Wafer pre-alignment apparatus and method

Abstract

An apparatus comprising: a base; a drive device disposed on the base; a sensor unit disposed on the base; and an engagement device. The drive device has an output shaft with a wafer receiving surface and is configured to rotate the output shaft about a rotation axis. The sensor unit detects a wafer supported on the wafer receiving surface. The engagement device is configured to engage and disengage a translation mechanism between the drive device and the sensor unit. When the engagement device engages the translation mechanism, rotation of the output shaft about the rotation axis by the drive device changes the relative position of the sensor unit and the rotation axis.

Description

[Technical field]

[0001] The present invention relates to semiconductor wafer processing. [Background technology]

[0002] It may be necessary to determine the orientation of a semiconductor wafer prior to performing various processing operations on the semiconductor wafer. Some methods used to identify the orientation of a wafer may include providing a notch around the periphery of the wafer and utilizing a device to rotate the wafer such that the notch can be detected by a sensor to determine that the wafer is oriented in the desired direction. Summary of the Invention [Problem to be solved by the invention]

[0003] The present disclosure advantageously provides an apparatus comprising a base, a drive device disposed on the base and having an output shaft with a wafer receiving surface and configured to rotate the output shaft about a rotational axis, a sensor unit disposed on the base and configured to detect a wafer supported on the wafer receiving surface, and an engagement device configured to engage and disengage a translation mechanism between the drive device and the sensor unit, wherein when the engagement device engages the translation mechanism, rotation of the output shaft about the rotational axis by the drive device changes the relative positional relationship between the sensor unit and the rotational axis.

[0004] The present disclosure further advantageously provides an apparatus comprising a base, a drive device disposed on the base, the drive device having an output shaft with a wafer receiving surface and configured to rotate the output shaft about a rotational axis, a sensor unit disposed on the base, the sensor unit configured to sense a wafer supported on the wafer receiving surface, a carriage slidably coupled to the base, the carriage having the sensor unit mounted thereon, and an engagement device configured to engage and disengage a coupling between the drive device and the carriage, wherein when the engagement device engages the coupling, rotation of the output shaft about the rotational axis by the drive device changes a relative positional relationship between the sensor unit and the rotational axis. The present disclosure provides an apparatus comprising a base, a drive device disposed on the base, the drive device having an output shaft with a wafer receiving surface and configured to rotate the output shaft about a rotation axis, a sensor unit disposed on the base and configured to detect a wafer supported on the wafer receiving surface, and an engagement device configured to engage and disengage a translation mechanism between the drive device and the sensor unit, and further advantageously provides a method of rotating a wafer on the wafer receiving surface by engaging the translation mechanism between the drive device and the sensor unit, rotating the output shaft about the rotation axis by the drive device to change a relative positional relationship between the sensor unit and the rotation axis, disengaging the translation mechanism between the drive device and the sensor unit, and rotating the output shaft about the rotation axis by the drive device. [Brief description of the drawings]

[0005] A more complete understanding of the present invention and many of the attendant advantages thereof will be readily apparent from the following detailed description, especially when considered in conjunction with the accompanying drawings. [Figure 1] 1 is a top front left perspective view of a wafer pre-alignment apparatus according to an embodiment of the present invention; FIG. [Diagram 2] 2 is a top view of the wafer pre-alignment apparatus shown in FIG. 1 with the outer housing shown as transparent. [Diagram 3]2 is a front view of the wafer pre-alignment apparatus shown in FIG. 1 with the outer housing shown as transparent; [Figure 4] 4 is a cross-sectional view of the wafer pre-alignment apparatus taken along line 4-4 in FIG. 3. [Diagram 5] 2 is a left side elevational view of the wafer pre-alignment apparatus shown in FIG. 1 with the outer housing shown as transparent. [Figure 6] 6 is a cross-sectional view of the wafer pre-alignment apparatus taken along line 6-6 in FIG. 5. [Figure 7] 2 is a bottom view of the wafer pre-alignment apparatus shown in FIG. 1 with the outer housing shown as transparent. [Figure 8A-8B] FIG. 8A is a bottom schematic view of the rotating member and bottom plate of a wafer pre-alignment apparatus with the bottom plate in a first position, and FIG. 8B is a bottom schematic view of the rotating member and bottom plate of FIG. 8A with the bottom plate in a second position. [Figure 9] 13 is a schematic bottom view of a rotating member and a bottom plate of a wafer pre-alignment apparatus according to another embodiment. FIG. [Figure 10A-10B] FIG. 10A is a schematic bottom view of a rotating member and bottom plate of a wafer pre-alignment apparatus according to yet another embodiment, with the bottom plate in a first position, and FIG. 10B is a schematic bottom view of the rotating member and bottom plate of FIG. 10A, with the bottom plate in a second position. [Figure 11A-11B] FIG. 11A is a bottom schematic view of a rotating member and bottom plate of a wafer pre-alignment apparatus according to yet another alternative embodiment, with the bottom plate in a first position, and FIG. 11B is a bottom schematic view of the rotating member and bottom plate of FIG. 11A, with the bottom plate in a second position. [Figure 12] 13 is a bottom schematic view of a rotating member and a bottom plate of a wafer pre-alignment apparatus according to another further alternative embodiment. [Figure 13] 1 illustrates one embodiment of a clutch configured to engage and disengage a power transmission from the rotation of an output shaft of a drive device to the rotation of a rotating member, and to engage and disengage a power transmission from the rotation of the output shaft of a drive device to a linear member engaged to the rotating member. [Figure 14] FIG. 2 is a schematic diagram of a computer on which an embodiment of the pre-alignment apparatus of the present invention can be implemented. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, components having substantially the same functions and configurations are denoted by the same reference numerals, and duplicated descriptions will be given only when necessary.

[0007] A semiconductor wafer pre-alignment apparatus is described herein that advantageously accommodates a variety of semiconductor wafer diameters.

[0008] Semiconductor wafers may be provided with notches or markings that can be used to identify the orientation of the wafer to ensure that the wafer is in the desired orientation for processing. For example, a single notch may be provided around the circumference of the wafer. If the pre-alignment apparatus includes a wafer platform that supports and rotates the wafer, and a fixed read head that scans the edge of the wafer as it rotates, such an apparatus has an obvious disadvantage. In such an apparatus, the read head sensor has a range of only 20 mm, so the sensor must be positioned radially for wafers of different diameters.

[0009] The semiconductor wafer pre-alignment apparatus described herein advantageously uses the same motor to both rotate the wafer and move the read head radially, allowing it to be used with wafers of different sizes. In one embodiment of the apparatus, when the apparatus needs to move the read head radially, an actuator (such as an air cylinder or solenoid) drives a rack gear linearly towards a rotating gear. The rotating gear is rigidly fixed to the rotating motor. Once engaged, the motor can drive the rack and read head to the appropriate radial position.

[0010] 1 illustrates an apparatus 100 that may be used, for example, as a semiconductor wafer alignment apparatus to align semiconductor wafers for inspection and / or processing. The apparatus 100 may be advantageously used with semiconductor wafers having a variety of diameters, as can be seen from the concentric circles 10 illustrated in FIG.

[0011] The device 100 includes a base 200 , a drive device 300 , a sensor unit 400 , and an engagement device 600 .

[0012] The base 200 shown in FIG. 1 comprises a housing (or outer housing) 210 having a top wall 212, a bottom wall 214, a first side wall 216, a second side wall 218, a third side wall 220, and a fourth side wall 222. The top wall 212 comprises an opening 224 for a portion of the drive 300 to pass through. The top wall 212 further comprises a slot 226 for a portion of the sensor unit 400 to pass through. The slot 226 allows for relative motion between the sensor unit 400 and the drive 300. The base 200 can be either mounted to a support in a fixed position, for example, by fixing the base 200 relative to a floor of a manufacturing facility, or movably mounted, for example, by mounting the base 200 on a movable stage that can provide movement relative to the floor along one or more of the X, Y, and Z axes by using drive motors. The base 200 may be mounted by attaching the bottom wall 214 to a support, or by attaching one of the other walls of the housing 210 to a support.

[0013] The drive 300 is disposed on the base 200. The drive 300 comprises an output shaft 302 having a wafer platform 304 attached to an end 303 of the output shaft 302. The wafer platform 304 has a wafer receiving surface 306 configured to receive a semiconductor wafer. The wafer receiving surface 306 supports the wafer (see circle 10) and may comprise a surface that provides friction between the wafer and the wafer receiving surface 306 to prevent the wafer from moving relative to the wafer receiving surface 306. Alternatively or in addition to a surface, the wafer receiving surface 306 may be provided with suction holes and the wafer platform 304 may be provided with a suction device to hold the wafer on the wafer receiving surface 306 and prevent the wafer from moving relative to the wafer receiving surface 306. The wafer platform 304 may be fixed to the end 303 of the output shaft 302 such that the wafer platform 304 does not rotate relative to the output shaft 302. Alternatively, the wafer platform 304 can be coupled to the end 303 such that the wafer platform 304 can selectively rotate relative to the output shaft 302 or cannot rotate relative to the output shaft 302, for example, using a clutch configured to engage and disengage a transmission of rotation of the output shaft 302 to rotation of the wafer platform 304.

[0014] The drive 300 is configured to rotate the output shaft 302 about a rotation axis 302a. The drive 300 can be, for example, an electric motor. The drive 300 includes a housing 310 attached to the housing 210. In the embodiment shown in FIGS. 1-4, the housing 310 is fixedly attached to the top wall 212, although the housing 310 can be attached to another wall of the housing 210 of the base 200. The drive 300 includes a stator 312 mounted in fixed relationship to the housing 310 and a rotor 314 that rotates relative to the stator 312. The rotor 314 is supported via bearings 316 by a rotation support 315 mounted in fixed relationship to the housing 310. The output shaft 302 is part of or connected to the rotor 314 such that rotation of the rotor 314 results in rotation of the output shaft 302 about the rotation axis 302a.

[0015] The output shaft 302 includes a lower portion 318 having a lower end 320. A rotating member 322 is coupled to the lower end 320 of the output shaft 302. The rotating member 322 may be fixed to the lower end 320 such that the rotating member 322 does not rotate relative to the output shaft 302. Alternatively, the rotating member 322 may be coupled to the lower end 320 such that the rotating member 322 can selectively rotate or not rotate relative to the output shaft 302, for example, using a clutch configured to engage and disengage a transmission of rotation of the output shaft 302 to the rotation of the rotating member 322.

[0016] The sensor unit 400 is disposed on the base 200. The sensor unit 400 detects a wafer supported on the wafer receiving surface 306. The sensor unit 400 includes a read head 402 having an optical sensor 404 facing in the -Z direction toward the top surface of the wafer that can detect the wafer, such as the edge of the wafer or a mark / notch formed on the wafer, within a detection region 406 to align the semiconductor wafer for inspection and / or processing (see, for example, FIGS. 3 and 6). The read head 402 is attached to a support member 408 that extends from within the housing 210 through the slot 226.

[0017] The device 100 includes a translation mechanism 500 between the drive device 300 and the sensor unit 400. The translation mechanism 500 includes a carriage 410 slidably coupled to the base 200, and the sensor unit 400 is attached to the carriage 410 via a support member 406 attached to the carriage 410. In the embodiment shown in Figs. 1-7, the housing 310 of the drive device 300 is attached to the housing 210 of the base 200, and the first slide members 330 and 332 are attached to opposing outer surfaces of the housing 310. Alternatively, the first slide members 330 and 332 may be directly attached to the wall of the housing 210. The carriage 410 is provided with second slide members 412, 414 fixed thereto. The second slide members 412, 414 are slidably supported by the first slide members 330, 332, respectively, and allow the carriage 410 to slide along the X-axis. In the embodiment shown in Figures 1-7, the first sliding members 330 and 332 have respective slots 331 and 333 extending longitudinally along the X-axis, and the second sliding members 412 and 414 are slide rails provided within the slots 331 and 333, respectively, but alternatively, the second sliding members 412 and 414 can be provided with slots extending longitudinally along the X-axis, and the first sliding members 330 and 332 can be slide rails provided within the slots.

[0018] The translation mechanism 500 further includes a rotating member 322 coupled to the output shaft 302 and a linear member 440 connected to the carriage 410. In the embodiment of FIGS. 1-7, the linear member 440 is a rack having a number of teeth 441 arranged in a straight line. The linear member 440 is mounted on a bottom plate 442, which is attached to the second slide members 412 and 414 by flexure members 450 and 460, respectively. Thus, the linear member 440 is connected to the carriage 410 via the bottom plate 442 and the flexure members 450, 460. The upper ends 452 and 462 of the flexure members 450 and 460 are fixedly attached to the second slide members 412 and 414, and the lower ends 454 and 464 of the flexure members 450 and 460 are fixedly attached to the opposite side of the bottom plate 442. Flexure members 450 and 460 are flexible elements that can bend when a cantilever force is applied to lower ends 454 and 464 about fixed upper ends 452 and 462. The carriage 410, base plate 442, and flexure members 450 and 460 form a four-bar linkage.

[0019] The engagement device 600 is configured to engage and disengage the translation mechanism 500 between the drive device 300 and the sensor unit 400, and when the engagement device 600 engages the translation mechanism, rotation of the output shaft 302 about the rotation axis 302a by the drive device 300 changes the relative positional relationship between the sensor unit 400 and the rotation axis 302a, and thus the relative positional relationship between the sensor unit 400 and the wafer receiving surface 306. When the engagement device 600 disengages the translation mechanism 500, rotation of the output shaft 302 about the rotation axis 302a by the drive device 300 does not change the relative positional relationship between the sensor unit 400 and the rotation axis 302a.

[0020] The engagement device 600 includes an actuator 602 configured to move the linear member 440 into contact with the outer circumferential surface 324 of the rotating member 322 to engage the linear member 440 with the rotating member 322. In the embodiment shown in FIGS. 1-7 , the actuator 602 is configured to move the linear member 440 into contact with the outer circumferential surface 324 of the rotating member 322 to engage the teeth 441 of the linear member 440 with the teeth 326 on the outer circumferential surface 324 of the rotating member 322.

[0021] In the embodiment shown in FIGS. 1-7, the actuator 602 is an air cylinder 610 that, when actuated, extends a piston rod 612 along the Y axis. The actuator 600 may alternatively be a solenoid. When the air cylinder 610 is not actuated, the piston rod 612 is retracted by an internal biasing member along the Y axis, such as a spring. The air cylinder 610 has a first end 611 having a support member 613 connecting the first end 611 to a bracket 614. The bracket 614 is attached to the carriage 410 to maintain the air cylinder first end 611 in a fixed relationship with the carriage 410. The piston rod 612 has a coupling member 616 attached to its distal end. The coupling member 616 extends and retracts along the Y axis as the piston rod 612 moves. The coupling member 616 is coupled by a pin 618 to a connecting member 620 fixedly attached to the bottom plate 442.

[0022] Actuation of the actuator 602 bends the flexure members 450 and 460, moving the linear member 440 into contact with the outer circumferential surface 324 of the rotating member 322 and engaging the linear member 440 with the rotating member 322. When the actuator 602 is actuated, the air cylinder 610 extends the piston rod 612 along the Y axis, moving the coupling member 616 along the Y axis and pushing the base plate 442 via the pin 618 and the connecting member 620, deflecting the flexure members 450 and 460 and moving the linear member 440 attached to the base plate 442. Thus, actuation of the actuator 602 moves the linear member 440 from a disengaged position in which the teeth 441 of the linear member 440 do not engage with the teeth 326 of the rotating member 322 to an engaged position in which the teeth 441 of the linear member 440 engage (i.e., mesh) with the teeth 326 of the rotating member 322. When actuator 602 is deactivated, air cylinder 610 retracts piston rod 612 along the Y axis (e.g., by the force of an internal biasing member), thereby moving coupling member 616 along the Y axis and pulling base plate 442 via pin 618 and connecting member 620, thereby straightening flexure members 450 and 460 and moving linear member 440 attached to base plate 442. Deactivation moves linear member 440 from an engaged position where teeth 441 of linear member 440 engage (i.e., mesh) with teeth 326 of rotating member 322 to a disengaged position where teeth 441 of linear member 440 do not engage teeth 326 of rotating member 322.

[0023] The amount of bending or deflection of flexure members 450 and 460 can be determined, for example, based on the distance required to move between engaged and disengaged states of teeth 441 and 326 (e.g., based on the height of teeth 441 of linear member 440 and the height of teeth 326 of rotating member 322) and based on a predetermined clearance distance. In embodiments where teeth are not present, but rather frictional engagement is used, the amount of bending or deflection of flexure members 450 and 460 can be determined, for example, based on a predetermined clearance distance.

[0024] When the linear member 440 is engaged with the rotating member 322 (i.e., when the linear member 440 is in an engagement position where the teeth 441 of the linear member 440 are engaged with the teeth 326 of the rotating member 322), the rotation of the output shaft 302 by the drive device 300 causes the rotation of the rotating member 322, so that the teeth 326 of the rotating member 322 drive the teeth 441 of the linear member 440 in a direction along the X-axis. As a result, the linear member 440, the bottom plate 442, the flexure members 450, 460 and the carriage 410 are driven in a direction along the X-axis, the second sliding members 412, 414 slide along the first sliding members 330, 332, respectively, and the carriage 410 and the sensor unit 400 slide in a direction along the X-axis. Thus, when the linear member 440 is engaged with the rotating member 322, clockwise and counterclockwise rotation of the output shaft 302 by the drive device 300 results in translational movement of the sensor unit 400 along the X-axis, moving the sensor unit 400 closer to or further from the rotation shaft 302a, thereby changing the relative position between the sensor unit 400 and the rotation shaft 302a, and therefore the relative position between the sensor unit 400 and the wafer receiving surface 306. The change in the relative position between the sensor unit 400 and the rotation shaft 302a allows the apparatus 100 to be used with a variety of different diameter semiconductor wafers, such that the relative position between the sensor unit 400 and the rotation shaft 302a can be adjusted such that the sensing area 406 of the optical sensor 404 can be aligned with the outer edge area of ​​the wafer. Thus, the sensor unit 400 and the rotation axis 302a can be adjusted to be closer to each other for use with smaller diameter wafers, and the sensor unit 400 and the rotation axis 302a can be adjusted to be farther away from each other for use with larger diameter wafers.

[0025] Conversely, when the linear member 440 is disengaged from the rotating member 322 (i.e., when the linear member 440 is in a disengaged position in which the teeth 441 of the linear member 440 are not engaged with the teeth 326 of the rotating member 322), rotation of the output shaft 302 by the drive device 300 does not result in the teeth 326 of the rotating member 322 driving the teeth 441 of the linear member 440 in a direction along the X-axis. Thus, when the linear member 440 is disengaged from the rotating member 322, clockwise and counterclockwise rotation of the output shaft 302 by the drive device 300 does not result in translational movement of the sensor unit 400 along the X-axis and therefore does not change the relative positional relationship between the sensor unit 400 and the rotating shaft 302a. Thus, once the linear member 440 is disengaged from the rotating member 322, the apparatus 100 can be used to align a semiconductor wafer for inspection and / or processing by rotating the wafer using the drive apparatus 300 and scanning the wafer within the sensing area 406 using the optical sensor 404.

[0026] In the embodiment shown in FIGS. 1-7 , the engagement device 600 is configured to engage and disengage a coupling 550 between the drive device 300 and the carriage 410. The coupling 550 includes a rotating member 322 and a linear member 440. When the rotating member 322 and the linear member 440 are engaged (i.e., when the linear member 440 is in an engaged position in which the teeth 441 of the linear member 440 are engaged with the teeth 326 of the rotating member 322), the drive device 300 and the carriage 410 are coupled to each other such that clockwise and counterclockwise rotation of the output shaft 302 by the drive device 300 results in translation of the sensor unit 400 along the X-axis, moving the sensor unit 400 toward or away from the rotation shaft 302a, thereby changing the relative positional relationship between the sensor unit 400 and the rotation shaft 302a, and therefore changing the relative positional relationship between the sensor unit 400 and the wafer receiving surface 306. Conversely, when the linear member 440 is disengaged from the rotating member 322 (i.e., when the linear member 440 is in a disengaged position where the teeth 441 of the linear member 440 are not engaged with the teeth 326 of the rotating member 322), the drive device 300 and the carriage 410 are not coupled to each other, so that the rotation of the output shaft 302 by the drive device 300 does not cause the teeth 326 of the rotating member 322 to drive the teeth 441 of the linear member 440 in a direction along the X-axis. Thus, when the linear member 440 is disengaged from the rotating member 322, the clockwise and counterclockwise rotation of the output shaft 302 by the drive device 300 does not result in translational movement of the sensor unit 400 along the X-axis and therefore does not change the relative positional relationship between the sensor unit 400 and the rotating shaft 302a.

[0027] Similar to the embodiment of Figures 1-7, Figures 8A and 8B show an embodiment in which the rotating member 322a is configured as a gear having an outer circumferential surface 324a with teeth 326a. Additionally, a linear member 440a is attached to a base plate 442a. The linear member 440a is configured as a rack having a number of teeth 441a arranged in a straight line. Figures 8A and 8B show the linear member 440a engaged with the rotating member 322a (i.e., in an engaged position in which the teeth 441a of the linear member 440a are engaged with the teeth 326a of the rotating member 322a). Thus, in this engaged state, rotation of the rotating member 322a in a counterclockwise direction (as shown in FIG. 8A) causes translation of the bottom plate 442a (and the connected carriage and sensor unit) along the X-axis in the first direction 20a by sliding the second sliding member 412a along the first sliding member 330a. (For simplicity of illustration, only one first sliding member and one second sliding member are shown in FIGS. 8A and 8B, but additional first and second sliding members can be included to provide stability to the sliding motion.) Furthermore, in this engaged state, rotation of the rotating member 322a in a clockwise direction (as shown in FIG. 8B) causes translation of the bottom plate 442a (and the connected carriage and sensor unit) along the X-axis in a second direction 22a opposite to the first direction 20a by sliding the second sliding member 412a along the first sliding member 330a.

[0028] 9-12 show an alternative embodiment of the present invention.

[0029] FIG. 9 illustrates an embodiment in which the rotating member 322b has an outer circumferential surface 324b that is frictionally engageable with the surface 441b of the linear member 440b. The outer circumferential surface 324b and / or the surface 441b may comprise a surface material that provides friction between the surfaces when they are in contact with each other to prevent them from sliding relative to each other as the rotating member 322b rotates. FIG. 9 illustrates the linear member 440b engaged with the rotating member 322b (i.e., the outer circumferential surface 324b is in contact with the surface 441b). Thus, in this engaged state, rotation of the rotating member 322b in a counterclockwise direction (as shown in FIG. 9) results in translation of the base plate 442b (as well as the connected carriage and sensor unit) along the X-axis in the first direction 20b by sliding the second sliding member 412b along the first sliding member 330b. (For simplicity of illustration, only one first sliding member and one second sliding member are shown in FIG. 9, but additional first and second sliding members may be included to provide stability against the sliding motion.) Furthermore, in this engaged state, rotation of the rotating member 322b in a clockwise direction results in translational motion of the bottom plate 442b (as well as the connected carriage and sensor unit) along the X-axis in a second direction opposite to the first direction 20b, by sliding the second sliding member 412b along the first sliding member 330b.

[0030] 10A and 10B show an embodiment in which the rotating member 322c is provided with a belt and pulley arrangement to transfer the rotation of the rotating member 322c to the translation of the sensor unit. Thus, the drive includes pulleys 340c and 342c rotatably mounted on the housing of the drive. The rotating member 322c has an outer circumferential surface 324c that drives a belt 344c around the pulleys 340c and 342c. The belt 344c is fixed to a member 440c that is attached to a bottom plate 442c. In this embodiment, a clutch 323c is provided at the connection between the lower end of the output shaft of the drive and the rotating member 322c. The clutch 323c is configured to engage and disengage the power transmission from the rotation of the output shaft to the rotation of the rotating member 322c. FIGS. 10A and 10B show the member 440c engaged to the rotating member 322c due to the engaged state of the clutch 323c and the presence of the belt 344c. Thus, in this engaged state, rotation of the rotating member 322c in a counterclockwise direction (as shown in FIG. 10A) results in translation of the base plate 442c (and the connected carriage and sensor unit) along the X-axis in the first direction 20c by sliding the second sliding member 412c along the first sliding member 330c. (For simplicity of illustration, only one first sliding member and one second sliding member are shown in FIGS. 10A and 10B, but additional first and second sliding members can be included to provide stability to the sliding motion.) Furthermore, in this engaged state, rotation of the rotating member 322c in a clockwise direction (as shown in FIG. 10B) causes the second sliding member 412c to slide along the first sliding member 330c, thereby resulting in translational movement of the base plate 442c (as well as the connected carriage and sensor unit) along the X-axis in a second direction 22c opposite to the first direction 20c.

[0031] The clutches described above and below can be any conventional clutch that allows for engagement and disengagement of the transmission from the rotation of the output shaft to the rotation of the rotating member. Note that a clutch such as that described above with respect to Figures 10A and 10B can be incorporated into any of the embodiments shown in Figures 1-9 as the engagement device 600, thereby eliminating the need for the actuator 602 and eliminating the need for the movement of the bottom plate in the direction of the Y axis. Thus, the rotating member and the linear member can remain engaged, and the clutch can be used to engage or disengage the transmission from the rotation of the output shaft to the rotation of the rotating member, and thus to engage or disengage the transmission of the output shaft to rotate the rotating member and thus drive the movement of the linear member. Additionally, in such a configuration, the flexure member can be made of a stiffer material.

[0032] 11A and 11B show an embodiment in which the rotating member 322d includes a member 340d fixedly connected to the rotating member 322d. The member 340d can extend from the outer peripheral surface 424d of the rotating member 322d as shown, or can be provided on the outer edge of the rotating member 322d at a position spaced from the rotation axis of the rotating member 322d. The member 340d is pivotally connected to the arm member 342d by a first pivot joint 344d. The arm member 342d is pivotally connected to the member 440d by a second pivot joint 346d to provide a connection between the rotating member 322d and the member 440d. The member 440d is attached to a bottom plate 442d. In this embodiment, a clutch 323d is provided at the connection between the lower end of the output shaft of the drive device and the rotating member 322d. The clutch 323d is configured to engage and disengage the power transmission from the rotation of the output shaft to the rotation of the rotating member 322d. Figures 11A and 11B show the member 440d engaged to the rotating member 322d due to the engaged state of the clutch 323d and the presence of a linkage including the arm member 342d. Thus, in this engaged state, when the rotating member 322d rotates in a clockwise direction (as shown in Figure 11A), the bottom plate 442d (and the connected carriage and sensor unit) translates in the first direction 20d along the X-axis by sliding the second sliding member 412d along the first sliding member 330d. (For simplicity of illustration, only one first sliding member and one second sliding member are shown in FIGS. 11A and 11B, but additional first and second sliding members can be included to provide stability to the sliding motion.) Furthermore, in this engaged state, when the rotating member 322d rotates in a counterclockwise direction (as shown in FIG. 11B), the second sliding member 412d slides along the first sliding member 330d, thereby causing the bottom plate 442d (as well as the connected carriage and sensor unit) to translate along the X-axis in a second direction 22d opposite to the first direction 20d.

[0033] FIG. 12 shows an embodiment in which the rotating member 322e includes a drive arm 340e fixedly connected to the rotating member 322e and extending from an outer peripheral surface 424e of the rotating member 322e. The drive arm 340e has an elongated shape with a cam slot 342e extending longitudinally along the drive arm 340e. A cam follower 344e is fixedly attached to the member 440e. The member 440e is mounted on a base plate 442e that is connected to the carriage via a flexure member. The cam follower 344e is disposed within the cam slot 342e such that pivotal movement of the drive arm 340e due to rotation of the rotating member 322e drives the cam follower 344e in the X-axis direction by the cam slot 342e. In this embodiment, a clutch 323e is provided at the connection between the lower end of the output shaft of the drive device and the rotating member 322e. The clutch 323e is configured to engage and disengage the power transmission from the rotation of the output shaft to the rotation of the rotating member 322e. Figure 12 shows the clutch 323e in an engaged state and the member 440e engaged to the rotating member 322e due to the presence of the drive arm 340e, the cam slot 342e and the cam follower 344e. Thus, in this engaged state, rotation of the rotating member 322e in a counterclockwise direction (as shown in Figure 12) results in translation of the base plate 442e (and the connected carriage and sensor unit) along the X-axis in the first direction 20e by sliding the second sliding member 412e along the first sliding member 330e. (For simplicity of illustration, only one first sliding member and one second sliding member are shown in FIG. 12, but additional first and second sliding members may be included to provide stability against the sliding motion.) Furthermore, in this engaged state, rotation of the rotating member 322e in a clockwise direction results in translational motion of the bottom plate 442e (as well as the connected carriage and sensor unit) along the X-axis in a second direction opposite to the first direction 20e, by sliding the second sliding member 412e along the first sliding member 330e.

[0034] The apparatus of the present invention advantageously provides a drive arrangement that can be used to both rotate the semiconductor wafer about the axis of rotation and to adjust the positional relationship between the sensor unit and the axis of rotation. Adjusting the positional relationship between the sensor unit and the axis of rotation advantageously allows the apparatus to be used with semiconductor wafers of various sizes having a wide range of diameters.

[0035] 1-7, the apparatus 100 can be utilized, for example, by placing a semiconductor wafer on the wafer receiving surface 306 of the wafer platform 304, actuating the actuator 602 to bend the flexure members 450 and 460 to engage the teeth 441 with the teeth 326, actuating the drive device 300 to rotate the output shaft 302 and the rotating member 322 to drive the carriage 410 and the sensor unit 400 in a direction along the X-axis toward the rotation axis 302a, and utilizing the optical sensor 404 to detect the presence or absence of the semiconductor wafer within the detection area 406. When the optical sensor 404 detects the presence of an edge of the semiconductor wafer moving within the detection area 406, the drive device 330 and / or the engagement device 600 can be stopped to stop the movement of the carriage 410 and the sensor unit 400 in a direction along the X-axis toward the rotation axis 302a. Once the optical sensor 404 is positioned at a desired position relative to a semiconductor wafer on the wafer receiving surface 306, the apparatus 100 can be used to align the semiconductor wafer for inspection and / or processing by using the drive mechanism 300 to rotate the wafer and the optical sensor 404 to scan the wafer across the sensing area 406.

[0036] The apparatus 100 advantageously allows for adjustment of the relative position between the sensor unit 400 and the rotation axis 302a using the same drive used to rotate the semiconductor wafer about the rotation axis. Changing the relative position between the sensor unit 400 and the rotation axis 302a allows the apparatus 100 to be used with a variety of different diameter semiconductor wafers such that the relative position between the sensor unit 400 and the rotation axis 302a can be adjusted such that the sensing area 406 of the optical sensor 404 can be aligned with the outer edge region of the wafer. Thus, the sensor unit 400 and the rotation axis 302a can be adjusted to be closer to each other for use with smaller diameter wafers, and the sensor unit 400 and the rotation axis 302a can be adjusted to be farther from each other for use with larger diameter wafers.

[0037] 13 illustrates one embodiment of a clutch 700 configured to engage and disengage a power transmission from the rotation of the output shaft 302 of the drive 300 to the rotation of a rotating member 702 and to engage and disengage a power transmission from the rotation of the output shaft 302 of the drive 300 to a linear member 440 engaged to the rotating member 702. The clutch 700 can be used with a rotating member 702 configured as a gear having a toothed outer circumferential surface 703 and a linear member 440 configured as a rack having a linear array of teeth 441, as contemplated by the depiction of FIG. 13. Alternatively, the clutch 700 can be used as a clutch with any of the other embodiments shown herein.

[0038] The clutch 700 includes a drive 710 that drives a shaft 704 to which a rotating member 702 is attached in a Z direction. For example, the drive 710 can be an air cylinder, solenoid, or the like that drives the shaft 704 in a linear direction and passively enables rotation of the shaft 704 so that the rotating member 702 can be rotationally driven by the drive 300 when the rotating member 702 is engaged with the output shaft 302. The lower end 320 of the output shaft 302 has a disk 320a having a lower engagement surface 321. When the drive 710 is actuated to drive the shaft 704 in the Z direction, the upper engagement surface 706 of the rotating member 702 contacts and engages the lower engagement surface 321 (e.g., by friction using grooves, teeth, etc.), and when the drive 710 is no longer actuated, the drive shaft 704 moves in the -Z direction and the rotating member 702 disengages from the output shaft 302. Note that the amount of movement of shaft 704 to effect this engagement may be small and is exaggerated in Figure 13 for purposes of illustration. During this Z movement, the teeth on circumferential surface 703 may slide against teeth 441, and in other embodiments, components (e.g., belt 344c, member 340d, arm member 342d) may slide or flex relative to one another to allow for this small relative movement.

[0039] To allow movement of the shaft 704, the shaft 704 may be rotatably mounted using bearings 720. The outer periphery of the bearings 720 may be rigidly mounted to the drive 710 by a mounting bracket 724 attached to the bottom wall 214 as shown, or may be rigidly mounted directly to the bottom wall 214. The inner periphery of the bearings 720 slidably engages a slide 722 fixed to the shaft 704, allowing the shaft 704 to move along the Z axis as well as rotate about the Z axis.

[0040] FIG. 14 illustrates an embodiment of a computer 800 capable of implementing embodiments of the present invention. Although computer 800 is illustrated with respect to a particular device or equipment, it is contemplated that other devices or equipment (e.g., network elements, servers, etc.) in FIG. 14 may deploy the illustrated hardware and components of system 800. Computer 800 is programmed (e.g., via computer program code or instructions) to provide the functionality described herein and includes a communication mechanism, such as a bus 802, for passing information between other internal and external components of computer system 800. One or more processors 804 for processing information are coupled to bus 802 to perform a set of operations on the information as specified by the computer program code.

[0041] The computer 800 also includes a memory 806 coupled to the bus 810. The memory 806, such as a random access memory (RAM) or other dynamic storage device, stores information including processor instructions. The memory 806 is also used by the processor 804 to store temporary values ​​during execution of the processor instructions. The computer system 800 also includes a read only memory (ROM) 808 or other static storage device coupled to the bus 802 for storing static information including instructions that are not changed by the computer system 800. The computer 800 includes a communication interface 810 that allows the computer 800 to communicate with other devices or equipment (e.g., network elements, servers, etc.).

[0042] Information including user input instructions is provided to bus 802 for use by processor 804 from a user interface 812, such as a keyboard including alphanumeric keys operated by a human user, a display device, and a pointing device (such as a mouse or trackball or cursor direction keys).

[0043] A drive 814 (e.g., drive 300) can communicate with processor 804 via bus 802 to send and receive data, operational instructions / commands, or other information therebetween. Processor 804 can control the operation of drive 814 using operational instructions / commands to control the rotation (e.g., start, stop, direction (e.g., clockwise, counterclockwise), speed, etc.) of an output shaft (e.g., output shaft 302) of drive 814.

[0044] The engagement devices 816 (e.g., actuator 602, clutch 323c, clutch 323d, clutch 323e, etc.) may communicate with the processor 804 via the bus 802 to transmit and receive data, operation instructions / commands, or other information therebetween. The processor 804 may control the operation of the engagement devices 816 using operation instructions / commands to control the actuation of the engagement devices 816.

[0045] The optical sensor 818 (e.g., the optical sensor 404) may be in communication with the processor 804 via the bus 802 to send and receive data, operational instructions / commands, or other information therebetween. The processor 804 may control the operation of the optical sensor 818 using operational instructions / commands to control the operation of the optical sensor 818 in conjunction with the operation of the drive device 814 and / or the engagement device 818.

[0046] For example, as described above, a semiconductor wafer can be placed on the wafer receiving surface of the wafer platform, the processor 804 (using either instructions entered by a user via the user interface 812 or instructions stored in the memory 806) sends a command to the engagement device 816 to actuate it, the processor 804 (using either instructions entered by a user via the user interface 812 or instructions stored in the memory 806) sends a command to the drive device 814 to rotate its output shaft to drive the optical sensor 818 along the X-axis in a direction toward the axis of rotation, and the processor 804 (using either instructions entered by a user via the user interface 812 or instructions stored in the memory 806) sends a command to the optical sensor 818 to detect the presence or absence of the semiconductor wafer. When the optical sensor 818 detects the presence of an edge of the moving semiconductor wafer within the sensing region and transmits such data to the processor 804, the processor 804 sends a command to the drive device 814 and / or the engagement device 816 to stop moving the optical sensor 818 in a direction along the X-axis toward the axis of rotation. Once the optical sensor 818 is positioned at a desired location relative to a semiconductor wafer on the wafer receiving surface, the process 804 can perform alignment of the semiconductor wafer for inspection and / or processing by rotating the wafer with the drive 814 and scanning the wafer within a sensing area with the optical sensor 818.

[0047] It should be noted that the exemplary embodiments shown and described herein illustrate preferred embodiments of the present invention and are in no way intended to limit the scope of the claims herein. Numerous modifications and variations of the present invention are possible in light of the above teachings. It should therefore be understood that, within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.

Claims

1. A base and a drive device disposed on the base, the drive device having an output shaft with a wafer receiving surface, the drive device configured to rotate the output shaft about a rotation axis; a sensor unit disposed on the base and configured to detect a wafer supported on the wafer receiving surface; an engagement device for engaging and disengaging a translation mechanism between the drive device and the sensor unit; When the engagement device engages with the translation mechanism, rotation of the output shaft about the rotation shaft by the drive device changes the relative positional relationship between the sensor unit and the rotation shaft.

2. The apparatus of claim 1 , wherein when the engagement device disengages the translation mechanism, rotation of the output shaft about the rotation axis by the drive device does not change a relative positional relationship between the sensor unit and the rotation axis.

3. The translation mechanism includes: A rotating member connected to the output shaft; a carriage slidably coupled to the base and carrying the sensor unit; a linear member connected to the carriage, an outer circumferential surface of the rotating member is engageable with the linear member upon actuation of the engagement device such that rotation of the rotating member moves the carriage relative to the axis of rotation; 2. The apparatus of claim 1.

4. The engagement device includes an actuator that brings the linear member into contact with the outer circumferential surface to engage the linear member with the rotating member.

4. The apparatus of claim 3.

5. the linear member is attached to a carriage by a flexure member, and the actuator is actuated to bend the flexure member to move the linear member so as to contact the outer circumferential surface, thereby engaging the linear member with the rotating member; 5. The apparatus of claim 4.

6. the carriage, the linear member, and the flexure member form a four-bar linkage; 6. The apparatus of claim 5.

7. the rotating member is a gear; the linear member is a rack having a plurality of teeth arranged in a straight line, the gear is engageable with the plurality of teeth; 5. The apparatus of claim 4.

8. the outer circumferential surface of the rotating member is capable of frictionally engaging a surface of the linear member; 5. The apparatus of claim 4.

9. a rotating member coupled to the output shaft, the engagement device being a clutch that engages and disengages a transmission device that transmits rotation of the output shaft to rotation of the rotating member; the translation mechanism includes a carriage slidably coupled to the base, the sensor unit being mounted on the carriage; the translation mechanism further includes a drive member connecting the rotating member to the carriage such that rotation of the rotating member moves the carriage relative to the axis of rotation.

2. The apparatus of claim 1.

10. the drive member is a linear member connected to the carriage, the linear member engaging an outer circumferential surface of the rotating member such that rotation of the rotating member moves the carriage relative to the rotation axis; 10. The apparatus of claim 9.

11. the rotating member is a gear; The linear member is a rack having a plurality of teeth arranged in a straight line, and the gear meshes with the plurality of teeth.

11. The apparatus of claim 10.

12. The outer circumferential surface of the rotating member is frictionally engaged with a surface of the linear member.

11. The apparatus of claim 10.

13. The driving member is a belt and pulley arrangement, the belt being driven by the rotating member, the belt being connected to the carriage; or a linkage including an arm member having a first end pivotally connected to the rotating member and a second end pivotally connected to the carriage; a drive arm having a cam slot, the carriage including a cam follower disposed within the cam slot; 10. The apparatus of claim 9.

14. A base and a drive disposed on the base, the drive having an output shaft with a wafer receiving surface and configured to rotate the output shaft about a rotation axis; a sensor unit disposed on the base and configured to detect a wafer supported on the wafer receiving surface; a carriage slidably coupled to the base, the carriage having the sensor unit mounted thereon; an engagement device that engages and disengages the coupling between the drive device and the carriage, When the engagement device engages the coupling, the rotation of the output shaft about the rotation shaft by the drive device changes the relative positional relationship between the sensor unit and the rotation shaft.

15. when the engagement device disengages the coupling, rotation of the output shaft about the rotation shaft by the drive device does not change a relative positional relationship between the sensor unit and the rotation shaft; 15. The apparatus of claim 14.

16. The coupling is A rotating member connected to the output shaft; a linear member connected to the carriage; an outer circumferential surface of the rotating member is engageable with the linear member upon actuation of the engagement device such that rotation of the rotating member moves the carriage relative to the axis of rotation; 15. The apparatus of claim 14.

17. the coupling includes a rotating member coupled to the output shaft, the engagement device is a clutch that engages and disengages a transmission device that transmits rotation of the output shaft to the rotation of the rotating member; the coupling further includes a drive member connecting the rotating member to the carriage such that rotation of the rotating member moves the carriage relative to the axis of rotation.

15. The apparatus of claim 14.

18. A base and a drive disposed on the base, the drive having an output shaft with a wafer receiving surface and configured to rotate the output shaft about a rotation axis; a sensor unit disposed on the base and configured to detect a wafer supported on the wafer receiving surface; an engagement device for engaging and disengaging a translation mechanism between the drive device and the sensor unit; the translation mechanism is engaged between the drive device and the sensor unit, and the drive device rotates the output shaft about the rotation axis to change a relative positional relationship between the sensor unit and the rotation axis; disengaging the translation mechanism between the drive device and the sensor unit and rotating the output shaft about the rotation axis by the drive device to rotate the wafer on the wafer receiving surface; The method includes:

19. when the translation mechanism is disengaged, rotation of the output shaft about the rotation shaft by the drive device does not change the relative positional relationship between the sensor unit and the rotation shaft; 20. The method of claim 18.

20. 20. The method of claim 18, further comprising sensing alignment of the wafer with the sensor unit when the translation mechanism is disengaged and the output shaft is rotated by the drive.

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