JP2008028103A - Wafer prober - Google Patents

Abstract

A wafer prober capable of appropriately adjusting an overdrive amount (contact pressure) regardless of the type of probe card.
A scanning probe microscope is used to measure the depth of a needle mark formed by contact (needle contact) of an electrode probe of a probe card with an electrode pad of an IC formed on a wafer. 19 is provided. The probe card 14 and the scanning probe microscope 19 are juxtaposed, and the wafer 12 is held by the wafer chuck 15, and the horizontal contact mechanism 16 allows the needle contact position below the probe card 14 and the scanning probe microscope 19 below. It is moved horizontally between the needle trace measurement positions. The elevating / lowering mechanism 17 drives the wafer chuck 15 at the needle contact position and performs needle contact with a predetermined overdrive amount. The needle trace depth determination unit in the control unit 20 corrects the overdrive amount when the needle trace depth measured by the scanning probe microscope 19 is out of the standard range.
[Selection] Figure 1

Description

  The present invention relates to a wafer prober used during a wafer test during a semiconductor manufacturing process.

  In the semiconductor manufacturing process, there is a wafer test process for electrically inspecting the quality of individual semiconductor integrated circuits (ICs) formed on a semiconductor wafer (hereinafter simply referred to as a wafer). This wafer test is usually performed in a state where a probe card is mounted on an apparatus called a wafer prober and the electrode probe of the probe card is in contact with an electrode pad of a desired IC.

  Since the electrode pad of the IC is usually made of aluminum, an insulating oxide film is formed on the surface thereof. For this reason, in order to ensure good conduction between the electrode probe and the electrode pad, after the electrode probe is brought into contact with the electrode pad, pressure is applied so that the electrode probe is further pushed into the electrode pad, and an oxide film on the surface of the electrode pad is formed. Need to be destroyed. Further pushing the electrode probe after physically contacting the electrode pad is called overdrive, and this pushing amount (that is, the contact pressure between the electrode probe and the electrode pad) is called overdrive amount. ing.

  The IC has a plurality of electrode pads, and a plurality of electrode probes are provided on the probe card in accordance with the position of each electrode pad. The position of the tip of each electrode probe in the height direction varies slightly due to mounting errors, deterioration, etc. Therefore, the above overdrive is also required to completely connect all electrode probes to the opposing electrode pads. is there.

  As described above, overdrive is necessary to ensure electrical conduction between the electrode probe and the electrode pad, but if this overdrive amount is excessive, the wiring layer or electrode pad arranged under the electrode pad Damage to the passivation layer (protective layer) formed on the periphery of the substrate. Further, when the depth of the needle trace (contact trace) on the electrode pad becomes deep due to excessive overdrive, problems such as voids occur when soldering the wire. Therefore, the amount of overdrive needs to be set to an appropriate value so that good conductivity is obtained and no malfunction occurs.

  Normally, the wafer prober is configured so that the setting of the overdrive amount can be changed, and the reference position of the wafer chuck holding the wafer is changed according to the set value of the overdrive amount. Conventionally, this overdrive amount has been set by the operator observing the needle trace on the electrode pad with a microscope and determining the appropriate overdrive amount from the size of the needle trace.

In this setting method, since the setting value varies depending on the worker, an automatic method has been proposed without using the worker (see Patent Documents 1 and 2). In Patent Document 1, a reference needle trace and a comparison target needle trace are detected and compared by a camera, and the overdrive amount is corrected based on the deviation amount. In Patent Document 2, the length of the needle trace is detected by a camera, and the overdrive amount is corrected so that the length of the needle trace falls within a predetermined standard.
JP-A-5-36765 JP-A-7-29946

  By the way, the probe card is called a cantilever type (or horizontal type) in which electrode probes are attached obliquely downward from the periphery toward the center, and a vertical type in which electrode probes are attached vertically from top to bottom. There is something called. In the cantilever type probe card, since the electrode probe contacts obliquely with respect to the surface of the electrode pad, the amount of overdrive is easily reflected in the size of the needle trace, and the methods described in Patent Documents 1 and 2 are effective. On the other hand, in the vertical probe card, since the electrode probe contacts the surface of the electrode pad perpendicularly, the size of the needle trace hardly changes even if the overdrive amount changes. Is not valid.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a wafer prober capable of appropriately adjusting the overdrive amount (contact pressure) regardless of the type of the probe card.

  In order to achieve the above object, the wafer prober of the present invention brings the electrode probe of the probe card into contact with the electrode pad of the semiconductor integrated circuit formed on the wafer at a predetermined contact pressure, and makes contact with the tester through the probe card. In the wafer prober that transmits and receives signals, the contact trace measuring means for measuring the depth of the contact trace generated on the surface of the electrode pad by the contact with the electrode probe, and the contact trace measured by the contact trace measuring means Determining means for determining whether or not the depth of the contact is within a standard range, and contact for correcting the contact pressure when the determination means determines that the depth of the contact mark is outside the standard range A wafer prober, comprising: a pressure correction unit;

  The probe card and the contact mark measuring means are arranged side by side, and a wafer holding means for holding the wafer with the formation surface of the semiconductor integrated circuit facing upward, and the wafer holding means are provided under the probe card. A horizontal movement means for horizontally moving between the first position of the first and the second position under the contact mark measurement means, a vertical movement means for moving the wafer holding means up and down, the horizontal movement means and the vertical movement The moving means is controlled, the wafer holding means is moved up and down at the first position, the electrode pad and the electrode probe are brought into contact with each other based on the contact pressure, and then the wafer holding means is moved to the first position. It is preferable to provide movement control means for retracting from the position and moving to the second position.

  Preferably, a test start signal output means is provided for outputting a test start signal for causing the tester to start supplying a test signal when the depth of the contact mark is within the standard range.

  Preferably, a plurality of the electrode pads are provided in the semiconductor integrated circuit, and the probe card is provided with a plurality of the electrode probes according to the electrode pads.

  A probe that outputs a probe card replacement instruction signal for instructing replacement of the probe card when the depth of the contact mark of each electrode pad varies and exceeds both the upper limit and the lower limit of the standard range It is preferable to provide card exchange instruction signal output means.

  Further, the movement control means may be arranged on another semiconductor integrated circuit in the wafer when the depth of the contact mark of each electrode pad varies and exceeds either the upper limit or the lower limit of the standard range. The wafer holding means is aligned so that the electrode probe is positioned at the same time, and the electrode pad of the semiconductor integrated circuit is brought into contact with the electrode probe based on the contact pressure corrected by the contact mark measuring means. preferable.

  Further, the contact mark measuring means performs scanning in a state where the scanning probe is separated from the surface of the electrode pad, and obtains unevenness information based on a force or current acting between the scanning probe and the electrode pad. A scanning probe microscope is preferable.

  In addition, the contact mark measuring means is configured to detect unevenness by detecting a displacement amount of the cantilever which is provided at the tip of the cantilever and is displaced by an atomic force acting between the scanning probe and the electrode pad. It is preferably an atomic force microscope that acquires information.

  According to the wafer prober of the present invention, after the electrode probe is brought into contact with the electrode pad of the semiconductor integrated circuit formed on the wafer, the depth of the contact mark formed on the electrode pad is measured, and the measured contact Since the contact pressure between the electrode probe and the electrode pad is corrected based on the depth of the mark, the contact pressure can be appropriately adjusted regardless of the type of probe card such as a vertical type or a cantilever type.

  FIG. 1 shows the configuration of a wafer prober 10 and a tester 11 used during a wafer test. The wafer prober 10 includes a probe card 14 having electrode probes 13 arranged in accordance with the arrangement of electrode pads of the IC formed on the wafer 12, and a wafer for holding the wafer 12 with the IC formation surface 12a facing upward. The chuck 15, the horizontal movement mechanism 16 that horizontally moves the wafer chuck 15 in the horizontal direction (XY direction), the elevation movement mechanism 17 that moves the wafer chuck 15 up and down in the vertical direction (Z direction), the horizontal movement mechanism 16, and the elevation A base 18 that holds the moving mechanism 17, a scanning probe microscope 19 that is juxtaposed in the Y direction with respect to the probe card 14 and measures the unevenness of each electrode pad surface of the IC, and each part via a cable (not shown) And a control unit 20 that comprehensively controls the control unit 20.

  The probe card 14 is configured as a vertical probe card, and the electrode probe 13 formed of a metal such as tungsten is substantially perpendicular (Z direction) to the surface 12 a of the wafer 12 held by the wafer chuck 15. It is attached to become. The probe card 14 is not limited to the vertical type, and may be a cantilever type.

  The horizontal movement mechanism 16 moves the wafer chuck 15 between a “needle contact position” (first position) indicated by a solid line and a “needle trace measurement position” (second position) indicated by a two-dot chain line. At the same time, positioning is performed so that the electrode probe 13 of the probe card 14 is positioned on the electrode pad of the desired IC formed on the wafer 12 at the needle contact position. The horizontal movement mechanism 16 also adjusts the horizontal position of the wafer chuck 15 at the needle mark measurement position, and positions the scanning probe microscope 19 on the electrode pad of a desired IC.

  The raising / lowering moving mechanism 17 moves the wafer chuck 15 close to / separated from the probe card 14 or the scanning probe microscope 19 in a state where the positioning is performed by the horizontal moving mechanism 16. The raising / lowering moving mechanism 17 raises the wafer chuck 15 to a height obtained by adding a predetermined overdrive amount to the height at which the tip of the electrode probe 13 physically contacts the electrode pad at the needle contact position, Press (needle contact) the electrode pad. In the needle trace measurement position, the lifting / lowering movement mechanism 17 raises the wafer 12 together with the wafer chuck 15 and brings the electrode pad of the IC applied to the needle close to the scanning probe microscope 19 to the electrode probe.

  As shown in FIG. 2, the control unit 20 includes a movement control unit 30, a microscope control unit 31, a needle trace depth determination unit 32, a test start signal output unit 33, an overdrive amount correction unit 34, and a probe card replacement instruction signal. The output unit 35 is configured.

  The movement control unit 30 controls the operations of the horizontal movement mechanism 16 and the elevation movement mechanism 17. The microscope control unit 31 controls probe scanning of the scanning probe microscope 19. The needle trace depth determination unit 32 determines whether or not the needle trace depth of each electrode pad measured by the scanning probe microscope 19 is within the standard range.

  The test start signal output unit 33 outputs a test start signal to the tester body 22 when the needle mark depths of all the electrode pads of the IC applied with the needle are within the standard range. The overdrive amount correction unit 34 corrects the overdrive amount when the needle mark depth exceeds either the upper limit or the lower limit of the standard range. The probe card exchange instruction signal output unit 35 outputs a probe card exchange instruction signal to a notification device (not shown) such as a monitor when the needle mark depth exceeds both the upper limit and the lower limit of the standard range.

  Further, the movement control unit 30 controls the up-and-down movement mechanism 17 based on a predetermined overdrive amount to perform needle contact, but when the overdrive amount is corrected by the overdrive amount correction unit 34, The lifting / lowering mechanism 17 is controlled based on the amount of overdrive.

  Returning to FIG. 1, the tester 11 is connected to the tester main body 22, a test head 24 connected to the tester main body 22 via the rotating shaft 23, and rotating on the rotating shaft 23 as a fulcrum, and to the lower surface of the test head 24. A performance board 25 for exchanging electrical signals with the probe card 14 of the wafer prober 10 is provided. The test head 24 can be pulled away from the wafer prober 10 at the time of maintenance or replacement of the probe card 14, and the terminal of the probe card 14 and the terminal of the performance board 25 are connection terminal mechanisms using springs, so-called pogo pins. It has a structure.

  The tester body 22 has a built-in computer (not shown). During the test, the test head 24 is controlled based on a test program stored in the computer to generate a test signal. The test head 24 inputs the generated test signal to the test target IC in the wafer 12 via the performance board 25 and the probe card 14. The output signal from the test target IC is returned to the tester main body 22, and the tester main body 22 determines whether the IC is good or bad.

  FIG. 3 shows the configuration of the wafer 12. The wafer 12 is semiconductor silicon formed in a substantially disk shape, and ICs 40 are formed in a two-dimensional matrix on the surface 12a. Specific examples of the IC 40 include a logic IC such as a CPU and a microcomputer, a memory IC such as a DRAM and a flash EEPROM, and an image sensor such as a CCD and a CMOS sensor. The IC 40 has a rectangular shape, and electrode pads 41 are arranged at equal intervals along two opposing sides. The electrode pad 41 is an external electrode for inputting / outputting a signal to / from the internal circuit. Note that the number and arrangement of the ICs 40 provided on the wafer 12 and the number and arrangement of the electrode pads 41 provided on the IC 40 are not limited to the above example, and are appropriately changed depending on the type of the IC 40.

  FIG. 4 shows a cross section of the wafer 12 where the electrode pad 41 is formed. In the portion where the electrode pad 41 is formed, a first interlayer insulating film 43 is laminated on the substrate 42 of the wafer 12. The first interlayer insulating film 43 is connected to an internal circuit in the IC 40. A wiring layer 44 is laminated. A second interlayer insulating film 45 having an opening 45 a for exposing the wiring layer 44 is laminated on the first interlayer insulating film 43 and the wiring layer 44. An electrode pad 41 is formed on the wiring layer 44 so as to cover the opening 44 a, and a protective film 46 is provided around the electrode pad 41. The substrate 42 is made of silicon, the first and second interlayer insulating films 43 and 45 are made of silicon oxide, the wiring layer 44 and the electrode pad 41 are made of aluminum, and the protective film 46 is made of silicon nitride. In addition, the forming material of each part is not restricted to this, You may change suitably.

  During the wafer test, the electrode probe 13 is positioned so as to be positioned vertically above the center of the electrode pad 41, and the tip of the electrode probe 13 is pressed perpendicularly to the surface of the electrode pad 41. The electrode pad 41 has a thickness of about 800 nm, and the surface thereof is oxidized to form an oxide film 41a having a thickness of about 100 nm. As shown in FIG. 5, the electrode probe 13 breaks through the oxide film 41 a on the surface of the electrode pad 41 to form a needle trace 41 b having a depth corresponding to the overdrive amount on the electrode pad 41. The planar shape of the needle mark 41b is substantially circular. When the probe card 14 is configured as a cantilever type, the electrode probe is in contact with the electrode pad surface obliquely, so that the planar shape of the needle trace is a shape close to an ellipse.

  FIG. 6 shows the configuration of the scanning probe microscope 19. The scanning probe microscope 19 measures a displacement of the cantilever 51, a cantilever 51 provided with a scanning probe 50 at a distal end portion, a support portion 52 that supports a proximal end portion of the cantilever 51, and a support portion 52. A displacement measuring device 53, a Z-direction piezoelectric body 54 that moves the support portion 52 in the Z direction, an XY-direction piezoelectric body 55 that moves the support portion 52 in the XY direction, a Z-direction piezoelectric body 54, and an XY-direction piezoelectric body 55. Control that receives a displacement measurement signal from the piezoelectric drive device 56 to be driven and the displacement measurement device 53 and generates a control signal (voltage signal) for driving the Z-direction piezoelectric member 54 so as to keep the displacement of the cantilever 51 constant. And a signal generation circuit 57.

  The scanning probe 50 is attached to the lower surface side of the tip of the cantilever 51 toward the surface of the electrode pad 41 that is a measurement object. The scanning probe 50 and the electrode pad 41 are separated from each other, and an atomic force corresponding to the separation distance is generated between the scanning probe 50 and the electrode pad 41. The cantilever 51 is deflected and displaced by the action of the atomic force.

  The displacement measuring device 53 includes a semiconductor laser 53a and a split photodiode 53b. The semiconductor laser 53 a irradiates the upper surface of the tip portion of the cantilever 51 with laser light. The divided photodiode 53b receives the laser beam reflected by the cantilever 51. The position of the laser beam received by the split photodiode 53b varies depending on the amount of deflection of the cantilever 51, and a signal corresponding to the received position is input to the control signal generation circuit 57 as a displacement measurement signal.

  The piezoelectric body driving device 56 drives the XY direction piezoelectric body 55 to move the cantilever 51 supported by the support portion 52 two-dimensionally along the XY direction substantially parallel to the surface of the electrode pad 41 and performs control. The Z-direction piezoelectric body 54 is driven based on a control signal from the signal generation circuit 57, and the displacement of the cantilever 51 is made constant (that is, the separation distance between the scanning probe 50 and the electrode pad 41 is made constant).

  The control signal output from the control signal generation circuit 57 corresponds to the unevenness information on the surface of the electrode pad 41, and this control signal is input to the needle trace depth determination unit 32 in the control unit 20 of the wafer prober 10. The microscope control unit 31 in the control unit 20 controls the XY direction piezoelectric body 55 via the piezoelectric body driving device 56. The control unit 20 acquires unevenness information on the surface of the electrode pad 41 while scanning the scanning probe 50 in the X and Y directions by the microscope control unit 31, and determines the depth d of the needle track 41 b by the needle track depth determination unit 32. (Comparison with the standard range). The depth d is a distance from the surface of the electrode pad 41 to the deepest portion of the needle trace 41b.

  Next, the operation of the wafer prober 10 configured as described above will be described with reference to the flowchart of FIG. First, the wafer 12 set in a loader unit (not shown) is transferred onto the wafer chuck 15 and held by the wafer chuck 15 with the IC 40 formation surface facing upward (step S1). The wafer chuck 15 holding the wafer 12 moves to the needle contact position under the probe card 14 (step S2). At this time, the position of the wafer chuck 15 is adjusted in the XY directions so that the electrode probes 13 of the probe card 14 are positioned on the electrode pads 41 of the first IC 40a (see FIG. 3) on the wafer 12. Is aligned (step S3).

  Next, the movement control unit 30 controls the elevation moving mechanism 17 based on a preset value of a predetermined overdrive amount, adjusts the height reference position of the wafer chuck 15, and then moves the wafer chuck 15. A certain amount is raised in the Z direction, and needle contact with each electrode probe 13 and the corresponding electrode pad 41 is executed (step S4). At this time, a test signal is not supplied to the electrode probe 13 and only physical needle contact is performed.

  After this stylus contact, the wafer chuck 15 is lowered and moved to the needle mark measurement position under the scanning probe microscope 19 by horizontal movement while holding the wafer 12 (step S5). At this time, the position of the wafer chuck 15 is adjusted in the X and Y directions, and alignment is performed so that the IC 40 a subjected to the needle contact is positioned under the scanning probe microscope 19.

  Next, the wafer chuck 15 is raised in the Z direction, and the scanning probe 50 of the scanning probe microscope 19 is brought close to one electrode pad 41 of the IC 40a. In this state, the operation of the scanning probe microscope 19 is controlled, the surface of the electrode pad 41 is scanned by the scanning probe 50, and unevenness information is acquired. When scanning is completed for one electrode pad 41, the scanning probe 50 is brought close to the other electrode pad 41 of the IC 40a, and scanning is performed in the same manner. This operation is repeated, and the unevenness on the surface of each electrode pad 41 of the IC 40a is measured (step S6).

  When the scanning of each electrode pad 41 is completed, the wafer chuck 15 is lowered and moved to the needle contact position by horizontal movement while holding the wafer 12 (step S7). At the same time, the unevenness information of each electrode pad 41 is input from the control signal generation circuit 57 in the scanning probe microscope 19 to the needle trace depth determination unit 32 in the control unit 20, and the needle trace of each electrode pad 41 is input. It is determined whether or not the depth d is within the standard range (step S8). The standard range of the needle mark depth is preferably in the range of 1/3 to 1/2 of the film thickness of the electrode pad 41. In this embodiment, the film thickness of the electrode pad 41 is about 800 nm, and a preferable standard range is a range of about 270 nm to 400 nm.

  As shown in FIG. 8A, when the needle mark depth d (distinguished as A to J) of each electrode pad 41 of the IC 40a is within the standard range (YES determination in step S8), a test is performed. A test start signal is transmitted from the start signal output unit 35 to the tester body 22 (step S9). Thereafter, needle contact similar to that described above is performed on the desired IC 40, and the tester body 22 starts supplying the test signal to the test head 24 and executes the test of the IC 40 during needle contact (step S10). ). At this time, the test may be started as it is for the wafer subjected to the inspection of the needle trace depth, or may be changed to a new wafer before the test is started.

  On the other hand, when the needle trace depth d is not within the standard range (NO determination in step S8), the needle trace depth determination unit 32 further determines whether both the upper limit and the lower limit of the standard range are exceeded. Determination is made (step S11). As shown in FIG. 8B, when the needle trace depth d exceeds the upper limit and the lower limit (YES determination in step S11), it cannot be dealt with by correcting the overdrive amount, and is in use. The probe card 14 is determined to be defective (NG) of the electrode probes 13 (step S12). At this time, a probe card replacement instruction signal is transmitted from the probe card replacement instruction signal output unit 35 to a notification device such as a monitor, and the operator is instructed to replace the probe card 14.

  If either the upper limit or the lower limit of the standard range is exceeded (NO determination in step S11), the overdrive amount correction unit 34 corrects the overdrive amount (step S13). Specifically, as shown in FIG. 9A, when the needle trace depth d is below the lower limit of the standard range, the overdrive amount is too small, and the electrical connection between the electrode probe 13 and the electrode pad 41 is reduced. As a result, the amount of overdrive is increased by correction. On the other hand, as shown in FIG. 9B, when the needle mark depth d exceeds the standard upper limit value, the overdrive amount is too large, and the wiring layer 44 under the electrode pad 41 and the surroundings of the electrode pad 41 are Since damage to the protective film 46 becomes a problem, the amount of overdrive is reduced by correction.

  Thereafter, alignment is performed so that each electrode probe 13 of the probe card 14 is positioned on the electrode pad 41 of the second IC 40b (see FIG. 3) (step S14), and the process proceeds to the needle contact of step S4. . In step S4, needle contact is performed based on the corrected overdrive amount. Thereafter, the above operation is repeated. If the overdrive amount is properly corrected in step S13, the next needle mark depth determination (step S8) is passed and the test is started.

  As described above, according to the wafer prober 10 of the present invention, after the electrode probe is brought into contact with the electrode pad of the IC formed on the wafer, the depth of the contact mark formed on the electrode pad is measured. Because the contact pressure between the electrode probe and electrode pad is corrected based on the measured contact mark depth, the overdrive amount can be accurately adjusted regardless of the type of probe card such as vertical or cantilever type. be able to.

  In the above embodiment, the scanning probe microscope 19 is configured as an atomic force microscope, and the displacement of the cantilever 51 is measured by the displacement measuring device 53 configured by an optical lever method. The present invention is not limited to this, and the displacement of the cantilever 51 may be measured by a displacement measuring device configured by a laser interference method or a tunnel current detection method.

  Further, the scanning probe microscope 19 is not limited to an atomic force microscope, and can also be configured as a scanning tunnel microscope that acquires unevenness information based on a tunnel current flowing between the scanning probe and the electrode pad.

It is a schematic diagram which shows the structure of a tester and a wafer prober. It is a block diagram which shows the structure of a control part. It is a top view which shows the structure of a wafer. It is sectional drawing which shows the cross section of the electrode pad part of a wafer. It is sectional drawing which shows the cross section of the electrode pad at the time of needle | hook contact. It is a schematic diagram which shows the structure of a scanning probe microscope. It is a flowchart which shows operation | movement of a wafer prober. It is a graph illustrating measurement data of needle trace depth, (A) is when the measured value is within the standard range, (B) is when the measured value exceeds the upper and lower limits of the standard range Indicates. It is a graph which illustrates the measurement data of needle trace depth, (A) shows the case where a measured value exceeds a standard lower limit, and (B) shows the case where a measured value exceeds a standard upper limit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Wafer prober 11 Tester 12 Wafer 13 Electrode probe 14 Probe card 15 Wafer chuck (wafer holding means)
16 Horizontal movement mechanism (horizontal movement means)
17 Elevating / moving mechanism (Elevating / moving means)
19 Scanning probe microscope (contact trace measuring means)
20 control unit 30 movement control unit (movement control means)
31 Microscope control unit 32 Needle mark depth determination unit (determination means)
33 Test start signal output unit (test start signal output means)
34 Overdrive amount correction unit (contact pressure correction means)
35 Probe replacement instruction signal output unit (probe replacement instruction signal output means)
40 Semiconductor Integrated Circuit 41 Electrode Pad 41a Oxide Film 41b Needle Trace 50 Scanning Probe 51 Cantilever 53 Displacement Measuring Device

Claims (8)

In a wafer prober that sends and receives signals to and from a tester through the probe card by bringing the electrode probe of the probe card into contact with the electrode pad of the semiconductor integrated circuit formed on the wafer at a predetermined contact pressure,
Contact trace measuring means for measuring the depth of the contact trace generated on the surface of the electrode pad by contact with the electrode probe;
Determining means for determining whether or not the depth of the contact mark measured by the contact mark measuring means is within a standard range;
Contact pressure correction means for correcting the contact pressure when the determination means determines that the depth of the contact mark is outside the standard range;
A wafer prober characterized by comprising: The probe card and the contact trace measuring means are arranged side by side,
Wafer holding means for holding the wafer with the formation surface of the semiconductor integrated circuit facing upward;
Horizontal moving means for horizontally moving the wafer holding means between a first position under the probe card and a second position under the contact mark measuring means;
Elevating and moving means for moving the wafer holding means up and down;
Controlling the horizontal movement means and the elevation movement means, moving the wafer holding means up and down at the first position, and contacting the electrode pad and the electrode probe based on the contact pressure; Movement control means for retracting the wafer holding means from the first position and moving the wafer holding means to the second position;
The wafer prober according to claim 1, wherein:   The test start signal output means for outputting a test start signal for starting the test signal supply to the tester when the depth of the contact mark is within the standard range is provided. Or the wafer prober of 2.   4. The electrode pad according to claim 1, wherein a plurality of electrode pads are provided in the semiconductor integrated circuit, and a plurality of electrode probes are provided on the probe card in accordance with the electrode pads. Or a wafer prober.   Probe card replacement for outputting a probe card replacement instruction signal for instructing replacement of the probe card when the depth of the contact mark of each electrode pad varies and exceeds both the upper limit and the lower limit of the standard range 5. A wafer prober according to claim 4, further comprising instruction signal output means.   When the depth of the contact mark of each electrode pad varies and exceeds one of the upper limit and the lower limit of the standard range, the movement control unit is arranged on the other semiconductor integrated circuit in the wafer. The wafer holding means is aligned so that the electrode probe is positioned, and the electrode pad of the semiconductor integrated circuit is brought into contact with the electrode probe based on the contact pressure corrected by the contact mark measuring means. A wafer prober according to claim 4 or 5.   The contact mark measuring means performs scanning in a state where the scanning probe is separated from the surface of the electrode pad, and obtains unevenness information based on a force or current acting between the scanning probe and the electrode pad. 7. The wafer prober according to claim 1, wherein the wafer prober is a scanning probe microscope.   The contact mark measuring means detects unevenness information by detecting a displacement amount of the cantilever that is displaced by an atomic force acting between the scanning probe and the electrode pad, the scanning probe being provided at a tip of the cantilever. 8. The wafer prober according to claim 7, wherein the wafer prober is an atomic force microscope to be acquired.

Images