Prober and probe alignment method

Abstract

To provide a prober and a probe alignment method each of which enables alignment between a probe and an electrode of a semiconductor device to be highly accurately performed.SOLUTION: A probe alignment method comprises: a probe detection step of capturing an image of a probe by a probe position detection camera (150) arranged in a chuck holding portion or the vicinity thereof while a wafer chuck is retracted from the chuck holding portion that detachably holds the wafer chuck (34), thereby detecting the tip position of the probe; an electrode detection step of capturing an image of the surface of a wafer held by the wafer chuck by an alignment camera (152) in such a state that the wafer chuck is held by the chuck holding portion, thereby detecting the position of an electrode of a device formed on the wafer; and a step of aligning the probe with the electrode by relatively moving a probe card and the wafer chuck on the basis of the tip position of the probe and the position of the electrode.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a prober and a probe alignment method, and more particularly to a prober and a probe alignment method for inspecting a plurality of semiconductor devices formed on a semiconductor wafer. [Background technology]

[0002] In the manufacturing process of semiconductor devices, various inspections are performed at various manufacturing steps to ensure quality and improve yield. For example, in wafer-level inspection, at the stage where multiple chips corresponding to individual semiconductor devices are formed on a semiconductor wafer (hereinafter referred to as a wafer), the electrodes (pads) of the semiconductor devices are connected to a tester and a test signal is supplied. Then, the signal output by the semiconductor device in response to this test signal is measured by the tester to electrically inspect whether the semiconductor device is operating normally.

[0003] In recent years, the miniaturization and high integration of semiconductor devices has led to the miniaturization of electrodes on wafers, which has created a demand for wafer-level inspection to perform high-precision alignment (positioning) between probes (needles) electrically connected to a tester and the electrodes of semiconductor devices.

[0004] Patent Document 1 discloses a prober including a probe card on which a plurality of probes are arranged, a wafer chuck for holding a wafer, and an alignment device for detachably supporting the wafer chuck and moving the wafer chuck in the X, Y, Z, and θ directions. This prober further includes, as components for aligning the electrodes of a semiconductor device with the probes, a probe position detection camera for detecting the tip positions of the probes and an alignment camera for detecting the positions of the electrodes of the wafer, and aligns the electrodes with the probes by moving the wafer chuck relative to the tips of the probes using the alignment device based on the detection results of the probe tip positions by the probe position detection camera and the detection results of the positions of the electrodes of the wafer by the alignment camera. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2016-162803 A Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, in the prober disclosed in Patent Document 1, the probe position detection camera is supported on the X-axis moving stage (also called the X-carriage) of the alignment device, and is disposed at a different horizontal position from the wafer chuck which is detachably supported on the X-axis moving stage via a Z-axis moving / rotating part, resulting in the following problems:

[0007] That is, in the prober disclosed in Patent Document 1, the probe position detection camera is arranged at a position horizontally away from the wafer chuck, so that if a movement error occurs in the alignment device due to the effects of thermal deformation of components of the alignment device, processing accuracy, etc., the relative position between the wafer chuck and the probe position detection camera is likely to fluctuate. This causes an error in the alignment based on the detection result of the probe tip position by the probe position detection camera and the detection result of the wafer electrode position by the alignment camera, which is one of the factors preventing high-precision alignment.

[0008] The present invention has been made in view of the above circumstances, and has an object to provide a prober and a probe alignment method that are capable of aligning electrodes of a semiconductor device and a probe with high accuracy. [Means for solving the problem]

[0009] In order to solve the above problems, a prober according to a first aspect of the present invention comprises a wafer chuck for holding a wafer, a probe card having a probe on a surface facing the wafer chuck, an alignment device having a chuck holding part for removably holding the wafer chuck and for moving the wafer chuck held in the chuck holding part, a chuck retraction mechanism for retracting the wafer chuck from the chuck holding part, a probe position detection camera arranged at or near the chuck holding part for capturing an image of the probe, an alignment camera for capturing an image of the surface of the wafer held by the wafer chuck, and a control unit for aligning the probe and the electrode by moving the probe card and the wafer chuck relatively based on the tip position of the probe detected from the image of the probe and the position of the electrode detected from the image of the surface of the wafer.

[0010] A prober according to a second aspect of the present invention is the first aspect, wherein the chuck holding part has a rotation axis parallel to the direction in which the wafer chuck and the probe card face each other, and the probe position detection camera is positioned so that the rotation axis coincides with the optical axis of the probe position detection camera.

[0011] A prober according to a third aspect of the present invention is the prober of the first or second aspect, wherein the probe position detection camera is adjusted so as to be focused on the surface of the wafer held by the wafer chuck.

[0012] A probe alignment method according to a fourth aspect of the present invention includes a probe detection step of taking an image of the probe with a probe position detection camera arranged on or near the chuck holding part, with the wafer chuck retracted from the chuck holding part that detachably holds the wafer chuck, and detecting the tip position of the probe; an electrode detection step of taking an image of the surface of the wafer held on the wafer chuck with an alignment camera, with the wafer chuck held on the chuck holding part, and detecting the positions of electrodes of a device formed on the wafer; and a step of moving the probe card and the wafer chuck relatively based on the tip position of the probe and the positions of the electrodes, to align the probe and the electrodes. Effect of the Invention

[0013] According to the present invention, it is possible to perform highly accurate alignment between electrodes of a semiconductor device and a probe. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view showing the appearance of a prober according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view showing a prober according to an embodiment of the present invention. [Diagram 3] FIG. 3 is a schematic diagram showing the configuration of a measurement unit in a prober according to an embodiment of the present invention. [Figure 4] FIG. 4 is a schematic diagram showing the configuration of the measurement section in the measurement unit shown in FIG. [Diagram 5] FIG. 5 is a functional block diagram showing the configuration of a control device of a prober according to an embodiment of the present invention. [Figure 6] FIG. 6 is a diagram showing a procedure for aligning the electrodes of a semiconductor device formed on a wafer with a probe. [Figure 7] FIG. 7 is a partial cross-sectional view showing an example of the arrangement of a probe position detection camera. [Figure 8] FIG. 8 is a flow chart illustrating an alignment method according to one embodiment of the present invention. [Figure 9] FIG. 9 is a flow chart showing the probe detection process of FIG. [Figure 10] FIG. 10 is a flow chart showing the electrode detection process of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a prober and a probe alignment method according to the present invention will be described with reference to the accompanying drawings.

[0016] [Prober configuration] First, an overview of a multi-stage prober will be described with reference to Figures 1 and 2. Figures 1 and 2 are an external perspective view and a plan view, respectively, showing a prober according to an embodiment of the present invention.

[0017] 1 and 2, the prober 10 according to this embodiment includes a loader section 14 that supplies and collects a wafer W to be inspected, and a measurement unit 12 disposed adjacent to the loader section 14. The measurement unit 12 has a plurality of measurement sections 16, and when a wafer W is supplied from the loader section 14 to each measurement section 16, each measurement section 16 inspects the electrical characteristics of each chip on the wafer W (wafer level inspection). The wafer W inspected by each measurement section 16 is then collected by the loader section 14. The prober 10 also includes an operation panel 22, a control device (see FIG. 5) to be described later, and the like.

[0018] The loader section 14 has a load port 18 on which the wafer cassette 20 is placed, and a transport unit 24 that transports the wafer W between each measuring section 16 of the measuring unit 12 and the wafer cassette 20. The transport unit 24 is provided with a transport unit drive mechanism (not shown) and is configured to be movable in the XZ direction and rotatable in the θ direction (around the Z direction). The transport unit 24 also has a transport arm 26 that is configured to be freely extended and retracted back and forth by the transport unit drive mechanism. An adsorption pad (not shown) is provided on the upper surface of the transport arm 26, and the transport arm 26 holds the wafer W by vacuum adsorbing the back surface of the wafer W with the adsorption pad. As a result, the wafer W in the wafer cassette 20 is taken out by the transport arm 26 of the transport unit 24 and transported to each measuring section 16 of the measuring unit 12 while being held on its upper surface. The inspected wafer W is returned from each measuring section 16 to the wafer cassette 20 by the reverse route.

[0019] Fig. 3 is a schematic diagram showing the configuration of a measurement unit in a prober according to one embodiment of the present invention, Fig. 4 is a schematic diagram showing the configuration of a measurement section in the measurement unit shown in Fig. 3.

[0020] 3, the measurement unit 12 has a stacked structure (multi-stage structure) in which a plurality of measurement parts 16 are stacked in multiple stages, and each measurement part 16 is two-dimensionally arranged along the X direction and the Z direction. In this embodiment, as an example, four measurement parts 16 are stacked in three stages in the Z direction in the X direction.

[0021] The measurement unit 12 includes a housing (not shown) having a lattice shape in which a plurality of frames are combined in a lattice shape. This housing is formed by combining a plurality of frames extending in the X direction, Y direction, and Z direction in a lattice shape, and components of the measurement section 16 are disposed in each space formed by these frames.

[0022] Each measurement unit 16 has the same configuration, and includes a head stage 30, a probe card 32, and a wafer chuck 34, as shown in Fig. 4. Each measurement unit 16 is provided with a test head (not shown). The test head is supported above the head stage 30 by a test head holding unit (not shown).

[0023] The head stage 30 is supported by a frame member (not shown) that constitutes a part of the housing, and a probe card 32 is detachably attached and fixed to the head stage 30. The probe card 32 attached and fixed to the head stage 30 is provided so as to face a wafer holding surface 34a of a wafer chuck 34. The probe card 32 is replaced depending on the wafer W (device) to be inspected.

[0024] The probe card 32 is provided with a plurality of probes 36 in the form of cantilevers, spring pins, or the like, which are arranged corresponding to the positions of the electrode pads of each chip of the wafer W to be inspected. Each probe 36 is electrically connected to a terminal of a test head (not shown), and power and test signals are supplied from the test head to each chip via each probe 36, and the output signal from each chip is detected by the test head to measure whether it is operating normally.

[0025] The probe 36 has spring characteristics, and contacts the electrode pad with a predetermined contact pressure by raising the contact point from the tip position of the probe 36. When the probe 36 contacts the electrode pad in an overdrive state during electrical testing, the tip of the probe 36 sinks into the surface of the electrode pad and forms a needle mark on the surface of the electrode pad. Note that the overdrive refers to a state in which the electrode pad, i.e., the surface of the wafer W, is raised by a distance α to a position higher than the tip position of the probe 36 so that the electrode pad and the probe 36 are surely in contact with each other, taking into consideration the inclination between the wafer W and the arrangement surface of the tips of the probes 36 and the variation in the tip position of the probe 36. The amount of movement by which the surface of the wafer W is further raised from the tip position (contact position) of the probe 36, i.e., the above distance α, is referred to as the overdrive amount.

[0026] The wafer chuck 34 fixes the wafer W by vacuum suction. The wafer chuck 34 has a wafer holding surface 34a on which the wafer W to be inspected is placed, and a plurality of suction ports 40 are provided on the wafer holding surface 34a (only one is shown in FIG. 4). The suction port 40 is connected to a suction device (vacuum source, such as a vacuum pump or an ejector) 44 via a suction path 42 formed inside the wafer chuck 34. A wafer suction solenoid valve 46 is provided on the suction path connecting the suction device 44 and the suction path 42. The wafer suction solenoid valve 46 is controlled by a wafer suction solenoid valve control unit 110 (see FIG. 5).

[0027] Inside the wafer chuck 34, a heating / cooling mechanism (not shown) is provided as a heating / cooling source so that the electrical characteristics of the wafer W to be inspected can be inspected at a high temperature (for example, up to 150° C.) or at a low temperature (for example, down to −40° C.). As the heating / cooling mechanism, an appropriate heater / cooler can be used, for example, a double-layer structure with a heating layer of a surface heater and a cooling layer with a passage for a cooling fluid, or a single-layer heating / cooling device with a cooling pipe wrapped around a heater embedded in a thermal conductor. Also, instead of electrical heating, a device that circulates a thermal fluid or a Peltier element can be used.

[0028] The wafer chuck 34 is detachably supported and fixed to an alignment device 70. The alignment device 70 moves the wafer chuck 34 in the X, Y, Z, and θ directions to perform relative alignment between the wafer W held by the wafer chuck 34 and the probe card 32.

[0029] Alignment device 70 includes a Z stage (Z-axis moving / rotating part) 72 that detachably supports and fixes wafer chuck 34 and moves wafer chuck 34 in the Z-axis direction and rotates in the θ direction around the Z-axis, an X carriage (X-axis moving base) 74 that supports Z stage 72 and moves it in the X-axis direction, and a Y carriage (Y-axis moving base) 76 that supports X carriage 74 and moves it in the Y-axis direction.

[0030] The Z stage 72, the X carriage 74, and the Y carriage 76 each include a mechanical drive mechanism including a motor, and are configured to move the wafer chuck 34 in the Z, X, and Y directions. Furthermore, the Z stage 72 is configured to rotate the wafer chuck 34 in the θ direction around the Z axis (an example of a rotation axis parallel to the direction in which the probe card 32 and the wafer chuck 34 face each other). The mechanical drive mechanism may be, for example, a ball screw drive mechanism combining a servo motor and a ball screw, or a linear motor drive mechanism or a belt drive mechanism. The Z stage 72, the X carriage 74, and the Y carriage 76 are configured to change the moving distance, moving direction, moving speed, and acceleration of the wafer chuck 34 by each control unit described later. In this embodiment, specifically, the following configuration is provided.

[0031] The Z stage 72 is equipped with a Z-axis drive motor 122 (e.g., a stepping motor, a servo motor, a linear motor, etc.) (see FIG. 5) for moving the wafer chuck 34 in the Z-axis direction, and a Z-axis encoder (e.g., a rotary encoder or a linear scale, etc.) (not shown) for detecting the movement distance of the wafer chuck 34 in the Z-axis direction. The Z-axis drive motor 122 is controlled based on a motor control signal from a Z-axis movement control unit 106 (see FIG. 5), which will be described later, and drives the wafer chuck 34 to move to a target position at a desired movement speed or acceleration. In addition, the Z-axis encoder outputs an encoder signal in accordance with the movement of the wafer chuck 34.

[0032] The Z stage 72 also includes a rotary drive motor 124 (e.g., a stepping motor, a servo motor, a linear motor, etc.) (see FIG. 5) for rotating the wafer chuck 34 in the θ direction, and a rotary encoder (e.g., a rotary encoder, etc.) (not shown) for detecting the rotation angle of the wafer chuck 34 in the θ direction. The rotary drive motor 124 is controlled based on a motor control signal from a θ rotation control unit 108 (see FIG. 5) described later, and drives the wafer chuck 34 to move to a target position at a desired rotation speed or acceleration. The rotary encoder also outputs an encoder signal in accordance with the rotation of the wafer chuck 34.

[0033] The X-carriage 74 is equipped with an X-axis drive motor 118 (e.g., a stepping motor, a servo motor, a linear motor, etc.) (see FIG. 5) for moving the wafer chuck 34 in the X-axis direction, and an X-axis encoder (e.g., a rotary encoder, a linear scale, etc.) (not shown) for detecting the movement distance of the wafer chuck 34 in the X-axis direction. The X-axis drive motor 118 is controlled based on a motor control signal from an X-axis movement control unit 102 (see FIG. 5), which will be described later, and drives the wafer chuck 34 to move to a target position at a desired movement speed or acceleration. In addition, the X-axis encoder outputs an encoder signal in accordance with the movement of the wafer chuck 34.

[0034] The Y carriage 76 includes a Y-axis drive motor 120 (e.g., a stepping motor, a servo motor, a linear motor, etc.) (see FIG. 5) for moving the wafer chuck 34 in the Y-axis direction, and a Y-axis encoder (e.g., a rotary encoder or a linear scale, etc.) (not shown) for detecting the movement distance of the wafer chuck 34 in the Y-axis direction. The Y-axis drive motor 120 is controlled based on a motor control signal from a Y-axis movement control unit 104 (see FIG. 5), which will be described later, and drives the wafer chuck 34 to move to a target position at a desired movement speed or acceleration. In addition, the Y-axis encoder outputs an encoder signal in accordance with the movement of the wafer chuck 34.

[0035] The alignment device 70 is provided for each stage of the measurement unit 12 (see FIG. 3), and is configured to be movable between the multiple measurement parts 16 arranged at each stage by an alignment device driving mechanism (not shown). That is, the alignment device 70 is shared between the multiple measurement parts 16 (four in this example) arranged at the same stage, and moves between the multiple measurement parts 16 arranged at the same stage. The alignment device 70 that has moved to each measurement part 16 is fixed in a predetermined position by a positioning and fixing device (not shown), and the wafer chuck 34 is moved in the X, Y, Z, and θ directions to perform relative alignment between the wafer W held by the wafer chuck 34 and the probe card 32. The alignment device 70 includes a probe position detection camera 150 (not shown in FIG. 4; see FIGS. 6 and 7) and an alignment camera 152 in order to detect the relative positional relationship between the electrode pads of each chip of the wafer W held by the wafer chuck 34 and the probes 36. The alignment device drive mechanism is composed of a mechanical drive mechanism such as a ball screw drive mechanism, a linear motor drive mechanism, or a belt drive mechanism.

[0036] A ring-shaped seal member (Z-axis seal rubber) 78 having elasticity and formed in an annular shape along the outer periphery is provided on a wafer chuck support surface 72a of a Z stage 72 constituting the upper surface of the alignment device 70. A suction port 80 is provided inside the ring-shaped seal member 78 of the wafer chuck support surface 72a. The suction port 80 is connected to the suction device 44 via a suction path 82 formed inside the Z stage 72. A chuck fixing solenoid valve 84 is provided in the suction path connecting the suction device 44 and the suction path 82. The chuck fixing solenoid valve 84 is controlled by a chuck fixing solenoid valve control unit 112 (see FIG. 5) described later.

[0037] Positioning pins 88 are provided on the outer side of the ring-shaped seal member 78 on the wafer chuck support surface 72a of the Z stage 72 so that the relative positional relationship of the wafer chuck 34 with respect to the alignment device 70 is always constant. The positioning pins 88 are provided at a plurality of locations on the wafer chuck support surface 72a (only two are shown in FIG. 4). The positioning pins 88 may be provided at equal intervals along the circumferential direction centered on the central axis of the wafer chuck 34, or may be provided at non-equidistant intervals or randomly. On the lower surface of the wafer chuck 34, V-blocks 90, which are positioning members, are provided at positions corresponding to the positioning pins 88. When the wafer chuck 34 is fixed by vacuum suction, the corresponding positioning pins 88 are engaged in the V-grooves of the V-blocks 90 to restrict the horizontal movement of the wafer chuck 34 (X-direction and Y-direction), thereby positioning the alignment device 70 and the wafer chuck 34 relative to each other.

[0038] In this embodiment, the alignment device 70 fixes the wafer chuck 34 by vacuum suction, but any fixing means other than vacuum suction may be used as long as it is capable of fixing the wafer chuck 34. For example, the wafer chuck 34 may be fixed by mechanical means (such as a clamp).

[0039] FIG. 5 is a functional block diagram showing the configuration of a control device of a prober according to an embodiment of the present invention.

[0040] As shown in FIG. 5, the control device of the prober 10 according to this embodiment includes an overall control unit 100, an X-axis movement control unit 102, a Y-axis movement control unit 104, a Z-axis movement control unit 106, a θ rotation control unit 108, a wafer suction solenoid valve control unit 110, a chuck fixing solenoid valve control unit 112, and a chuck retraction control unit 114.

[0041] The overall control unit 100 performs overall control of each unit constituting the prober 10. Specifically, the overall control unit 100 controls a contact operation for adsorbing and holding the wafer chuck 34 on the probe card 32 side, and a release operation for releasing (separating) the wafer chuck 34 from the probe card 32 side. The overall control unit 100 also performs movement control for moving the alignment device 70 between the measurement units 16, and controls the operation of wafer-level inspection by the test head. The overall control unit 100 is an example of a control unit.

[0042] The X-axis movement control unit 102 controls the drive of the X-axis drive motor 118 provided on the X-carriage 74 to move the X-carriage 74 in the X-axis direction, thereby moving the wafer chuck 34 in the X-axis direction. The Y-axis movement control unit 104 controls the drive of the Y-axis drive motor 120 provided on the Y-carriage 76 to move the Y-carriage 76 in the Y-axis direction, thereby moving the wafer chuck 34 in the Y-axis direction. The Z-axis movement control unit 106 controls the drive of the Z-axis drive motor 122 provided on the Z-stage 72 to raise and lower the Z-stage 72, thereby moving the wafer chuck 34 in the Z-axis direction. The θ-rotation control unit 108 controls the drive of the rotation drive motor 124 provided on the Z-stage 72 to rotate the Z-stage 72 in the θ direction, thereby rotating the wafer chuck 34 in the θ direction. This allows the wafer chuck 34 and the probe card 32 to move relatively to each other.

[0043] The wafer suction solenoid valve control unit 110 controls the ON / OFF (open / close) of the wafer suction solenoid valve 46 to adjust the suction pressure by the suction port 40 and selectively switch between fixed and unfixed states of the wafer W on the wafer chuck 34.

[0044] The chuck fixing solenoid valve control unit 112 controls the ON / OFF (open / close) of the chuck fixing solenoid valve 84 to adjust the suction pressure by the suction port 80 and selectively switch between fixed and unfixed states of the wafer chuck 34 relative to the Z stage 72.

[0045] The chuck retraction control unit 114 controls the chuck retraction mechanism 60 to retract the wafer chuck 34 from the wafer chuck support surface (chuck holding portion) 72a of the Z stage 72, and returns the retracted wafer chuck 34 to the wafer chuck support surface 72a (see Figure 6).

[0046] [Alignment procedure] 6A and 6B are diagrams showing a procedure for aligning electrodes of a semiconductor device formed on a wafer W with the probes 36. Fig. 6(a) shows a state in which the wafer chuck 34 has been retracted from the wafer chuck support surface 72a, and Fig. 6(b) shows a state in which the wafer chuck 34 has been placed on the wafer chuck support surface 72a.

[0047] As shown in Fig. 6, a probe position detection camera 150 is disposed on a Z stage 72 of an alignment device 70. The Z stage 72 is an example of a chuck holding unit of the present invention. Also, as shown in Fig. 6, a head stage 30, an alignment camera 152, and a chuck retraction mechanism 60 are disposed (fixed) above the measurement unit 16. Note that in the example shown in Fig. 6, the head stage 30, the alignment camera 152, and the chuck retraction mechanism 60 are disposed in this order from the left in the figure, but the order of the arrangement is not limited to the example shown in Fig. 6, and may be reversed, for example.

[0048] (Probe detection) The probe position detection camera 150 is equipped with an imaging element (e.g., a CCD (Charge Coupled Device) or the like) and is used to detect the tip position of the probe 36. The probe position detection camera 150 is disposed so that its optical axis coincides with the rotation axis (parallel to the Z axis) of the Z stage 72. In addition, the probe position detection camera 150 is adjusted so that its focal position FP coincides with the surface of the wafer W held by suction on the wafer chuck 34.

[0049] 6(a), the wafer chuck 34 is retracted from the wafer chuck support surface 72a. Then, the X-carriage 74 and the Y-carriage 76 move the probe position detection camera 150 to a position below the probe 36, and the probe position detection camera 150 captures an image of the probe 36 from below.

[0050] The overall control unit 100 analyzes (eg, pattern matching, etc.) the image of the probe captured by the probe position detection camera 150 to detect the tip position of the probe .

[0051] (Detection of the location of the electrodes on the device) The alignment camera 152 includes an imaging element (eg, a CCD (Charge Coupled Device) or the like) and is used to detect the positions of the electrodes of the device.

[0052] 6(b), the wafer chuck 34 is placed on the wafer chuck support surface 72a. The wafer W held by suction on the wafer chuck 34 is moved to below the alignment camera 152 by the X-carriage 74 and the Y-carriage 76, and the alignment camera 152 captures an image of the device formed on the surface of the wafer W.

[0053] The overall control unit 100 analyzes the image of this device (for example, pattern matching, etc.) to detect the positions of the electrodes of the device.

[0054] (Chuck retraction mechanism) Next, the retraction mechanism 60 for temporarily holding the wafer chuck 34, which has been removed from the alignment device 70, at a position (retracted position) different from the position facing the probe card 32 will be described.

[0055] The chuck retraction mechanism 60 includes a holding portion 62 for moving the wafer chuck 34. Although not shown, the chuck retraction mechanism 60 is formed in a shape slightly larger (for example, a substantially similar shape) than the wafer chuck 34 when viewed in the XY plane. The holding portions 62 are provided at multiple locations (for example, three or more locations) in the circumferential direction of the chuck retraction mechanism 60, and are formed in an L-shaped cross section toward the center of the chuck retraction mechanism 60. The chuck retraction mechanism 60 includes a drive mechanism for moving the holding portion 62 in the radial direction of the chuck retraction mechanism 60.

[0056] When the wafer chuck 34 is to be retracted from the wafer chuck support surface 72a, the chuck fixing solenoid valve 84 is first closed to set the wafer chuck 34 in an unfixed state.

[0057] Next, the wafer chuck 34 is moved to below the chuck retraction mechanism 60 by the X-carriage 74 and the Y-carriage 76. In addition, the holding portion 62 is moved radially outward (in the opening direction).

[0058] Next, the Z stage 72 moves the wafer chuck 34 upward in the drawing (in the +Z direction) until the wafer chuck 34 is accommodated within the holding portion 62 of the chuck retraction mechanism 60 .

[0059] Next, after the holder 62 is moved radially inward (closing direction), the Z stage 72 is moved downward (-Z direction) in the figure, so that the flange portion on the outer periphery of the wafer chuck 34 is caught by the holder 62, and the wafer chuck 34 moves away from the wafer chuck support surface 72a, as shown in FIG.

[0060] On the other hand, when placing the wafer chuck 34 on the wafer chuck support surface 72 a, the X-carriage 74 and the Y-carriage 76 move the wafer chuck support surface 72 a below the wafer chuck 34 held by the chuck retraction mechanism 60 .

[0061] Next, the positioning pins 88 and the V-block 90 are used to position the wafer chuck support surface 72 a and the wafer chuck 34 by the Z stage 72 , the X carriage 74 and the Y carriage 76 .

[0062] Next, the wafer chuck 34 is moved upward (in the +Z direction) in the figure. Then, the wafer chuck 34 is lifted by the Z stage 72, and after the flange portion of the wafer chuck 34 is separated from the holding portion 62, the holding portion 62 is moved in the opening direction.

[0063] Next, the Z stage is moved downward (in the -Z direction) in the figure to move the chuck retraction mechanism 60 away from the wafer chuck 34. Also, the chuck fixing solenoid valve 84 is opened to adsorb the wafer chuck 34. As a result, the wafer chuck 34 is fixed to the wafer chuck support surface 72a, as shown in FIG. 6(b).

[0064] According to this embodiment, the probe position detection camera 150 is disposed on the Z stage 72 (corresponding to the chuck holding section of the present invention) so that the optical axis of the probe position detection camera 150 coincides with the rotation axis of the Z stage 72, and therefore it is possible to effectively suppress relative movement between the probe position detection camera 150 and the wafer chuck 34 in all areas (areas in which the alignment device 70 can move) without being affected by movement errors of the alignment device 70. This allows the tip of the probe 36 to be brought into contact with a target position on the wafer W with high precision.

[0065] [Example of probe position detection camera placement] Next, an example of the arrangement of the probe position detection camera 150 will be described with reference to Fig. 7. The example shown in Fig. 7(b) shows an example in which a countersunk hole 72b is formed in the Z stage 72 and the probe position detection camera 150 is arranged therein. In contrast to this, the example shown in Fig. 7(a) shows an example in which a countersunk hole 34b is also formed on the lower surface side of the wafer chuck 34 and the probe position detection camera 150 is arranged therein.

[0066] In the example shown in FIG. 7(a), the working distance of the probe position detection camera 150 when focusing on the surface of the wafer W can be shortened as compared with the example shown in FIG. 7(b) (WD1 < WD2). Therefore, as shown in FIG. 7(a), if the working distance is shortened, it becomes possible to detect the tip position of the probe 36 with higher accuracy.

[0067] In addition, in the present embodiment, as one of the preferred embodiments, a configuration in which the optical axis of the probe position detection camera 150 coincides with the rotation axis of the Z stage 72 is shown. However, the present invention is not limited to this, and the optical axis of the probe position detection camera 150 and the rotation axis of the Z stage 72 may be displaced. Even in this case, compared with the case where the probe position detection camera 150 is installed at a position other than the Z stage 72 (such as the X carriage 74 and the Y carriage 76), it is less affected by the movement error of the alignment device 70, and the relative variation between the probe position detection camera 150 and the wafer chuck 34 can be reduced.

[0068] In addition, although a configuration in which the probe position detection camera 150 is placed on the Z stage 72 is shown, the present invention is not limited to this. Any configuration may be used as long as the probe position detection camera 150 is arranged in the vicinity of the Z stage 72 and interlocks with the operation of the Z stage 72 (the wafer chuck support surface (chuck holding portion) 72a). For example, the probe position detection camera 150 may be attached to the Z stage 72 via an arm or the like. Further, the probe position detection camera 150 does not necessarily have to be movable in conjunction with the operation of the Z stage 72. For example, the focal position may be moved in conjunction with the operation of the Z stage 72 so that the probe 36 can be focused on the tip position.

[0069] In addition, in the present embodiment, as one of the preferred embodiments, the focal position FP of the probe position detection camera 150 is made to coincide with the surface of the wafer W. However, the present invention is not limited to this. For example, the focal position FP of the probe position detection camera 150 does not necessarily have to exactly coincide with the surface of the wafer W (the position of the electrode).

[0070] [Alignment method] FIG. 8 is a flow chart illustrating an alignment method according to one embodiment of the present invention.

[0071] First, the tip position of the probe 36 is detected using the probe position detection camera 150 (step S10: probe detection step), and the position of the electrode of the device formed on the surface of the wafer W is detected using the alignment camera 152 (step S20: electrode detection step). Then, based on the detection results of the tip position of the probe 36 and the position of the electrode of the device, alignment between the probe 36 and the electrode of the device is performed (step S30).

[0072] In the example shown in FIG. 8, the probe detection step (step S10) and the electrode detection step (step S20) are performed in this order, but these steps may be performed in reverse.

[0073] FIG. 9 is a flow chart showing the probe detection process of FIG.

[0074] First, as described with reference to FIG. 6(a), the wafer chuck 34 is retracted from the Z stage 72 by the chuck retraction mechanism 60 (step S100).

[0075] Next, the probe position detection camera 150, which is arranged so that its optical axis coincides with the rotation axis of the Z stage 72, is moved under the probe 36 (step S102), and an image of the probe 36 is captured using the probe position detection camera 150 (step S104).

[0076] Next, the overall control unit 100 detects the position of the tip of the probe 36 from the image captured in step S104 (step S106).

[0077] FIG. 10 is a flow chart showing the electrode detection process of FIG.

[0078] First, as described with reference to FIG. 6(b), the wafer chuck 34 is placed on the Z stage 72 and held by suction (step S200).

[0079] Next, the wafer W held by the wafer chuck 34 is moved under the alignment camera 152 (step S202), and an image of the surface of the wafer W is captured using the alignment camera 152 (step S204).

[0080] Next, the overall control unit 100 detects the positions of the electrodes of the devices formed on the wafer W from the image captured in step S204 (step S206).

[0081] According to this embodiment, the probe position detection camera 150 is provided on the Z stage 72, and preferably, the probe position detection camera 150 is disposed so that the rotation axis of the Z stage 72 and the optical axis of the probe position detection camera 150 coincide with each other, so that it is possible to effectively suppress the relative movement between the probe position detection camera 150 and the wafer chuck 34 in all areas (areas in which the alignment device 70 can move) without being affected by the movement error of the alignment device 70. This allows the tip of the probe 36 to contact the target position on the wafer W with high precision.

[0082] In addition, in this embodiment, the wafer chuck 34 is retracted from the wafer chuck support surface 72a when the probe position is detected, but this is not limiting, and for example, the surface of the wafer chuck 34 may be partially transparent so that an image of the probe 36 can be captured through this transparent portion. In this case, it is possible to omit the chuck retraction mechanism 60.

[0083] In this embodiment, an example of a multi-stage type prober having multiple measurement units 16 has been described, but the present invention is not limited to this and can also be applied to a single-stage type prober having only one measurement unit. [Explanation of symbols]

[0084] 10... prober, 12... measurement unit, 14... loader section, 16... measurement section, 18... load port, 20... wafer cassette, 22... operation panel, 24... transfer unit, 26... transfer arm, 30... head stage, 32... probe card, 34... wafer chuck, 34a... wafer holding surface, 36... probe, 40... suction port, 42... suction path, 44... suction device, 44... suction device, 45... pressure device, 46... solenoid valve for suction of wafer, 60... chuck retraction mechanism, 62... holding section, 70... alignment device, 72... Z stage, 72a... wafer chuck support surface, 74... X carriage, 76... Y carriage , 78... ring-shaped seal member, 80... suction port, 82... suction path, 84... solenoid valve for fixing chuck, 88... positioning pin, 90... V-block, 92... Z-axis movement mechanism, 94... θ rotation mechanism, 100... overall control unit, 102... X-axis movement control unit, 104... Y-axis movement control unit, 106... Z-axis movement control unit, 108... θ rotation control unit, 110... solenoid valve control unit for suctioning wafer, 112... solenoid valve control unit for fixing chuck, 114... chuck retraction control unit, 118... X-axis drive motor, 120... Y-axis drive motor, 122... Z-axis drive motor, 124... rotation drive motor, 150... probe position detection camera, 152... alignment camera

Claims

1. a wafer chuck for holding the wafer; a probe card having a probe on a surface facing the wafer chuck; an alignment device having a chuck holding part that detachably holds the wafer chuck and that moves the wafer chuck held by the chuck holding part; a chuck retraction mechanism capable of holding the wafer chuck detached from the chuck holding portion at a position different from a position facing the probe card; a probe position detection camera that captures an image of the probe disposed on or near the chuck holding portion; an alignment camera that captures an image of the surface of the wafer held by the wafer chuck; a control unit that performs alignment between the probe and the electrode by relatively moving the probe card and the wafer chuck based on the tip position of the probe detected from the image of the probe and the position of the electrode detected from the image of the surface of the wafer; A prober comprising:

2. the chuck holding portion has a rotation axis parallel to a direction in which the wafer chuck and the probe card face each other, the probe position detection camera is disposed so that the rotation axis and the optical axis of the probe position detection camera coincide with each other.

2. The prober of claim 1.

3. the probe position detection camera is adjusted so as to be focused on the surface of the wafer held by the wafer chuck; 3. The prober according to claim 1 or 2.

4. a probe detection step of capturing an image of a probe by a probe position detection camera disposed on or in the vicinity of a chuck holding portion, in a state in which the wafer chuck is retracted from the chuck holding portion that detachably holds the wafer chuck, and detecting a tip position of the probe; an electrode detection step of capturing an image of a surface of the wafer held by the wafer chuck with an alignment camera while the wafer chuck is held by the chuck holding portion, and detecting positions of electrodes of devices formed on the wafer; a step of relatively moving the probe card and the wafer chuck based on the tip positions of the probes and the positions of the electrodes to align the probes and the electrodes; A probe alignment method comprising:

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