Wafer chuck for handling wafers

Abstract

The invention mainly relates to a wafer chuck (1) for handling a wafer, in particular in a wafer processing device, further preferred in an acoustic scanning microscope, having a holding device for the wafer, wherein the holding device has a free space (12) for receiving the wafer (50) and a carrier (10) having several wafer contact fingers (16, 18) for the wafer (50) which are movable relative to the carrier (10), wherein the wafer contact fingers (16, 18) are arranged in a ring around the free space (12) for the wafer (50), preferably in one plane, wherein the wafer contact fingers (16, 18) are movable towards or away from the free space (12) for the wafer (50), wherein preferably only one actuating device (20) for the wafer contact fingers (16, 18) is provided, which, when actuated, simultaneously moves or can simultaneously move the wafer contact fingers (16, 18).

Description

TECHNICAL FIELD

[0001] The present invention relates to a wafer chuck for handling a wafer, in particular in a wafer processing device, further preferred in an acoustic scanning microscope.

[0002] The present invention also relates to a use of a wafer chuck and to a wafer processing device, preferably an acoustic scanning microscope. BACKGROUND

[0003] It is known that so-called wafer chucks are used to fix plate-like objects, such as silicon wafers, for example in acoustic scanning microscopes, to position and fix the wafer accordingly. For this purpose, the wafer is placed on a suitable holder, which can be adjusted to the scanning plane. Here, a prerequisite is that the wafer is contacted on the substrate side. If a full-area contact to the substrate wafer is not permitted, so-called vacuum chucks are used, which contact and hold the wafer only at the outer edge, but still contact the wafer surface.

[0004] The depth of field of the ultrasound probe used for inspecting the wafer in acoustic scanning microscopy is usually in the range of about 100 pm. It is therefore necessary to align the wafer within the depth of field of the probe to the scanning plane. Furthermore, vibrations and other types of mechanical shifts of the order of the pixel size should be avoided when imaging with ultrasound, in order to prevent artifacts when inspecting with the acoustic scanning microscope. For this purpose, the wafer must be kept stable and vibration-free throughout the inspection. The requirement for lateral stability allows only deviations of less than 10 pm, and tilting positions of less than 100 pm in the direction of propagation of the acoustic waves are desirable. In order to prevent scanning artifacts, it is necessary to keep the vibrations below an amplitude of 10 pm.

[0005] In the prior art, soft chucks are also used to fix the wafer, which fix the wafer on a stable base. Here, the base position can be adjusted in the Z direction in order to orient the wafer. During operation, the soft chuck produces particles on the wafer, which can be detected when performing contamination and particle measurements. Many manufacturing processes in semiconductor production have very high cleanliness requirements for active surfaces. However, the particles produced on the chuck leave a unique signature, which is referred to as a "tool fingerprint". For many manufacturing processes, these fingerprints or signatures are to be avoided.

[0006] When inspecting complex structures, the wafer is also subjected to transmission inspection with ultrasound in the acoustic scanning microscope. In this inspection, the wafer is arranged between a transmitting probe and a receiving probe, i.e. the probes are located, for example, above or below the wafer. The transmission of the acoustic waves in the wafer is disturbed by the holding chuck of the wafer and the holder. Furthermore, there are regions on the wafer that cannot be inspected.

[0007] The use of acoustic scanning microscopes for ultrasonic imaging of wafers requires water as a coupling medium. During the scanning of the wafer, the water is moved and can cause vibrations and other movements of the wafer. Since the wafer is usually supported on only three points, the elastic properties of the wafer in the low frequency range can cause it to form low frequency vibrations by exciting simple vibration modes, which can produce clearly recognizable disturbances and artifacts in the ultrasonic imaging due to the large amplitudes. SUMMARY

[0008] It is an object of the present application to provide the possibility of reproducibly fixing a wafer in a wafer processing device, such as an acoustic scanning microscope, in a simple manner.

[0009] This object is achieved by a wafer chuck for handling a wafer, in particular in a wafer processing device, further preferably in an acoustic scanning microscope, having a fixing device for the wafer, wherein the fixing device has a free space for receiving the wafer and a carrier, the carrier having a number of wafer contact fingers for the wafer, which are movable relative to the carrier, wherein the wafer contact fingers are arranged in a ring around the free space for the wafer, preferably in one plane, wherein the wafer contact fingers are movable towards the free space for the wafer or are movable away from the free space for the wafer, wherein preferably only one actuating device for the wafer contact fingers is provided, which simultaneously moves or can simultaneously move the wafer contact fingers when actuated.

[0010] The present application is based on the idea that in a wafer chuck for a wafer processing device, such as an acoustic scanning microscope, the wafer is received in a free space of the fixing device and held and fixed using a number of wafer contact fingers, which are arranged around the free space for the wafer and are in contact with the edge or edge region of the wafer. For this purpose, the movable wafer contact fingers are arranged in a ring around the free space, preferably in one plane, and are moved towards the wafer arranged in the free space in order to fix the wafer. If the wafer is removed, the contact between the wafer contact fingers and the edge or edge region of the respective wafer is released, during which the wafer contact fingers are moved away from the free space or the wafer. In order to achieve the reversible movement and the simultaneous movement of the wafer contact fingers, an actuating device is provided, which simultaneously moves the number of wafer contact fingers.

[0011] Since the wafer positioned in free space is held by the wafer chuck and several wafer contact fingers which can be moved synchronously or are moved synchronously, a complete examination or acoustic transmission of the wafer by means of an acoustic scanning microscope is possible, for example, since there are no interfering structures on the top side and the bottom side of the wafer. The wafer contact fingers hold the wafer in a form-fit or press-fit manner in which the wafer contact fingers are in contact with the periphery of the wafer in the holding position. The stabilization of the wafer at the edge is thereby achieved, which prevents disturbing vibrations and movements of the wafer, for example, during the examination with the acoustic scanning microscope. In this way, the ultrasound images generated by the acoustic scanning microscope are free from artifacts or image disturbances.

[0012] Within the scope of the present application, the wafer chuck according to the present application can be used in other wafer processing devices, such as defect analysis devices, coating devices, lithography devices, wafer inspection devices, wafer manufacturing devices and wafer processing devices, in order to fix a wafer in the wafer processing device. If the following is described by way of example with the wafer fixation in an acoustic scanning microscope, the related explanations also apply accordingly to the other wafer processing devices.

[0013] A further feature of the present application is that repeatable results can be achieved by using the wafer chuck, since the wafer contact fingers come into contact with the edge or the edge region of the wafer on the basis of a defined and synchronous movement during the fixation. Here, the wafer contact fingers are moved simultaneously, i.e. synchronously, towards the edge region or the edge of the wafer by means of the actuating device.

[0014] By contacting the wafer edge with the wafer contact fingers, a high repeatability of the wafer positioning is also achieved.

[0015] To this end, in an advantageous embodiment of the wafer chuck, the following is provided: the holder has several wafer contact fingers each having a pivot axis, wherein the wafer contact fingers are pivotable about their pivot axes, wherein the pivot axes of the wafer contact fingers are oriented parallel to one another, wherein a preferably single actuating device for the wafer contact fingers is provided such that, when the actuating device is actuated, the wafer contact fingers are pivoted or pivotable simultaneously about their pivot axes.

[0016] In an alternative embodiment, several wafer contact fingers can be moved linearly and reversibly, wherein, when the actuating device is actuated, the wafer contact fingers which are linearly guided and moved simultaneously can come into contact with the edge region of the wafer or can be moved away from the wafer.

[0017] In particular, more than three wafer contact fingers are arranged on the holder, which are arranged in a ring around the free space for the wafer, in particular at a distance and / or in one plane. By means of the actuating device, the wafer contact fingers are moved in the direction of the wafer, in particular pivoted towards the wafer, or moved away from the wafer, in particular pivoted away from the wafer, when the contact with the wafer is released. The actuating device is preferably actuated or moved by means of a drive device.

[0018] In another embodiment, the following is provided: when the actuating device is actuated, the wafer contact fingers come into contact with or can come into contact with the edge of the wafer, or the contact of the respective wafer contact finger with the wafer is released or can be released. In this way, the wafer is positioned in the free space of the holding device, preferably in the plane of the wafer contact fingers.

[0019] Furthermore, one embodiment of the wafer chuck is characterized in that the holding device has a retaining ring as a holder, which has a disc-shaped receiving opening configured as a free space for receiving the wafer, wherein in particular the retaining ring is made of an electrically conductive material, in particular of metal, further preferably of steel or stainless steel. By means of the retaining ring, an integral design of the holder is achieved, on which the wafer contact fingers are arranged. In this case, the disc-shaped or circular receiving opening of the retaining ring forms the free space for the wafer, which is positioned in the free space for application, for example, to a scanning microscope or to other wafer processing devices.

[0020] To this end, according to one embodiment, the wafer chuck is further provided as follows: the wafer contact fingers are arranged in a ring on the retaining ring, wherein in particular the retaining ring is configured with notches for receiving the wafer contact fingers. The wafer contact fingers are preferably arranged at a distance around the receiving opening of the retaining ring.

[0021] In particular, according to another aspect, the actuating device for the wafer contact fingers has several control curves, each for each wafer contact finger, wherein the control curves are each in operative connection with a wafer contact finger. By means of the control curves, the wafer contact finger in operative connection therewith can be moved towards or away from the wafer. The wafer contact finger is reversibly movable due to its pivotability. By means of the respective control curve, the wafer contact finger will be moved in a guided manner by means of the actuating device. Thereby, also an exact adjustment of the wafer to be examined is possible.

[0022] In particular, the actuating device for the wafer contact fingers is configured as a control ring, wherein in particular the control ring is movable relative to the holder, in particular relative to one or said retaining ring for the wafer contact fingers, and / or in particular the control ring is made of an electrically conductive material, in particular of metal, further preferably of steel or stainless steel.

[0023] In one embodiment, the control ring is preferably rotatable coaxially with the holding ring, wherein the adjustment ring is also guided coaxially with the holding ring. Since the adjustment ring is provided with control curve segments corresponding to the wafer contact fingers, it is possible for the wafer contact fingers to be guided to the positions specified by the control curve segments on the adjustment ring.

[0024] One advantageous refinement of the wafer chuck is that the wafer chuck has at least two different types of wafer contact fingers. By way of example, it is thus possible to selectively hold a wafer in a form-fit in the free space or receiving hole for the wafer by means of wafer contact fingers of a first type or to hold the wafer in a force-fit by means of wafer contact fingers of a second type. When the wafer is fixed in a force-fit, the side of the free end of the wafer contact finger is configured perpendicularly, so that the wafer is held in its position by static friction. In the case of a form-fit, the free end of the wafer contact finger which comes into contact with the wafer has, for example, a (holding) groove or a chamfer. In this case, the wafer is guided into the holding groove and fixed, for example, by sliding friction. In particular, the wafer contact finger is provided with a form- and / or function-complementary end for form-fitting the wafer in order to form a form-fit with the edge of the wafer in order to fix the wafer in a form-fit.

[0025] In a further embodiment of the wafer chuck, the control ring for the wafer contact fingers is provided with control curve segments for each type of wafer contact finger, respectively, wherein the control curve segments for each type of wafer contact finger differ from one another. This makes it possible to move each type of wafer contact finger simultaneously on the basis of the respective control curve segment.

[0026] Furthermore, an improved version of the wafer chuck is characterized in that the control curve segments for the wafer contact fingers are configured, when the control ring is moved in a first rotational direction, by means of the first type of control curve segments for the first type of wafer contact fingers to pivot the first type of wafer contact fingers towards the wafer, while by means of the second type of control curve segments for the second type of wafer contact fingers to pivot the second type of wafer contact fingers away from the wafer, and, when the control ring is moved in a second rotational direction opposite to the first rotational direction, by means of the first type of control curve segments for the first type of wafer contact fingers to pivot the first type of wafer contact fingers away from the wafer, while by means of the second type of control curve segments for the second type of wafer contact fingers to pivot the second type of wafer contact fingers towards the wafer. Thereby, the first type of wafer contact fingers and the second type of wafer contact fingers can be alternately brought into contact with the wafer. In this case, it is possible to arrange it such that the first type of wafer contact fingers fix the wafer in a press fit, while the second type of wafer contact fingers fix the wafer in a form fit.

[0027] Within the scope of the present application, the wafer chuck can have several different types of wafer contact fingers. In this case, the wafer contact fingers are configured to hold the wafer by a press fit with the wafer edge or by a form fit with the wafer edge. Furthermore, in another embodiment, the wafer contact fingers can be configured with a support surface for the wafer. For example, a wafer chuck according to the present application has at least three or only three wafer contact fingers for a (retentive) form fit with the wafer, and further has several (at least three) wafer contact fingers for a (retentive) press fit with the wafer. Furthermore, the wafer chuck can have wafer contact fingers with a support surface, in addition to or instead of the press fit wafer contact fingers or the form fit wafer contact fingers. Thereby, the wafer can be repeatedly fixed in a free space for the wafer.

[0028] For example, when using a (semi-)automatic loading and unloading system, the wafer contact fingers with a support surface are used to place the wafer on the support surface, while the wafer is then fixed with the press fit wafer contact fingers or the form fit wafer contact fingers. After the fixing, the wafer contact fingers with a support surface are released from the contact with the respective wafer, for example by a pivoting away movement.

[0029] According to an advantageous embodiment of the wafer chuck, in a further aspect it is provided that the holding device is configured to hold a frame having a polygonal or polygon-like free space, in particular a closed free space, in particular a receiving hole, for receiving the wafer, wherein in particular the frame having the polygonal or polygon-like free space, in particular the receiving hole, is made of an electrically conductive material, in particular of a metal, further preferably of steel or stainless steel. For example, the free space for the wafer is rectangular or square in one plane. The pivotable wafer contact fingers are arranged in a peripheral region of the polygonal or polygon-like free space to hold the wafer arranged in the free space. The free space for the wafer is preferably configured complementary to the wafer shape. To this end, the wafer to be fixed can for example be polygonal, in particular rectangular or square. The free space for the wafer is preferably configured as a receiving hole or is configured with a support surface for the wafer, wherein the wafer contact fingers are arranged around the free space for the wafer.

[0030] For fixing the wafer, in a further aspect of the wafer chuck it is provided that the wafer contact fingers are arranged adjacent to the polygonal or polygon-like free space of the holding frame.

[0031] According to an improved solution of the wafer chuck, advantageously it is provided that the actuating device for the wafer contact fingers has one, in particular a single, control body, in particular a control string and / or a control rod, for the wafer contact fingers, or has a plurality of preferably cooperating control bodies, in particular control strings and / or control rods, for the wafer contact fingers, wherein the one control body or the plurality of control bodies is / are in operative connection with the wafer contact fingers, in particular is / are tied together with the wafer contact fingers, wherein in particular the one control body or the plurality of control bodies for the wafer contact fingers is / are made of an electrically conductive material, in particular of a metal, further preferably of steel or stainless steel. By means of the one or the plurality of movable control bodies, the wafer contact fingers arranged along the outer periphery of the polygonal or polygon-like free space for the wafer or of the receiving hole can be moved simultaneously, i.e. synchronously. In this case, it is preferably provided that a plurality of wafer contact fingers on a plurality of polygonal sides are pivotable synchronously or are synchronously pivotable. The one or the plurality of control bodies can be configured to be flexible or rigid.

[0032] In one embodiment of the control body, the control body is configured with several or all wafer contact fingers, in particular flexible control ropes, which are arranged on the holding frame, for example by using diverting pulleys, diverting guides or the like at the edge region of the free space, in particular the receiving hole, and which are connected with the wafer contact fingers to be pivoted. If, in another embodiment, the control body has one preferably rigid control lever each on each side of the polygonal free space or receiving hole, it is within the scope of the application, for example, to further provide that the movable control levers are connected with one another using diverting means. Furthermore, it is within the scope of the application for the control body for wafer contact fingers to have at least one control rope and / or at least one control lever.

[0033] Furthermore, one improved embodiment of the wafer chuck is characterized in that the one control body or several control bodies for wafer contact fingers are movably guided along the polygonal or polygon-like free space of the holding frame, in particular along the sides of the receiving hole.

[0034] In order to move the one or several control bodies connected with the wafer contact fingers, the wafer chuck is further provided with drive means for the one control body or several control bodies.

[0035] Furthermore, one embodiment of the wafer chuck is characterized in that at least one or several first wafer contact fingers are moved in a pivoting direction when the one control body or several control bodies are moved in a movement direction, preferably along the polygonal or polygon-like free space of the holding frame, in particular the receiving hole, while at least one other wafer contact finger is moved against or is movable against the pivoting direction of the one or several first wafer contact fingers.

[0036] According to another aspect, the wafer chuck preferably has at least two different types of wafer contact fingers, which are arranged at the edge of the polygonal or polygon-like free space of the holding frame, in particular at the edge of the receiving hole.

[0037] Furthermore, one improved embodiment of the wafer chuck is provided as follows: when the one or several control bodies are moved in a first direction, one or several wafer contact fingers of a first type are pivoted towards or are pivotable towards the wafer, while one or several wafer contact fingers of a second type are pivoted away from or are pivotable away from the wafer.

[0038] In one preferred embodiment of the wafer chuck, it is further provided that the wafer contact fingers each have a free end facing the wafer edge, wherein the free ends of the wafer contact fingers are configured such that the wafer contact fingers hold the wafer by a press fit with the wafer edge or by a form fit with the wafer edge.

[0039] In order to fix the wafer in a form-fitting manner by means of the wafer chuck, the following is provided: The free ends of the wafer contact fingers are formed with a groove for receiving the wafer edge region or a chamfer for receiving the wafer edge region.

[0040] Furthermore, in one refinement, it is preferred that the wafer contact fingers are each configured at least partially elastically and / or are each at least partially composed of an elastic material. This makes it possible to configure the wafer contact fingers such that the elasticity and the path of the wafer contact fingers can be set for each wafer contact finger to a predetermined holding force, preferably a maximum holding force, wherein the force acting on the wafer edge can be defined, for example, by the path curve segment or control curve segment for one or several wafer contact fingers and by the elasticity of the wafer contact fingers. The wafer contact fingers can also be configured as elastic elements due to their elasticity. Furthermore, it is possible within the scope of the application for the wafer contact fingers to be composed of a damping material or to be configured with a damping material, for example, for the wafer contact surface. In one embodiment, it is further provided that the wafer contact fingers are moved by means of a spring or spring element or the like.

[0041] Preferably, the wafer contact fingers are at least partially composed of an electro static discharge (ESD) material.

[0042] Furthermore, the aforementioned objects are achieved by a use of a wafer chuck in a wafer processing device, preferably in an acoustic scanning microscope, wherein the wafer chuck is configured in accordance with the above. In order to avoid repetition, explicit reference is hereby made to the above description.

[0043] Furthermore, the aforementioned objects are also achieved by a wafer processing device, preferably an acoustic scanning microscope, which is configured with a wafer chuck according to the application as described above. In order to avoid repetition, explicit reference is hereby made to the above description.

[0044] Further features of the present application are derived from the description of embodiments according to the present application, in conjunction with the claims and the drawings. Individual features or combinations of several features can realize embodiments according to the present application.

[0045] Within the scope of the present application, features marked with "in particular" or "preferably" are to be understood as optional features. BRIEF DESCRIPTION OF DRAWINGS

[0046] Without limiting the general inventive concept, the present application will be explained below by means of embodiments and with reference to the drawings, in which the inventive details, if not explained in greater detail herein, are evident from the drawings. Therein:

[0047] Figure 1schematic perspective view of a substrate for a wafer chuck for an acoustic scanning microscope according to the present application,

[0048] Figure 2 schematic perspective view of a wafer chuck according to the present application,

[0049] Figure 3 schematic perspective view of a wafer chuck according to the present application, Figure 2 schematic top view of a wafer chuck in

[0050] Figure 4 schematic top view of a wafer chuck according to another embodiment, and

[0051] Figure 5 schematic top view of a wafer chuck according to a different embodiment. DETAILED DESCRIPTION

[0052] In the drawings, same or similar elements and / or components are denoted by the same reference numbers, so that they will not be described repeatedly.

[0053] Figure 1 A schematic view of a substrate 10 is shown, which is a component of a wafer chuck 1 for an acoustic scanning microscope. Figure 2 and Figure 3 A perspective view and a top view of the wafer chuck 1 are shown.

[0054] The substrate 10 has a receiving hole 12 for a wafer in its center, which is arranged in the center of the receiving hole 12. The substrate 10 is configured with recesses 14 adjoining the receiving hole 12 around the circular receiving hole 12, in which wafer contact fingers 16, 18 are arranged alternately along the circumference of the receiving hole 12. The wafer contact fingers 16, 18 have respective pivots 26, 28, about which the wafer contact fingers 16, 18 are mounted pivotable. The pivots 26, 28 are oriented here perpendicular to the flat surface of the substrate 10.

[0055] Above the receiving slots 14, or in other words above the wafer contact fingers 16, 18 arranged in the receiving slots, an adjustment ring 20 is provided (see Figure 2 , Figure 3 ). The adjustment ring 20 is configured here as an actuating device for the wafer contact fingers 16, 18. The adjustment ring 20 is drawn transparent in the view Figure 3 so that the receiving slots 14 arranged below the adjustment ring and the wafer contact fingers 16, 18 arranged in the receiving slots can be seen. It can be seen from Figure 1 that the wafer contact fingers 16, 18 each have a protrusion 19 on their upper side (see Figure 1 ).

[0056] The adjustment ring 20 has control curve segments 22, 24 into which the protrusions 19 of the wafer contact fingers 16, 18 engage, so that the adjustment ring 20 is in operative connection with the wafer contact fingers 16, 18. In this way, when the adjustment ring 20 is rotated relative to the base plate 10, the control curve segments 22, 24 cause the wafer contact fingers 16, 18 to pivot. In Figure 2 In the view shown, the free ends of the wafer contact fingers 18 have been pivoted out of the recesses 14, and the wafer contact fingers 16 are located in the respective recesses 14. Depending on the direction of rotation of the adjustment ring 20, the wafer contact fingers 16 or the wafer contact fingers 18 alternately come into contact with a wafer arranged in the receiving hole 12.

[0057] In Figures 1 to 3 In the embodiment shown, the wafer contact fingers 16 are configured to secure the wafer in a press fit, wherein the wafer contact fingers 16 are in particular configured to be resilient, so that the free ends of the wafer contact fingers 16 bear against the wafer outer edge. The wafer contact fingers 18 differ from the wafer contact fingers 16, wherein the wafer contact fingers 18 are in particular designed to be received in a form fit. For example, the wafer contact fingers 18 have corresponding grooves or notches or similar structures here, in order to bring the edge region of the wafer into contact with the grooves or notches of the wafer contact fingers 18.

[0058] The wafer chuck 1 is for example a component of a specimen holder, and can be adjusted to be parallel to the scanning plane of a scanning microscope, in order to be able to be examined by means of an acoustic scanning microscope. For this purpose, the specimen holder has for example corresponding adjustment means.

[0059] Figure 4 A top view of a wafer chuck 1 according to a further embodiment is shown. The wafer chuck 1 has a rectangular base body 100 here. The base body 100 is embodied as a frame-shaped support, and has a rectangular receiving hole 112 for a rectangular wafer 50, indicated in dashed lines, as a free space for the wafer 50. The receiving hole 112 is rectangular, i.e. polygonal, and is thus complementary in shape to the rectangular shape of the wafer 50. Within the scope of the present application, the receiving hole 112 and the wafer 50 can have polygonal structures which differ from the shapes described above.

[0060] On the base body 100, along each side of the rectangular receiving hole 112, there are arranged pivotable wafer contact fingers 116, 117, 118 for the wafer 50. The wafer contact fingers 116 are configured here as straight, elongate bodies. The wafer contact fingers 117 are configured as curved or arcuate bodies. The wafer contact fingers 118, which are arranged opposite the wafer contact fingers 117, are configured as support fingers, wherein the wafer contact fingers 118 have corresponding support faces 128 for the wafer 50.

[0061] The wafer contact fingers 116, 117, 118 are mounted pivotable and each have a pivot axis 119. In order to pivot the wafer contact fingers 116, 117, 118 synchronously about their pivot axes 119, the wafer contact fingers 116, 117, 118 are connected with a closed pull cable 130.

[0062] The pull cable 130 is guided here along the side edges of the rectangular receiving hole 112, wherein at the corners of the rectangular receiving hole 112 deflection pulleys 132 are arranged, about which the pull cable 130 is routed with a deflection angle of approximately 270°. One of the deflection pulleys 132 is provided with a drive device 140, the other deflection pulleys 132 are configured as driven pulleys. The pull cable 130 is connected here with the wafer contact fingers 116, 117, 118, so that when the pull cable 130 is moved by means of the deflection pulleys 132 driven by the drive device 140, the wafer contact fingers 116, 117, 118 are simultaneously pivoted.

[0063] The wafer contact finger 118 with the support surface 128 is mounted opposite to the other wafer contact fingers 116, 117, so that the pivoting movement or the pivoting direction of the wafer contact finger 118 is opposite to the pivoting direction of the other wafer contact fingers 116, 117.

[0064] When the wafer 50 is placed in the receiving hole 112, the wafer contact fingers 116, 117 are pivoted outward, the wafer contact finger 118 with the support surface 128 is pivoted inward, so that the wafer 50 comes into contact with or rests on the support surface 128 of the wafer contact finger 118. It is also possible within the scope of the invention to arrange several wafer contact fingers 118 each with a support surface 128 for a wafer 50 at the receiving hole 112. Then, the wafer contact fingers 116, 117 are pivoted toward the wafer 50, the wafer contact finger 118 is pivoted away from the wafer 50.

[0065] Figure 5 A further embodiment of a wafer chuck 1 with a rectangular base body 100 is shown, wherein the base body 100 has a support surface 113 as a free space for a wafer 50 arranged thereon. Along the rectangular support surface 113, pivotable wafer contact fingers 116, 118 are arranged. The wafer contact fingers 116, 126 are mounted pivotable about their respective pivot axes 119.

[0066] For performing the synchronous pivotal movement of the wafer contact fingers 116, the wafer contact fingers 116 are connected with a pull rope 130 which is guided around a diverting pulley 132. Furthermore, the pull rope 130 is connected with a, in particular rigid, guide rod 134 for the wafer contact fingers 126 which is arranged on a (longitudinal) side of the support surface 113, wherein the guide rod 134 has a respective control curve section 135 for the wafer contact fingers 126 connected therewith. The guide rod 134 is here configured to be rigid and is connected with the pull rope 130, so that when the pull rope 130 is moved, the guide rod 134 performs a linear movement, so that by means of the control curve sections 135 on the guide rod 134, the wafer contact fingers 126 are caused to perform a synchronous pivotal movement together with the wafer contact fingers 116 which are directly connected with the pull rope 130.

[0067] All features described above, including features extractable from the drawings alone, and individual features disclosed in combination with other features, whether as single features or as combinations of features, are considered essential to the invention. Embodiments according to the invention can be realized by means of single features or combinations of several features.

[0068] Legend of the figures

[0069] 1 wafer chuck

[0070] 10 substrate

[0071] 12 receiving hole

[0072] 14 recess

[0073] 16 wafer contact finger

[0074] 18 wafer contact finger

[0075] 19 protrusion

[0076] 20 adjustment ring

[0077] 22 control curve section

[0078] 24 control curve section

[0079] 26 pivot

[0080] 29 pivot

[0081] 50 wafer

[0082] 100 base body

[0083] 112 receiving hole

[0084] 113 receiving surface

[0085] 116, 117, 118 wafer contact finger

[0086] 119 pivot

[0087] 126 wafer contact finger

[0088] 128 support surface

[0089] 130 pull cord

[0090] 132 turning pulley

[0091] 134 guide rod

[0092] 135 control curve segment

[0093] 140 drive means

Claims

1. A wafer chuck for manipulating a wafer, the wafer chuck having a fixing device for the wafer, wherein the fixing device has a free space for receiving the wafer and a support, the support having a plurality of wafer contact fingers movable relative to the support, wherein the wafer contact fingers are arranged in a ring around the free space for the wafer, wherein the wafer contact fingers are movable toward or away from the free space for the wafer, wherein an actuation device is provided for the wafer contact fingers, such that when the actuation device is actuated, the wafer contact fingers move simultaneously or can move simultaneously. in, The support has several wafer contact fingers, each with a pivot, wherein each wafer contact finger is pivotable about its pivot, wherein the pivots of the wafer contact fingers are oriented parallel to each other, wherein the actuation device for the wafer contact fingers is configured such that when the actuation device is actuated, the wafer contact fingers simultaneously pivot or are pivotable about their pivots.

2. The wafer chuck according to claim 1, characterized in that: When the actuation device is actuated, the wafer contact finger makes contact with or may make contact with the edge of the wafer, or the contact between each of the wafer contact fingers and the wafer is released or may be released.

3. The wafer chuck according to claim 1, characterized in that: The fixing device has a retaining ring as a support, the retaining ring having a disc-shaped receiving hole configured to be in free space for receiving the wafer.

4. The wafer chuck according to claim 3, characterized in that: The retaining ring is made of conductive material, metal, steel or stainless steel.

5. The wafer chuck according to claim 3, characterized in that: The wafer contact fingers are arranged in a ring on the retaining ring.

6. The wafer chuck according to claim 5, characterized in that: The retaining ring is provided with a notch for receiving the wafer contact finger.

7. The wafer chuck according to claim 1, characterized in that: The actuation device for the wafer contact finger has a plurality of control curve segments, each for a wafer contact finger, wherein each control curve segment is functionally connected to the wafer contact finger.

8. The wafer chuck according to claim 7, characterized in that: The actuation device for the wafer contact finger is configured as a control loop.

9. The wafer chuck according to claim 8, characterized in that: The control ring is movable relative to the support, or movable relative to a retaining ring or the retaining ring used for the wafer contact finger, and / or the control ring is made of a conductive material, metal, steel or stainless steel.

10. The wafer chuck according to claim 8, characterized in that: The wafer chuck has at least two different types of wafer contact fingers.

11. The wafer chuck according to claim 10, characterized in that: The control ring for the wafer contact finger has control curve segments for each type of wafer contact finger, wherein the control curve segments for each type of wafer contact finger are different from each other.

12. The wafer chuck according to claim 11, characterized in that: When the control ring rotates along a first rotation direction, the control curve segment for the wafer contact finger is configured to: pivot the first type of wafer contact finger toward the wafer using the first type of control curve segment for the first type of wafer contact finger, and simultaneously pivot the second type of wafer contact finger away from the wafer using the second type of control curve segment for the second type of wafer contact finger; and when the control ring moves along a second rotation direction opposite to the first rotation direction, the control curve segment for the wafer contact finger is configured to: pivot the first type of wafer contact finger away from the wafer using the first type of control curve segment for the first type of wafer contact finger, and simultaneously pivot the second type of wafer contact finger toward the wafer using the second type of control curve segment for the second type of wafer contact finger.

13. The wafer chuck according to claim 1, characterized in that: The fixing device is configured as a retaining frame having a polygonal free space for receiving the wafer, and / or a closed free space or receiving hole.

14. The wafer chuck according to claim 13, characterized in that: The retaining frame, having the free space or receiving hole of the polygon, is made of conductive material, metal, steel, or stainless steel.

15. The wafer chuck according to claim 13, characterized in that: The wafer contact is arranged to be adjacent to the free space of the polygon of the retaining frame or to the receiving hole of the retaining frame.

16. The wafer chuck according to claim 1, characterized in that: The actuation device for the wafer contact finger has a control body for the wafer contact finger, or a control rope and / or a control lever, or has several cooperating control bodies for the wafer contact finger, or has several cooperating control ropes and / or control levers for the wafer contact finger, wherein the one or more control bodies are functionally connected to or bound together with the wafer contact finger.

17. The wafer chuck according to claim 16, characterized in that: The one or more control bodies used for the wafer contact fingers are made of conductive material, metal, steel or stainless steel.

18. The wafer chuck according to claim 16, characterized in that: The one or more control bodies used for the wafer contact fingers are movably guided along the side of the free space of the bracket or along the side of the receiving hole of the bracket.

19. The wafer chuck according to claim 16, characterized in that: A drive device is provided for the one or more control bodies.

20. The wafer chuck according to claim 16, characterized in that: When one or more control bodies move along the direction of motion, or along the free space of the bracket or along the receiving hole of the bracket, at least one or more first wafer contact fingers move along the pivot direction, and at the same time, at least one other wafer contact finger moves or is movable in the opposite direction to the pivot direction of the one or more first wafer contact fingers.

21. The wafer chuck according to claim 16, characterized in that: The wafer chuck has at least two different types of wafer contact fingers.

22. The wafer chuck according to claim 21, characterized in that: When one or more control bodies move along a first direction, one or more first-type wafer contact fingers pivot toward or can pivot toward the wafer, while one or more second-type wafer contact fingers pivot away from or can pivot away from the wafer.

23. The wafer chuck according to claim 1, characterized in that: Each of the wafer contact fingers has a free end facing the edge of the wafer, wherein the free end of the wafer contact finger is configured such that the wafer contact finger holds the wafer by pressing against the edge of the wafer or by conforming to the shape of the edge of the wafer.

24. The wafer chuck according to claim 23, characterized in that: The wafer contact refers to the free end being configured with a groove for receiving the edge region of the wafer or a chamfer for receiving the edge region of the wafer.

25. The wafer chuck according to claim 1, characterized in that: The wafer contact fingers are configured to be at least partially elastic, and / or the wafer contact fingers are at least partially made of elastic material.

26. The wafer chuck according to claim 1, characterized in that: The wafer contact is at least partially composed of an electrostatic discharge material.

27. The wafer chuck according to claim 1, characterized in that: The wafer contact fingers are arranged in a ring around the free space for the wafer in a plane.

28. The wafer chuck according to claim 1, characterized in that: Only one actuation device is provided for the chip contact finger.

29. Use of a wafer chuck according to any one of claims 1 to 28 in a wafer processing apparatus.

30. The use according to claim 29, characterized in that: The wafer processing apparatus is configured as an acoustic scanning microscope.

31. A wafer processing apparatus having a wafer chuck according to any one of claims 1 to 28.

32. The wafer processing apparatus according to claim 31, characterized in that: The wafer processing apparatus is configured as an acoustic scanning microscope.

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