JP2008131015A - Registration method of wafer electrode, alignment method of wafer, and recording medium with these methods stored - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a registration method for a wafer electrode and an alignment method for a wafer capable of improving the reliability of wafer processing, such as inspection, and reducing the load of operator, by releasing the operator from each operation for reference pattern selecting and pattern matching. <P>SOLUTION: The alignment method for wafer is provided with a process of imaging an arbitrary scribe line of a wafer W on a placement table 11 by a first CCD camera 14 and registering its position; a process of recognizing an electrode pad of a chip which is in a predetermined positional relation with the registration position of the scribe line under illuminance in which an edge line E of an chip image P appears by a first CCD camera 14, and registering the illuminance and the size of the chip image; a process of registering coordinates of the placement table 11 when the electrode pad is recognized by the first CCD camera 14; and a process of performing the alignment of the electrode pad where the coordinates are registered. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wafer electrode registration method and a wafer alignment method applied when, for example, an electrical characteristic inspection of a wafer is performed. More specifically, the wafer electrode is directly detected to improve the reliability of wafer alignment. The present invention relates to a wafer electrode registration method, a wafer alignment method, and a recording medium on which these methods are recorded.

  In the semiconductor manufacturing process, wafer alignment is performed in various situations. An example of an apparatus that performs wafer alignment is a wafer inspection apparatus. For example, as shown in FIGS. 8A and 8B, this type of inspection apparatus includes a loader chamber 1 for loading and unloading a wafer W and a prober chamber 2 for inspecting the electrical characteristics of the wafer W. I have. The loader chamber 1 includes a transfer arm 3 that transfers the wafer W in the cassette C to the prober chamber 2, and a pre-alignment mechanism 4 that performs pre-alignment of the wafer W while the wafer W is transferred by the transfer arm 3. . The prober chamber 2 includes a placing table 5 on which the pre-aligned wafer W is placed, movable in the X, Y, Z, and θ directions, a probe card 6 disposed above the placing table 5, and a probe card 6. An alignment mechanism 7 that aligns the plurality of probes 6A and the wafer W on the mounting table 5 is provided, and is driven under the control of a control device (not shown). The probe card 6 is fixed to the opening of the head plate 8. A test head T is disposed on the upper surface of the head plate 8, and the probe card 6 is electrically connected to a tester (not shown) via the head plate 9.

  Thus, the pre-alignment mechanism 4 optically detects the rotatable turntable 4A on which the wafer W is placed and the orientation flat (orientation flat) or notch formed on the outer peripheral edge of the wafer W. Means (not shown), and by detecting an orientation flat or a notch of the wafer W with an optical detection means while the turntable 4A on which the wafer W is mounted rotates, the wafer W is preliminarily set in a predetermined direction. Align.

  Further, as shown in FIGS. 8A and 8B, the alignment mechanism 7 is attached to the side of the mounting table 5 so as to image the first CCD camera 7A for imaging the wafer W and the probe 6A. And a pair of left and right guide rails 7D for guiding the alignment bridge 7C to the probe center. The first CCD camera 7A includes a second CCD camera 7B, an alignment bridge 7C that supports the first CCD camera 7A, and a pair of left and right guide rails 7D that guide the alignment bridge 7C to the probe center. Then, the inspection electrode (hereinafter referred to as “electrode pad”) of the wafer W is imaged and the probe 6A is imaged by the second CCD camera 7B, and the electrode pad and probe of the wafer W based on the respective imaging position data. Align with 6A.

  When performing alignment of the wafer W, the operator selects a characteristic portion in the chip formed on the wafer W, for example, a characteristic wiring pattern, etc. as a reference pattern for alignment based on the design data in advance. The pattern is registered in the storage unit of the control device. Then, when performing the alignment prior to the inspection, the wafer W is adjusted in a fixed direction via the alignment mechanism 7 and the mounting table 5, and the scribe lines at a plurality of locations on the wafer W are registered by the first CCD camera 7A. Thereafter, each chip having a predetermined positional relationship with the registered position is imaged. Then, so-called pattern matching is performed in which the reference pattern and the wiring pattern corresponding to the reference pattern in the chip image are compared to select a wiring pattern that matches the reference pattern. Then, a specific position in the wiring pattern that matches the reference pattern is selected and registered.

  Then, the position of the electrode pad having a predetermined positional relationship with the specific position of the wiring pattern is calculated using design data, and the calculated position is registered as position data (coordinate value) of the electrode pad. Thus, a plurality of chips formed on the wafer W are registered by registering a plurality of coordinates of the electrode pads based on a plurality of scribe lines and aligning these electrode pads and the corresponding probes 6A. The electrical characteristic inspection can be performed.

  However, recently, due to the miniaturization of the chip wiring pattern and the like, the wiring pattern and the like are deformed and deformed in the process of forming the chip on the wafer W, and as a result, the wiring pattern and the like that can be used as a reference pattern for alignment It is becoming difficult to select characteristic patterns. Therefore, a heavy load is imposed on the operator in selecting the reference pattern. Even if the reference pattern is selected, when performing pattern matching after alignment, if the wiring pattern in the chip repeats a similar pattern as shown in FIG. 9, for example, a cross mark at the center of the display screen Where the original specific position should be aligned with M, there is a risk of misidentifying a part that is very similar to the specific position diagonally above and below, that is, a part surrounded by a circle, as the specific position, and if alignment is continued without noticing the misperception, The reliability of inspection is impaired.

  The present invention has been made to solve the above-described problems, and can improve the reliability of wafer processing such as inspection, and frees the operator from the operations of selecting a reference pattern and pattern matching. It is an object of the present invention to provide a wafer electrode registration method, a wafer alignment method, and a recording medium on which these methods are recorded, which can reduce the load.

  In the wafer electrode registration method according to claim 1 of the present invention, when a predetermined process is performed on a plurality of chips formed on the wafer, the mounting table on which the wafer is mounted and the imaging unit move relatively, A method of imaging a chip at an arbitrary position of the wafer with a predetermined illuminance by the imaging means, detecting an electrode of the chip, and registering the position of the electrode, wherein the size of the electrode of the chip is Teaching, controlling the illuminance when imaging the electrode of the chip by the imaging means to reveal the electrode image contour by the imaging means, and recognizing the size of the outline And the step of registering the size of the contour and the illuminance at that time when the size of the contour is within an allowable value. It is intended to.

  The wafer electrode registration method according to claim 2 of the present invention is the wafer electrode registration method according to claim 1, wherein when the predetermined process is executed, the wafer is illuminated with the illuminance when the contour is obtained. Illuminating; obtaining an electrode image of the wafer under the illumination by the imaging means; recognizing the electrode; and determining whether the size of the electrode image is appropriate based on the size of the registered contour. And a step of subjecting the wafer to a predetermined process when the contour of the electrode image is within an allowable value.

  In the wafer alignment method according to claim 3 of the present invention, when the predetermined processing is performed on the plurality of chips formed on the wafer, the mounting table and the imaging unit move relative to each other, and the imaging unit A method of aligning the wafer by imaging the wafer at a predetermined illuminance, imaging an arbitrary scribe line of the wafer on the mounting table by the imaging means, and registering the position thereof; The step of recognizing the electrode of the chip in a predetermined positional relationship with the registration position of the scribe line by the imaging means under the illuminance where the outline of the electrode image appears, and registering the information; and the electrode by the imaging means A step of registering the position of the mounting table at the time of recognition, and a step of providing the position-registered electrode for alignment; and

  The wafer alignment method according to claim 4 of the present invention is the wafer alignment method according to claim 3, wherein the electrode recognition and registration step includes a step of teaching the size of the electrode of the chip and the imaging. Means for controlling the illuminance at the time of imaging the electrode of the chip to show the outline of the electrode image by the imaging means and recognizing the electrode, and whether or not the size of the outline is appropriate by the teaching. And a step of registering the size of the contour and the illuminance at that time when the size of the contour is within an allowable value.

  In the wafer alignment method according to claim 5 of the present invention, in the invention according to claim 4, the step of providing the alignment includes illuminating the wafer with illuminance when the contour is obtained. Obtaining an electrode image of the wafer under the illumination by the imaging means and recognizing the electrode; determining whether the size of the electrode image is appropriate based on the size of the registered contour; and the electrode And a step of subjecting the wafer to a predetermined process when the contour of the image is within an allowable value.

  According to a sixth aspect of the present invention, there is provided the wafer alignment method according to any one of the third to fifth aspects, wherein the step of recognizing the electrode and the step of providing the alignment are the imaging steps. It is carried out under a high magnification of the means.

  In the recording medium according to claim 7 of the present invention, when the predetermined processing is performed on the plurality of chips formed on the wafer, the mounting table on which the wafer is mounted and the imaging unit move relatively, A recording medium recording a program for imaging a chip at an arbitrary position on the wafer with a predetermined illuminance by an imaging means, detecting an electrode of the chip, and registering the position of the electrode. According to the present invention, the computer is driven to execute the wafer electrode registration method according to claim 1 or claim 2.

  Further, in the recording medium according to claim 8 of the present invention, when the predetermined processing is performed on the plurality of chips formed on the wafer, the mounting table and the imaging unit move relative to each other, and the wafer is moved by the imaging unit. 7. A recording medium on which a program for aligning the wafer is recorded by imaging at a predetermined illuminance, and the computer is driven by the program, and the recording medium according to claim 3. This wafer alignment method is executed.

  According to the present invention, the reliability of wafer processing such as inspection can be improved, and the load of the operator can be reduced by releasing the operator from each of the operations of selecting a reference pattern and pattern matching. It is possible to provide a registration method, a wafer alignment method, and a recording medium on which these methods are recorded.

  Hereinafter, the present invention will be described based on the embodiment shown in FIGS. In each figure, FIG. 1 is a block diagram showing the configuration of an inspection apparatus used for carrying out an embodiment of the method of the present invention, and FIGS. 2A and 2B are images of illumination and electrode pads, respectively. FIGS. 3A and 3B are diagrams showing a wafer when an embodiment of the wafer alignment method of the present invention is applied, and FIG. 3A is a wafer. FIG. 4B is an enlarged plan view showing an intersection of scribe lines at the center of the wafer, and FIGS. 4A and 4B are respectively a wafer alignment method and a wafer electrode according to the present invention. 5 is a flowchart showing an embodiment of a registration method, FIGS. 5A and 5B are flowcharts showing the subsequent steps of the flowchart shown in FIG. 1, and FIG. 6 is a display screen on which an assist relief function generated during alignment is displayed. The To FIG, 7 is a diagram showing a display screen assist function appears to occur during alignment having no assist repair function shown in FIG.

  First, an inspection apparatus including a recording medium on which a wafer electrode registration method and a wafer alignment method according to the present invention are recorded will be described. For example, as shown in FIG. 1, the inspection apparatus 10 includes a movable mounting table 11 on which a wafer W as an inspection object is mounted, a probe card 12 disposed above the mounting table 11, and the probe. An alignment mechanism 13 for aligning the plurality of probes 12A of the card 12 and the wafer W on the mounting table 11, first and second imaging means (for example, CCD cameras) 14 and 15 constituting the alignment mechanism 13, The control device 17 includes a display device 16 having a display screen 16A for displaying images captured by the first and second CCD cameras 14 and 15, and a control device 17 including a computer for controlling these components. Under the control, the alignment mechanism 13 aligns the wafer W on the mounting table 11 and the plurality of probes 12A of the probe card 12. And then, it is configured to have electrical contact causes a plurality of probes 12A and the wafer W inspecting electrical characteristics of the wafer W.

  In addition, the inspection apparatus 10 includes an input unit 18 such as a keyboard as shown in FIG. 1, and can input various inspection conditions through the input unit 18, and the menu 16A and icons ( Various programs and the like can be implemented by designating (not shown).

  As shown in FIG. 1, the mounting table 11 includes a drive mechanism 11A and a detector (eg, an encoder) 11B, and moves in the X, Y, Z, and θ directions via the drive mechanism 11A and moves via the encoder 11B. It is configured to detect the quantity. 11 A of drive mechanisms drive the XY table in which the mounting base 11 is arrange | positioned, for example, the horizontal drive mechanism (not shown) which mainly has a motor and a ball screw, the raising / lowering driving mechanism built in the mounting base 11, and mounting A θ drive mechanism that rotates the mounting table 11 in the θ direction. The encoder 11 </ b> B detects the movement distances in the X and Y directions of the XY table via the rotation speed of the motor, and transmits each detection signal to the control device 17. The control device 17 controls the drive mechanism 11A based on the signal from the encoder 11B, thereby controlling the amount of movement of the mounting table 11 in the X and Y directions.

  The alignment mechanism 13 includes the first and second CCD cameras 14 and 15 and the alignment bridge 19 as described above. As shown in FIG. 1, the first CCD camera 14 is attached to the alignment bridge 19, and the second CCD camera 15 is attached to the side of the mounting table 11. Each of the first and second CCD cameras 14 and 15 has two magnifications, a low magnification and a high magnification, and images the probe 12A and the wafer W at a low magnification or a high magnification.

  The first CCD camera 14 advances from the back of the prober chamber to the probe center via the alignment bridge 19 and is positioned between the probe card 12 and the mounting table 11, where the mounting table 11 moves in the X and Y directions. While moving, the wafer W illuminated by an illuminating lamp (not shown) is imaged at a low magnification or a high magnification, an imaging signal is transmitted to the control device 17, and a wafer image is displayed on the display screen 16A via the control device 17. Display above. The second CCD camera 15 includes a plurality of CCD cameras 15 from the bottom of the probe card 12 while the mounting table 11 moves in the X and Y directions below the probe card 12 after the alignment bridge 19 is retracted to the back of the probe chamber. The probe tip of the probe 12A is imaged at a predetermined magnification, an imaging signal is transmitted to the control device 17, and a probe image is displayed on the display screen 16A via the control device 17.

  The control device 17 includes a central processing unit 17A, a program storage unit 17B in which various programs including a program for executing the wafer electrode registration method and the wafer alignment method of the present invention are stored, The storage unit 17C that stores data, the image processing units 14A and 15A that perform image processing on the imaging signals from the first and second CCD cameras 14 and 15, and the image signals from these image processing units 14A and 15A Image storage units 14B and 15B for storing data, and display control units 14C and 15C for displaying captured images and the like on the display screen 16A based on these image signals, and a central processing unit 17A and a program storage Signals are transmitted and received between the unit 17B and the storage unit 17C, and various components of the inspection apparatus 10 are controlled.

  An input unit 18 is connected to the central processing unit 17A, and various data signals input from the input unit 18 are processed by the central processing unit 17A and stored in the storage unit 17C. In the present embodiment, a program for executing the wafer electrode registration method and wafer alignment method of the present embodiment is stored in the program storage unit 17B, and a display screen 16A, an operation panel 16B, and the like are displayed on the display device 16. . The operation panel 16B performs an operation of moving the first and second CCD cameras 14 and 15 relative to the wafer W or the probe card 12 during alignment, or registers image information such as position data of the probe card 12. It has functions such as That is, the first CCD camera 14 moves in the X and Y directions relative to the mounting table 11 by pressing the horizontal movement operation key K1 of the operation panel 16B, and the up / down movement operation key of the operation panel 16B. It is configured to move in the Z direction relative to the mounting table 11 by pressing K2. The second CCD camera 15 is configured such that the mounting table 11 moves relative to the probe card 12 in the X, Y, and Z directions by pressing the horizontal movement operation key K1 and the vertical movement operation key K2. ing.

  The central processing unit 17A is connected to image storage units 14B and 15B and display control units 14C and 15C, and images captured by the first and second CCD cameras 14 and 15 are displayed on the central processing unit 17A and the display control unit. Displayed on the display screen 16A via 14C and 15C, respectively. In addition to the current captured images by the first and second CCD cameras 14 and 15, past captured images and processed images can be stored in the image storage units 14B and 15B.

  Programs such as a wafer electrode registration method and a wafer alignment method of the present invention are stored in the program storage unit 17B via various recording media. Moreover, these programs can also be downloaded to various inspection apparatuses by a communication medium. In the present embodiment, the controller 17 which is a computer is driven to execute the wafer electrode registration method and wafer alignment method programs stored in the program storage unit 17B.

  Thus, in this embodiment, the illuminating lamp is configured to automatically adjust the illuminance when the wafer W is illuminated. Further, the image of the chip taken by the first CCD camera 14 changes in brightness of the image depending on the illuminance of the illuminating lamp, and the illuminance matches the cross mark M at the center of the screen as shown in FIG. The pad image P of the electrode pad in the chip becomes brighter than the surroundings, or the pad image P becomes darker than the surroundings as shown in FIG. And the electrode pad can be surely recognized by the first CCD camera 14. Since the phenomenon that the pad image P becomes bright or dark varies depending on the material and illuminance of the electrode pad, the operator selects and sets the optimum illuminance for each material of the electrode pad.

  Therefore, in this embodiment, in the pad image P of the electrode pad by the first CCD camera 14, the operator selects the illuminance at which the edge line E of the pad image P appears most clearly, for example, as shown in FIG. The illuminance is stored in the storage unit 17C. At the same time, the position of the mounting table 11 when the operator recognizes the pad image P on the display screen 16A is stored in the storage unit 17C as the coordinate value of the electrode pad. Therefore, when the alignment of the wafer W is executed, the first CCD camera 14 can reliably recognize the electrode pad by illuminating the wafer W with the illuminance stored in advance under the control of the control device 17. It will be possible. As described above, in this embodiment, since the electrode pad can be directly recognized by the first CCD camera 14, the electrode pad is not erroneously recognized by pattern matching, and the alignment reliability of the wafer W can be improved. it can. The illumination lamp is attached to, for example, the alignment bridge 19 so as to illuminate a portion that can be imaged by the first CCD camera 14.

  On the other hand, conventionally, the first CCD camera 14 detects the wiring pattern in the chip, calculates the position of the electrode pad based on the positional relationship between the position and the design of the electrode pad, Since the position is obtained indirectly, if the operator misidentifies the specific position of the wiring pattern and performs a specified operation when registering the position of the electrode pad, the position of the electrode pad deviates from the original position, and the inspection reliability Sex is reduced.

  Next, an embodiment of the wafer electrode registration method and wafer alignment method (hereinafter simply referred to as “alignment method”) according to the present invention will be described with reference to FIGS. The wafer electrode registration method is executed as part of the wafer alignment method. Note that the alignment of the probe 12A is completed before the alignment of the wafer W.

  First, for example, when an alignment method program is selected on the display screen 16A, the display screen 16A and the operation panel 16B are displayed on the display device 16, and the program is executed via the control device 17 according to the flow shown in FIGS. To do. At this time, the first CCD camera 14 of the alignment mechanism 13 is located at the probe center. In this state, first, the electrode pads of the wafer are registered as shown in FIG. First, when the pre-aligned wafer W is mounted on the mounting table 11 (step S1), the control device 17 is activated to automatically move the mounting table 11 in the X and Y directions. Is detected, the central processing unit 17A calculates the center of the wafer W (step S2).

  Thereafter, the operator operates the horizontal movement operation key K1 to move the mounting table 11 so that the low magnification field of view of the first CCD camera 14, that is, the intersection of the scribe lines near the center of the wafer enters the display screen 16A. The scribe line is aligned with the cross mark M at the center of the display screen, and the position coordinates of the mounting table 11 at that time are registered (step S3). Similarly, the mounting table 11 is moved so that, for example, the scribe line on the left side of one chip in the wafer center scribe line enters the display screen, and this scribe line is aligned with the cross mark M at the center of the display screen. After registering the coordinates of the mounting table 11 at that time, the central processing unit 17A calculates the shift (rotation amount) in the θ direction of the wafer based on the registration coordinates of the scribe line near the wafer center and the registration coordinates on the left side of the wafer center. (Step S4).

  Further, after the mounting table 11 is automatically moved so that the scribe line on the right side of, for example, 10 preset chips on the wafer center enters the display screen 16A, the operator presses the horizontal movement operation key K1. The mounting table 11 is finely moved by operation, and the scribe line is aligned with the cross mark M at the center of the display screen, and the coordinates of the mounting table 11 at that time are registered (step S5). At this time, the mounting table 11 moves to a coordinate position reflecting the already calculated rotation amount. Subsequently, after the deviation in the θ direction of the wafer is calculated based on the registered coordinate values obtained in steps S4 and S5 in the central processing unit 17A, the mounting table 11 is rotated to eliminate the deviation in the θ direction of the wafer. Then, the wafer is arranged in a certain direction (step S6).

  After aligning the wafer in a certain direction by a series of operations from step S1 to step S6, the coordinates of the electrode pads necessary for alignment with the probe 12A are registered. For this purpose, the operator switches the first CCD camera 14 to a high magnification, aligns the scribe line near the center of the previous wafer with the cross mark M at the center of the display screen, and registers the coordinates of the scribe line at the center of the wafer (step). S7). Then, the operator operates the horizontal movement operation key K1 to display a predetermined position of an appropriate micro pattern in the chip near the scribe line at the center of the wafer on the display screen, and this position is a cross mark M at the center of the display screen. In addition, the coordinates of the micro pattern are registered (step S8). The registration of the micro pattern is performed only at one place in the wafer.

  Thereafter, in a high magnification state, the operator moves the mounting table 11 to display on the display screen the electrode pads to be aligned that are in a predetermined positional relationship with the micropattern, and the cross mark between the center of the pad image and the center of the display screen At this time, the coordinates of the electrode pad at that time are registered (step S9). Based on the coordinates of the micro pattern and the coordinates of the electrode pad, the positional relationship between the micro pattern and the electrode pad is calculated by the central processing unit 17A. The registration of the electrode pad coordinates is normally performed for four locations corresponding to four registered probes for one micropattern. This frees the operator from conventional operations of selecting a reference pattern and pattern matching.

  By the way, when the coordinates of the electrode pad are registered in step S9, the wafer electrode registration method of the present invention is used. That is, as shown in FIG. 4B, the size (size) of the electrode pad is input and teaching is performed on the operation panel 16B (step S93). The size of the electrode pad teaches the approximate size of the electrode pad with graphics. Next, electrode pad recognition is optimized (step S92). When optimizing, the operator observes the appearance of the edge line of the electrode pad while controlling the illuminance of the illuminating lamp, and selects the illuminance when the edge line can be seen to the maximum. Then, the first CCD camera 14 recognizes the electrode pad under the selected illuminance, and determines whether or not the difference between the size of the electrode pad and the size of the taught graphics is within an allowable value. To do. If the size of the electrode pad is within the allowable value, the illuminance at that time and the size of the electrode pad are stored in the setup file of the storage unit 17C (step S93). If the size of the electrode pad is outside the allowable value, an error is determined and another electrode pad is searched.

  After registering the electrode pads as described above, alignment is performed at the time of wafer inspection according to the flow shown in FIGS. 5A and 5B using the registration data, and then the original electrical characteristic inspection is executed. To do. In this alignment, first, as shown in FIG. 5A, the wafer on the mounting table 11 is arranged in a predetermined direction by the same procedure (step S1 to step S6) as when the electrode pad was registered in step S11. Thereafter, with the first CCD camera at a high magnification, the mounting table 11 automatically moves to the registered coordinates of the scribe line at the wafer center, the left side and the right side, and detects the micropattern at each position, After registering the respective coordinates, the deviation in the θ direction of the wafer is eliminated based on these coordinates (step S12). As a result, the wafer is arranged in a predetermined direction with high accuracy, and the alignment between the electrode pad of the wafer W and the corresponding probe 12A can be performed with high accuracy.

  Thereafter, it is confirmed that the mounting table 11 automatically moves to the wafer center, left side, right side, upper side, and lower side while the first CCD camera 14 remains at a high magnification, and can detect a micropattern at each position. (Step S13). The ability to detect the micropattern at any location indicates that the wafer is at a sufficient level. Further, after the first CCD camera 14 remains at a high magnification, the mounting table 11 automatically moves to a preset chip to be aligned and detects the micropattern, and then is calculated from the micropattern in step S9. Based on the positional relationship, the electrode pad is automatically moved to recognize the electrode pad and aligned with the corresponding probe 12A (step S14). Thereafter, the electrode pad of the wafer W and the corresponding probe 12A are in electrical contact via the mounting table 11, and the electrical characteristics of each chip of the wafer W are inspected.

  Here, the recognition of the electrode pad is performed according to the flow shown in FIG. That is, when the mounting table 11 automatically moves to the electrode pad as described above, the illumination lamp is turned on with the illuminance registered at the time of setup (step S141), and the electrode pad is illuminated. With this illumination, a clear edge line appears in the pad image of the display screen 16A captured by the first CCD camera 14, and the electrode pad is recognized (step S142). Thereafter, the size of the chip image is automatically compared with the size of the graphic registered in step S9 (step S143). If the edge line is within the allowable value, it is determined that the pad image is appropriate. As described above, the electrode pad is used for alignment with the probe 12A.

  Therefore, in the present embodiment, when the alignment of the wafer W is performed, the first CCD camera 14 is used to detect an electrode pad having a predetermined positional relationship with an appropriate micropattern, and the coordinates of the electrode pad are directly set. Since it is registered and used for alignment, the operator is relieved from the work of selecting a characteristic micro pattern as in the prior art, and the reliability of alignment can be improved.

  While the electrical characteristic inspection of the wafer W is repeated, for example, the probe 12A may be displaced due to some reason. In this case, the alignment assist function is activated to interrupt the alignment. Therefore, in this embodiment, an assist relief function is added, and the defect of the probe 12A can be solved via this assist relief function, and alignment can be continued in a short time.

  That is, when the assist relief function is activated, four screens are automatically displayed on the display screen 16A, for example, as shown in FIG. A probe image of the defective probe 12A in which the alignment mark M is displaced from the needle tip is displayed on the display screen 16A on the upper left of the display device 16, and a registered image corresponding to the probe image is displayed on the display screen 16C on the right side thereof. The In this registered image, the alignment mark M 'is located at a predetermined needle tip. In addition, the operation panel 16B is displayed below the registered image, and the current state and instructions of the defect in the probe image are displayed as character information 16D on the left side of the operation panel 16B. The operator moves the probe image in the display screen 16A by pressing the horizontal movement operation key K1 of the operation panel 16B in accordance with the instructions of the character information 16D while viewing the registered image in the display screen 16C. When the probe image matches the registered image, the problem of the predetermined probe 12A is resolved, and the operator stops the assist relief function by pressing the confirmation end key K3. As a result, the assist function is automatically canceled and the operation returns to the alignment operation, and the alignment can be accurately continued. The registration image in the display screen 16C is obtained by imaging the probe tips of the probes 12A at the four corners of the probe card 12 at the time of the probe registration described above, and the probe image is registered in the image storage unit 14B each time together with the position data and the imaging conditions. Is.

  On the other hand, in the case of an existing assist function that does not have the assist relief function, a probe image in which the alignment mark M is displaced from the needle tip is displayed in the display screen 16A and an operation panel as shown in FIG. 16B is displayed, and the registration image corresponding to the probe image is not displayed. When the existing assist function is generated in this way, only the captured image is displayed on the display screen 16A. Therefore, the operator can determine which needle tip of the plurality of needle tips should be aligned with the alignment mark M to cancel the assist function. Absent. In order to cancel the assist function, the registered position must be accurately remembered or the probe registration manual must be referred to, and much time must be taken to return to the alignment. Further, when the assist function is canceled, if the alignment mark M is aligned with a needle tip different from the original needle tip, the subsequent alignment cannot be performed accurately, resulting in an inspection failure.

  As described above, according to the present embodiment, when the wafer W placed on the placement table 11 is imaged by the first CCD camera 14 and used for the inspection of the wafer W, the wafer is loaded by the first CCD camera 14. The step of imaging an arbitrary scribe line of the wafer W on the table 11 and registering the position thereof, and the electrode pad of the chip having a predetermined positional relationship with the registration position of the scribe line by the first CCD camera 14 Recognizing under the illuminance at which the edge line E of the image P appears, registering the illuminance and the size of the chip image, and registering the coordinates of the mounting table 11 when the electrode pad is recognized by the first CCD camera 14 And the step of providing the coordinate-registered electrode pad for alignment, the wafer W can be detected by reliably detecting the electrode pad for alignment. It is possible to improve the reliability of the inspection, release the operator from the task of pattern selection and pattern matching during alignment, it is possible to reduce the load of the operator.

  According to the present embodiment, the step of recognizing and registering the electrode pad includes the step of teaching the size of the electrode pad of the chip, and the time when the electrode pad of the chip is imaged by the first CCD camera 14. A step of controlling the illuminance to reveal the edge line E of the pad image P by the first CCD camera 14 and recognizing the electrode pad, and a step of determining whether or not the size of the edge line E is appropriate based on the size of teaching. When the size of the edge line E is within the allowable value, the step of registering the size of the edge line E and the illuminance at that time is included. Can be detected directly and reliably.

  According to the present embodiment, the alignment process includes the step of illuminating the wafer W with the illuminance when the edge line E is obtained, and the illumination under which the edge line E is obtained by the first CCD camera 14. The step of obtaining the pad image P of the wafer W and recognizing the electrode pad, the step of determining the suitability of the size of the pad image P based on the registered size of the edge line, and the edge line E of the pad image P And the step of subjecting the wafer W to inspection when the value is within an allowable value, the electrode pad of the wafer W and the probe 12A corresponding thereto can be reliably brought into contact with each other, and the reliability of the inspection is improved. Can do.

  In addition, according to the present embodiment, a recording medium on which a program of a wafer electrode registration method and a wafer alignment method is recorded is stored in the program storage unit 17C of the inspection apparatus 10, whereby the wafer electrode registration method of the present invention and The wafer alignment method can be reliably executed.

  In the above-described embodiment, the wafer W inspection apparatus 10 has been described as an example. However, the present invention can be applied to various semiconductor manufacturing apparatuses that require wafer alignment. In short, any method for registering wafer electrode pads by the method of the present invention and performing wafer alignment using registered data is included in the present invention.

  The present invention can be suitably used in semiconductor manufacturing apparatuses and inspection apparatuses.

It is a block diagram which shows the structure of the test | inspection apparatus used in order to implement one Embodiment of the method of this invention. (A), (b) is a top view for demonstrating the relationship between illumination and the captured image of an electrode pad, respectively. (A), (b) is a figure which shows the wafer in the case of applying one Embodiment of the wafer alignment method of this invention, (a) is a top view which shows the whole wafer, (b) is a center part of a wafer, It is a top view which expands and shows the intersection of a scribe line. (A), (b) is a flowchart which shows one Embodiment of the wafer alignment method of this invention, and the registration method of a wafer electrode, respectively. (A), (b) is a flowchart which shows the post process of the flowchart shown in FIG. 1, respectively. It is a figure which shows the display screen on which the assist relief function which generate | occur | produces at the time of alignment is displayed. FIG. 7 is a diagram showing a display screen on which an assist function that occurs during alignment without the assist relief function shown in FIG. 6 is displayed. It is a figure which shows an example of an inspection apparatus, (a) is a front view which fractures | ruptures and shows a part of front, (b) is a top view which shows the inside of an inspection apparatus. It is a top view which shows the characteristic part of the wafer used for the conventional wafer alignment method.

Explanation of symbols

12A probe (object)
14 First CCD camera (imaging means)
16 Display screen 16A Imaging screen 16B Operation panel 16C Registered image M, M 'alignment mark (alignment mark)
W wafer

Claims (8)

  When performing predetermined processing on a plurality of chips formed on the wafer, the mounting table on which the wafer is mounted and the imaging unit move relative to each other, and the chip at an arbitrary position of the wafer is predetermined by the imaging unit. A method of imaging with illuminance, detecting the electrode of the chip, and registering the position of the electrode, teaching the size of the electrode of the chip, and imaging the electrode of the chip by the imaging means Controlling the illuminance when recognizing and recognizing the electrode by showing the contour of the electrode image by the imaging means, determining whether or not the size of the contour is appropriate based on the size by teaching, and the contour Registering the size of the contour and the illuminance at that time when the size of the wafer is within an allowable value.   A step of illuminating the wafer with illuminance when the contour is obtained, and a step of recognizing the electrode by obtaining an electrode image of the wafer under the illumination by the imaging means when performing the predetermined processing; And determining whether or not the size of the electrode image is appropriate based on the size of the registered contour, and subjecting the wafer to a predetermined process when the contour of the electrode image is within an allowable value. The wafer electrode registration method according to claim 1, wherein:   When performing predetermined processing on a plurality of chips formed on a wafer, the mounting table and the imaging unit move relative to each other, and the wafer is aligned with a predetermined illuminance by the imaging unit. A method of imaging an arbitrary scribe line of the wafer on the mounting table by the imaging unit and registering the position thereof, and a registration position of the scribe line by the imaging unit and a predetermined positional relationship. Recognizing the electrode of the chip under the illuminance at which the outline of the electrode image appears, registering the information, registering the position of the mounting table when the electrode is recognized by the imaging means, and the position A method for aligning a registered electrode for alignment, and a wafer alignment method comprising:   The electrode recognition and registration step includes the steps of teaching the size of the electrode of the chip and the illuminance at the time of imaging the electrode of the chip by the imaging means to thereby define the contour of the electrode image by the imaging means. A step of recognizing the electrode; a step of determining whether or not the size of the contour is appropriate based on the size of the teaching; and a size of the contour when the size of the contour is within an allowable value. 4. The wafer alignment method according to claim 3, further comprising the step of registering the illuminance at that time.   The alignment step includes illuminating the wafer with illuminance when the contour is obtained, obtaining an electrode image of the wafer under the illumination by the imaging means, and recognizing the electrode, And determining whether or not the size of the electrode image is appropriate based on the size of the registered contour, and subjecting the wafer to a predetermined process when the contour of the electrode image is within an allowable value. The wafer alignment method according to claim 4.   6. The wafer alignment method according to claim 3, wherein the electrode recognition step and the alignment step are performed under a high magnification of the imaging means.   When performing predetermined processing on a plurality of chips formed on the wafer, the mounting table on which the wafer is mounted and the imaging unit move relative to each other, and the chip at an arbitrary position of the wafer is predetermined by the imaging unit. Claim 1 or Claim 2 is a recording medium which records a program for registering the position of an electrode after imaging with illuminance and detecting the electrode of the chip, wherein the computer is driven by the program. 8. A recording medium comprising the wafer electrode registration method according to claim 1.   When performing predetermined processing on a plurality of chips formed on a wafer, the mounting table and the imaging unit move relative to each other, and the wafer is aligned with a predetermined illuminance by the imaging unit. A recording medium recording a program for executing the wafer alignment method according to any one of claims 3 to 6, wherein the computer is driven by the program. .

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