JP2008053282A - Prober - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a prober capable of accurately detecting the places of moving stages on an X-axis and a Y-axis even when the Y-axis and a base are deformed thermally when a wafer chuck is heated/cooled. <P>SOLUTION: The prober has the wafer chuck 16 with a built-in heating/cooling member, an X-axis stage 14 rotating the wafer chuck 16 and conducting movements in the Z-axis and X-axis directions, a Y-axis stage 13 conducting the movement in the Y-axis direction of the wafer chuck 16, and the base 12 moving and supporting the Y-axis stage 13. The prober is calibrated by linear scales 41 and 42 fitted in parallel with the vertical direction apart from the X-axis stage 13 on one side face of the direction that the X-axis stage 14 of the Y-axis stage 13 is moved, and an arm 40 with heads 43 and 44 fitted on the side face of the X-axis stage 14 and opposed to the linear scales 41 and 42, respectively. The prober corrects and detects the value of the linear scale 41 reading the place of the X-axis stage 14 by the reading of the linear scale 42. Such a prober is used. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wafer in which terminals of a semiconductor tester (hereinafter simply referred to as a tester) are connected to electrode pads of a die in order to inspect electrical characteristics of a plurality of semiconductor chips (hereinafter referred to as dies) formed on the semiconductor wafer. The present invention relates to a probing machine (hereinafter referred to as a prober), and more particularly to a prober that can accurately detect the amount of movement of a wafer chuck even if pitching occurs due to the influence of ambient heat on a stage of a prober that moves a die.

  In the semiconductor manufacturing process, various processes are performed on a thin disk-shaped semiconductor wafer to form a plurality of dies each having a device which is a semiconductor device. Each die is inspected for electrical characteristics and then separated into individual pieces by a dicer, and then fixed and assembled to a lead frame or the like. The inspection of the electrical characteristics of each die is performed by a wafer test system that combines a prober and a tester.

  The prober is connected to a tester via a mounted probe card and configured to test the electrical characteristics of each die by applying a probe needle to the wafer chip. The wafer is fixed to the wafer chuck, and the probe needle is brought into contact with the electrode pad of each die. The tester supplies power and various test signals to the terminals connected to the probe needle, and the signals output to the die electrodes are detected by the tester. This signal is analyzed on the tester side and each die is operating normally. Is confirmed to work.

  FIG. 1 is a diagram showing a schematic configuration of a wafer test system 100. The wafer test system 100 includes a prober 10 and a tester 30. As shown, the prober 10 includes a wafer chuck 16, a Z-axis movement / rotation unit 15, a probe needle position detection camera 18, a camera movement mechanism 17, an X-axis movement stage 14, a Y-axis movement stage 13, a base 12, and a gantry 11 , Columns 19 and 20, a head stage 21, a wafer alignment camera 22, a card holder 23, and a probe card 24.

  The wafer chuck 16 holds a wafer W on which a plurality of dies are formed. The wafer chuck 16 is moved in the Z-axis direction by the Z-axis moving / rotating unit 15 and rotates around the Z-axis. . The probe needle position detection camera 18 detects the position of the probe needle 25 and is attached on the camera moving mechanism 17. The camera moving mechanism 17 moves the probe needle position detection camera 18 in the Z-axis direction. The Z-axis moving / rotating unit 15 and the camera moving mechanism 17 are mounted on the X-axis moving stage 14, and the X-axis moving stage 14 supports these and moves in the X-axis direction.

  The X-axis moving stage 14 is provided on a Y-axis moving stage 13 that supports this and moves in the Y-axis direction, and the Y-axis moving stage 13 is supported on the base 12. Furthermore, the base 12 is installed on the gantry 11. The head stage 21 is supported above the wafer chuck 16 by support columns 19 and 20 provided on the base 12. A card holder 23 having a probe card 24 is attached to the head stage 21. The wafer alignment camera 22 is supported on the base 12 by a support (not shown) and photographs the upper surface of the wafer W.

  Since the operation of the moving / rotating mechanism configured as described above is widely known, the description thereof is omitted here. The probe card 24 has a probe needle 25 arranged according to the electrode arrangement of a device (die) to be inspected, and is exchanged according to the device to be inspected. The probe needle position detection camera 18 detects the arrangement and height position of the probe needle 25, and the wafer alignment camera 22 images and detects the position of the electrode pad of the die on the wafer W.

  The tester 30 includes a test head 31 and a contact ring 32 provided on the test head 31. The probe card 25 is provided with a terminal connected to each probe, and the contact ring 32 has a spring probe arranged so as to contact the terminal. The test head 31 is held with respect to the prober 10 by a support mechanism (not shown).

  FIG. 2 is a perspective view of the main part on the mount 11 of the prober 10 of FIG. 1, and the same reference numerals are given to the same components as those in FIG. Two guide rails 1 are provided in parallel on the base 12, and the Y-axis moving stage 13 is movable on the guide rail 1. A drive motor 29 and a ball screw 27 that is rotated by the drive motor 29 are provided in a portion between the two guide rails 1 on the base 12. The ball screw 27 is engaged with the bottom surface of the Y-axis moving stage 13, and the Y-axis moving stage 13 slides on the guide rail 1 by the rotation of the ball screw 27.

  Two parallel guide rails 2 orthogonal to the above-described two guide rails 1 are provided on the Y-axis movement stage 13 in plan view, and the X-axis movement stage 14 is disposed on the guide rail 2. Can be moved. A drive motor 28 and a ball screw 26 rotated by the drive motor 28 are provided in a portion between the two guide rails 2 on the Y-axis moving stage 13. The ball screw 26 is engaged with the bottom surface of the X-axis moving stage 14, and the X-axis moving stage 14 slides on the guide rail 2 by the rotation of the ball screw 26.

  Here, the die inspection by the wafer test system 100 will be briefly described. When performing die inspection, the X-axis moving stage 14 is moved so that the probe needle position detection camera 18 shown in FIG. 1 is located under the probe needle 25, and the probe moving position is detected by the camera moving mechanism 17. The detection camera 18 moves in the Z-axis direction and is focused, and the tip position of the probe needle 25 is detected by the probe needle position detection camera 18. The position of the tip of the probe needle 25 in the horizontal plane (X and Y coordinates) is detected by camera coordinates, and the vertical position is detected by the camera focal position.

  The detection of the tip position of the probe needle 25 must be performed whenever the probe card 24 is replaced, and may be appropriately performed every time a predetermined number of dies are measured even when the probe card 24 is not replaced. The probe card 24 is generally provided with several to thousands of probe needles 25. When the number is large, the tip positions of all the probe needles 25 are not detected and are usually specified. The tip position of the probe is detected.

  Next, the X-axis moving stage 14 is moved to the position indicated by the broken line in FIG. 1, and the wafer W is positioned below the wafer alignment camera 22 with the wafer W to be inspected held by the wafer chuck 16. In this state, the position of the die electrode pad on the wafer W is detected by the wafer alignment camera 22. It is not necessary to detect the positions of all the electrode pads of one die, and it is only necessary to detect the positions of several electrode pads. Further, it is not necessary to detect the electrode pads of all the dies on the wafer W, and the positions of the electrode pads of several dies may be detected.

  As described above, when the arrangement of the probe needles 25 and the arrangement of the electrode pads are detected, based on the detection result, the Z-axis movement is performed so that the arrangement direction of the probe needles 25 and the arrangement direction of the electrode pads coincide. The wafer chuck 16 is rotated by the rotating unit 15. Thereafter, the wafer chuck 16 is moved by the X-axis moving stage 14 and the Y-axis moving stage 13 so that the electrode pad of the die to be inspected is positioned below the probe needle 25. After the movement of the wafer chuck 16 is completed, the wafer chuck 16 is raised in the Z-axis direction by the Z-axis moving / rotating unit 15, and the raising is stopped in a state where the electrode pad is in contact with the probe needle 25. In this state, power and signals are supplied from the tester 30 to perform inspection.

  The prober is described in Patent Document 1 and the like and is widely known, so further explanation is omitted.

  By the way, the inspection of the die by the wafer test system 100 is often performed in accordance with the environment in which the die is used. In this case, the die is heated and cooled by a wafer chuck that holds the wafer on which the die is formed. In other words, the wafer chuck is heated by a heater provided in the wafer chuck, and the wafer chuck is cooled by circulating a coolant through a coolant passage provided in the wafer chuck. A Peltier element or a chiller using a thermoelectric effect may be used for heating and cooling the wafer chuck.

JP 2004-039752 A (Overall)

  However, when the wafer chuck is heated and cooled for heating and cooling the die, it is difficult to completely insulate the wafer chuck. Therefore, the heat or cold of the wafer chuck 16 is applied to the X-axis moving stage 14 and the Y-axis. It may be transmitted to the moving stage 13 and the base 12. Then, the X-axis moving stage 14, the Y-axis moving stage 13, and the base 12 are expanded or contracted by this heat or cold, and normally, the curved deformation is convex upward or curved downward. When the X-axis moving stage 14 and the Y-axis moving stage 13 are moved, pitching occurs, and the moving accuracy of the moving stage is affected.

  This problem will be described in more detail. Here, the case where the Y-axis moving stage 13 is curved upward and deformed by the heat of the wafer chuck 16 will be described with reference to FIGS. In die inspection by the wafer test system 100, the die size and measurement time differ depending on the type of device to be measured. For example, if the measurement time at high temperature is long, the heat is directly transmitted to the Y-axis moving stage 13 and the stage. The shape of 13 is deformed from the state shown in (a) to the upward curved deformation state shown in (b) where the upper side is expanded. This deformation is called the bimetal effect.

  Although not shown in FIG. 2, a linear scale for measuring the distance that the X-axis moving stage 14 has moved on the rail 2 is provided separately from the Y-axis moving stage 13. A linear scale for measuring the distance that the Y-axis moving stage 13 has moved on the rail 1 is provided separately from 12. The moving distance is read by a head provided opposite to the linear scale. FIGS. 3A and 3B show a linear scale 33 provided on the Y-axis moving stage 13.

  Since the linear scale 33 is provided below the Y-axis moving stage 13, it is attached to the X-axis moving stage 14 when the Y-axis moving stage 13 is not deformed as shown in FIG. By reading the linear scale 33 with the head 35 provided at the tip of the arm 34, the position and movement amount of the X-axis moving stage 14 can be accurately measured. However, as shown in (b), when the Y-axis moving stage 13 is deformed into a convex curved deformation state due to heat, the relationship between the moving amount of the scale head and the moving amount of the wafer chuck 16 changes due to the change in pitching. There is a problem that the position and movement amount of the wafer chuck 16 cannot be measured accurately.

  The present invention solves such problems, and even when the wafer chuck is heated and cooled, and the stage is deformed by heat or cold air, the position and amount of movement of the wafer chuck can be accurately detected. The purpose is to provide a prober.

  A prober of the present invention that achieves the above object is a prober for connecting each terminal of a tester to an electrode of a device via a probe needle in order to electrically inspect the operation of a device formed on the wafer. A wafer chuck containing a first heating / cooling member for holding the wafer, an X-axis moving stage for rotating the wafer chuck and moving in the Z-axis and X-axis directions, and a Y-axis for moving the wafer chuck in the Y-axis direction A moving stage, a base for supporting the movement of the Y-axis moving stage, and one side surface of the Y-axis moving stage in the moving direction of the X-axis moving stage are provided in parallel to the vertical direction independently of the Y-axis moving stage. Are attached to the side surfaces of the first and second linear scales and the X-axis moving stage, and are opposed to the first and second linear scales, respectively. And a prober characterized in that the movement amount of the wafer chuck is detected by correcting the read value of the first linear scale with the read value of the second linear scale. is there.

  In this case, the movement amount Lc of the wafer chuck is set to θp as the pitching change accompanying the movement of the X-axis moving stage, sin θp = θp at a minute angle, h between the first and second linear scales, and the first linear scale. When the distance from the scale to the top surface of the wafer chuck is hc, the reading distance of the head facing the first linear scale at this time is La, and the reading distance of the head facing the second linear scale is Lb. From the relationship of Lc = La− (hc × θp) and La = Lb− (h × θp), it can be calculated from the formula Lc = La− (Lb−La) × hc / h. The first and second linear scales may be formed on a single scale plate.

  Further, the above-described prober is further provided with a low thermal expansion coefficient member provided on one side surface in the moving direction of the Y-axis moving stage of the base, in parallel with the vertical direction independently of the base. And a fourth linear scale, and an arm that is attached to the side surface of the Y-axis moving stage and has a head that faces each of the third and fourth linear scales. The read value of the linear scale may be detected by correcting with the read value of the fourth linear scale.

  In this case, the movement amount Mc of the wafer chuck is set to θq as a pitching change accompanying the movement of the Y-axis moving stage, sin θq = θq at a small angle, k between the third and fourth linear scales, and the third linear scale. When the distance from the scale to the top surface of the wafer chuck is kc, the reading distance of the head facing the third linear scale at this time is Ma, and the reading distance of the head facing the fourth linear scale is Mb. , Mc = Ma− (kc × θq), Ma = Mb− (k × θq), and can be calculated from the equation Mc = Ma− (Mb−Ma) × kc / k. The third and fourth linear scales may be formed on a single scale plate.

  According to the present invention, a linear scale that detects the amount of movement of the X-axis moving stage and a linear scale that detects the amount of movement of the Y-axis moving stage even when the wafer chuck is heated and cooled and the stage is deformed by heat or cold air. Is configured by two linear scales parallel to each other in the vertical direction, so that the true movement amount of each stage is obtained from the difference between the detection values of the movement amounts using the two linear scales. Even when the wafer chuck is heated and cooled, the amount of movement of the wafer chuck can be accurately detected.

  Hereinafter, embodiments of the present invention will be described in detail based on specific examples with reference to the accompanying drawings. In addition, about the same structural member as the structural member demonstrated in FIGS. 1-3, the same code | symbol is attached | subjected and demonstrated.

  FIG. 4A shows the configuration of the prober 10 according to the first embodiment of the present invention, and shows the same parts as FIG. Two guide rails 1 are provided in parallel on the base 12, and the Y-axis moving stage 13 is movable on the guide rail 1. A drive motor 29 and a ball screw 27 that is rotated by the drive motor 29 are provided in a portion between the two guide rails 1 on the base 12. The Y-axis moving stage 13 slides on the guide rail 1 by the rotation of the ball screw 27.

  Two parallel guide rails 2 orthogonal to the two guide rails 1 are provided on the Y-axis movement stage 13, and the X-axis movement stage 14 can move on the guide rail 2. ing. A drive motor 28 and a ball screw 26 rotated by the drive motor 28 are provided in a portion between the two guide rails 2 on the Y-axis moving stage 13. The X-axis moving stage 14 slides on the guide rail 2 by the rotation of the ball screw 26.

  A probe needle position detection camera 18 that moves up and down by a camera moving mechanism 17 and a wafer chuck 16 that can move up and down by a Z-axis moving / rotating unit 15 are provided on the X-axis moving stage 14. A wafer W to be inspected is placed on the wafer chuck 16. Reference numeral 24 denotes a probe card. Since the inspection of all the dies on the wafer W has been described above, further description is omitted.

  In the prober 10 configured as described above, in the first embodiment, on one side surface of the Y-axis moving stage 13 in the moving direction of the X-axis moving stage 14, here on the side surface without the drive motor 29, A linear scale plate 3 is attached. The linear scale plate 3 is composed of a member having a low coefficient of thermal expansion. On the linear scale plate 3, a reference linear scale 41 as a first linear scale and a correction linear scale as a second linear scale are provided. 42 is provided in parallel with the plate thickness direction (vertical direction) of the Y-axis moving stage 13. In the first embodiment, the reference linear scale 41 and the correction linear scale 42 are formed on one linear scale plate 3, but the reference linear scale 41 and the correction linear scale 42 are It may be formed on a separate and independent linear scale plate.

  Further, in the first embodiment, an arm 40 having a head (described later) facing the reference linear scale 41 and the correction linear scale 42 is provided on the side surface of the X-axis moving stage 14. Therefore, when the X-axis moving stage 14 moves on the rail 2, the head can simultaneously read the scales (scales) of the reference linear scale 41 and the correction linear scale 42. The base 12 is provided with a normal linear scale for detecting the amount of movement of the Y-axis moving stage 13, but illustration and description thereof are omitted here.

  The linear scale plate 3 is formed of a member having a low coefficient of thermal expansion, and is configured not to be deformed even if the X-axis moving stage 14 is deformed by heat. That is, the linear scale plate 3 is independent of the X-axis moving stage 14 and is not affected by the thermal deformation of the X-axis moving stage 14.

  FIG. 4B shows an example in which the linear scale plate 3 is independently attached to the X-axis moving stage 14. In this example, only the central portion of the linear scale plate 3 is fixed to the side surface of the X-axis moving stage 14 with the fixture 5, and both sides of the linear scale plate 3 are not fixed to the X-axis moving stage 14. This is because, when the X-axis moving stage 14 is thermally deformed, the X-axis moving stage 14 is curved downward convexly as shown by a broken line, or conversely curved upward, but the X-axis moving stage 14 This is because the central portion of the wing does not deform. In this example, arc-shaped elongated holes 6 and 7 centering on the fixture 5 are provided on both sides of the linear scale plate 3, and projecting from the elongated holes 6 and 7 on the side surface of the X-axis moving stage 14. The pins 8 and 9 are engaged, but this configuration may be omitted.

  FIG. 5A shows a state where the Y-axis moving stage 13 of the prober 10 of the present invention shown in FIG. 4A is not thermally deformed. In this figure, the linear scale plate 4 is not shown, and only the reference linear scale 41 and the correction linear scale 42 are shown. The arm 40 provided on the side surface of the X-axis moving stage 14 is provided with a head 43 at a position facing the reference linear scale 41 and a head 44 at a position facing the correction linear scale 42. Yes.

  Consider a case where the X-axis movement stage 14 is moved from the solid line position to the position indicated by the broken line in a state where the Y-axis movement stage 13 is not thermally deformed. At this time, the read value of the reference linear scale 41 by the head 43 and the read value of the correction linear scale 42 by the head 44 are the same. If the read value is L, the moving distance of the wafer chuck 16 is also L. .

  Next, as shown in FIG. 5B, the Y-axis movement stage 13 is thermally deformed, and the X-axis movement stage 14 is changed from a solid line position to a broken line in a state where the Y-axis movement stage 13 is deformed downward. Consider the case of moving to the indicated position. When the Y-axis moving stage 13 is deformed, the movement of the X-axis moving stage 14 that moves on the Y-axis moving stage 13 becomes non-linear and pitching occurs. At this time, since the reference linear scale 41 and the correction linear scale 42 are not thermally deformed, there is a difference between the read value of the reference linear scale 41 by the head 43 and the read value of the correction linear scale 42 by the head 44. When the Y-axis moving stage 13 is thermally deformed downward and convex, the read value La of the reference linear scale 41 by the head 43 is smaller than the read value Lb of the correction linear scale 42 by the head 44.

  In this case, the movement distance Lc of the wafer chuck 16 in the X-axis direction can be detected as follows. First, let θp be the change in pitching associated with the movement of the X-axis moving stage 14. θp is a minute angle, and there is a relationship of sin θp = θp at a minute angle. Here, the distance between the reference linear scale 41 and the correction linear scale 42 is h, the distance from the reference linear scale 41 to the top surface of the wafer chuck 16 is hc, and the movement distance of the wafer chuck 16 is Lc. When the reading distance of the head 43 facing the scale 41 is La and the reading distance of the head facing the correction linear scale 42 is Lb, Lc = La− (hc × θp), La = Lb− (h × θp) Therefore, Lc = La− (Lb−La) × hc / h.

  FIG. 6 shows the configuration of the prober 10 according to the second embodiment of the present invention. The prober 10 of the first embodiment detects the true movement distance of the wafer chuck 16 in the X-axis direction when the Y-axis movement stage 13 is deformed. The prober 10 of the second embodiment In addition to this, the true movement distance of the wafer chuck 16 in the Y-axis direction when the base 12 is deformed is detected. For this reason, the linear scale plate 4 is further attached to the prober 10 of the second embodiment on one side surface of the base 12 in the moving direction of the Y-axis moving stage 13.

  The linear scale plate 4 is composed of a member having a low coefficient of thermal expansion. On the linear scale plate 4, a reference linear scale 46 as a third linear scale and a correction linear scale as a fourth linear scale are provided. 47 is provided in parallel with the thickness direction (vertical direction) of the base 12. In the second embodiment, the reference linear scale 46 and the correction linear scale 47 are formed on one linear scale plate 4, but the reference linear scale 46 and the correction linear scale 47 are: It may be formed on a separate and independent linear scale plate.

  Furthermore, in the second embodiment, an L-shaped arm 45 having a head (described later) facing the reference linear scale 46 and the correction linear scale 47 is provided on the side surface of the Y-axis moving stage 13. . Accordingly, when the Y-axis moving stage 13 moves on the rail 1, the head can read the scales of the reference linear scale 46 and the correction linear scale 47 simultaneously.

  The linear scale plate 4 is formed of a member having a low coefficient of thermal expansion, and is configured not to be deformed even when the base 12 is deformed by heat. That is, the linear scale plate 4 is independent of the base 12 and is not affected by thermal deformation of the base 12. The linear scale plate 4 can be attached to the side surface of the base 12 in the same manner as the method in which the linear scale plate 3 described in the first embodiment is independently attached to the Y-axis moving stage 13.

  Here, as shown in FIG. 7, consider a case where the base 12 is thermally deformed, and the Y-axis moving stage 13 moves from the solid line position to the position indicated by the broken line in a state where the base 12 is deformed downward. When the base 12 is deformed, the movement of the Y-axis moving stage 13 that moves on the base 12 becomes non-linear and pitching occurs. At this time, since the reference linear scale 46 and the correction linear scale 47 are not thermally deformed, there is a difference between the read value of the reference linear scale 46 by the head 48 and the read value of the correction linear scale 47 by the head 49. When the base 12 is deformed downward, the read value Ma of the reference linear scale 46 by the head 48 is smaller than the read value Mb of the correction linear scale 47 by the head 49.

  In this case, the movement distance Mc of the wafer chuck 16 in the Y direction can be detected as follows. First, let θq be the change in pitching associated with the movement of the Y-axis moving stage 14. θq is a minute angle, and there is a relationship of sin θq = θq at a minute angle. Here, the distance between the reference linear scale 46 and the correction linear scale 47 is k, the distance from the reference linear scale 46 to the top surface of the wafer chuck 16 is kc, and the movement distance of the wafer chuck 16 is Mc. When the reading distance of the head 43 facing the scale 46 is Ma and the reading distance of the head 49 facing the correction linear scale 47 is Mb, Mc = Ma− (hc × θp), Ma = Mb− (h × θp ), Mc = Ma− (Mb−Ma) × hc / h.

  The present invention can be applied to any prober as long as it is a normal prober. Also, any stage other than the prober is effective as long as the pitching changes due to the influence of heat or the like.

It is a side view which shows the basic composition of the wafer test system which test | inspects the chip | tip on a wafer with a prober and a tester. It is a perspective view which shows schematic structure of the principal part of the prober shown in FIG. (A) is explanatory drawing which shows the relationship between a linear scale and a head when the Y-axis movement stage of the prober shown in FIG. 2 is not thermally deformed, and (b) is the Y-axis movement stage of the prober shown in FIG. It is explanatory drawing which shows the relationship between a linear scale in case there exists thermal deformation, and a head. (A) is a perspective view of the main part of the prober showing the configuration of the first embodiment of the prober of the present invention, (b) is an explanatory diagram showing an example of installation of the linear scale of (a) on the Y-axis moving stage. is there. (A) is explanatory drawing which shows the relationship between a linear scale and a head in case the Y-axis movement stage of the prober of this invention shown to Fig.4 (a) does not have a thermal deformation, (b) is Fig.4 (a). It is explanatory drawing which shows the relationship between a linear scale and a head in case the Y-axis movement stage of the prober of this invention shown has a thermal deformation. It is a perspective view of the prober principal part which shows the structure of 2nd Embodiment of the prober of this invention. It is explanatory drawing which shows the relationship between a linear scale and a head in case there exists thermal deformation in the base of the prober of this invention shown in FIG.

Explanation of symbols

1, 2 Guide rail 10 Prober 11 Base 12 Base 13 Y-axis moving stage 14 X-axis moving stage 15 Z-axis moving / rotating part 16 Wafer chuck 40, 45 Arm 41, 46 Reference linear scale 42, 47 Correction linear scale 43, 44, 48, 49 heads

Claims (6)

A prober for connecting each terminal of a tester to an electrode of the device via a probe needle in order to electrically inspect the operation of the device formed on the wafer,
A wafer chuck containing a first heating / cooling member for holding the wafer;
An X-axis moving stage for rotating the wafer chuck and moving in the Z-axis and X-axis directions;
A Y-axis moving stage for moving the wafer chuck in the Y-axis direction;
A base for moving and supporting the Y-axis moving stage;
The Y axis moving stage is provided on one side surface in the moving direction of the X axis moving stage in parallel to the vertical direction independently of the Y axis moving stage, and is composed of a member having a low coefficient of thermal expansion. 1 and a second linear scale;
An arm that is attached to a side surface of the X-axis moving stage and has a head that faces each of the first and second linear scales;
2. A prober according to claim 1, wherein the movement amount of the wafer chuck is detected by correcting the read value of the first linear scale with the read value of the second linear scale. The prober according to claim 1, wherein a movement amount Lc of the wafer chuck is
The change in pitching accompanying the movement of the X-axis moving stage is θp, sin θp = θp at a minute angle, the interval between the first and second linear scales is h, and the first linear scale to the top surface of the wafer chuck. When the distance is hc, the reading distance of the head facing the first linear scale at this time is La, and the reading distance of the head facing the second linear scale is Lb,
From the relationship of Lc = La− (hc × θp), La = Lb− (h × θp),
A prober calculated from the formula Lc = La− (Lb−La) × hc / h. The prober according to claim 1 or 2,
The prober, wherein the first and second linear scales are formed on a single scale plate. The prober according to any one of claims 1 to 3, further comprising:
Third and fourth linear scales, which are provided on one side surface of the base in the moving direction of the Y-axis moving stage, are formed independently of the base and parallel to the vertical direction, and are composed of members having a low coefficient of thermal expansion. When,
An arm that is attached to a side surface of the Y-axis moving stage and includes a head that faces the third and fourth linear scales;
The prober characterized in that the movement amount of the wafer chuck is detected by correcting the reading value of the third linear scale with the reading value of the fourth linear scale. 5. The prober according to claim 4, wherein a movement amount Mc of the wafer chuck is
The change in pitching accompanying the movement of the Y-axis moving stage is θq, sin θq = θq at a minute angle, the distance between the third and fourth linear scales is k, and the third linear scale to the top surface of the wafer chuck When the distance is kc, the reading distance of the head facing the third linear scale at this time is Ma, and the reading distance of the head facing the fourth linear scale is Mb,
From the relationship of Mc = Ma− (kc × θq), Ma = Mb− (k × θq),
A prober calculated from the formula Mc = Ma− (Mb−Ma) × kc / k. The prober according to claim 3 or 4, wherein
The prober, wherein the third and fourth linear scales are formed on a single scale plate.

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