing chamber housing 12, and until all the processed wafer silicone wafer W′ are unloaded from the processing chamber housing 12 into the wafer cassette 34.
As already stated hereinbefore, each of the processed wafers W′ may be stuck on the silicone rubber surface of the pedestal 18. Nevertheless, according to the present invention, it is possible to ensure a removal of the processed wafers W′ from the pedestals 18 when the upper end portions 48A and 48B of the gripper arms 42A and 42B, carrying the processed wafer W′ gripped by the gripper guides 50A, 50B and 50C, are moved from the wafer-gripping position (see:
In particular, as stated above, after the peripheral edge of the processed wafer W′ is gripped by the generally V-shaped grooves 50A2, 50B2 and 50C2 of the gripper guides 50A, 50B and 50C, as shown in
In
Also, when the gripper guides 50 are disengaged from the processed wafer W′, it may be subjected to a reaction force so that the wafer W′ is removed from the pedestal 18. Further, when the wafer W′ is relatively weakly stuck on the silicone rubber surface of the pedestal 18, it is possible to remove the processed wafer W′ from the pedestal 18 by using the gripper guides 50, but one or two of the gripper guides 50 may be disengaged from the processed wafer W′, so that the processed wafer W′ may fall off from the upper end portions 48A and 48B of the gripper arms 42A and 42B (see:
JP-2000-306982A discloses a stopper member having a generally U-shaped groove for receiving a peripheral edge of a wafer to thereby hold the wafer on a pedestal. In this stopper member, the generally U-shaped groove has a width which is slightly larger than a thickness of the wafer, and thus a secure hold of the wafer on the pedestal can be ensured. Nevertheless, this stopper member should not be substituted for the gripper guides 50A, 50B and 50C of
In the above-described embodiment, each of the gripper guides 50A, 50B and 50C (see:
Also, the ridge element 50A6, 50B6 and 50C6 should have a height of at least 0.2 mm before the removal of the processed wafer W′ from the pedestal 18 can be ensured when the wafer W′ is strongly stuck on the silicone rubber surface of the pedestal 18. The higher the height of the ridge element 50A6, 50B6 and 50C6, the larger a damage to which the wafer W′ is subjected upon the removal of the wafer W′ from the pedestal 18. Accordingly, the height of the ridge element 50A6, 50B6 and 50C6 should be at most 0.5 mm. Preferably, the height of the ridge element 50A6, 50B6 and 50C6 should fall within a range from 0.3 mm to 0.4 mm.
Further, before the removal of the processed wafer W′ from the pedestal 18 can be ensured when the wafers W′ is strongly stuck on the silicone rubber surface of the pedestal 18, the ridge element 50A6, 50B6 and 50C6 should have a sufficient strength. Thus, a thickness of the ridge element 50A6, 50B6 and 50C6 should be at least 0.5 mm.
Finally, it will be understood by those skilled in the art that the foregoing description is of a preferred embodiment of the apparatus, and that various changes and modifications may be made to the present invention without departing from the spirit and scope thereof.
Claims
1. A wafer transfer apparatus for transferring a semiconductor wafer, which comprises:
- a wafer gripper composed of first and second gripper arms which are pivotally joined to each other;
- a first gripper guide attached to said first gripper arms;
- a second gripper guide attached to said second gripper arms; and
- a driving unit that operates said first and second grippers such that the semiconductor wafer is releasably gripped with said first and second gripper guides of said first and second gripper arms,
- wherein each of said first and second gripper guides is formed with a groove for receiving a peripheral edge of the semiconductor wafer, and said groove is configured as a generally V-shaped groove featuring a ridge element protruded from an outer side edge thereof.
2. The wafer transfer apparatus as set forth in claim 1, wherein an end portion of said first gripper arm is formed as a curved end portion to which said first gripper guide is attached, and an end portion of said second gripper arm is formed as a semi-circularly curved end portion to which said second gripper guide is attached.
3. The wafer transfer apparatus as set forth in claim 2, wherein said semi-circularly curved end portion terminates with an arch extension which is detachably connected thereto, and said second gripper guide is attached to said arch extension.
4. The wafer transfer apparatus as set forth in claim 3, wherein said arch extension has a third gripper guide attached thereto.
5. The wafer transfer apparatus as set forth in claim 1, wherein said generally V-shaped groove is defined by a bottom wall face, and a pair of tapered side wall faces extending from the lateral sides of the bottom wall face, and said ridge element is protruded from an outer side edge defining one of the tapered side wall faces.
6. The wafer transfer apparatus as set forth in claim 5, wherein said bottom wall face is configured as an arch bottom wall face having substantially a same curvature as that of a peripheral edge of the semiconductor wafer.
7. The wafer transfer apparatus as set forth in claim 6, wherein said arch bottom wall face has a width which is substantially equivalent to a thickness of the semiconductor wafer.
8. A wafer gripper for gripping a semiconductor wafer, which comprises:
- first and second gripper arms which are pivotally joined to each other;
- a first gripper guide attached to said first gripper arms; and
- a second gripper guide attached to said second gripper arm,
- wherein each of said first and second gripper guides is formed with a groove for receiving a peripheral edge of the semiconductor wafer, and said groove is configured as a generally V-shaped groove featuring a ridge element protruded from an outer side edge thereof.
9. The wafer gripper as set forth in claim 8, wherein an end portion of said first gripper arm is formed as a curved end portion to which said first gripper guide is attached, and an end portion of said second gripper arm is formed as a semi-circularly curved end portion to which said second gripper guide is attached.
10. The wafer gripper as set forth in claim 9, wherein said semi-circularly curved end portion terminates with an arch extension which is detachably connected thereto, and said second gripper guide is attached to said arch extension.
11. The wafer gripper as set forth in claim 10, wherein said arch extension has a third gripper guide attached thereto.
12. The wafer gripper as set forth in claim 8, wherein said generally V-shaped groove is defined by a bottom wall face, and a pair of tapered side wall faces extending from the lateral sides of the bottom wall face, and said ridge element is protruded from an outer side edge defining one of the tapered side wall faces.
13. The wafer gripper as set forth in claim 12, wherein said bottom wall face is configured as an arch bottom wall face having substantially a same curvature as that of a peripheral edge of the semiconductor wafer.
14. The wafer gripper as set forth in claim 13, wherein said arch bottom wall face has a width which is substantially equivalent to a thickness of the semiconductor wafer.
15. A wafer gripper guide comprising:
- a body portion which is formed with a groove for receiving a peripheral edge of a semiconductor wafer, said groove being configured as a generally V-shaped groove featuring a ridge element protruded from an outer side edge thereof; and
- an attachment portion extended from said body portion.
16. The wafer gripper guide as set forth in claim 15, wherein said generally V-shaped groove is defined by a bottom wall face, and a pair of tapered side wall faces extending from the lateral sides of the bottom wall face, and said ridge element is protruded from an outer side edge defining one of the tapered side wall faces.
17. The wafer gripper guide as set forth in claim 16, wherein said bottom wall face is configured as an arch bottom wall face having substantially a same curvature as that of a peripheral edge of the semiconductor wafer.
18. The wafer gripper guide as set forth in claim 17, wherein said arch bottom wall face has a width which is substantially equivalent to a thickness of the semiconductor wafer.
19. The wafer gripper guide as set forth in claim 15, wherein said ridge element has a height of at most 0.5 mm.
Type: Application
Filed: Dec 21, 2005
Publication Date: Aug 17, 2006
Applicant: NEC ELECTRONICS CORPORATION (KAWASAKI)
Inventor: Toshio Iida (Kumamoto-shi)
Application Number: 11/312,430
International Classification: A45F 5/00 (20060101);