Prober and its control method

Abstract

To provide a prober and a control method therefor, for preventing a failure from being caused by interruption of attachment of a wafer.SOLUTION: A prober control method includes the steps of: starting an inspection in a state in which a wafer (W) attached to a wafer chuck (12) by vacuum sources (VC2, VC1) is made to be close to a probe card by an alignment device (20); and, when it is determined, on the basis of output of a pressure sensor (S4) disposed between the wafer chuck and a vacuum source during the inspection, that a wafer attachment state by the vacuum source is abnormal, separating the vacuum source from the wafer chuck and changing over to attachment by a temporary attachment vacuum source (VT, P).SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] In the manufacturing process of semiconductor devices, various inspections are performed in various manufacturing processes to ensure quality and improve yield. For example, in wafer-level inspection, when a plurality of 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, and it is electrically inspected whether the semiconductor device operates normally.

[0003] As described above, such a wafer may have warpage. When performing wafer-level inspection, the wafer is adsorbed on a wafer chuck to correct the warpage, so that the wafer is kept in a flat state (see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As shown in FIG. 6(a), when inspecting the wafer W, the wafer W to be inspected is sucked and held on the surface of the wafer chuck 50 using a vacuum source 52. As a result, the wafer W is kept in a flat state following the surface of the wafer chuck 50, and the probe needles 56 of the probe card 54 are brought into contact with the electrodes of the semiconductor devices formed on the surface of the wafer W for inspection.

[0006] When the inspection is completed, as shown in FIG. 6(b), after separating the probe card 54 from the wafer chuck 50, the suction by the vacuum source 52 is released. Thereby, even if the wafer W warps upward from the wafer chuck 50, it is possible to prevent contact with the probe needles 56.

[0007] By the way, when the suction from the vacuum source 52 is interrupted while the wafer W is being sucked, as shown in FIG. 7, the wafer W warps while the probe card 54 and the wafer chuck 50 remain close to each other. In this case, the warped wafer W may collide with the probe needles 56 and damage the probe needles 56.

[0008] The present invention has been made in view of such circumstances, and an object thereof is to provide a prober and a control method thereof for preventing problems caused by interruption of wafer suction.

Means for Solving the Problems

[0009] In order to solve the above problems, a prober according to a first aspect of the present invention includes a wafer chuck that sucks and holds a wafer, a probe card having probes on a surface facing the wafer chuck, an alignment device that moves the wafer chuck, a vacuum source for sucking and holding the wafer on the wafer chuck, a pressure sensor disposed between the wafer chuck and the vacuum source, a temporary suction vacuum source, and a control device that, when performing an inspection by bringing the wafer close to the probe card by the alignment device, switches the vacuum source from the wafer chuck to the temporary suction vacuum source when it is determined that the suction state of the wafer by the vacuum source is abnormal based on the output of the pressure sensor.

[0010] In a prober according to a second aspect of the present invention, in the first aspect, the control device controls the alignment device to move the wafer chuck away from the probe card.

[0011] The prober according to the third aspect of the present invention includes, in the first or second aspect, a solenoid valve provided between the wafer chuck and the vacuum source. The pressure sensors are respectively arranged on the wafer chuck side and the vacuum source side with respect to the solenoid valve. The control device determines the adsorption state of the wafer by the vacuum source based on the measured values of the pressures output from the pressure sensors on the wafer chuck side and the vacuum source side.

[0012] The prober according to the fourth aspect of the present invention is, in any one of the first to third aspects, the temporary adsorption vacuum source is a vacuum tank or a vacuum pump.

[0013] The control method of the prober according to the fifth aspect of the present invention includes: starting an inspection with the wafer adsorbed and held by the wafer chuck by the vacuum source in a state where the wafer is brought close to the probe card by the alignment device; and during the inspection, when it is determined that the adsorption state of the wafer by the vacuum source is abnormal based on the output of the pressure sensor arranged between the wafer chuck and the vacuum source, disconnecting the vacuum source from the wafer chuck and switching to adsorption by the temporary adsorption vacuum source.

[0014] The control method of the prober according to the sixth aspect of the present invention includes, in the fifth aspect, during the inspection, when it is determined that the adsorption state of the wafer by the vacuum source is abnormal based on the output of the pressure sensor arranged between the wafer chuck and the vacuum source, controlling the alignment device to move the wafer chuck away from the probe card.

Advantages of the Invention

[0015] According to the present invention, when an abnormality is detected in the adsorption state by the vacuum source, by switching to adsorption by the temporary adsorption vacuum source, it is possible to prevent the wafer from warping toward the probe card side and prevent damage to the probe.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

MODE FOR CARRYING OUT THE INVENTION

[0017] Hereinafter, embodiments of a prober and a control method thereof according to the present invention will be described with reference to the accompanying drawings.

[0018] [First Embodiment] (Configuration of Prober) FIG. 1 is a front view showing a measurement unit of a prober according to a first embodiment of the present invention.

[0019] In the measurement unit 10 according to the present embodiment, two vacuum sources VC2 and VC3 (for example, a vacuum source such as a factory where a probe is installed, a vacuum pump, an ejector, etc.) are provided on the wafer chuck 12. When performing wafer level inspection, the wafer W is adsorbed and held on the wafer holding surface 12a of the wafer chuck 12 by the vacuum source VC2. And when the wafer chuck 12 and the probe card 14 are in a state of approaching each other during wafer level inspection or the like, if there is a problem with the adsorption by the vacuum source VC2 (for example, when the function of the vacuum source VC2 deteriorates or stops, or the vacuum adsorption line between the wafer chuck 12 and the vacuum source VC2 is blocked), the solenoid valve V1 is operated to disconnect the vacuum adsorption line L (reference numeral L20 in FIG. 2) leading to the vacuum source VC2 from the wafer chuck 12, and connect the vacuum adsorption line (vacuum tank line; reference numeral L3 in FIG. 2) leading to the vacuum tank (temporary adsorption vacuum source) VT to the wafer chuck 12. Thereby, even when there is a problem with the adsorption by the vacuum source VC2, it is possible to maintain the state in which the wafer W is adsorbed to the wafer chuck 12. According to the above configuration, when there is a problem with the adsorption by the vacuum source VC2, it is possible to prevent the wafer W from immediately warping toward the probe card 14 side and contacting the probe 16.

[0020] First, with reference to FIG. 1, the schematic configuration of the probe measurement unit will be described. As shown in FIG. 1, the measurement unit 10 includes a wafer chuck 12, a probe card 14, and a head stage 18.

[0021] The head stage 18 is supported by a frame member (not shown) that constitutes a part of the housing of the measurement unit 10, and the probe card 14 is detachably mounted and fixed. The probe card 14 mounted and fixed to the head stage 18 is provided so as to face the wafer holding surface 12a of the wafer chuck 12. Note that the probe card 14 is replaceable according to the wafer W (device) to be inspected.

[0022] The probe card 14 is provided with a plurality of probes 16 in the shape of cantilevers or spring pins, etc., which are arranged corresponding to the positions of the electrode pads of each chip of the wafer W to be inspected. Each probe 16 is electrically connected to a terminal of a test head (not shown), and a power supply and a test signal are supplied to each chip from the test head via each probe 16, and the output signal from each chip is detected by the test head to measure whether it operates normally.

[0023] The probe 16 has spring characteristics and contacts the electrode pad with a predetermined contact pressure by raising the contact point above the tip position of the probe 16. Also, when an electrical inspection is performed, if the electrode pad is contacted in an overdrive state, the tip of the probe 16 sinks into the surface of the electrode pad, and pinholes are formed on the surface of the electrode pad respectively.

[0024] The wafer chuck 12 vacuum-sucks and fixes the wafer W. The wafer chuck 12 has a wafer holding surface 12a on which the wafer W to be inspected is placed, and a plurality of suction ports 28 are provided on the wafer holding surface 12a. The suction ports 28 are connected to a vacuum source VC2 via a suction path 30 formed inside the wafer chuck 12.

[0025] Inside the wafer chuck 12, a heating / cooling mechanism (not shown) as a heating / cooling source is provided so that the wafer W to be inspected can be inspected for electrical characteristics in a high-temperature state (for example, up to 150°C) or a low-temperature state (for example, down to -40°C). As the heating / cooling mechanism, it is possible to use a heater, something that circulates a heat transfer fluid, or a Peltier element.

[0026] The wafer chuck 12 is detachably supported and fixed to the alignment device 20. The alignment device 20 performs relative alignment between the wafer W held by the wafer chuck 12 and the probe card 14 by moving the wafer chuck 12 in the X, Y, Z, and θ directions.

[0027] The alignment device 20 removably supports and fixes the wafer chuck 12, moves the wafer chuck 12 in the Z-axis direction, and rotates it in the θ direction about the Z-axis as the rotation center. It includes a Z stage (Z-axis movement / rotation unit) 22, an X carriage (X-axis moving stage) 24 that supports the Z stage 22 and moves in the X-axis direction, and a Y carriage (Y-axis moving stage) 26 that supports the X carriage 24 and moves in the Y-axis direction.

[0028] The Z stage 22, the X carriage 24, and the Y carriage 26 include, for example, a mechanical drive mechanism including a motor, and are configured to be movable in the ZXY directions respectively for the wafer chuck 12. Further, the Z stage 22 is configured to be rotatable about the Z axis (a rotation axis parallel to the direction in which the probe card 14 and the wafer chuck 12 face each other) in the θ direction for the wafer chuck 12. The mechanical drive mechanism may be configured by, for example, a ball screw drive mechanism combining a servo motor and a ball screw, or may be configured by a linear motor drive mechanism or a belt drive mechanism, etc. Note that the Z stage 22, the X carriage 24, and the Y carriage 26 are configured to be able to change the moving distance, moving direction, moving speed, and acceleration of the wafer chuck 12 by the control device 40.

[0029] The control device 40 comprehensively controls each part constituting the measurement unit 10. The control device 40 can be realized by, for example, a general-purpose computer such as a personal computer or a workstation, and includes an operation unit and a display unit for receiving operation inputs. The control device 40 controls operations during wafer-level inspection by the probe card 14 (for example, adsorption of the wafer W to the wafer chuck 12 and release of the adsorption state, etc.).

[0030] (Adsorption mechanism) Figure 2 is a block diagram showing the adsorption mechanism in the measurement unit 10.

[0031] The vacuum source VC1 is connected via a vacuum suction line L1 to a probe configuration device equipped with a suction (or aspiration) mechanism. Such probe configuration devices include, for example, a cleaning unit (a unit for removing deposits such as chips adhering to the probe 16) inside the measurement unit 10, and a wafer transfer arm inside the loader.

[0032] The pressure sensor S1 detects the pressure in the vacuum suction line L1 from the vacuum source VC1 to the probe configuration device and outputs it to the control device 40.

[0033] Based on the detection result by the pressure sensor S1, the control device 40 detects the suction (or aspiration) state in the probe configuration device. For example, when the pressure in the vacuum suction line L1 rises during suction (or aspiration) in the probe configuration device, the control device 40 can detect an abnormality in the suction (or aspiration) state in the probe configuration device and, for example, stop the operation of the probe configuration device or display a warning on the display unit.

[0034] The vacuum source VC2 is connected via a vacuum suction line L2 to a suction path 30 formed inside the wafer chuck 12, and sucks and holds the wafer W on the wafer holding surface 12a of the wafer chuck 12.

[0035] The electromagnetic valve V1 switches the vacuum source connected to the wafer chuck 12. In the following description, among the vacuum suction line L2, the line on the upstream side (the vacuum source VC2 side) with respect to the electromagnetic valve V1 is designated as L20, and the lines on the downstream side (the wafer chuck 12 side) with respect to the electromagnetic valve V1 are designated as L21 and L22.

[0036] The vacuum suction line L2 branches into two vacuum suction lines L21 and L22 on the downstream side of the solenoid valve V1 (on the wafer chuck 12 side). A solenoid valve V3 and a pressure sensor S3 are provided in the vacuum suction line L21, and a solenoid valve V2 and a pressure sensor S2 are provided in the vacuum suction line L22. The solenoid valves V3 and V2 open and close the vacuum suction lines L21 and L22, respectively. The pressure sensors S3 and S2 detect the pressures in the vacuum suction lines L21 and L22, respectively, and output them to the control device 40.

[0037] The vacuum suction line L21 is connected to a suction passage 30 leading to a suction port 28 formed on the inner peripheral side of the wafer holding surface 12a of the wafer chuck 12, and the vacuum suction line L22 is connected to a suction passage 30 leading to a suction port 28 formed on the outer peripheral side of the wafer holding surface 12a of the wafer chuck 12.

[0038] When the size of the wafer W adsorbed on the wafer holding surface 12a is small (for example, a wafer with a diameter of 8 inches), the solenoid valve V3 of the vacuum suction line L21 is opened and the solenoid valve V2 of the vacuum suction line L22 is closed. Thereby, the small-sized wafer W can be adsorbed using only the suction port 28 formed on the inner peripheral side of the wafer holding surface 12a (for example, a region with a diameter of about 8 inches on the inner peripheral side).

[0039] On the other hand, when the size of the wafer W adsorbed on the wafer holding surface 12a is large (for example, a wafer with a diameter of 12 inches), the solenoid valve V3 of the vacuum suction line L21 and the solenoid valve V2 of the vacuum suction line L22 are opened. Thereby, the large-sized wafer W can be adsorbed using all the suction ports 28 formed on the inner peripheral side and the outer peripheral side of the wafer holding surface 12a (for example, a region with a diameter of about 12 inches).

[0040] In this embodiment, the vacuum suction line L2 is branched into two on the downstream side of the solenoid valve V1. However, for example, when the sizes of the wafers W to be inspected are diverse, it may be branched into three or more, or when the sizes of the wafers W to be inspected are constant, it may not be branched.

[0041] The pressure sensor S4 is arranged on the upstream vacuum adsorption line L20, detects the pressure in the vacuum adsorption line L20 between the vacuum source VC2 and the electromagnetic valve V1, and outputs it to the control device 40.

[0042] Based on the detection results by the pressure sensors S2, S3, and S4, the control device 40 detects the adsorption state of the wafer W on the wafer chuck 12. When the wafer W is adsorbed and the wafer chuck 12 and the probe card 14 are in a close state, if the pressure in at least one of the lines from the vacuum adsorption line L20 to L22 increases, the control device 40 controls the electromagnetic valve V1 to close (disconnect) the vacuum adsorption line L20 and connect it to the vacuum adsorption line L3.

[0043] The vacuum adsorption line L3 is connected to the vacuum source VC3. On the vacuum adsorption line L3, a pressure sensor S5, a vacuum tank VT, a hand valve HV, and an electromagnetic valve V4 are provided in order from the downstream side (the electromagnetic valve V1 side).

[0044] The electromagnetic valve V4 is arranged between the vacuum source VC3 and the vacuum tank VT, and opens and closes the vacuum adsorption line L3 between the vacuum source VC3 and the vacuum tank VT.

[0045] While the electromagnetic valve V4 is open, the vacuum source VC3 evacuates the vacuum tank VT arranged on the vacuum adsorption line L3.

[0046] The pressure sensor S5 detects the pressure between the electromagnetic valve V1 and the vacuum tank VT, and outputs it to the control device 40.

[0047] The hand valve HV is a valve for opening the vacuum tank VT to the atmosphere. The opening and closing of the hand valve HV can be either manual or automatic.

[0048] (Probe control method) Next, in the adsorption mechanism according to the present embodiment, a procedure for switching the adsorption of the wafer W based on the detection result of the adsorption state of the wafer W will be described. FIG. 3 is a flowchart showing a method for controlling a prober according to the first embodiment of the present invention.

[0049] First, the control device 40 acquires the measured value of the pressure in the vacuum adsorption line L20 output from the pressure sensor S4 on the vacuum source VC2 side, and checks the operation of the pressure sensor S4 (step ST10).

[0050] Next, with the hand valve HV closed, the control device 40 opens the solenoid valve V4 (starts evacuation of the vacuum tank VT) to evacuate the vacuum tank VT. Then, the control device 40 acquires the measured value of the pressure output from the pressure sensor S5 on the vacuum tank VT side, and detects the degree of vacuum in the vacuum tank VT. If the degree of vacuum in the vacuum tank VT is less than the threshold value, for example, if the evacuation of the vacuum tank VT is not sufficient (No in step ST12), an error is output (step ST16).

[0051] On the other hand, when the degree of vacuum in the vacuum tank VT is equal to or higher than the threshold value, for example, when the vacuum tank VT is kept under vacuum (Yes in step ST12), the control device 40 starts the initialization of the measurement unit 10, for example, cleaning of the measurement unit 10, adsorption and holding of the probe card 14, connection of the upstream side (L20) and the downstream sides (L21 and L22) of the vacuum adsorption line L2 by switching the solenoid valve V1, and other processes are performed (step ST14).

[0052] When the initialization of the measurement unit 10 is completed, the wafer W is loaded onto the wafer chuck 12 (step ST18). Then, the vacuum source VC2 is operated to perform vacuum adsorption (vacuum) of the wafer W (step ST20). In step ST20, when the size of the wafer is small, the solenoid valve V3 is opened and the solenoid valve V2 is closed, but when the size of the wafer is large, both the solenoid valves V3 and V2 are opened.

[0053] Next, the control device 40 determines the adsorption state of the wafer W (step ST22). In step ST22, the control device 40 determines the adsorption state based on the measured values of the pressures output from the pressure sensors (S2 and S3) on the downstream side (wafer chuck 12 side). In step ST22, when the size of the wafer is small, only the output of the pressure sensor S3 is acquired, but when the size of the wafer is large, the outputs of both the pressure sensors S3 and S2 are acquired to determine the adsorption state.

[0054] When the control device 40 determines that the adsorption state of the wafer W is abnormal, for example, when it detects that the pressure is high and the degree of vacuum is low (Yes in step ST22), it proceeds to the retry / recovery process (step ST26) and outputs a message to the operator to perform the retry / recovery process. In step ST26, the unloading and reloading of the wafer W are performed.

[0055] On the other hand, when the control device 40 determines that the adsorption state of the wafer W is normal, for example, when the pressure is low and the degree of vacuum is maintained (No in step ST22), the control device 40 controls the Z stage 22 to raise the wafer chuck 12 toward the probe card 14, and the inspection of the wafer W is started (step ST24).

[0056] During the inspection of the wafer W, the control device 40 monitors the measured values of the pressures output from the pressure sensor S4 on the vacuum source VC2 side and the pressure sensors S2 and S3 on the adsorption side (wafer chuck 12 side) (step ST28). When an abnormality is detected in at least one of the measured values of the pressures output from the pressure sensors S2 to S4, for example, when it is detected that the pressure is high and the degree of vacuum is low (step ST28), the control device 40 controls the solenoid valve V1 to disconnect the upstream vacuum adsorption line L20 from the downstream vacuum adsorption lines L21 and L22, and connects the vacuum adsorption line (vacuum tank line) L3 to the downstream vacuum adsorption lines L21 and L22 (step ST30). Also, the solenoid valve V4 is closed to disconnect the vacuum tank VT from the vacuum source VC3 (step ST30). In step ST30, when an abnormality is detected in the adsorption state by the vacuum source VC2, by switching to adsorption by the vacuum tank VT, it is possible to prevent the wafer W from warping toward the probe card 14 side.

[0057] Further, the control device 40 transmits a TEST END signal indicating the end (interruption) of the inspection to the measurement unit 10 (step ST32).

[0058] Next, when there is a response to the TEST END signal from the measurement unit 10 (Yes in step ST34), the control device 40 immediately controls the Z stage 22 to lower the wafer chuck 12 (step ST36). On the other hand, when there is no response to the TEST END signal from the measurement unit 10 (No in step ST34), the control device 40 controls the Z stage 22 to lower the wafer chuck 12 within a predetermined time (step ST38). Then, the control device 40 outputs a maintenance call to the operator of the probe or the like (step ST40).

[0059] Here, the predetermined time in step ST38 is set, for example, to the time during which the adsorption state by the vacuum tank VT can be maintained.

[0060] In addition, in the present embodiment, a difference is provided in the start timing of the descent of the Z stage 22 according to the presence or absence of a response to the TEST END signal. However, the descent of the Z stage 22 may be started immediately without going through such a process.

[0061] When an abnormality is detected in the adsorption state by the vacuum source VC2, since the vacuum sources VC1 and VC3 may also use the same vacuum source at the probe installation location, abnormalities may also occur in the other vacuum sources VC1 and VC3. In the present embodiment, when an abnormality is detected in the adsorption state by the vacuum source VC2, by switching to adsorption by the vacuum tank VT, it is possible to prevent the wafer W from warping toward the probe card 14 side. And since the adsorption by the vacuum tank VT is not permanent, the Z stage 22 is quickly lowered. Thereby, it is possible to prevent the wafer W from warping toward the probe card 14 side and contacting the probe card 14.

[0062] In addition, in the present embodiment, when an abnormality is detected in at least one of the measured pressure values output from the pressure sensor S4 on the upstream side (the vacuum source VC2 side) and the pressure sensors S2 or S3 on the downstream side (the wafer chuck 12 side) with respect to the solenoid valve V1, the adsorption is switched to the adsorption by the vacuum tank VT. However, the present invention is not limited to this. For example, a pressure sensor may be arranged only on either the upstream side (the vacuum source VC2 side) or the downstream side (the wafer chuck 12 side), and when an abnormality is detected in the measured pressure value output from the pressure sensor, the adsorption may be switched to the adsorption by the vacuum tank VT. Also, the processing may be changed according to which side, the upstream side (the vacuum source VC2 side) or the downstream side (the wafer chuck 12 side), the abnormality is detected. For example, when an abnormality is detected in the measured pressure value output from the pressure sensor S4 on the upstream side (the vacuum source VC2 side), the adsorption is switched to the adsorption by the vacuum tank VT, and when an abnormality is detected in the measured pressure value output from the pressure sensors S2 or S3 on the downstream side (the wafer chuck 12 side), the Z stage 22 may be immediately lowered without switching to the adsorption by the vacuum tank VT.

[0063] [Second Embodiment] Next, a second embodiment will be described. In the following description, for components having the same configuration as those in the above-described embodiment, the same reference numerals will be used and the description thereof will be omitted.

[0064] FIG. 4 is a block diagram showing an adsorption mechanism in a prober according to a second embodiment of the present invention.

[0065] As shown in FIG. 4, in the adsorption mechanism according to the second embodiment, instead of the vacuum tank VT and the vacuum source VC3 on the vacuum adsorption line L3, a vacuum pump P (temporary adsorption vacuum source) is provided.

[0066] Also in this embodiment, when the control device 40 detects an abnormality in the adsorption state by the vacuum source VC2, it can prevent the wafer W from warping toward the probe card 14 side by switching to adsorption by the vacuum pump P.

[0067] [Third Embodiment] Next, a third embodiment will be described. In the following description, for components having the same configuration as those in the above-described embodiment, the same reference numerals will be used and the description thereof will be omitted.

[0068] FIG. 5 is a block diagram showing an adsorption mechanism in a prober according to a third embodiment of the present invention.

[0069] As shown in FIG. 5, in the adsorption mechanism according to the third embodiment, both the vacuum adsorption lines L20 and L3 are connected to a common vacuum source VC1.

[0070] Also in this embodiment, when the control device 40 detects an abnormality in the adsorption state by the vacuum source VC1, it can prevent the wafer W from warping toward the probe card 14 side by switching to adsorption by the vacuum tank VT. [Description of Reference Numerals]

[0071] 10…Measurement unit, 12…Wafer chuck, 14…Probe card, 16…Probe, 18…Head stage, 20…Alignment device, 22…Z stage, 24…X carriage, 26…Y carriage, 28…Suction port, 30…Suction path, 40…Control device, W…Wafer, VC1~VC3…Vacuum source, L1~L3…Vacuum adsorption line, V1~V4…Solenoid valve, S1~S5…Pressure sensor, HV…Hand valve, VT…Vacuum tank, P…Vacuum pump

Claims

1. A wafer chuck for sucking and holding a wafer, A probe card having probes on a surface facing the wafer chuck, An alignment device for moving the wafer chuck, A vacuum source for sucking and holding the wafer on the wafer chuck, A pressure sensor disposed between the wafer chuck and the vacuum source, A temporary suction vacuum source, When inspecting by bringing the wafer close to the probe card by the alignment device, based on the output of the pressure sensor, when it is determined that the suction state of the wafer by the vacuum source is abnormal, the vacuum source is disconnected from the wafer chuck, and a control device that switches to suction by the temporary suction vacuum source, A prober comprising:

2. During the inspection, when the control device determines that the suction state of the wafer by the vacuum source is abnormal based on the output of the pressure sensor, the control device controls the alignment device to move the wafer chuck away from the probe card. The prober according to claim 1.

3. Comprising a solenoid valve provided between the wafer chuck and the vacuum source, The pressure sensors are respectively disposed on the wafer chuck side and the vacuum source side with respect to the solenoid valve, The control device determines the suction state of the wafer by the vacuum source based on measured values of pressures output from the pressure sensors on the wafer chuck side and the vacuum source side. The prober according to claim 1 or 2.

4. The temporary suction vacuum source is a vacuum tank or a vacuum pump. The prober according to any one of claims 1 to 3.

5. A step of starting an inspection with the wafer sucked and held on the wafer chuck by a vacuum source in a state where the wafer is brought close to the probe card by an alignment device, During the inspection, when it is determined that the suction state of the wafer by the vacuum source is abnormal based on the output of a pressure sensor disposed between the wafer chuck and the vacuum source, a step of disconnecting the vacuum source from the wafer chuck and switching to suction by a temporary suction vacuum source, A control method for a prober including:

6. When it is determined that the adsorption state of the wafer by the vacuum source is abnormal based on the output of a pressure sensor disposed between the wafer chuck and the vacuum source during the inspection, the method for controlling a prober according to claim 5, comprising the step of controlling the alignment apparatus to move the wafer chuck away from the probe card.

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