JP4931617B2 - Prober - Google Patents

Description

  In the present invention, in order to inspect the electrical characteristics of a plurality of semiconductor devices (chips) (hereinafter referred to as dies) formed on a semiconductor wafer, terminals of a semiconductor tester (hereinafter simply referred to as a tester) are used as electrode pads of the die. The present invention relates to a prober that realizes an improvement in processing speed (throughput) with a small increase in ground contact area with respect to a connected wafer probing machine (hereinafter referred to as a prober).

  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. Such inspection of the electrical characteristics of each die is performed by a wafer test system that combines a prober and a tester, and is called probing inspection.

  The prober is connected to a tester via a mounted probe card, and is configured to test the electrical characteristics of each die by bringing a probe needle (hereinafter referred to as a probe) into contact with an electrode of the die. The wafer is fixed to the wafer chuck. The tester supplies power and various test signals to the terminals connected to the probe, the signals output to the die electrodes are detected by the tester, and this signal is analyzed on the tester side to ensure that each die is normal. Check if it works.

  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 position detection camera 18, a camera movement mechanism 17, a Y-axis movement stage 14, an X-axis movement stage 13, a base 12, a gantry 11, Supports 19 and 20, a head stage 21, a wafer alignment camera 22, a card holder 23, and a probe card 24 are included.

  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 position detection camera 18 detects the position of the probe 25 and is attached on the camera moving mechanism 17. The camera moving mechanism 17 moves the probe 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 Y-axis moving stage 14, and the Y-axis moving stage 14 supports them and moves in the Y-axis direction.

  The Y-axis moving stage 14 is provided on an X-axis moving stage 13 that supports this and moves in the X-axis direction, and the X-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.

  Two guide rails 1 are provided in parallel on the base 12, and the X-axis moving stage 13 is movable on the guide rail 1. A drive motor and a ball screw rotated by the drive motor are provided in a portion between the two guide rails 1 on the base 12. The ball screw is engaged with the bottom surface of the X-axis moving stage 13, and the X-axis moving stage slides on the guide rail 1 by the rotation of the ball screw.

  Two parallel guide rails 2 orthogonal to the above-described two guide rails 1 are provided on the X-axis movement stage 13, and the Y-axis movement stage 14 can move on the guide rail 2. It has become. A drive motor and a ball screw that is rotated by the drive motor are provided in a portion between the two guide rails 2 on the X-axis moving stage 13. The ball screw is engaged with the bottom surface of the Y-axis moving stage 14, and the Y-axis moving stage 14 slides on the guide rail 2 by the rotation of the ball screw.

  A linear motor may be used instead of the ball screw.

  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 25 arranged according to the electrode arrangement of the device (die) to be inspected, and is exchanged according to the device to be inspected. The probe position detection camera 18 detects the arrangement and height position of the probe 25, and the wafer alignment camera 22 detects 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).

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

  The detection of the tip position of the probe 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 several thousand or more probes 25. When the number is large, the tip positions of all the probes 25 are not detected, and usually a specific probe. The tip position is detected.

  Next, the Y-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 25 and the arrangement of the electrode pad are detected, based on the detection result, the Z-axis movement / rotation is performed so that the arrangement direction of the probe 25 and the arrangement direction of the electrode pad coincide with each other. The wafer chuck 16 is rotated by the portion 15. Thereafter, the wafer chuck 16 is moved by the Y-axis moving stage 14 and the X-axis moving stage 13 so that the electrode pad of the die to be inspected is located below the probe 25. Then, 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 stops while the electrode pad is in contact with the probe 25. In this state, power and signals are supplied from the tester 30 to perform inspection.

  As described in Patent Document 1, conventionally, the probe card 24 is provided with a number of probes capable of inspecting a plurality of dies at the same time, and the tester 31 outputs a signal for inspecting a plurality of dies at the same time. Multi-probing has been performed to improve inspection efficiency in a wafer test system by simultaneously analyzing signals output from a die.

  Although the conventional prober has been described above, the configuration of the described prober is widely known, and thus further description thereof is omitted.

JP-A-6-168991 (Overall)

  In the semiconductor manufacturing process, in order to reduce the manufacturing cost, the wafer is increased in size and further miniaturized (integrated), and the number of dies formed on one wafer becomes very large. Yes. Along with this, the time required for inspecting a single wafer with a prober has become longer, and there is an increasing demand for improvement in throughput.

  The easiest way to increase the probing test throughput on the production line is to increase the number of probers. However, when the number of probers is increased, there is a problem that the installation area of probers in the production line also increases. Further, if the number of probers is increased, the cost of the apparatus will increase accordingly. Therefore, it is required to increase the throughput while suppressing an increase in installation area and an increase in apparatus cost.

  An object of the present invention is to increase the throughput by suppressing an increase in installation area and apparatus cost required for the entire probing inspection.

  In order to achieve the above object, the prober and probing inspection method of the present invention are provided with two probe cards, a wafer chuck, a wafer chuck moving mechanism, and a probe position detection camera in one prober, and a common wafer alignment camera. In this way, throughput of two probers can be obtained substantially, but since the wafer alignment camera is shared, the space (installation area) required for one wafer alignment camera can be reduced. Costs can be reduced.

  That is, the prober of the present invention is a prober for connecting each terminal of the tester to an electrode of the semiconductor device in order to inspect the semiconductor device formed on the wafer by a tester, and is a first probe that holds the wafer. A wafer chuck, a second wafer chuck that holds the wafer, and a probe that contacts the electrode of the semiconductor device on the wafer held by the first wafer chuck and connects the electrode to a terminal of the tester A first probe card having, and a second probe card having a probe that contacts an electrode of the semiconductor device on the wafer held by the second wafer chuck and connects the electrode to a terminal of the tester; An alignment camera for detecting a position of an electrode of the semiconductor device on the wafer held by the first and second wafer chucks; and the first wafer. A moving mechanism for moving the chuck, wherein at least the first wafer chuck is moved to the first probe card so that the wafer held by the first wafer chuck can be brought into contact with the probe of the first probe card. And at least the first wafer chuck can be moved below the alignment camera so that the position of the electrode of the semiconductor device of the wafer held on the first wafer chuck can be detected. 1 moving mechanism and a moving mechanism for moving the second wafer chuck, wherein at least the second wafer chuck can be brought into contact with the probe of the second probe card. 2 wafer chucks to the bottom of the second probe card and in front of the wafer held by the second wafer chuck. A second moving mechanism capable of moving at least the second wafer chuck to a position under the alignment camera so that the position of the electrode of the semiconductor device can be detected, and the first moving mechanism and the first moving mechanism The second moving mechanism moves the first wafer chuck and the second wafer chuck independently of each other.

  In order to perform the wafer alignment operation, it is necessary to move the wafer held on the wafer chuck under the wafer alignment camera by the diameter of the wafer, and the space (installation area) is quite large. Therefore, if the space (installation area) required for one wafer alignment camera is reduced, the effect of reducing the installation area is great.

  If a wafer alignment camera is used in common, the wafer held on the other wafer chuck cannot be aligned when the wafer held on one wafer chuck is aligned. However, as described above, the size of the wafer is increased. The degree of integration has been advanced, and the time required for inspecting one wafer has become longer. Since the above alignment time is relatively short, there is no problem, and two sets of sequences can be set as appropriate. It is possible to prevent substantially no waiting time for alignment.

  Each of the first moving mechanism and the second moving mechanism is provided on an X-axis moving base extending in the X-axis direction, an X-axis moving stage moving on the X-axis moving base, and an X-axis moving stage, It is desirable to provide a moving / rotating mechanism for moving and rotating the first or second wafer chuck in a direction other than the X-axis direction, and to configure the X-axis moving base in common.

  The driving structure of the moving mechanism having such an X-axis moving base and an X-axis moving stage is realized by, for example, a linear motor or a ball screw. When a linear motor is used, a stator is placed on the X-axis moving base, A mover is provided on the axis movement stage. When a ball screw is used, a fixed ball screw is provided on the X-axis movement base, and a rotation nut is provided on the X-axis movement stage.

  The moving / rotating mechanism of the first moving mechanism and the second moving mechanism is configured to include first and second probe position detection cameras for detecting the positions of the probes of the first and second probe cards, respectively. It is desirable to do.

  It is desirable that the wafer transfer mechanism for transferring the wafer from the wafer cassette can transfer the wafer at the same position to both the first and second wafer chucks. Such a wafer transfer mechanism includes a robot arm and an arm moving mechanism that moves the robot arm to a wafer transfer position between the wafer cassette, the first wafer chuck, and the second wafer chuck. .

  According to the present invention, it is possible to increase the throughput while suppressing an increase in installation area and apparatus cost required for the entire probing inspection.

  FIG. 2 is a diagram showing a schematic configuration of the wafer test system 100 according to the embodiment of the present invention. In the conventional wafer test system 100 shown in FIG. 1, a wafer chuck 16, a Z-axis movement / rotation unit 15, a probe position detection camera 18, a camera movement mechanism 17, a Y-axis movement stage 14, an X-axis movement stage 13, and a probe Whereas one set of cards 24 is provided, the wafer test system 100 of the present embodiment is different in that two such sets are provided. That is, this embodiment is different from the conventional example in that two wafer holding / moving mechanisms for holding and moving the wafer W are provided, and two probe cards 24 (testers) are also provided.

  As shown in FIG. 2, the prober 10 according to the embodiment has a casing that includes a base 12, a gantry 11, columns 19 and 20, and a head stage 21. A guide rail 41 and a linear motor stator 42 are provided on the base 12 of the housing, and the first and second wafer holding / moving mechanisms are arranged to be precisely movable. Card holders 23A and 23B are provided on both sides of the head stage 21, and probe cards 24A and 24B are attached to the card holders 23A and 23B. A wafer alignment camera 22 is provided at the center of the card holder 23.

  Each of the first and second wafer holding / moving mechanisms has the same configuration as the conventional example, and includes wafer chucks 16A and 16B, Z-axis moving / rotating units 15A and 15B, probe position detection cameras 18A and 18B, and a camera moving mechanism. 17A and 17B, Y-axis moving stages 14A and 14B, and X-axis moving stages 13A and 13B. Under the X-axis moving stages 13A and 13B, linear motor movers 43A and 43B are attached, so that the first and second wafer holding / moving mechanisms can move the guide rail 41 independently. It is.

  FIG. 3 is a top view of the wafer test system 100 according to the embodiment. As shown in FIG. 3, the guide rail 41 and the stator 42 extend almost from end to end in the X-axis direction, and the X-axis moving stages 13A and 13B (first and second wafer holding / moving mechanisms) The guide rail 41 can move within a range that does not interfere with each other. In other words, the X-axis moving stage 13A located on the left side can move from the left end to a position where the left end portion of the held wafer under the probe card 24 contacts the probe 25, and is located on the right side. The axial movement stage 13B is movable from the right end to a position where the probe 25 contacts the right end portion of the held wafer under the probe card 24.

  As shown in FIG. 3, two wafer cassettes 60A and 60B can be further arranged in the wafer test system 100 of the embodiment, and the wafer W is taken out from the two arranged wafer cassettes 60A and 60B. A wafer transport mechanism is provided for transporting the wafer W, which has been transported onto 16A and 16B and has been inspected, from the wafer chucks 16A and 16B to the wafer cassettes 60A and 60B. The wafer transfer mechanism includes an arm base 51 and an arm 52 provided on the arm base 51. The wafer transfer mechanism is well known and will not be described. However, the wafer transfer mechanism can be taken out of any wafer cassette, and the wafer chucks 16A and 16B are placed under the alignment camera 22 by the wafer chuck. The wafers on the two wafer chucks 16A and 16B can be returned to either wafer cassette.

  In the wafer test system 100 of the embodiment, a linear motor is used to move the X-axis moving stages 13A and 13B. The linear motor is provided with a mover that changes a magnetic pole by a coil or the like with respect to a stator that extends long, and moves by changing the magnetic pole generated by the mover. Since the stator does not change, it is possible to move each mover independently by placing a plurality of movers on one stator and controlling the magnetic poles generated by each mover independently. Therefore, as shown in FIG. 4A, if the movable elements 43A and 43B are provided below the X-axis moving stages 13A and 13B and placed on one stator 42, the X-axis movement is achieved. The stages 13A and 13B can be moved independently.

  A linear motor can be used as a drive structure for moving the Y-axis moving stages 14A and 14B.

  Further, it is possible to use a ball screw instead of a linear motor to move the X-axis moving stages 13A and 13B. In this case, as shown in FIG. 4 (B), a ball screw 71 having an axial center extending in the X-axis direction is used, and rotation in which a ball combined with the ball screw 71 is incorporated below the X-axis moving stages 13A and 13B. If the nut portions 72A and 72B are provided and the rotation amounts of the rotary nut portions 72A and 72B are controlled, the X-axis moving stages 13A and 13B can be moved independently.

  Next, the inspection operation and wafer transfer in the wafer test system 100 of the embodiment will be described with reference to FIGS.

  As shown in FIG. 5, the wafer transfer mechanism takes out the first wafer W1 from the wafer cassette 60B (or 60A), and a first wafer holding / moving mechanism (X-axis moving stage) located under the alignment camera 22. 13A) on the first wafer chuck 16A. After the alignment operation of the held wafer W1 is completed, the X-axis moving stage 13A moves to the left side, that is, so that the wafer W1 is positioned below the probe card 24A. During this time, the second wafer holding / moving mechanism (X-axis moving stage 13B) is stopped at the left position as shown. In this state, the inspection of the wafer W1 is started.

  As shown in FIG. 6, when the transfer of the first wafer W1 onto the first wafer chuck 16A is completed, the wafer transfer mechanism takes out the second wafer W2 from the wafer cassette 60B and is at the position shown in the figure. The wafer is transferred onto the second wafer chuck 16B of the second wafer holding / moving mechanism (X-axis moving stage 13B). After the alignment operation is performed on the held wafer W2, the X-axis moving stage 13B moves to the left side, that is, so that the wafer W2 is positioned below the probe card 24B, and inspection of the wafer W2 is started.

  Thereafter, the X-axis moving stage on the side where the inspection is completed moves to the center, and the wafer transfer mechanism transfers the inspected wafer to the wafer cassette 60B, takes out the uninspected wafer, and is positioned in the center. It is transferred onto the wafer chuck of the axis movement stage.

  Thereafter, the above operation is repeated, and when all the wafers in the wafer cassette 60B have been inspected, the same operation is repeated for the wafers in the wafer cassette 60A.

  The present invention is applicable to any prober as long as it is a prober.

It is a figure which shows the basic composition of the conventional wafer test system which test | inspects the die | dye on a wafer with a prober and a tester. It is a figure which shows the basic composition of the wafer test system of the Example of this invention. It is a top view of the wafer test system of an example. It is a figure which shows the example of the drive structure which moves an X-axis stage. It is a figure explaining the test | inspection operation | movement and wafer conveyance in the wafer test system of an Example. It is a figure explaining the test | inspection operation | movement and wafer conveyance in the wafer test system of an Example.

Explanation of symbols

13, 13A, 13B X-axis moving stage 14, 14A, 14B Y-axis moving stage 15, 15A, 15B Z-axis moving / rotating part 16, 16A, 16B Wafer chuck 22 Alignment camera 23A, 23B Card holder 24A, 24B Probe card 30A 30B Tester 41 Guide rail W, W1, W2 Wafer

Claims (5)

A prober for connecting each terminal of the tester to an electrode of the semiconductor device in order to inspect the semiconductor device formed on the wafer with a tester,
A first wafer chuck for holding a wafer;
A second wafer chuck for holding the wafer;
A first probe card having a probe that contacts the electrode of the semiconductor device on the wafer held by the first wafer chuck and connects the electrode to a terminal of the tester;
A second probe card having a probe that contacts an electrode of the semiconductor device on the wafer held by the second wafer chuck and connects the electrode to a terminal of the tester;
An alignment camera for detecting a position of an electrode of the semiconductor device on the wafer held by the first and second wafer chucks;
A moving mechanism for moving the first wafer chuck, wherein at least the first wafer chuck is moved so that the wafer held by the first wafer chuck can be brought into contact with a probe of the first probe card. At least the first wafer chuck to the bottom of the alignment camera so that the position of the electrode of the semiconductor device on the wafer held by the first wafer chuck can be detected. A movable first moving mechanism;
A moving mechanism for moving the second wafer chuck, wherein at least the second wafer chuck is moved so that the wafer held by the second wafer chuck can come into contact with the probe of the second probe card. At least the second wafer chuck is below the alignment camera so that the position of the electrode of the semiconductor device on the wafer held by the second wafer chuck can be detected down to the bottom of the second probe card. A movable second moving mechanism, and
The prober, wherein the first moving mechanism and the second moving mechanism move the first wafer chuck and the second wafer chuck independently of each other. Each of the first moving mechanism and the second moving mechanism is
An X-axis moving base extending in the X-axis direction;
An X-axis moving stage that moves on the X-axis moving base;
A moving / rotating mechanism provided on the X-axis moving stage and moving and rotating the first or second wafer chuck in a direction other than the X-axis direction;
The prober according to claim 1, wherein the X-axis movement base is common.   The moving / rotating mechanisms of the first moving mechanism and the second moving mechanism are provided with first and second probe position detection cameras for detecting the positions of the probes of the first and second probe cards, respectively. The prober according to claim 2 provided.   The prober according to any one of claims 1 to 3, further comprising a wafer transfer mechanism for transferring a wafer between a wafer cassette and the first and second wafer chucks. The wafer transfer mechanism is
Robot arm,
The prober according to claim 4, further comprising: an arm moving mechanism that moves the robot arm to a wafer transfer position common to the wafer cassette, the first wafer chuck, and the second wafer chuck.

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