JP2010219110A - Probe method and probe device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To calibrate relative relationship of optical axis positions of two opposite imaging optical systems without removing a wafer from a wafer stage and moving a target pattern to an optical axis position of the optical system, and calibrate a size of one pixel of image data of the two optical systems and a mounting angle of a camera collectively. <P>SOLUTION: The first optical system 32 including a projection optical system 42 for projecting a two-dimensional pattern for calibration, and the second optical system 22 arranged so as to face to the first optical system 32 are included. The first optical system recognizes an electrode of a semiconductor crystal substrate 26 to be inspected. The second optical system recognizes a contact electrode 38. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a probe method and a probe apparatus for performing electrical characteristic inspection in a manufacturing process of a semiconductor element or the like, and more particularly to a method for bringing an electrode pad of a measurement target element into contact with a contact electrode with high accuracy and a probe apparatus for realizing the method. .

  In the manufacturing process of semiconductor elements, semiconductor elements having the same structure are regularly arranged and formed on one semiconductor crystal substrate, and these semiconductor elements are separated into individual semiconductor elements in a dicing process. In general, a probe test for evaluating the electrical characteristics of a semiconductor element formed on one semiconductor crystal substrate in a manufacturing process before being separated into pieces by a dicing process is performed.

  In probe inspection, for each semiconductor element that is regularly arranged on a semiconductor crystal substrate, a contact electrode is brought into contact with the electrode pad of the semiconductor element, and an input electrical signal is sequentially input to each semiconductor element. The performance evaluation of the electrical characteristics is performed by observing the electrical signal output for.

  The probe apparatus includes a wafer stage that holds a semiconductor crystal substrate to be inspected on which a semiconductor element to be probed is formed and can be moved in the horizontal, vertical, and rotational directions, and is formed on the semiconductor crystal substrate to be inspected. An alignment function means is provided for detecting an electrode pad of a semiconductor element and bringing the contact electrode into contact with the electrode pad accurately.

  For example, the following first to fourth probe devices are disclosed as probe devices having alignment function means.

  The first probe device is provided with a mounting table on the XYZ stage so as to be capable of rotating in order to relatively align the contact electrode and the electrode pad, and a semiconductor crystal substrate to be inspected is mounted on the mounting table. The probe device (refer to Patent Document 1) that performs electrical measurement by bringing the electrode of the substrate into contact with the probe of the probe card provided above the mounting table and the probe method using this probe device (Patent Document) 2) is disclosed.

  This probe apparatus is provided on the Z stage of the XYZ stage so that the field of view is upward and the in-focus plane is located above the semiconductor crystal substrate to be inspected on the mounting table. A first imaging means; a second imaging means provided above the substrate on the mounting table so that the field of view faces downward; and a lower imaging means for imaging the semiconductor crystal substrate to be inspected. An alignment function means is provided that includes a target for adjusting the height position of the focal plane of the first imaging means and the second imaging means.

  Then, while aligning the focal planes of the first imaging means and the second imaging means, the first imaging means and the second imaging means respectively image the contact electrode and the electrode pad to obtain the respective Z coordinates, and Based on the Z coordinate, a method for obtaining the height position of the electrode pad with respect to the contact electrode is employed. The target is provided on the Z stage of the XYZ stage, and is located at a position corresponding to the focal plane of the first imaging unit and outside the visual field of the first imaging unit and below the focal plane. It is configured to move forward and backward between positions.

  The second probe device includes a probe card unit to which a probe card is attached, a mounting table on which a semiconductor crystal substrate to be inspected is mounted, an XY stage that drives the mounting table in the X and Y directions, and on the XY stage. A driving mechanism for driving the provided mounting table in a vertical direction and a rotating direction, and driving the mounting table to align and contact the semiconductor crystal substrate to be tested and the measuring needle of the probe card to contact the semiconductor to be tested This is a probe device for measuring electrical characteristics of a crystal substrate (see Patent Document 3). In this probe apparatus, a camera for detecting the position of the tip of the measuring needle of the probe card is detachably attached to the mounting table, and an alignment mark for recognizing the position of the camera is provided at a predetermined position of the apparatus body. Yes.

  The third probe device holds the semiconductor crystal substrate to be inspected on the surface and can move any semiconductor element arranged on the surface of the semiconductor crystal substrate to be inspected to a chuck that can be moved up and down in a direction perpendicular to the surface. A first optical position detecting means for optically detecting a position in the plane; a second optical position detecting means for optically detecting a position in the plane of the contact electrode to be brought into contact with the electrode pad of the semiconductor element; And a target provided on the chuck and used for alignment between the first and second optical position detection means (see Patent Document 4).

  The fourth probe apparatus does not use the physical target body used in the above-described first to third probe apparatuses, and can determine the reference position of each camera provided on the support base and the stage. (See Patent Document 5). This probe device includes a support base for holding a contact electrode, a stage on which a semiconductor crystal substrate to be inspected arranged opposite to the support base is placed, and predetermined test points on the semiconductor crystal substrate to be inspected. A test point camera provided on the support base for recognition and a probe camera provided on the stage for recognizing the contact electrode are provided. Then, the spot light is advanced along one optical axis of the test point camera and the probe camera, and the spot light is incident on the other camera to determine the reference position of these two cameras. ing.

Japanese Patent No. 2986141 Japanese Patent No. 2986142 Japanese Patent No. 2666172 Japanese Patent No. 2906094 JP 2003-303865 A

  Probe devices that measure the electrical characteristics of the measurement target element are required to operate with sufficiently high accuracy in repeated and repetitive operations. Therefore, thermal expansion and contraction of the mechanical system that supports the optical system, mechanical system or optical system movement. It is required to always correct the time misalignment and the pixel resolution of the camera attached to the optical system.

  Here, when it is assumed that the probe device functions as an electrical property inspection apparatus for a semiconductor element, the measurement target element refers to a semiconductor element or the like. However, the technical scope of the present invention is that the measurement target element is a semiconductor element. It is not limited to only. In the following description, a semiconductor element having an electrode pad is taken up for the sake of convenience, but the measurement target element to which the present invention is applied is not limited to the semiconductor element.

  In the first to third probe devices described above, the two optical systems used for recognizing the contact electrode and the electrode on the measurement target element are provided on separate support bases and stages that can be moved relative to each other. In order to perform accurately, it is necessary to determine the reference positions of the two optical systems. Therefore, the method for aligning the contact electrode and the measurement target element is to recognize the target object installed on the focal plane including the optical axis of one optical system with the other camera, and from the mutual position of the recognized target object. Assuming that the optical axis of the optical system exists at a position separated by a predetermined distance, a method of determining the reference positions of the two optical systems is employed.

  However, in the first to third probe devices described above, the positional relationship between the optical system for measuring the measurement target element (imaging optical system including a camera for image processing) and the measurement target element, and the contact electrode The method of measuring the positional relationship between an optical system for measurement (imaging optical system including a camera for image processing) and a contact electrode is a test in a high temperature environment, a test in a low temperature environment, and a mechanical system itself. It cannot be said that it has been established considering changes over time. The reference position of the optical system is not invariant and may cause errors in positioning.

  Here, an optical system for recognizing an electrode pad that is a measurement target element, which is an imaging optical system including a camera for image processing, may be hereinafter referred to as a measurement target element recognition optical system. An imaging optical system including a camera for recognizing a contact electrode and including a camera for image processing may be hereinafter referred to as a contact electrode recognition optical system.

  The positional relationship between the optical system for imaging the measurement target element and the optical system for imaging the contact electrode must always be corrected in order to maintain accuracy, but in the first to fourth probe devices described above, In the probe method, it is necessary to physically set the target pattern to be corrected at the focal position of the two optical systems. The stage itself may be at a low temperature or a high temperature in order to match the temperature environment of the element to be measured, and the target pattern itself is affected by the temperature. Also, the position where the target pattern is placed competes with the position where the contact electrode recognition optical system captures the image of the contact electrode. Therefore, if the target pattern is moved or the contact electrode recognition optical system is not moved, the object measurement is in operation. There is a problem that the correction value cannot be measured during (during testing).

  The above-described probe method using the fourth probe apparatus is improved in that it is not necessary to place the target pattern on the stage, but the spot light imaged in the image processing for correcting the optical system is point-imaged. In that point, ambiguity occurs in the identification. When a point image is used, since the focus height can only be determined based on the degree of blur of the point image, the accuracy becomes low, and it is difficult to reduce the alignment error in the height direction. Then, according to the method using a point image, the size of one pixel of the camera, the camera mounting angle with respect to the imaging optical system including the camera for image processing only by observing the center position deviation of the optical axis. It is necessary to measure separately.

  The inventor of the present invention includes a projection optical system that projects a calibration two-dimensional pattern on one of the measurement target element recognition optical system or the contact electrode recognition optical system, and the calibration two-dimensional pattern is measured on the measurement target element recognition optical system. It has been recognized that the above-described problems can be solved by adopting a configuration in which imaging is performed by both the system and the contact electrode recognition optical system.

  Therefore, the object of the present invention is to be able to collectively measure the size of one pixel of the camera and the camera mounting angle for the above two recognition optical systems without being affected by the temperature of the semiconductor crystal substrate to be inspected. There is provided a probe method capable of calibrating the relative relationship between position coordinates respectively acquired in two optical systems with high accuracy without retracting the wafer from the wafer stage, and a probe apparatus for realizing the probe method. It is to provide.

  According to the gist of the present invention based on the above philosophy, the following probe method and a probe device for realizing the probe method are provided.

  The probe method of the basic configuration of the present invention is a probe method for evaluating the electrical characteristics of the measurement target element by bringing a contact electrode into contact with the electrode of the measurement target element having an electrode, and a two-dimensional pattern real image forming step; A first optical system image data acquisition step, a second optical system image data acquisition step, and a calibration step are included.

  The two-dimensional pattern real image forming step is a step of forming a real image of the relative coordinate calibration two-dimensional pattern by the projection optical system. The first optical system image data acquisition step is a step of capturing image data of a real image of a two-dimensional pattern by the first optical system. The second optical system image data acquisition step is a step of capturing image data of a real image of a two-dimensional pattern by the second optical system. The calibration step is based on the image data of the real image of the two-dimensional pattern respectively acquired by the first and second optical systems, and the first optical system position coordinates and the second optical system of the image data acquired by the first optical system This is a step of calibrating the relative relationship between the image data acquired in step 2 and the second optical system position coordinates.

  The above-described probe method of the basic configuration of the present invention is implemented by the probe device of the basic configuration of the present invention. A probe apparatus having a basic configuration according to the present invention is a probe apparatus that evaluates electrical characteristics of a measurement target element by bringing a contact electrode into contact with the electrode of the measurement target element having an electrode, and projects a two-dimensional pattern for calibration A first optical system including the projection optical system and a second optical system disposed so as to face the first optical system.

  The two-dimensional pattern real image forming step described above is realized by the projection optical system, and the first and second optical system image data acquisition steps are realized by the first and second optical systems. Then, the image data of the real image of the two-dimensional pattern formed by projection is captured by the first and second optical systems, respectively, and acquired by the first optical system based on the image data of the real image of these two-dimensional patterns. A calibration step for calibrating the relative relationship between the first optical system position coordinates of the image data and the second optical system position coordinates of the image data acquired by the second optical system is realized.

  Based on the above-described probe method and probe device of the basic configuration of the present invention, there are provided first and second probe methods and first and second probe devices for realizing these methods, respectively.

  In the first probe method of the present invention, the first optical system image data acquisition step described above is an optical system for recognizing an electrode and is an imaging optical system including a camera for image processing. The system is configured to capture image data of a real image of a two-dimensional pattern formed on the plane of an opaque planar object placed at the imaging position of the projection optical system, and the second optical system image data acquisition step is a contact The second optical system, which is an optical system for recognizing electrodes and an imaging optical system including a camera for image processing, is configured as a step of capturing real image data of a two-dimensional pattern.

  The first and second optical system adjustment steps and an electrical characteristic measurement step are further included. The first and second optical system adjustment steps are based on the image data of the real image of the two-dimensional pattern acquired by the first and second optical systems, respectively, and the resolution of the respective image data of the first and second optical systems, and the first And calibrating the mounting angles of the respective cameras of the second optical system. The electrical characteristic measurement step is a step of measuring the electrical characteristics of the measurement target element by bringing the measurement target element and the contact electrode into contact with each other while sequentially moving relative to each other.

  The above-described first probe method of the present invention is implemented by the first probe device of the present invention. The first and second optical systems of the first probe device of the present invention are configured as a measurement target element recognition optical system and a contact electrode recognition optical system, respectively.

  The first optical system is an imaging optical system for recognizing electrodes, and is an imaging optical system including a camera for image processing. The plane of an opaque planar object placed at the imaging position of the projection optical system The optical system captures image data of a real image of the two-dimensional pattern formed in The second optical system is an imaging optical system for recognizing a contact electrode, including a camera for image processing, and is a real image data of a two-dimensional pattern formed by the projection optical system. Configured as an optical system.

  Then, the first and second optical systems respectively obtain the real image data of the acquired two-dimensional pattern, the resolutions of the respective image data of the first and second optical systems, and the respective first and second optical systems. The camera mounting angle is measured. The first probe device of the present invention is configured to measure the electrical characteristics of the measurement target element by bringing the measurement target element and the contact electrode into contact with each other while sequentially moving relative to each other.

  According to a second probe method of the present invention, the first optical system image data acquisition step described above is an optical system for recognizing a contact electrode of the first optical system and includes an image processing camera. The optical system is configured as a step of capturing real image data of a two-dimensional pattern, and the second optical system image data acquisition step is an optical system for recognizing an electrode and an image. By taking an imaging optical system including a camera for processing, it is configured as a step to capture image data of a real image of a two-dimensional pattern formed on the plane of an opaque planar object placed at the imaging position of the projection optical system Is done.

  In the second probe method of the present invention, the first and second optical system adjustment steps and the electrical characteristic measurement step are the same as in the first probe method described above.

  The above-described second probe method of the present invention is implemented by the second probe apparatus of the present invention. The first and second optical systems of the second probe device of the present invention are configured as a contact electrode recognition optical system and a measurement target element recognition optical system, respectively.

  The first optical system is an optical system for recognizing a contact electrode, and is an imaging optical system including a camera for image processing. The first optical system captures real image data of a two-dimensional pattern formed by the projection optical system. It is formed as an optical system for capturing.

  The second optical system is an optical system for recognizing electrodes and is an imaging optical system including a camera for image processing. It is in the plane of an opaque planar object placed at the imaging position of the projection optical system. It is formed as an optical system that captures image data of a real image of the formed two-dimensional pattern.

  The second probe device of the present invention is the same as the first probe device described above except for the configuration of the first and second optical systems.

  In the above-described probe device (including the first and second probe devices), the real image of the two-dimensional pattern formed by the projection optical system is converted into the first and second optical systems by the cameras of the first and second optical systems. The image is formed on the imaging surface of the camera, and the center position of the two-dimensional pattern is formed on each imaging surface of the cameras of the first and second optical systems so as to coincide with the center position of each imaging surface. In addition, it is preferable to further include a projection optical system posture position adjusting means for adjusting the posture and position of the projection optical system.

  According to the probe method of the basic configuration of the present invention using the probe device of the basic configuration of the present invention, a real image of this two-dimensional pattern is used in each of the first and second optical systems using a two-dimensional pattern instead of a point image pattern. Image data is captured. Then, calibration of the relative relationship between the first optical system position coordinate of the image data acquired by the first optical system and the second optical system position coordinate of the image data acquired by the second optical system is performed. Therefore, it is possible to collectively measure the size of one pixel of the camera and the camera mounting angle necessary for this calibration.

  Since a real image formed by the projection optical system is used as the two-dimensional pattern, calibration can be performed with high accuracy without being affected by the temperature of the semiconductor crystal substrate to be inspected placed on the wafer stage. In addition, if the first optical system and the second optical system are moved to opposite positions while avoiding the position of the wafer stage, it is possible to perform calibration with high accuracy without retracting the wafer from the wafer stage. .

  In the first probe device of the present invention, the first and second optical systems are configured as a measurement target element recognition optical system and a contact electrode recognition optical system, respectively. The second optical system is configured as a contact electrode recognition optical system and a measurement target element recognition optical system, respectively. Since either configuration of the probe device has the same effect, the configuration of the probe device to be used belongs to a design matter determined in consideration of convenience in actual use.

  Here, the effect obtained by the first probe device of the present invention will be described. However, if the first and second optical systems are read as a contact electrode recognition optical system and a measurement target element recognition optical system, respectively, the second probe is used. This is an explanation of the effect on the device.

  The real image of the above-described two-dimensional pattern formed by the projection optical system is focused on the image planes of the first and second optical systems when observed by the first and second optical systems. When the 2D pattern is projected from the first optical system side, it can be adjusted so that a real image of this 2D pattern is formed at a position that matches the imaging distance of the measurement target element. .

  In this state, if an opaque planar object is placed at the position of the real image of the two-dimensional pattern formed by the projection optical system, the real image of the two-dimensional pattern can be observed by the first optical system. Can capture image information of a two-dimensional pattern. When the two-dimensional pattern image information is taken in by the first optical system in this way, the image information is stored in the storage device.

  If the opaque planar object is removed, the real image of the two-dimensional pattern can be observed by the second optical system, and the image information of the two-dimensional pattern can be captured by the second optical system. . In this case, the image information is stored in the storage device. The image information captured by the first and second optical systems stored in this manner is read from the storage device, and the first optical system position coordinates and the second optical system position coordinates are relative to each other based on the image information of both. Relationship calibration is performed.

  As described above, the real image of the two-dimensional pattern formed by the projection optical system plays a role corresponding to the physical target used in the conventional first to third probe devices described above.

  If a spatially identical pattern such as a two-dimensional lattice pattern is used as a two-dimensional pattern, the respective optical systems necessary for calibration of the first and second optical system position coordinates can be obtained. It is easy to measure the size of one pixel of the camera and the camera mounting angle, and the first and second optical system position coordinates can be easily calibrated.

  In addition, if it is a place where the first and second optical systems can be arranged at positions facing each other, it is not necessary to face the both across the target pattern. The above-described calibration can be performed only by moving to the real image position.

  The optical axes of the first and second optical systems and the optical axis of the projection optical system need to share the optical axis. The probe device of the basic configuration of the present invention, and the first and second probe devices include the projection optical system posture position adjusting means, so that the optical axis of the projection optical system satisfies the first and second conditions so as to satisfy this condition. It is possible to adjust with respect to the optical axis of the second optical system.

  In other words, the real image of the two-dimensional pattern formed by the projection optical system is formed on the imaging surfaces of the first and second optical system cameras by the projection optical system posture position adjusting means by the first and second optical system cameras. The projection optical system's posture and position are adjusted by forming an image so that the center position of the two-dimensional pattern coincides with the center position of each imaging surface of each camera of the first and second optical systems. Thus, it is possible to set so that the optical axis of the first and second optical systems and the optical axis of the projection optical system share a common optical axis.

It is a schematic block diagram of the probe apparatus of embodiment of this invention. It is a diagram showing a schematic configuration of a projection optical system, a measurement object element recognition optical system and a contact electrode recognition optical system, (A) is a schematic three-dimensional structure diagram of these optical systems, (B) is a diagram of these optical systems It is the schematic sectional drawing cut | disconnected by the plane containing an optical axis. It is a schematic structural diagram showing the configuration of the projection optical system posture position adjusting means, (A) shows a cross section cut by a plane substantially orthogonal to the optical axis of the imaging optical system provided with the projection optical system posture position adjusting means It is a figure, (B) is a figure which shows the cross section cut | disconnected by the plane containing the optical axis of an imaging optical system. It is a figure which uses for description of the step which acquires the image data of the real image of a two-dimensional pattern by a measurement object element recognition optical system. It is a figure which uses for the description of the step which acquires the image data of the real image of a two-dimensional pattern by a contact electrode recognition optical system. It is a figure which shows a mode that a contact electrode is aligned by a contact electrode recognition optical system. It is a figure which shows a mode that the electrode pad of the surface of a wafer is aligned by a measurement object element recognition optical system. It is a figure used for description of the electrical property measurement step which measures the electrical property of the chip | tip currently formed in the wafer by making the electrode pad and contact electrode of the surface of a wafer contact mutually, performing relative movement sequentially.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Each drawing schematically shows each component so that the present invention can be understood, and the present invention is not limited to the illustrated examples. In addition, the same constituent elements are denoted by the same reference numerals in the respective drawings, and redundant description of these functions may be omitted.

<Probe device according to an embodiment of the present invention>
With reference to FIG. 1, FIG. 2 (A) and (B), as a probe device according to an embodiment of the present invention, the first and second optical systems are configured as a measurement target element recognition optical system and a contact electrode recognition optical system, respectively. An embodiment of the first probe apparatus will be described. The only difference from the second probe device is whether the projection optical system is installed in either the first optical system or the second optical system. The feature of the present invention is sufficient to take up the embodiment of the first probe device. Can be explained.

  First, a schematic configuration of a probe apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a probe apparatus according to an embodiment of the present invention.

  A probe apparatus according to an embodiment of the present invention includes a first optical system 32 that includes a projection optical system 42 that projects a two-dimensional pattern for calibration, and a second optical system that is disposed so as to face the first optical system 32 22 and configured.

  Here, the first optical system 32 is an optical system for recognizing electrodes of a semiconductor crystal substrate to be inspected (hereinafter also referred to as a wafer 26), and includes a measurement target element imaging camera 28 for image processing. The imaging optical system has a function of capturing image data of a real image of a two-dimensional pattern formed on the plane of an opaque planar object placed at the imaging position of the projection optical system.

  The second optical system 22 is an optical system for recognizing the contact electrode 38 and an imaging optical system including the contact electrode imaging camera 18 for image processing, and is a two-dimensional formed by the projection optical system 42 It has a function of capturing image data of a real image of a pattern. Since the contact electrode 38 may be configured as a set of a plurality of electrodes, in FIG. 1, a plurality of contact electrodes are shown as the contact electrode 38, but the contact electrode 38 may be configured by a single electrode. is there. Further, as the contact electrode 38, a pogo pin or a vertical needle contact electrode is often used. Therefore, the contact electrode 38 including the contact electrode having a pogo pin or a vertical needle shape is simply referred to as a contact electrode 38.

  A detailed configuration of the probe apparatus according to the embodiment of the present invention will be described below. A probe apparatus according to an embodiment of the present invention shown in FIG. 1 includes a wafer stage 16 on which a wafer 26 is mounted, a θ moving stage 15 for rotating the stage, a support base 14 for holding the stage, a contact electrode 38, and a contact electrode 38. A contact electrode fixing base 36 for holding the contact electrode, and a contact electrode support base 30 for holding the contact electrode fixing base 36, and a wafer 26 to be measured is mounted on the wafer stage 16.

  The support base 14 is fixed to the XYZ movement stage 12, and the XYZ movement stage 12 is fixed to the XYZ movement stage support base 10. Although not shown in FIG. 1, in addition to the XYZ moving stage 12 being fixed to the XYZ moving stage support base 10, the contact electrode support base 30 is also attached via an attached arm (not shown). Is fixed. That is, the probe apparatus according to the embodiment of the present invention is configured by integrating the contact electrode support 30 and the XYZ movement stage 12 with the XYZ movement stage support 10 as a base.

  On the wafer 26, semiconductor elements (hereinafter sometimes referred to as chips) in a state before being singulated as semiconductor elements are arranged on a lattice, and electrode pads or electrical pads for making electrical contact are arranged on the chips. Ball-shaped electrodes such as BGA (Ball Grid Array) are formed. Hereinafter, a ball-shaped electrode such as an electrode pad or BGA may be collectively referred to as an electrode pad.

  The support base 14 is provided with a contact electrode recognition optical system 22 as a second optical system including a contact electrode imaging camera 18 for imaging the contact electrode 38, and the contact electrode recognition optical system 22 is a method capable of adjusting an imaging distance. It is attached to the support base 14. On the other hand, a measurement target element recognition optical system 32 as a first optical system including a measurement target element imaging camera 28 that images the wafer 26 on the wafer stage 16 is attached to the contact electrode support base 30.

  With reference to FIGS. 2 (A) and 2 (B), schematic configurations of the measurement target element recognition optical system and the contact electrode recognition optical system will be described. 2 (A) and 2 (B) are diagrams showing schematic configurations of the projection optical system, the measurement target element recognition optical system, and the contact electrode recognition optical system, and FIG. 2 (A) is a schematic three-dimensional diagram of these optical systems. FIG. 2 (B) is a schematic cross-sectional view taken along a plane including the optical axis of these optical systems.

  As shown in FIGS. 2A and 2B, the measurement target element recognition optical system 32 and the contact electrode recognition optical system 22 are disposed so as to face each other, and are installed in the measurement target element recognition optical system 32. The projection optical system 42 is configured to form a real image 60 of a two-dimensional pattern. 2A and 2B, a light beam 62 and a light beam 64 schematically show the light beams output from the measurement target element recognition optical system 32 and the contact electrode recognition optical system 22, respectively.

  The measurement target element recognition optical system 32 includes a coaxial illumination optical system 40 including a light source 41 for illuminating the surface of the wafer 26. Irradiation light from the light source 41 is converted into a light beam by the coaxial illumination optical system 40 and reflected by the beam splitter 70 to illuminate the surface of the wafer 26. 2A and 2B show a state in which a real image 60 of a two-dimensional pattern is projected at the position of the wafer 26. FIG.

  However, in the description of the optical alignment of the measurement target element recognition optical system 32 and the contact electrode recognition optical system 22, it is understood that the position where the real image 60 of the two-dimensional pattern is appropriately read as the position where the wafer 26 is placed. I want. The measurement target element recognition optical system 32 and the contact electrode recognition optical system 22 are moved while maintaining a relative positional relationship with each other, so that the contact electrode 38 and the measurement target element of the measurement target element are formed at the position where the real image 60 of the two-dimensional pattern is formed. Measurement is performed by arranging electrode pads.

  The measurement target element recognition optical system 32 includes a projection optical system 42. The projection optical system 42 includes a two-dimensional pattern printed glass mask 52 on which a two-dimensional pattern is formed, and the light source 55 illuminates the two-dimensional pattern printed glass mask 52. The light beam transmitted through the two-dimensional pattern printing glass mask 52 passes through an imaging optical system 58 provided in the projection optical system 42, and is reflected by the beam splitter 72 to form a real image 60 of a two-dimensional pattern.

  By placing the opaque planar object 66 at a position where the real image 60 is formed, image data of the real image 60 is acquired by the measurement target element recognition optical system 32. The measurement target element imaging camera 28 forms an image of the real image 60 on the imaging surface 39. The measurement target element imaging camera 28 is naturally provided with an imaging lens (not shown) for forming an image of the real image 60 on the imaging surface 39.

  The contact electrode recognition optical system 22 includes a coaxial illumination optical system 20 including a light source 21 for illuminating the contact electrode 38. Irradiation light from the light source 21 is converted into a light beam by the coaxial illumination optical system 20 and reflected by the beam splitter 68 to illuminate the contact electrode 38.

  If the above-described opaque planar object 66 is removed, the image data of the real image 60 is acquired by the contact electrode recognition optical system 22. The contact electrode imaging camera 18 forms an image of the real image 60 on the imaging surface 19. The contact electrode imaging camera 18 is naturally provided with an imaging lens (not shown) for forming an image of the real image 60 on the imaging surface 19.

  The contact electrode fixing base 36 and the measurement target element recognition optical system 32 are fixed to the contact electrode support base 30. The contact electrode recognition optical system 22 is held on a support base 14 that can be adjusted smoothly in the X, Y, and Z directions, and the wafer stage 16 is further fixed on a θ moving stage 15 that can be adjusted in the θ direction. The Here, it is assumed that the measurement target element recognition optical system 32 and the contact electrode recognition optical system 22 are installed at positions adjusted in advance so that an image can be captured at the best imaging distance. Note that the Z-axis may have a single mechanism that can operate independently of the wafer stage 16.

  After the wafer 26 is transferred onto the wafer stage 16 by a loading device (not shown), the vertical and horizontal arrangements of the chips and the contact electrodes are arranged in order to bring the electrode pads on the chips into contact with the contact electrodes 38 accurately. The position of the contact electrode 38 is obtained by pattern matching by image processing in the contact electrode recognition optical system 22 so that the positions match, and the position of the wafer 26 (on the wafer) by pattern matching by image processing in the measurement target element recognition optical system 32. Determine the tip position).

  After the contact electrode 38 and the wafer 26 are positioned, the wafer stage 16 is controlled so that the electrode of the chip on the wafer 26 and the contact electrode 38 accurately overlap, and the electrode of the chip and the contact electrode on the wafer 26 are aligned. The electrical characteristics of the chips formed on the wafer 26 are measured by contacting them. Here, the positioning is sometimes referred to as alignment. As described above, in the probe apparatus according to the embodiment of the present invention, once the wafer is aligned, the contact electrode 38 and the electrode of the wafer 26 are brought into contact with each other while sequentially moving the wafer 26 and the contact electrode 38 relative to each other. Thus, the electrical characteristics of each chip formed on the wafer 26 are measured (electrical characteristic measurement step).

  Since the contact electrode 38 is fixed to the contact electrode support 30 through the contact electrode fixing base 36, it may not be necessary to perform alignment for each wafer. Further, the contact electrode 36 may be composed of electrodes for a plurality of chips so that a plurality of chips can be measured at the same time. In this case, the wafer 26 and the contact electrode 38 are arranged for the number of chips corresponding to each other. The contact electrode 38 and the electrode of the wafer 26 are brought into contact with each other while sequentially performing relative movement.

  Contact electrode alignment means that the contact electrode 38 attached to the contact electrode support 30 is imaged by the contact electrode imaging camera 18 of the contact electrode recognition optical system 22 to acquire image data, and image processing by pattern matching is performed. It means that the individual coordinates (position coordinates) of the contact electrode 38 are measured.

  Wafer alignment refers to imaging a specific pattern of a chip formed on the wafer 26 or a plurality of electrodes (in some cases, a single electrode) of the chip by the measurement target element imaging camera 28 of the measurement target element recognition optical system 32. The image data is acquired, and the rotation angle of the wafer stage 16 is adjusted by image processing by pattern matching so that each chip on the wafer 26 matches the determined direction, and the specific electrode on the chip is adjusted. This refers to adjusting the position offset. When the alignment of the contact electrode 38 and the alignment of the wafer 26 are accurately performed, the contact electrode 38 and the electrode of the chip on the wafer 26 can be moved in parallel.

  In coordinate measurement using image data, the resolution of one pixel of image data, the mounting angle of the camera that acquires the image data, and the coordinates of the center of the image data (optical axis position of the optical system) need to be calibrated with respect to the apparatus coordinate system. There is. When the contact electrode recognition optical system 22 and the measurement target element recognition optical system 32 are arranged to face each other, the coordinates of the image data center of the contact electrode recognition optical system 22 and the image data of the measurement target element recognition optical system 32 are displayed. The problem is how to calibrate the relative relationship with the central coordinate in the apparatus coordinate system.

  In the probe apparatus according to the embodiment of the present invention, using the real image of the projection optical system of the specific pattern provided in the measurement target element recognition optical system 32, the position of the specific feature point of the specific pattern is measured. By measuring the image with the system 32 and the contact electrode recognition optical system 22, the relative relationship between the coordinates of the image data center of the measurement target element recognition optical system 32 and the coordinates of the image data center of the contact electrode recognition optical system 22 is calibrated. To do.

  That is, a two-dimensional pattern real image forming step for forming the real image 60 of the relative coordinate calibration two-dimensional pattern is executed by the projection optical system 42, and the measurement target element recognition optical system 32 captures the image data of the real image 60 of the two-dimensional pattern. The first optical system image data acquisition step is executed, and the second optical system image data acquisition step for capturing the image data of the real image 60 of the two-dimensional pattern by the contact electrode recognition optical system 22 is executed. Subsequently, from the image data acquired in the first optical system image data acquisition step and the image data acquired in the second optical system image data acquisition step, the coordinates of the image data center of the measurement target element recognition optical system 32 (optical axis) Position) and a calibration step for calibrating the relative coordinates between the coordinates (optical axis position) of the center of the image data of the contact electrode recognition optical system 22 is executed.

  When the four steps from the two-dimensional pattern real image forming step to the calibration step are executed in this way, the position measured on the image data in the wafer alignment and the contact electrode alignment is one common apparatus coordinate system. It is possible to convert to coordinate values at. When the wafer alignment result and the contact electrode alignment result are obtained in one common apparatus coordinate system, the wafer stage 16 can be controlled so that the wafer electrode and the contact electrode can be accurately overlapped. Prior to executing from the two-dimensional pattern real image formation step to the calibration step, the contact electrode recognition optical system 22 calibrates the resolution of one pixel of the image data and the mounting angle of the camera that acquires the image data. The optical system adjustment step and the measurement target element recognition optical system 32 calibrate the resolution of one pixel of image data, the mounting angle of the camera that acquires the image data, and the coordinates (optical axis position of the optical system) of the center of the image data. 1 It is necessary to carry out the optical system adjustment step. The processing contents of these steps will be described in detail in <Pre-alignment of electrical characteristic measurement step> described later.

  By controlling the temperature of the measurement stage (wafer stage 16), a test under a high temperature environment (measurement of electrical characteristics) and a test under a low temperature environment (measurement of electrical characteristics) are performed. When the temperature changes, the wafer 26 expands and contracts, and a part of the probe device also expands and contracts. When a part of the probe device expands and contracts, the position of each part of the probe device is also displaced (moved).

  The position of the optical axis of the measurement target element recognition optical system 32 and the position of the optical axis of the contact electrode recognition optical system 22 are likely to be displaced when there is a temperature change. Therefore, it is necessary not only to align the measurement target element for each wafer but also to align the contact electrode 38. According to the probe method of the present invention, the contact electrode 38 can be aligned at an arbitrary timing.

  When a part of the probe device expands and contracts with a change in temperature, the extent of the expansion and contraction changes little by little as time passes until equilibrium is reached. When chips having defective characteristics are continuously found during probing, it is conceivable that the elements to be measured are aligned while the temporal change before reaching the above-described thermal equilibrium is continued.

  In the implementation of the probe method by the probe apparatus, 1) the measurement stage is raised, 2) the electrical characteristics test of the chip, 3) the measurement stage is lowered, and 4) the XY movement process is repeated by the designated number of chips. When a chip having a defective characteristic is continuously found during the execution of the probe method by the probe apparatus, it is necessary to quickly find the cause. In the probe method of the embodiment of the present invention, relative coordinate calibration (accuracy) between the optical axis of the measurement target element recognition optical system 32 and the optical axis of the contact electrode recognition optical system 22 is performed as necessary even during the test operation. Confirmation) can be carried out.

<Projection optical system posture adjustment>
Optical axis of measurement target element recognition optical system 32, optical axis of contact electrode recognition optical system 22, optical axis of projection optical system 42 that projects a specific pattern, optical axis of coaxial illumination optical system 40 that illuminates the measurement target element, contact Inserting beam splitters 68, 70 and 72 to construct the optical axis of the coaxial illumination optical system 20 for illuminating the electrodes on the same optical axis line, the respective optical axes from the direction perpendicular to the optical axis of the imaging light beam. These optical axes are made to coincide with each other.

  In such a configuration, even if there is a slight inclination in the incorporation accuracy of the beam splitters 68, 70, and 72, the incident light and the emitted light of the imaging light beam that travels straight through the beam splitter only move in parallel. The imaging of the recognition optical system 32 or the contact electrode recognition optical system 22 is not a big problem.

  Although the optical axis of the coaxial illumination optical system is bent by 90 degrees, it is designed with a spot size sufficient to illuminate the entire field of view, and it is not required to be precise at the position where the illumination is applied, so general optical machining There is no problem if there is accuracy.

  On the other hand, when the optical axis of the projection optical system 42 is bent at 90 degrees by the beam splitter 72, even a slight inclination affects the optical axis, and the pattern projection image is displaced. Further, since the measurement target element recognition optical system 32 passes through the same objective lens (not shown) for projection and imaging, the measurement target element is placed at a position within a working distance (WD) range. Even if it is placed, a slight difference in the optical path length may occur in the processing accuracy of the mechanical mechanism parts, and the focal positions of the camera and the projection lens are not equal.

  Furthermore, in general, a commercially available camera has a problem that the pattern does not coincide with the imaging center even if the projection light is designed to be the center of the optical axis because the imaging center does not necessarily coincide with the optical axis center. There is.

  Therefore, when the projection optical system 42 is incorporated, the projection optical system posture position adjusting means is provided, and the rotation, position, and focal length of the optical axis of the imaging optical system 58 included in the projection optical system 42 can be adjusted. It is good to do.

  With reference to FIGS. 3A and 3B, the configuration of the projection optical system posture position adjustment unit and the projection optical system posture position adjustment step using this projection optical system posture position adjustment unit will be described. 3 (A) and 3 (B) are schematic structural views showing the configuration of the projection optical system posture position adjusting means, and FIG. 3 (A) shows the imaging optical system 58 provided with the projection optical system posture position adjusting means. FIG. 3 (B) is a diagram showing a cross section cut along a plane including the optical axis of the imaging optical system 58. FIG.

  The projection optical system posture position adjusting means includes: a projection optical system external lens barrel 50; a projection optical system internal lens barrel 51; and an internal lens barrel alignment screw 53-1 for performing alignment and fixing of the projection optical system internal lens barrel 51. 53-2, 53-3, a two-dimensional pattern printing glass mask slide fixing screw 54 is provided.

  The projection optical system internal lens barrel 51 is housed in the projection optical system external lens barrel 50, and the projection optical system internal lens barrel 51 is aligned by the internal lens barrel alignment screws 53-1, 53-2, and 53-3. Is done. The projection optical system external lens barrel 50 is integrated with the light source 55 as the projection optical system 42 (see FIG. 2B). The two-dimensional pattern printing glass mask slide fixing screw 54 is a screw for fixing the two-dimensional pattern printing glass mask 52 integrated with the imaging optical system 58 included in the projection optical system 42 at an optimum position.

The projection optical system posture position adjustment step is performed as follows, for example.
(1) The measurement target element imaging camera 28 is attached to the measurement target element recognition optical system 32, and is fixed at a focused height.
(2) Two-dimensional pattern printing glass at the position where the focal point is best by inserting / removing the projection optical system inner tube 51 with the two-dimensional pattern printing glass mask 52 attached while observing the picked-up image of the measuring object imaging camera 28 The mask slide fixing screw 54 is used for fixing.
(3) The projection optical system inner lens barrel 51 is moved using the inner lens barrel alignment screws 53-1, 53-2, 53-3 attached to the projection optical system outer lens barrel 50, and the two-dimensional pattern The real image 60 is adjusted and fixed so as to be reflected at a predetermined position on the imaging surface 39 of the measurement target element imaging camera 28.
By performing optical axis correction by repeating (2) to (3), it is possible to cause the real image 60 of the two-dimensional pattern to be reflected at a predetermined position on the imaging surface 39 of the measurement target element imaging camera 28.

  That is, by executing the above-described projection optical system posture position adjustment step, the real image 60 of the two-dimensional pattern formed by the projection optical system 42 is formed on the imaging surface 39 of the measurement target element imaging camera 28, and the like. The image is formed on the imaging surface 19 of the contact electrode imaging camera 18. Then, the posture and position of the projection optical system 42 are adjusted so that the center position of the two-dimensional pattern matches the center positions of the imaging surfaces of the imaging surfaces 39 and 19, respectively.

<Pre-alignment of electrical characteristics measurement step>
With reference to FIG. 4 to FIG. 8, specific steps until the electrical characteristic measurement step for measuring the electrical characteristics of the measurement target element is executed by the probe apparatus according to the embodiment of the present invention will be described.

  As shown in FIGS. 1 and 2, it is assumed that the measurement target element recognition optical system 32 is disposed at a position looking from above and the contact electrode recognition optical system 22 is disposed at a position looking from above. The measurement target element recognition optical system 32 is fixed to the contact electrode support 30. The contact electrode recognition optical system 22 is fixed to the support base 14. The support base 14 is structured so as to be movable in X, Y and Z with high accuracy. A θ moving stage 15 that rotates in the θ direction is mounted on the support base 14, and a wafer stage 16 is mounted thereon. It is assumed that the projection optical system 42 that forms the real image 60 of the two-dimensional pattern is attached to the measurement element recognition optical system 32.

  Referring to FIG. 4, the acquisition of image data used in the first optical system image data acquisition step and the first optical system adjustment step of acquiring image data of the real image 60 of the two-dimensional pattern by the measurement target element recognition optical system 32 explain.

  As a point whose coordinates are known in the apparatus coordinate system, a + (lattice) mark is placed on the wafer stage 16 so that an image can be accurately measured (for example, the center position of the wafer stage 16 is used as a reference point). When the wafer stage 16 is at the origin of the drive axes X, Y and Z of the apparatus, and the coordinates of the mark are (0, 0, 0) in the apparatus coordinate system, the wafer stage 16 moves and the drive axis is (X , Y, Z), the coordinates of the mark on the wafer stage 16 are (X, Y, Z). The imaging light source 41 is turned on so that the mark on the wafer stage 16 is positioned directly below the measurement target element recognition optical system 32 (the position where the mark is directly below the optical system in FIG. 4), and the image data To get. The Z direction is adjusted so that the imaging distance is up to the wafer stage 16. At this time, the coordinates of the mark are known points in the apparatus coordinate system. The acquired image data is used for calibration of the optical system in the first optical system adjustment step. After obtaining the image data, the imaging light source 41 is turned off.

  Subsequently, the wafer stage 16 is moved to a position where the mark does not enter the field of view (a position where the mark deviates from the field of view of the optical system in FIG. 4). When the two-dimensional pattern real image forming step for forming the real image 60 of the two-dimensional pattern is executed, the real image 60 of the two-dimensional pattern is formed on the wafer stage 16 that coincides with the imaging distance. Image data of the real image 60 of the two-dimensional pattern is acquired by the measurement target element imaging camera 28 of the measurement target element recognition optical system 32. That is, the first optical system image data acquisition step is executed.

  Referring to FIG. 5, the acquisition of image data used in the second optical system image data acquisition step and the second optical system adjustment step for acquiring the image data of the real image 60 of the two-dimensional pattern by the contact electrode recognition optical system 22 will be described. To do.

  The wafer stage 16 is moved, the contact electrode recognition optical system 22 and the measurement target element recognition optical system 32 are moved to the corresponding positions shown in FIG. Image data of the real image 60 of the pattern is acquired. That is, the second optical system image data acquisition step is executed. When the real image 60 of the two-dimensional pattern is captured by the contact electrode imaging camera 18, the vertical direction (Z direction) is moved and adjusted to the imaging distance of the contact electrode recognition optical system 22. When the image data of the real image 60 of the two-dimensional pattern is acquired by the contact electrode recognition optical system 22, the coordinates are stored in the apparatus coordinate system of the wafer stage 16 at that time.

  In order to calibrate the camera mounting angle of the contact electrode recognition optical system 22 in the second optical system adjustment step following the second optical system image data acquisition step, the contact electrode recognition optical system 22 is Image data used in the second optical system adjustment step is acquired by moving a distance of about 3 (moving the support base 14 to which the contact electrode recognition optical system 22 is fixed in the X-axis direction).

  When acquisition of the image data used in the second optical system image data acquisition step and the second optical system adjustment step is completed, the second optical system adjustment step and then the first optical system adjustment step are executed. In the second optical system adjustment step, the resolution of one pixel of image data of the contact electrode recognition optical system 22 is calibrated, and then the camera mounting angle of the contact electrode recognition optical system 22 is calibrated.

  Since the image data used to calibrate the resolution of one pixel of image data in the second optical system adjustment step is the two-dimensional lattice pattern shown in FIG. 2 (A), the region surrounding one lattice is an image model. If the entire captured two-dimensional lattice pattern is pattern-matched, the coordinates of each lattice point on the image data are searched. The resolution of one pixel of the image data is calibrated by comparing the lattice interval on the searched image data (average lattice interval when a large number of lattices are imaged) with the lattice interval of a known two-dimensional lattice pattern. Is done. At the same time, the tilt angle with respect to the image coordinate system of the two-dimensional lattice point array is also obtained.

  The image data used to calibrate the camera mounting angle in the second optical system adjustment step also uses the image data acquired in the second optical system image data acquisition step. The image data in the second optical system adjustment step and the image data acquired in the second optical system image data acquisition step are those in which the visual field has moved in the X direction by about 2/3. One of the two-dimensional grid patterns captured in both images is selected (the same point is selected from two image data), and a vector connecting these two points is created. The direction of this vector indicates the direction of the device X axis. The direction angle of the vector with respect to the X axis of the image is the camera mounting angle of the contact electrode recognition optical system 22. When the second optical system adjustment step is completed, the contact electrode recognition optical system 22 has calibrated the resolution of one pixel of image data and the camera mounting angle of the contact electrode recognition optical system 22.

  When the calibration of the resolution of one pixel of image data and the camera mounting angle in the second optical system adjustment step is completed, the first optical system adjustment step is performed. In the first optical system adjustment step, the resolution of one pixel of the image data of the measurement target element recognition optical system 32 is calibrated from the two-dimensional lattice pattern shown in FIG. 2A acquired in the first optical system image data acquisition step. . At the same time, the inclination angle with respect to the image coordinate system of the two-dimensional lattice point array is also obtained. The measurement target element recognition optical system 32 is fixed to the contact electrode support base 30, and the contact electrode recognition optical system 22 is fixed to the support base 14 that can move in the X, Y, and Z directions. The angles are not independent, and one can be considered to have rotated a fixed angle with respect to the other.

  Since the measurement target element recognition optical system 32 and the contact electrode recognition optical system 22 capture the same lattice pattern, the inclination angle of the two-dimensional array of lattice points of the measurement target element recognition optical system 32 and the contact electrode recognition optical system If the difference from the inclination angle of the two-dimensional array of 22 grid points is obtained, the camera attachment angle of the measurement target element recognition optical system 32 is calibrated from the camera attachment angle of the contact electrode recognition optical system 22. In the probe method of the present invention, if one of the measurement target element recognition optical system 32 or the contact electrode recognition optical system 22 is calibrated for the camera mounting angle, the other is calculated using the inclination angle of the lattice point two-dimensional array. Is done.

  After the resolution of one pixel of the image data of the measurement target element recognition optical system 32 and the camera mounting angle of the measurement target element recognition optical system 32 are calibrated, the coordinates of the center of the image data of the measurement target element recognition optical system 32 ( (Optical axis position of the optical system) is calibrated. For the coordinate calibration at the center of the image data of the measurement target element recognition optical system 32, the one acquired as the image data used in the first optical system adjustment step is used. In this image, a + (lattice) mark is set on the wafer stage 16, and the coordinates of the mark are known in the apparatus coordinate system. The position of the mark is accurately measured on the image data. When one point on the image data, the image coordinates of that point and the coordinates in the device coordinate system are obtained, and the resolution of one pixel of the image data and the mounting angle of the camera are calibrated, The coordinates of the point in the device coordinate system are easily calculated. This coordinate is the coordinate at the center of the image data of the measurement target element recognition optical system 32.

  By the first optical system adjustment step, the resolution of one pixel of the image data of the measurement target element recognition optical system 32, the camera mounting angle of the measurement target element recognition optical system 32, and the center of the image data of the measurement target element recognition optical system 32 The coordinates are calibrated. In the second optical system adjustment step, the resolution of one pixel of image data of the contact electrode recognition optical system 22 and the camera mounting angle of the contact electrode recognition optical system 22 are calibrated. At this stage, the coordinates of the center of the image data of the contact electrode recognition optical system 22 are not calibrated. The coordinates of the center of the image data of the contact electrode recognition optical system 22 cannot be obtained unless the calibration step is executed.

  Therefore, the coordinates (optical axis) of the center of the image data of the measurement target element recognition optical system 32 from the image data acquired in the first optical system image data acquisition step and the image data acquired in the second optical system image data acquisition step. Position) and a calibration step for calibrating the relative coordinates between the center of the image data of the contact electrode recognition optical system 22 (optical axis position).

  The image data acquired in the first optical system image data acquisition step is an image of the two-dimensional lattice pattern shown in FIG. The position of the feature point (specific lattice point) of the two-dimensional lattice pattern can accurately measure the image coordinates on the image data of the measurement target element recognition optical system 32. Since all necessary parameters have already been calibrated in the measurement target element recognition optical system 32, when image coordinates are measured, the points can be converted to coordinates in the apparatus coordinate system. That is, the position of the feature point (specific lattice point) of the two-dimensional lattice pattern can be obtained as coordinates in the apparatus coordinate system.

  The image data acquired in the second optical system image data acquisition step is also an image of the two-dimensional lattice pattern shown in FIG. 2 (A). Also on the image data of the contact electrode recognition optical system 22, the image coordinates of the same point, that is, the feature point of the two-dimensional lattice pattern are measured. The coordinates of the feature points of the two-dimensional lattice pattern in the apparatus coordinate system have already been obtained by the measurement target element recognition optical system 32. Since the image coordinates of the point and the coordinates in the device coordinate system were obtained at one point on the image data, the image data acquired in the second optical system image data acquisition step (image of the contact electrode recognition optical system 22) The coordinates of the center of the image data are also obtained.

  The contact electrode recognition optical system 22 is fixed to a support base 14 that is movable in the X, Y, and Z directions (the wafer stage 16 is also fixed to the support base 14 via a θ moving stage 15). When acquiring image data in the second optical system image data acquisition step, since the coordinates in the apparatus coordinate system of the wafer stage 16 at that time are stored, the image acquired in the second optical system image data acquisition step When the coordinates of the image data center of the data are obtained, the relative coordinates between the wafer stage 16 (the reference point is the mark position) and the image center point of the contact electrode recognition optical system 22 are also obtained. If the relative coordinates between the wafer stage 16 (the reference point is the mark position) and the center of the image of the contact electrode recognition optical system 22 are calibrated, the contact electrode recognition optics can be used even if the wafer stage 16 is moved to an arbitrary position. The coordinates of the center of the image data of the system 22 can be known.

  As described above, the position of the feature point of the two-dimensional grid pattern measured by the measurement target element recognition optical system 32 and the contact electrode recognition optical system 22 is the same in the apparatus coordinate system by the calibration step. Then, the coordinates of the center of the image data of the contact electrode recognition optical system 22 are calibrated. When the calibration step is completed, not only the coordinates of the center of the image data of the measurement target element recognition optical system 32 but also the coordinates of the center of the image data of the contact electrode recognition optical system 22 are associated with one reference point.

  When the coordinates of the image data center of the measurement target element recognition optical system 32 and the coordinates of the image data center of the contact electrode recognition optical system 22 are calibrated in the apparatus coordinate system, the measurement target element recognition optical system 32 performs image processing. The position of the wafer 26 obtained by pattern matching (the position of the chip on the wafer) is converted into coordinates in the apparatus coordinate system, and the contact electrode 38 obtained by pattern matching by image processing in the contact electrode recognition optical system 22 is converted. The position is also converted to coordinates in the device coordinate system. The electrode of the chip on the wafer 26 converted into one apparatus coordinate system and the contact electrode 38 can be overlapped with high accuracy.

  When the calibration step is completed, the coordinates of the feature points of the two-dimensional lattice pattern are known, and the coordinate values are stored in a nonvolatile memory. The projection optical system 42 that forms the real image 60 of the two-dimensional pattern is mounted on the measurement target element recognition optical system 32, and the measurement target element recognition optical system 32 is fixed to the contact electrode support base 30, so that the measurement target can be simplified. When measuring the deviation between the optical axis of the element recognition optical system 32 and the optical axis of the contact electrode recognition optical system 22, a second optical system image data acquisition step is executed, and then the image of the contact electrode recognition optical system 22 is obtained. This can be done simply by measuring the coordinates of the feature points of the two-dimensional grid pattern using data.

  The probe apparatus according to the embodiment of the present invention includes a projection optical system 42 having a specific pattern, a two-dimensional pattern real image forming step, a first optical system image data acquisition step, a second optical system image data acquisition step, calibration All steps of the step, the first optical system adjustment step, and the second optical system adjustment step can be carried out without any special operation, so the calibration to determine the coordinates of the device is automatically and consistently performed. Can be done.

  In particular, when a deviation occurs between the optical axis of the measurement target element recognition optical system 32 and the optical axis of the contact electrode recognition optical system 22, and the amount of deviation is unacceptable, calibration is automatically performed. be able to.

  The projected real image 60 of the two-dimensional pattern is measured with high accuracy in advance. In the present invention, since the measurement target element recognition optical system 32 includes the projection optical system 42, before the measurement target element recognition optical system 32 is incorporated into the apparatus, a two-dimensional pattern aerial image (FIG. 2) The lattice spacing of the two-dimensional lattice pattern shown in (A)) is measured with sufficient accuracy.

  As shown in FIG. 5, since the measurement target element recognition optical system 32 cannot obtain the projected real image 60 of the two-dimensional pattern at the opposed positions, the lattice points of the lattice image that is the two-dimensional pattern are used during calibration. Take action to save the coordinates of. In this way, only by measuring the coordinates of the lattice point of the lattice that is a two-dimensional pattern only with the contact electrode recognition optical system 22, the optical axis of the measurement target element recognition optical system 32 and the light of the contact electrode recognition optical system 22 are measured. The relative coordinates with the axis can be calibrated.

  FIG. 6 is a diagram illustrating a state in which the contact electrode 38 is aligned by the contact electrode recognition optical system 22, and FIG. 7 is a diagram illustrating a state in which the wafer 26 is aligned by the measurement target element recognition optical system 32. FIG. 8 shows an electrical characteristic measurement step of measuring electrical characteristics of chips formed on the wafer by bringing the electrode pad on the surface of the wafer 26 and the contact electrode 38 into contact with each other while sequentially moving relative to each other. It is a figure where it uses for description.

  The Z-direction position (height) shown in FIG. 5 for calibrating the relative relationship between the optical axis position of the measurement target element recognition optical system 32 and the optical axis position of the contact electrode recognition optical system 22, and the alignment shown in FIGS. The Z direction position (height) for measuring the electrical characteristics in FIG. 8 is different. In the probe apparatus according to the embodiment of the present invention, after alignment, the contact electrode 38 is brought into contact with the electrode pad on the surface of the wafer 26, and the trace of the contact electrode 38 remaining on the electrode pad is measured. A parameter control function for adjusting the position may be provided.

  In general, the probe apparatus is tested in a high temperature environment or a low temperature environment. In the probe apparatus according to the embodiment of the present invention, the relative coordinates between the optical axis of the measurement target element recognition optical system 32 and the optical axis of the contact electrode recognition optical system 22 are calibrated using the real image 60 of the two-dimensional pattern. Therefore, unlike the case where a target pattern installed around the wafer stage 16 is used, there is no influence due to a change in test temperature.

  If a specific pattern such as a two-dimensional lattice image is used, the pattern can be accurately detected by autofocus even when displacement occurs in the Z direction under a high temperature environment and a low temperature environment. It is also effective to employ a structure that insulates the optical system when the temperature change is extremely large.

  By controlling the temperature of the wafer stage 16, a test under a high temperature environment and a test under a low temperature environment are carried out. However, the wafer 26 expands and contracts due to the temperature change, and a part of the probe device (such as a support base) also extends. It expands and contracts. The magnitude of the displacement of each part of the probe device and the displacement direction depend on the mechanical mechanism. The position of the optical axis of the measurement target element recognition optical system 32 and the position of the optical axis of the contact electrode recognition optical system 22 are likely to be displaced when there is a temperature change.

  The probe device according to the embodiment of the present invention has a function of accurately calibrating the optical axis of the measurement target element recognition optical system 32 and the optical axis of the contact electrode recognition optical system 22 whenever necessary. It is. Further, in the method of the present invention, the measurement target element recognition optical system 32 and the contact electrode recognition optical system can be obtained by moving the measurement target element recognition optical system 32 and the contact electrode recognition optical system 22 to the opposed positions shown in FIG. The relative coordinates with 22 can be calibrated easily and accurately.

10: XYZ moving stage support
12: XYZ moving stage
14: Support stand
15: θ movement stage
16: Wafer stage
18: Contact electrode imaging camera
19, 39: Imaging surface
20, 40: Coaxial illumination optical system
21, 41, 55: Light source
22: Contact electrode recognition optical system
26: Wafer
28: Measurement target imaging camera
30: Contact electrode support
32: Measurement target element recognition optical system
36: Contact electrode fixing base
38: Contact electrode
42: Projection optics
50: Projection optics external lens barrel
51: Projection optics internal lens barrel
52: 2D pattern printing glass mask
53-1, 53-2, 53-3: Internal barrel alignment screw
54: 2D pattern printing glass mask slide fixing screw
58: Imaging optics
60: Real image of a two-dimensional pattern
62, 64: Luminous flux
66: Opaque planar object
68, 70, 72: Beam splitter

Claims (8)

A probe method for evaluating an electrical characteristic of a measurement target element by bringing a contact electrode into contact with the electrode of the measurement target element having an electrode,
A two-dimensional pattern real image forming step for forming a real image of the relative coordinate calibration two-dimensional pattern by the projection optical system;
A first optical system image data acquisition step for capturing real image data of the two-dimensional pattern by the first optical system;
A second optical system image data acquisition step for capturing real image data of the two-dimensional pattern by the second optical system;
Based on the image data of the real image of the two-dimensional pattern respectively acquired by the first and second optical systems, the first optical system position coordinates of the image data acquired by the first optical system and the second optical system And a calibration step for calibrating the relative relationship between the acquired image data and the second optical system position coordinates. In the first optical system image data acquisition step, the first optical system is an optical system for recognizing the electrodes, and is an imaging optical system including a camera for image processing, whereby the projection optics Capturing real image data of the two-dimensional pattern formed in the plane of an opaque planar object placed at the imaging position of the system;
In the second optical system image data acquisition step, the second optical system is an optical system for recognizing the contact electrodes and is an imaging optical system including a camera for image processing, thereby It is a step of capturing real image data of a dimensional pattern,
The image data of the real image of the two-dimensional pattern acquired by the first and second optical systems, respectively, the resolution of the image data of the first and second optical systems, and the first and second optical systems, respectively. First and second optical system adjustment steps for adjusting the camera mounting angle and performing focusing of the first and second optical systems, respectively,
2. The electrical characteristic measurement step of measuring an electrical characteristic of the measurement target element by bringing the measurement target element and the contact electrode into contact with each other while sequentially moving relative to each other. The described probe method. In the first optical system image data acquisition step, the first optical system is an optical system for recognizing the contact electrode and is an imaging optical system including a camera for image processing. It is a step of capturing real image data of a dimensional pattern,
In the second optical system image data acquisition step, the second optical system is an optical system for recognizing the electrode, and is an imaging optical system including a camera for image processing, whereby the projection optics Capturing real image data of the two-dimensional pattern formed in the plane of an opaque planar object placed at the imaging position of the system;
The image data of the real image of the two-dimensional pattern acquired by the first and second optical systems, respectively, the resolution of the image data of the first and second optical systems, and the first and second optical systems, respectively. First and second optical system adjustment steps for adjusting the camera mounting angle and performing focusing of the first and second optical systems, respectively,
2. The electrical characteristic measurement step of measuring an electrical characteristic of the measurement target element by bringing the measurement target element and the contact electrode into contact with each other while sequentially moving relative to each other. The described probe method. The real image of the two-dimensional pattern formed by the projection optical system is imaged on the imaging surfaces of the first and second optical system cameras by the first and second optical system cameras, and the 2 The posture and position of the projection optical system so that the center position of the dimensional pattern is imaged on the respective imaging surfaces of the cameras of the first and second optical systems so as to coincide with the center position of the respective imaging surfaces. 4. The probe method according to claim 1, further comprising a projection optical system posture position adjusting step for adjusting the position. A probe apparatus for evaluating the electrical characteristics of the measurement target element by bringing a contact electrode into contact with the electrode of the measurement target element having an electrode,
A first optical system including a projection optical system for projecting a two-dimensional pattern for calibration, and a second optical system disposed so as to face the first optical system,
The image data of the real image of the two-dimensional pattern formed by projection is captured by the first and second optical systems, respectively, and acquired by the first optical system based on the image data of the real image of the two-dimensional pattern. A probe apparatus for calibrating a relative relationship between first optical system position coordinates of image data and second optical system position coordinates of image data acquired by the second optical system. The first optical system is an optical system for recognizing the electrode, and is an imaging optical system including a camera for image processing, and is an opaque planar object placed at an imaging position of the projection optical system Capturing real image data of the two-dimensional pattern formed on the plane of
The second optical system is an optical system for recognizing the contact electrode and an imaging optical system including a camera for image processing, and is a real image of the two-dimensional pattern formed by the projection optical system. Import image data,
The image data of the real image of the two-dimensional pattern acquired by the first and second optical systems, respectively, the resolution of the image data of the first and second optical systems, and the first and second optical systems, respectively. The first and second optical systems can be focused by adjusting the camera mounting angle.
6. The probe apparatus according to claim 5, wherein the measurement target element and the contact electrode are configured to contact each other while sequentially moving relative to each other to measure electrical characteristics of the measurement target element. . The first optical system is an optical system for recognizing the contact electrode and is an imaging optical system including a camera for image processing, and is a real image of the two-dimensional pattern formed by the projection optical system Image data of
The second optical system is an optical system for recognizing the electrodes, and is an imaging optical system including a camera for image processing, and is an opaque planar object placed at an image forming position of the projection optical system Capturing real image data of the two-dimensional pattern formed on the plane of
The image data of the real image of the two-dimensional pattern acquired by the first and second optical systems, respectively, the resolution of the image data of the first and second optical systems, and the first and second optical systems, respectively. The first and second optical systems can be focused by adjusting the camera mounting angle.
6. The probe apparatus according to claim 5, wherein the measurement target element and the contact electrode are configured to contact each other while sequentially moving relative to each other to measure electrical characteristics of the measurement target element. . The real image of the two-dimensional pattern formed by the projection optical system is imaged on the imaging surfaces of the first and second optical system cameras by the first and second optical system cameras, and the 2 The posture and position of the projection optical system so that the center position of the dimensional pattern is imaged on the respective imaging surfaces of the cameras of the first and second optical systems so as to coincide with the center position of the respective imaging surfaces. 8. The probe apparatus according to claim 5, further comprising a projection optical system posture position adjusting means for adjusting the angle.

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