Sorting device for sorting substrates

Abstract

The present invention relates to a sorting device for sorting substrates during semiconductor manufacturing, the sorting device comprising a sorting unit, the sorting unit having a substrate facing side pointing to the substrate to be sorted, the sorting unit being provided with at least three substrate edge clamps protruding from the substrate facing side of the sorting unit. The substrate edge clamps are configured to clamp the edge of the substrate to be sorted, wherein the at least three substrate edge clamps comprise: at least two controllable active positioning clamps for clamping the edge of the substrate at two controlled positions; and at least one clamping clamp, the at least one clamping clamp being used to apply a controlled clamping force on the edge of the substrate at least partially pointing to the positioning clamp. The sorting machine further comprises an individually controllable actuator connected to the sorting unit for individually controlling each of the controllable active positioning clamps.

Description

[0001] The invention relates to a sorting device for sorting substrates during semiconductor manufacturing. The invention also relates to an assembly of a sorter and a substrate table according to the invention. The invention also relates to a method for sorting substrates during semiconductor manufacturing.

[0002] Sorting devices for sorting substrates (e.g., wafers) during semiconductor manufacturing are known. Typically, the sorting device and / or the sorted substrate includes a reference device for placing the sorting device and the substrate in a predetermined position for further sorting the substrate. In addition, the substrate stage is provided with a reference device to correctly position the substrate after the sorting device has sorted the substrate. In view of the sorting devices disclosed in the art and the substrate stages disclosed in the art, it should be noted that some problems may arise in correctly positioning the substrate and maintaining the substrate in the correct position relative to the sorting device. It should also be noted that during semiconductor manufacturing, substrates such as wafers are extremely fragile and can easily break if the substrate is not correctly placed on the substrate stage. In fact, a reference device (e.g., a datum) present on the substrate stage may often be the cause of substrate breakage when it is incorrectly placed on the substrate stage.

[0003] In view of the above, there is a need for a sorting device that provides for correctly positioning a substrate and maintaining the substrate relative to the sorting device. In addition, there is a need for a substrate table adapted to receive a substrate and wherein the substrate is placed on the substrate table in a correct and predictable manner, wherein the substrate table is devoid of any reference device.

[0004] In order to meet the above needs, the present invention provides a sorting device for sorting substrates such as wafers during semiconductor manufacturing, the sorting device comprising a sorting unit, the sorting unit having a substrate facing side pointing to the substrate to be sorted, wherein the sorting unit is provided with at least three substrate edge clamps protruding from the substrate facing side of the sorting unit. The substrate edge clamps are configured to clamp the edge of the substrate to be sorted, wherein the at least three substrate edge clamps include: at least two controllable active positioning clamps for clamping the edge of the substrate at two controlled positions; and at least one clamping clamp, the at least one clamping clamp being used to apply a controlled clamping force on the edge of the substrate at least partially pointing to the positioning clamp, and wherein the sorting machine also includes an individually controllable actuator connected to the sorting unit for individually controlling each of the controllable active positioning clamps.

[0005] In the context of the present invention, the sorting of substrates comprises picking up a substrate from a first surface, moving the substrate between the first surface and the second surface, and placing the substrate on the second surface. Thus, the second surface is usually formed by a substrate table, which can be part of a molding or segmentation system for further processing of the substrate. The individually controllable actuators are usually free and steplessly adjustable, thereby allowing incremental adjustment of the positioning fixture. Thus, the substrate can be positioned in any desired (predetermined) position relative to the sorting unit.

[0006] It has been found that by providing a sorting device of the present invention, a sorting device is provided, wherein the position of the substrate is controlled and maintained by the sorting device itself by using at least two controllable active positioning clamps. By clamping the edge of the substrate, in the event of a deviation from a predetermined position being detected, the position of the substrate relative to the sorting unit can be easily adjusted and thus corrected. Any deviation may occur during the clamping process of the substrate and / or during the movement of the sorting device. The position of the substrate can be adjusted not only during the process of clamping the substrate using the sorting device, but also during the movement of the sorting device that clamps and sorts the substrate (i.e. "on the fly"). By providing the sorting device of the present invention, it is not necessary to position other reference devices on the substrate stage on which the sorted substrate is placed. By using the substrate edge clamp defined by the present invention, any deviation of the substrate from the predetermined position of the substrate stage can be easily corrected. It should be noted that the deviation of the position of the substrate relative to the substrate stage may be caused by the displacement of the substrate relative to the sorting unit during the clamping of the substrate by the sorting unit or during the movement of the sorting device, as well as due to the deviation caused by the movement of the sorting device itself.

[0007] In order to control the position of the substrate relative to the sorting unit, the sorting device may further include: a controller configured to determine the position of the substrate, compare the position of the substrate with a predetermined reference position, and control at least one of the individually controllable actuators based on the position of the substrate relative to the predetermined reference position. Therefore, controlling at least one of the individually controllable actuators generally includes repositioning the substrate relative to the sorting unit to prevent the position of the substrate from deviating from the predetermined reference position. The substrate can be repositioned by adjusting the position of at least one of the controllable movable positioning fixtures while maintaining a desired clamping force applied by the clamping fixture on the edge of the substrate, the clamping force being at least partially directed to the controllable movable positioning fixture.

[0008] It should be noted that, although any movement deviation of the sorting device can be corrected by repositioning the substrate sorted by the sorting device using the substrate edge clamp defined by the present invention, the sorting machine of the present invention may include at least one mechanical positioning element for orienting the sorting machine towards the environment. For example, before the sorting machine contacts the substrate and / or before the sorting machine places the substrate on the substrate table, at least one mechanical positioning element may be configured to cooperate with a corresponding positioning element. In an embodiment of the present invention, at least one mechanical positioning element may be implemented as a protruding pin. In a preferred embodiment of the present invention, the sorting machine may include at least three mechanical positioning elements for orienting the sorting machine towards the environment. In another embodiment of the present invention, at least one of the mechanical positioning elements for orienting the sorting machine towards the environment is configured to have limited thermal dependence (relative to the sorting machine).

[0009] The sorting unit of the present invention may be provided with a heater, which may be implemented as an electric heater to limit the change in the size of the sorting machine caused by the temperature change of the sorting unit, for example, to prevent the sorting machine from being too cold during the startup phase.

[0010] Furthermore, the sorting unit holding the movable positioning fixture and at least one clamping fixture can be rotatably connected to the holding frame of the sorting device. By rotatably connecting the sorting unit to the holding frame of the sorting device, the sorting unit can be easily oriented to be flush with the surface of the substrate to be sorted.

[0011] The individually controllable actuators preferably comprise servomotors for driving the actuators. Furthermore, the individually controllable actuators may comprise a shaft. The controllable movable positioning fixtures may be connected to the shaft via floating joints to allow for more precise positioning of the substrate relative to the sorting unit.

[0012] The clamping fixture may include at least one controllable actuator. In one embodiment of the present invention, the sorting device includes two or more clamping fixtures. Although each of the two or more clamping fixtures may include at least one individually controllable actuator, the two or more clamping fixtures may also include a single controllable actuator that simultaneously controls the movement of the two or more clamping fixtures. Preferably, the controllable actuator includes the clamping fixture and may include a pneumatic cylinder to provide sufficient clamping force applied to the edge of the substrate by at least one clamping fixture and at least two controllable movable positioning fixtures.

[0013] The sorting unit may be further provided with at least two safety clamps protruding from the substrate-facing side of the sorting unit, the safety clamps extending beyond the substrate edge clamps. In yet another embodiment of the present invention, at least two safety clamps (preferably three safety clamps) may provide the function of a mechanical positioning element as described above. By integrating the function of the mechanical positioning element and the function of the safety clamp into one and the same element, the present invention provides a sorting device with a simple and efficient construction. In a preferred embodiment, each of the substrate edge clamps is provided with a safety clamp, wherein the safety clamp is positioned adjacent to the substrate edge clamp.

[0014] In one embodiment of the present invention, the substrate-facing side of the sorting unit may be provided with a suction device configured to fix the position of the substrate to be sorted by applying negative pressure. Once the substrate is clamped by the substrate edge clamp of the sorting device and the position of the substrate is determined and adjusted if necessary, the optional suction device may maintain the substrate in a controllable manner during the movement of the sorting device.

[0015] Although the substrate edge clamps may have any configuration suitable for clamping the edge of a substrate to be sorted, at least one of the substrate edge clamps may consist of a single edge contact point. Alternatively, at least one of the substrate edge clamps may include at least two edge contact points. It is noted that the substrate edge clamps may have two or more edge contact points for 1) clamping the same substrate edge at different positions, or 2) clamping two or more different substrate edges (multiple edge substrates), where each edge is clamped by one edge contact point.

[0016] At least two controllable active positioning fixtures can be positioned relative to each other to enclose an angle of 60° to 120°. Preferably, at least two controllable active positioning fixtures can be positioned relative to each other to enclose an angle of 75° to 105°, more preferably an angle of 90°.

[0017] In another preferred embodiment of the invention, the holding fixture can be positioned relative to each controllable active positioning fixture. By providing a holding fixture positioned relative to each controllable active positioning fixture, a rotation of the substrate during (re)positioning of the substrate is prevented and, moreover, the pressure applied by the holding pressure, i.e. the minimum pressure required to clamp the substrate, can be further optimized. However, the sorting device can include only one holding fixture positioned relative to at least two controllable active positioning fixtures.

[0018] The sorting device of the present invention may further include a sensor for determining the position of a substrate carried by at least three substrate edge clamps. By providing a sorting machine including a sensor for determining the position of a substrate, any deviation from a predetermined position of the substrate can be automatically detected and corrected. Alternatively, the position of the individually controllable actuators can be known at any given moment, so that the position of the substrate can be derived from the position of the individually controllable actuators. This is generally applied to the case where the individually controllable actuators include servo motors driving the actuators, in which case the position of the individually controllable actuators is related to the position of the servo motors. In order to be able to accurately determine the position of the substrate based on the position of the individually controllable actuators, however, the sorting device may also include an internal sensor, based on the measurement results of the internal sensor, the individually controllable actuators can be calibrated from time to time.

[0019] In a possible embodiment, at least one substrate edge clamp may comprise a sensor, which is configured for determining the position of the at least one substrate edge clamp relative to the sorting device, in particular relative to at least one of the other substrate edge clamps. In particular, at least one holding clamp may be provided with a sensor, which is configured for determining the position of the holding clamp relative to at least one of the positioning clamps. By determining the position of the at least one substrate edge clamp relative to at least one of the other substrate edge clamps, and thus the distance between the clamps, the sensor allows to determine the size of the substrate, in particular the diameter of the substrate. In case the size of the substrate is determined, any deviations in the size can be compensated by repositioning the substrate relative to the sorting unit. The present invention also relates to an assembly of a sorter and a substrate table of the present invention,

[0020] Wherein, the substrate table is provided with at least one mechanical corresponding positioning element, so that the at least one mechanical corresponding positioning element is used to cooperate with at least one mechanical positioning element of the sorting machine that orients the sorting machine towards the environment. The at least one mechanical positioning element of the sorting machine can be freely moved radially in the at least one corresponding positioning element provided in the substrate table. In this regard, the substrate table can be provided with one or more radial slits for cooperating with one or more mechanical positioning elements (in the form of protruding pins) of the sorting machine.

[0021] In a typical case, the substrate table may be provided with means for maintaining the position of the substrate relative to the substrate table once the substrate is placed on the substrate table. The means may include a suction device for applying a negative pressure between the substrate and the surface of the substrate table receiving surface on which the substrate is placed. In view of maintaining the position of the substrate relative to the substrate table once the substrate is placed on the substrate table, the substrate must be positioned in its desired predetermined position on the substrate table. Therefore, during sorting of the substrate by the sorting device, i.e. before being received on the substrate table, the position of the substrate is controlled and the position of the substrate relative to the sorting unit is adjusted if necessary.

[0022] The invention also relates to a method for sorting substrates such as wafers during semiconductor manufacturing, comprising the following steps:

[0023] a) providing a substrate; and

[0024] b) clamping the edge of the substrate provided in step a) between at least three substrate edge clamps of a sorting machine according to any of the preceding claims,

[0025] Wherein, after step b), the method further comprises the following steps:

[0026] c) controlling the position of a substrate held by a substrate edge clamp, comprising the following steps:

[0027] c1) determining the position of the substrate;

[0028] c2) comparing the position determined in step c1) with a predetermined reference position; and

[0029] c3) in case the position of the substrate deviates from a predetermined reference position, repositioning the substrate by adjusting the position of at least one of the controllable movable positioning fixtures and maintaining a desired clamping force applied by the clamping fixture on an edge of the substrate at least partially directed toward the controllable movable positioning fixture.

[0030] The method of the present invention may further comprise the step of: after step c), applying a low pressure to the surface of the substrate clamped by the substrate edge clamp.

[0031] The method of the present invention may further comprise the following steps: after step c), at least two safety clamps of the sorting unit are brought to a position for receiving the substrate clamped by the sorter to prevent the substrate from being accidentally released from its clamping position. In a preferred embodiment, step c) may be performed during the sorting of the substrate clamped by the substrate edge clamp. The present invention will be further explained based on the non-limiting exemplary embodiments shown in the following figures. This article illustrates: Figure 1A and 1B is a cross-sectional view of a sorting unit of the present invention;

[0032] Figure 2 is a perspective view of a sorting unit of the present invention; and

[0033] Figure 3 is a perspective view of an assembly of the present invention, the assembly comprising a sorting device and a substrate table.

[0034] Figure 1A 1 shows a cross-sectional view of a sorting unit 1 of the present invention. The sorting unit 1 comprises substrate edge clamps 2, 3,

[0035] Figure 1A A controllable movable positioning fixture 2a and a clamping fixture 3a are shown. The positioning fixture 2a is connected to the actuator 5a via a shaft 4a. The positioning fixture 2a is connected to the shaft 4a via a floating joint 6a. Figure 1A The illustrated sorting unit 1 further comprises an actuator 5b for controlling a further positioning fixture 2b. Figure 1A Also shown is a pneumatic cylinder comprising an actuator 7a for controlling the clamping fixture 3a. Figure 1A The actuators 5a, 5b, 7a are shown mounted to a side 8 of the sorting cell 1 opposite to a substrate facing side 9 of the sorting cell 1 . Figure 1A Also shown are two safety clamps 10a, 10b which protrude from the substrate facing side 9 of the sorting unit 1. The safety clamps 10a, 10b extend beyond the substrate edge clamps 2,3.

[0036] Figure 1B A detailed view of the substrate edge clamp 2 is shown. Figure 1B A cross-sectional view is shown in which the sorting unit 1 clamps the substrate 11 by clamping the edge of the substrate 11 with the substrate edge clamp 2. The substrate 11 faces the substrate facing side 9 of the sorting unit 1. The substrate edge clamp 2 is provided with a protruding edge 12 for clamping the substrate 11 lightly.

[0037] Figure 2 A perspective view of a sorting unit 1 is shown, which comprises a substrate edge fixture 2, 3 consisting of a controllable active positioning fixture 2a, 2b and a clamping fixture 3a, 3b. The controllable active positioning fixture 2a, 2b is connected to a shaft 4a, 4b via a floating joint 6a, 6b. The shaft 4a, 4b is connected to an actuator 5a, 5b. The clamping fixture 3a, 3b is connected to a pneumatic cylinder including an actuator 7a, 7b. Figure 2 Also shown are safety clamps 10a, 10b, 10c, 1Od located adjacent to the substrate edge clamps 2, 3. Figure 2 The shown sorting unit 1 further comprises mechanical positioning elements 13a, 13b, 13c.

[0038] Figure 3 A perspective view of an assembly 40 of the present invention comprising a sorting device 20 and a substrate table 30 is shown. The sorting device comprises Figure 1A , 1B 2 and the sorting unit 1 shown. The sorting device comprises a frame 21 to which the sorting unit 1 is rotatably connected. The frame 21 of the sorting device 20 is provided with mechanical positioning element receiving parts 22a, 22b, 22c for receiving the mechanical positioning elements 13a, 13b, 13c of the sorting unit 1. Figure 3 Also shown are holding clamps 3a, 3b and safety clamps 10a, 10b, 10c.

[0039] The substrate stage 30 is provided with pin holes 31a, 31b, 31c, 31d for receiving the safety clamps 10a, 10b, 10c, 10d of the sorting unit 1. The substrate stage 30 further comprises mechanical corresponding positioning elements 32a, 32b, 32c for cooperating with the mechanical positioning elements 13a, 13b, 13c and the mechanical positioning element receiving parts 22a, 22b, 22c of the sorting machine 20. The substrate stage 30 further comprises a substrate receiving surface 33.

Claims

1. A sorting device for sorting substrates of wafers during semiconductor manufacturing, the sorting device comprising a sorting unit, the sorting unit having a substrate facing side pointing to a substrate to be sorted, the sorting unit being provided with at least three substrate edge clamps protruding from the substrate facing side of the sorting unit, wherein the substrate edge clamps are configured to clamp edges of the substrate to be sorted, It is characterized in that The at least three substrate edge fixtures include: - at least two controllable movable positioning clamps for clamping the edge of the substrate at two controlled positions; and - at least one clamping fixture for applying a controlled clamping force on an edge of the substrate at least partially directed towards the positioning fixture, The sorting device also includes an individually controllable actuator connected to the sorting unit, which is used to individually control each of the controllable movable positioning fixtures to correctly position the substrate and maintain the substrate relative to the sorting device, wherein one of the individually controllable actuators is connected to one of the controllable movable positioning fixtures.

2. The sorting device according to claim 1, characterized in that: The sorting apparatus includes a controller configured to determine a position of the substrate, compare the position of the substrate to a predetermined reference position, and control at least one of the individually controllable actuators based on the position of the substrate relative to the predetermined reference position.

3. The sorting device according to claim 1 or 2, characterized in that: The sorting device comprises at least one mechanical positioning element for orienting the sorting device towards the environment.

4. The sorting device according to claim 3, characterized in that: The sorting device comprises at least three mechanical positioning elements for orienting the sorting device towards the environment.

5. The sorting device according to claim 3, characterized in that: At least one of the mechanical positioning elements for orienting the sorting device towards the environment is configured to have a limited thermal dependency.

6. The sorting device according to claim 1 or 2, characterized in that: The sorting unit is provided with a heater.

7. The sorting device according to claim 1 or 2, characterized in that: The sorting unit holding the movable positioning fixture and the at least one clamping fixture is rotatably connected to a holding frame.

8. The sorting device according to claim 1 or 2, characterized in that: The individually controllable actuators include servo motors.

9. The sorting device according to claim 1 or 2, characterized in that: The clamping fixture comprises at least one controllable actuator.

10. The sorting device according to claim 9, characterized in that: The at least one controllable actuator comprises a pneumatic cylinder.

11. The sorting device according to claim 1 or 2, characterized in that: The sorting unit is provided with at least two safety clamps protruding from a substrate-facing side of the sorting unit, the safety clamps extending beyond the substrate edge clamps.

12. The sorting device according to claim 1 or 2, characterized in that: At least one of the substrate edge clamps consists of at least one single edge contact point.

13. The sorting device according to claim 1 or 2, characterized in that: A clamping fixture is positioned opposite each of the controllably movable positioning fixtures.

14. The sorting device according to claim 1 or 2, characterized in that: The sorting device comprises a sensor for determining a position of a substrate held by the at least three substrate edge clamps.

15. The sorting device according to claim 1 or 2, characterized in that: At least one of the substrate edge fixtures comprises a sensor configured to determine a position of the at least one substrate edge fixture relative to at least one of the other substrate edge fixtures.

16. An assembly comprising a sorting device according to any one of claims 3 to 15 and a substrate table, wherein: The substrate table is provided with at least one mechanical corresponding positioning element for cooperating with a positioning element of the sorting device for orienting the sorting device towards an environment.

17. A method for sorting substrates of a wafer during semiconductor manufacturing, comprising the steps of: a) providing a substrate; and b) clamping the edge of the substrate provided in step a) between at least three substrate edge clamps of a sorting device according to any one of the preceding claims, Characterized in that, after step b), the method further comprises the following steps: c) controlling the position of the substrate clamped by the substrate edge clamp, comprising the following steps: c1) determining the position of the substrate; c2) comparing the position determined in step c1) with a predetermined reference position; and c3) in case the position of the substrate deviates from the predetermined reference position, repositioning the substrate by adjusting the position of at least one of the controllable movable positioning fixtures and maintaining the required clamping force applied by the clamping fixture on the edge of the substrate at least partially directed toward the controllable movable positioning fixture.

18. The method according to claim 17, characterized in that The method comprises the following steps: after step c), applying a low pressure to the surface of the substrate clamped by the substrate edge clamp.

19. The method according to claim 17 or 18, characterized in that The method comprises the following steps: after step c), bringing at least two safety clamps of the sorting unit to a position for receiving the substrate clamped by the sorting device to prevent the substrate from being accidentally released from its clamping position.

20. The method according to claim 17 or 18, characterized in that Step c) is performed during sorting of the substrate held by the substrate edge clamp.

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