JP5539033B2 - Semiconductor measuring apparatus and measuring method - Google Patents

Description

  The present invention relates to a semiconductor measuring device and a measuring method for testing electrical characteristics of a semiconductor element, in particular, a power semiconductor element such as a power transistor, and a coaxial probe needle unit used in those devices or methods.

  Power semiconductor elements such as power transistors, rectifier diodes, thyristors, and power MOSFETs are used in a wide range of fields including electric power generation such as power generation and power transmission, electric railways, automobiles, and household appliances. Many measuring devices have been proposed to test the mechanical characteristics.

  For example, Patent Document 1 provides a wafer support frame that supports a wafer on which a semiconductor element is formed between a back electrode needle that can move up and down and an upper electrode needle, and the wafer support frame is a forcing terminal and a back electrode. Is a sensing device, and a measuring device is disclosed in which a Kelvin contact is made on the back side surface of a test semiconductor element. In Patent Document 2, the outer edge of the wafer on which the test semiconductor element is formed is supported by a wafer holder, and the contact area of the probe that contacts from the back surface of the wafer is made equal to the area of the back surface of the test semiconductor element. There has been proposed a measuring apparatus that detects a defect on the back surface of an element. Furthermore, in Patent Document 3, by providing a control means for controlling the movable amount of the probe that comes into contact with the semiconductor wafer from above and below, the probe can be brought into contact with an appropriate pressing force even on a thin wafer. A test apparatus is disclosed. However, in these conventional measuring apparatuses or test apparatuses, the wafer is supported at its outer edge by a wafer support frame or a wafer holder. Therefore, when the thickness of the wafer becomes thin, the wafer itself bends, and the probe needle and the semiconductor element. There is a problem that accurate contact cannot be made with the other electrodes.

  On the other hand, in Patent Document 4 and Patent Document 5, a wafer support base called a stage is brought into contact with the entire back surface of the wafer to support the wafer, and a measuring apparatus that prevents bending even with a thin wafer and Each test apparatus is disclosed. In these measurement apparatuses or test apparatuses, the contact between the back electrode of the wafer and the probe needle is such that a plurality of insertion holes are formed in the stage, and at the time of measurement, an insertion hole located almost directly below the test semiconductor element. The probe needle is moved to the bottom and the probe needle is raised at that position to bring the probe needle into contact with the back electrode of the wafer (Patent Document 4), or in each of a plurality of insertion holes provided on the stage A contact pin is inserted in advance, and at the time of measurement, the contact piece is moved to a position below the contact pin located almost directly below the test semiconductor element, and the contact piece is lifted at that position to push up the contact pin immediately above the wafer. It is made to contact with the back electrode of this (patent document 5). Thereby, in these measuring apparatuses or test apparatuses, the measurement current flows in the thickness direction of the wafer back electrode, and the potential difference from the back of the test semiconductor element to the contact point with the probe needle is superimposed on the measurement value as a resistance component. It is said that it is possible to measure with high accuracy.

  However, in the measurement apparatus and the test apparatus disclosed in Patent Document 4 and Patent Document 5, it is necessary to bring the probe needle or the contact pin into contact with the back electrode at a position almost directly below the test semiconductor element. Even if the wafer is switched to a new wafer or on the same wafer to be tested, when the test semiconductor element is switched to the next semiconductor element, the probe needle or contact piece for measurement is adjusted accordingly. It is necessary to move it below the insertion hole or contact pin located directly below. Therefore, in these conventional measuring devices and test devices, a device for moving the probe needle or the contact piece to just below the test semiconductor element is required, and the measurement time becomes longer by the time required for the movement. There is a disadvantage that the efficiency is lowered.

Japanese Utility Model Publication No. 4-14933 JP 2000-114325 A JP 2003-332395 A Japanese Utility Model Publication No. 3-45643 JP 2004-311799 A

  The present invention was made to eliminate the disadvantages and disadvantages of the conventional semiconductor measuring apparatus described above, and can support a test target wafer having a small thickness without bending, and the test target wafer can be switched to a new wafer. Or a semiconductor measuring apparatus and a measuring method that do not require the probe needle that contacts the back electrode of the wafer to be moved directly below the semiconductor element at the measurement position even when the semiconductor element to be measured on the same test target wafer is switched. An object of the present invention is to provide a coaxial probe needle unit used therefor.

  As a result of intensive studies to solve the above problems, the present inventors have held a plurality of probe needles arranged in a matrix form on a wafer chuck having a support surface for supporting a wafer to be tested, and performed measurement. Sometimes, a plurality of probe needles arranged in a matrix are non-selectively brought into contact with the back electrode of the wafer, and a probe needle positioned almost directly below the semiconductor element to be tested is selected, and the probe needle is used as a tester device. By electrically connecting, even when the wafer to be tested is switched or when the test semiconductor element is switched to the next semiconductor element, there is no need to mechanically move the probe needle to just below the test semiconductor element, It is always possible to test the electrical characteristics of the semiconductor element with high measurement accuracy by bringing the probe needle into contact with the back electrode almost directly below the test semiconductor element. And completed the present invention have found that the kill.

  That is, the present invention is a semiconductor measuring apparatus for testing the characteristics of a semiconductor element by contacting a probe needle to each of a plurality of semiconductor elements formed on a wafer and a back electrode of the wafer. A wafer chuck having a support surface for supporting a target wafer; a moving mechanism for moving the wafer chuck in a vertical direction and a horizontal direction relative to an upper probe needle located above the wafer chuck; A plurality of lower probe needles that are in contact with the back electrode of the wafer to be tested and are held in the wafer chuck and arranged in a matrix in the vertical and horizontal directions within the support surface; A tester device electrically connected and electrically connected to each of the plurality of lower probe needles via a selection switch; The above-described problem is solved by providing a semiconductor measurement device having a switching device that switches the selection switch so that a lower probe needle corresponding to a test semiconductor element is electrically connected to the tester device To do.

  In a preferred aspect of the semiconductor measuring apparatus of the present invention, the switching device includes information on the size and position of each semiconductor element on the wafer to be tested and / or information on the size and position of the electrode of each semiconductor element, Based on information on the positions of the plurality of lower probe needles held by the wafer chuck and information on deviation from a reference position of the wafer to be tested supported on the support surface of the wafer chuck, the semiconductor on the wafer to be tested Corresponding to the semiconductor element at the measurement position based on the correspondence between each element and means for obtaining the correspondence between the lower probe needle to be electrically connected to the tester device when measuring each semiconductor element Means for switching the selection switch so that the lower probe needle is electrically connected to the tester device.

  When the switching device includes the above-described means, when the wafer to be tested is supported on the wafer chuck, each of the plurality of semiconductor elements formed on the wafer to be tested and the lower probe needle Therefore, even when the test semiconductor elements are successively switched on the wafer based on the correspondence, the corresponding lower probe needle is selected each time, and the tester device and the electrical Can be connected. Information about which semiconductor element is currently at the measurement position and which semiconductor element is next moved to the measurement position can be obtained from, for example, a control device built in the semiconductor measurement apparatus.

  In a preferred aspect of the semiconductor measuring apparatus of the present invention, the wafer chuck includes a chuck top having a support surface that supports the wafer to be tested, and a chuck body that holds a plurality of lower probe needles. The surface is provided with a through-hole through which at least the upper tips of the plurality of lower probe needles are slidably slidable, and a suction groove for adsorbing and supporting the wafer under test by negative pressure. The probe needle has elastic means for urging each lower probe needle in the direction of the wafer under test supported on the support surface, and the chuck top is an upper tip of the plurality of lower probe needles However, with respect to the chuck body between the measurement position positioned above the support surface and the suction position positioned below the support surface in an unloaded state. And it is rotatably supported.

  When the wafer chuck is configured as described above, when the wafer to be tested is sucked and supported by the chuck top, first, the chuck top is moved to the sucking position, and the upper tip of the lower probe needle is supported by the chuck top. It can be positioned below the surface so as not to interfere with the adsorption support of the wafer under test. After the wafer to be tested is once adsorbed and supported on the support surface of the chuck top, the chuck top is moved to the measurement position, and the back electrode of the wafer to be tested supported on the chuck top and a plurality of lower probe needles Since the lower probe needle is only urged upward by the elastic means even if it is brought into contact, the upper tip of the lower probe needle moves downward while contacting the back electrode of the wafer under test, and the wafer under test The adsorption support is not destroyed.

  In the semiconductor measuring apparatus of the present invention, it is desirable that the lower probe needle has a coaxial structure having a conductive core wire and a conductive outer skin disposed coaxially with the core wire. When the lower probe needle has such a coaxial structure, the measurement signal can be transmitted to the tester device more accurately, so that highly accurate measurement is possible. In addition, it is desirable to provide heating means on the support surface of the wafer chuck so that the temperature environment during measurement is variable.

  Further, the present invention is a semiconductor measurement method for testing characteristics of a semiconductor element by contacting a probe needle with each of a plurality of semiconductor elements formed on a wafer and a back electrode of the wafer, A step of supporting a wafer to be tested on a wafer chuck having a support surface for supporting the target wafer; arranged on the back surface electrode of the wafer to be tested supported on the wafer chuck in a matrix in the vertical and horizontal directions within the support surface A step of bringing a plurality of lower probe needles into contact with each other; a step of moving a semiconductor element to be measured to a measurement position by moving the wafer chuck in a horizontal direction relative to an upper probe needle located above the wafer chuck Selecting a lower probe needle corresponding to the semiconductor element moved to the measurement position from the plurality of lower probe needles; A semiconductor measuring method comprising: a step of electrically connecting the wafer chuck to a tester device; and a step of moving the wafer chuck in a vertical direction relative to the upper probe needle to bring the electrode of the semiconductor element to be tested into contact with the upper probe needle. By providing this, the above-mentioned problems are solved.

  In a preferred aspect of the semiconductor measurement method of the present invention, the step of selecting the lower probe needle corresponding to the semiconductor element moved to the measurement position from the plurality of lower probe needles is the size of each semiconductor element on the wafer to be tested. Information on height and position and / or information on size and position of electrodes of each semiconductor element, information on positions of the plurality of lower probe needles held on the wafer chuck, and support on the support surface of the wafer chuck Correspondence between each semiconductor element on the wafer to be tested and the lower probe needle to be electrically connected to the tester device at the time of measuring each semiconductor element based on information on the deviation from the reference position of the wafer to be tested A step of obtaining a relationship; a semiconductor element moved to the measurement position based on the information about the semiconductor element moved to the measurement position and the correspondence It is intended to include the step of selecting a lower probe needle from the plurality of lower probe needles corresponding to.

  Furthermore, the present invention has a coaxial structure comprising a conductive core wire, an insulator that covers at least the upper end of the core wire and covers the outer periphery thereof, and a conductive sheath that covers the outer periphery of the insulator, By providing a coaxial probe needle unit comprising a stopper projecting radially in the vicinity of the upper part of the outer skin, and a coil spring fitted on the outer periphery of the outer skin, with the upper end abutted against the stopper. It solves the problem.

  Such a coaxial probe needle unit of the present invention is used in such a state that its lower part is inserted into a holding hole provided in the chuck body and its upper end is slidably passed through the through hole of the chuck top. . A step portion contracted in the radial direction is provided in the holding hole of the coaxial probe needle unit in the chuck body, and the lower end portion of the coil spring fitted on the outer periphery of the outer skin comes into contact with the step portion, thereby The coaxial probe needle unit of the invention is held by the chuck body while being biased in the direction of the test target wafer. The coaxial probe needle unit of the present invention preferably has an insulating sleeve on the outer periphery of the upper end of the core wire that is not covered with the insulator, and the insulating sleeve has a small friction coefficient, It is desirable that the core wire is made of a material that does not prevent the upper end of the core wire from sliding up and down in the through hole of the chuck top.

  In the semiconductor measuring device and the semiconductor measuring method of the present invention, the number of probe needles to be brought into contact with the electrodes of the individual semiconductor elements to be tested and the back electrode of the wafer is not particularly limited, and one probe needle is attached from above and below. It may be a single connection method that makes contact, or a Kelvin contact method that makes two probe needles contact each other from above and below. Further, the semiconductor elements targeted by the semiconductor measuring apparatus and the semiconductor measuring method of the present invention are formed on the wafer, and the probe needle is brought into contact with the electrode on each semiconductor element and the back electrode of the wafer. Any semiconductor device can be used as long as it can test electrical characteristics, but it is generally called a power device, such as a power transistor, a power MOSFET, a thyristor, a rectifier diode, an insulated gate bipolar transistor, or a triac. The semiconductor measuring apparatus and the semiconductor measuring method of the present invention are most effective.

  According to the semiconductor measuring apparatus and the semiconductor measuring method of the present invention, even when the semiconductor element at the measurement position is switched, it is not necessary to move the lower probe needle that contacts the back electrode of the wafer to the position immediately below it. Since no apparatus or moving process is required, the apparatus is simple and inexpensive, and no time is required for movement, there is an advantage that the measurement can be performed efficiently in a short measurement time.

  In addition, according to the semiconductor measuring apparatus and the semiconductor measuring method of the present invention, each of the plurality of lower probe needles arranged vertically and horizontally in a matrix form on the wafer support surface corresponds to each semiconductor element on the wafer to be tested. Since one, two, or more lower probe needles may be selected, the arrangement of the plurality of lower probe needles does not need to be a specific arrangement according to the wafer to be tested, and the number and arrangement of semiconductor elements vary. The wafer can be measured with a single semiconductor measuring apparatus, and has the advantage of high versatility.

  Furthermore, the semiconductor measuring apparatus and the semiconductor measuring method of the present invention provide the semiconductor device on the test target wafer and the tester at the time of measuring each semiconductor element based on the position information of each semiconductor element on the test target wafer. Means and process for obtaining a correspondence relationship between the apparatus and the lower probe needle to be electrically connected, and the lower probe needle corresponding to the semiconductor element to be measured is electrically connected to the tester device based on the correspondence relation. In the case where a means or a process for switching the selection switch is provided as described above, each semiconductor element is provided even when the wafer to be tested is switched or when semiconductor elements measured on the same wafer are sequentially switched. The corresponding lower probe needle can be automatically selected and electrically connected to the tester device, enabling efficient and quick measurement. An advantage that can be obtained.

  Further, the semiconductor device of the present invention includes a chuck top having a suction groove and supported so as to be movable between the measurement position and the suction position, and a lower probe needle biased by elastic means toward the test wafer. When it has, the advantage that the adsorption | suction support of the test object wafer can be performed smoothly is acquired.

  Furthermore, according to the coaxial probe needle unit of the present invention, the lower probe needle can be easily handled, can be easily mounted on the chuck body, and has a coaxial structure so that measurement signals can be transmitted to the tester device. Can be obtained with higher accuracy.

It is a side view which shows an example of the semiconductor measuring apparatus of this invention. It is a longitudinal cross-sectional view of a wafer chuck. It is a top view of a wafer chuck. It is a side view of a wafer chuck. It is a partial notch perspective view of a wafer chuck. It is the side view and side surface sectional drawing of a chuck top when it exists in an adsorption position. It is the side view and side surface sectional drawing of a chuck | zipper top when it exists in a measurement position. It is a perspective view of a coaxial probe needle unit. It is sectional drawing of a coaxial probe needle unit. It is a horizontal fragmentary sectional view of a chuck top. It is a conceptual diagram which shows the outline of an example of the measurement circuit in the semiconductor measuring device of this invention.

  Hereinafter, the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the illustrated one.

  FIG. 1 is a side view showing an example of a semiconductor measuring apparatus according to the present invention. In FIG. 1, reference numeral 1 denotes a semiconductor measuring apparatus according to the present invention. The semiconductor measuring apparatus 1 includes a wafer chuck 2, an XYZθ stage 3 on which the wafer chuck 2 is mounted, a tester device 4, and a switching device 5. ing. 6 is a chuck top which is one of the components of the wafer chuck 2, 7 is a probe card, 8 and 8 are probe needles attached to the probe card 7, and upper probe needles located above the wafer chuck 2. is there. As shown in FIG. 1, the tester device 4 is electrically connected to probe needles 8 and 8 via a probe card 7. Further, the wafer chuck 2 can be moved in the vertical direction and the horizontal direction with respect to the probe needles 8 and 8 by the XYZθ stage 3 and can also rotate around the Z axis. In the illustrated example, the probe needles 8 and 8 are attached to the probe card 7, but may be probe needles that are not attached to the probe card 7.

  FIG. 2 is a longitudinal sectional view of the wafer chuck 2 in FIG. As shown in the figure, the wafer chuck 2 includes a chuck top 6 and a chuck body 2a, and the chuck body 2a further includes an outer peripheral ring 2b, a housing 2c, and a chuck base 2d. The upper surface of the chuck top 6 is a support surface that supports the wafer to be tested.

  9, 9, 9... Are coaxial probe needle units, which constitute a lower probe needle. As shown in the figure, the coaxial probe needle units 9, 9, 9..., Which are lower probe needles, are inserted into the housing 2c, that is, the chuck body 2a by inserting the lower part thereof into a holding hole provided in the housing 2c. Is retained. Further, the core wires protruding from the lower ends of the coaxial probe needle units 9, 9, 9... Are collected in a state of being insulated from each other, and are connected to the external switching device 5 as a signal line 10. On the other hand, the upper portions of the coaxial probe needle units 9, 9, 9... Are inserted into a through hole provided in the chuck top 6 so as to be slidable in the vertical direction. It protrudes slightly above the upper surface of the top 6, that is, the support surface. Reference numeral 11 denotes a heater as a heating means built in the chuck top 6 and is connected to a power source (not shown).

  FIG. 3 is a plan view of the wafer chuck 2. 3, a large number of small circles 9 a represent the upper ends of the coaxial probe needle units 9, and the coaxial probe needle units 9, 9, 9... Are formed on the chuck top 6. It is in a state where the top end is seen from the through hole. As shown in FIG. 3, the coaxial probe needle units 9, 9, 9... Constituting the lower probe needle are arranged in a matrix in the vertical and horizontal directions within the support surface for supporting the test target wafer of the chuck top 6. Yes. In the example shown in the figure, the coaxial probe needle units 9, 9, 9... Constituting the lower probe needle are arranged at equal intervals in the vertical and horizontal directions, but the coaxial probe needle units 9, 9, 9. The arrangement interval of... May be different in the vertical and horizontal directions, and is not necessarily equal. Further, in the example shown in the figure, they are arranged in an aligned state in the vertical and horizontal directions, but they may be arranged in a zigzag pattern by alternately shifting the positions.

  A suction groove 12 is formed on the upper surface of the chuck top 6, that is, on the support surface. As shown in the drawing, the suction grooves 12 are arranged vertically and horizontally so as to substantially cover the support surface of the chuck top 6. If the suction grooves 12 communicate with each other and suck from one place, the suction force is passed through the suction grooves 12. It is designed to spread over the entire support surface. Reference numerals 13 and 13 denote lifting guide pins of the chuck top 6, and reference numerals 14, 14, and 14 denote cam followers. These functions will be described later.

  FIG. 4 is a side view of the wafer chuck 2. Reference numeral 15 is a cam groove, and 16 is a suction tube. The base side of the suction tube 16 is connected to the suction groove 12 described above, and the distal end side is connected to a suction device (not shown). When a suction device (not shown) is operated, the inside of the suction groove 12 is pulled to a negative pressure via the suction tube 16, and the chuck top 6 sucks the wafer to be tested placed on the support surface onto the support surface. I will support it.

  FIG. 5 is a partially cutaway perspective view of the wafer chuck 2. As shown in the figure, the coaxial probe needle units 9, 9, 9... Are held by the housing 2c with their lower portions inserted into the holding holes of the housing 2c, and their upper ends 9a, 9a, 9a,. Is inserted in the through holes 6 a, 6 a, 6 a... Provided in the chuck top 6 slidably and slightly protrudes from the upper surface of the chuck top 6. 2e is a fixing ring fixed to the housing 2c, 17 is a bearing interposed between the lower surface of the fixing ring 2e and the upper surface of the inner peripheral portion of the outer peripheral ring 2b, and 18 is a lower surface of the outer peripheral ring 2b. It is a sliding ring inserted between the upper surface of the outer peripheral part of the housing 2c. As shown in the figure, the cam follower 14 is fixed to the side surface of the chuck top 6.

  Next, the vertical movement mechanism of the chuck top 6 will be described with reference to FIGS. 6A and 6B show a state in which the chuck top 6 is at the suction position. At the suction position, the cam follower 14 fixed to the chuck top 6 is at the left end of the cam groove 15. As shown in the figure, the cam groove 15 is provided at a position where the left end is higher than the right end thereof. Therefore, when the cam follower 14 is positioned at the left end of the cam groove 15, the cam follower 14 At the same time, the chuck top 6 to which the cam follower 14 is fixed is also guided by the lifting guide pins 13 and is raised to the highest position. In this state, that is, when the chuck top 6 is in the suction position, the upper tips 9a, 9a, 9a... Of the coaxial probe needle units 9, 9, 9. It is located below the upper surface of the chuck top 6, that is, the support surface of the wafer to be tested.

  In this state, when the test target wafer W is placed on the support surface of the chuck top 6 and the suction grooves 12 and 12 are sucked to a negative pressure, the test target wafer W is sucked and supported on the support surface of the chuck top 6. It will be. When the chuck top 6 is in the suction position, the upper tips 9a, 9a, 9a, etc. of the coaxial probe needle units 9, 9, 9... Are located below the upper surface of the chuck top 6. Since it does not protrude on the support surface, the test target wafer W can be sucked and supported on the support surface without any trouble.

  7A and 7B show a state where the chuck top 6 is at the measurement position. That is, the outer peripheral ring 2b is in contact with the housing 2c through the sliding ring 18 and with the fixed ring 2e through the bearing 17 as shown in FIG. The outer ring 2b is rotated in the direction of the arrow shown in FIG. 6A and the cam follower 14 is moved to the right end of the cam groove 15 as shown in FIG. Accordingly, the chuck top 6 to which the cam follower 14 is fixed is guided by the lifting guide pins 13 and moves downward, and moves to the measurement position shown in FIG.

  When the chuck top 6 is in the measurement position, the upper tips 9a, 9a, 9a, ... of the coaxial probe needle units 9, 9, 9 ... are above the support surface of the chuck top 6 in the unloaded state. Will be located. However, when the wafer to be tested W is sucked and supported on the support surface of the chuck top 6, the coaxial probe needle units 9, 9, 9... Are moved while the chuck top 6 moves from the suction position to the measurement position. The top tips 9a, 9a, 9a... Are in contact with the back electrode of the wafer W to be tested, and are pushed downward while in contact. That is, the coaxial probe needle units 9, 9, 9... Are biased by elastic means in the direction of the test target wafer W supported on the support surface of the chuck top 6 as will be described later. Since the force to be set is weaker than the force to suck and support the test target wafer W on the support surface, the upper tips 9a, 9a, 9a... Come into contact with the back electrode of the test target wafer W, The coaxial probe needle units 9, 9, 9... Are pushed downward while their upper tips 9 a, 9 a, 9 a.

  FIG. 8 is a perspective view of the coaxial probe needle unit 9, and FIG. 9 is a cross-sectional view of the coaxial probe needle unit 9. As shown in the figure, the coaxial probe needle unit 9 is composed of a conductive core wire 9b, an insulator 9c that covers the outer periphery of the core wire 9b, leaving the upper end of the core wire 9b, and is coaxial with the core wire 9b and covers the outer periphery of the insulator 9c. It has a coaxial structure with a conductive outer covering 9d.

  As the material constituting the core wire 9b, any material can be used as long as it has conductivity and has a strength that does not easily wear and deform even when repeatedly contacted with the back electrode of the wafer W to be tested. For example, a conductive metal such as copper or tungsten can be used, and tungsten is preferably used. As the insulator 9c, any material may be used as long as it is an insulator. For example, an insulating resin such as polytetrafluoroethylene is preferably used. As a material constituting the outer skin 9d, any material may be used as long as it is a conductive material. However, it is preferable to use copper from the viewpoint of availability and high conductivity. .

  9f is a stopper protruding radially in the vicinity of the upper part of the outer skin 9d, 9e is a coil spring as elastic means fitted on the outer periphery of the outer skin 9d, and the upper end of the coil spring 9e is in contact with the lower surface of the stopper 9f. Yes. Although there is no special restriction | limiting in the material of the stopper 9f, For example, copper can be used. When the coaxial probe needle unit 9 is inserted into the holding hole of the housing 2c, the lower end portion of the coil spring 9e comes into contact with a stepped portion having a reduced radius formed near the lower portion of the holding hole, and the coaxial probe needle unit 9 Is biased upward, that is, in the direction of the test target wafer W that is sucked and supported by the chuck top 9. 9g is an insulating sleeve that covers the outer periphery of the tip portion of the core wire 9b that is not covered with the insulator 9c, and is an insulating material having a low friction coefficient, such as an insulating material such as polytetrafluoroethylene. Consists of resin.

  Since the coaxial probe needle unit 9 of the present invention is configured as described above, it has a simple structure and is easy to handle because it is integrated together. For example, as shown in FIG. It can be used as a lower probe needle in the semiconductor measuring device of the present invention by simply inserting it into the holding hole provided in 2c and allowing the upper part to pass through the through hole 6a provided in the chuck top 6. Further, since it has a coaxial structure, it has excellent advantages such as excellent measurement signal transmission and accurate measurement.

  FIG. 10 is a horizontal partial cross-sectional view showing a state in which the chuck top 6 is cut horizontally on the surface in which the heater 11 is built in the cross-sectional view of the wafer chuck 2 of FIG. As shown in the figure, the heater 11 is arranged over the almost front surface of the chuck top 6 by sewing between the coaxial probe needle units 9. Needless to say, the heater 11 is connected to a power source (not shown), and the temperature of the chuck top 6 can be raised by turning on the power source and operating the heater 11. The chuck top 6 incorporates a temperature sensor (not shown), and the temperature of the support surface of the chuck top 6 is adjusted by performing appropriate temperature control to test the characteristics of the semiconductor element at an arbitrary temperature. Can do. Instead of the heater 11 or together with the heater 11, a Peltier element may be disposed in the chuck top 6 to heat or cool the chuck top 6.

  FIG. 11 is a conceptual diagram showing an outline of an example of a measurement circuit in the semiconductor measurement apparatus of the present invention, and the chuck top 6 and the wafer chuck 2 are omitted. In FIG. 11, Wn is a test target wafer, and a plurality of semiconductor elements D (n, m), D (n, m + 1)... Are formed on the test target wafer Wn (in the figure, semiconductor elements are shown). D (n, m) and only two semiconductor elements D (n, m + 1) are shown). T is an electrode of each semiconductor element D (n, m), D (n, m + 1)..., And in the figure, the probe needles 8 and 8 which are upper probe needles are the semiconductor elements D (n, m). It is in contact with the electrode T.

  B is a back electrode of the wafer to be tested Wn. The back electrode B has a number of coaxial probe needle units 9 (p, q), 9 (p, q + 1), 9 (p, q + 2), 9 (p, q + 3) which are lower probe needles. ... are in contact (in the figure, coaxial probe needle units 9 (p, q), 9 (p, q + 1), 9 (p, q + 2), 9 (p, q + 3) 4 Only one). S (p, q), S (p, q + 1), S (p, q + 2), S (p, q + 3)... Are the respective coaxial probe needle units 9 (p, q), 9 (p, q + 1), 9 (p, q + 2), 9 (p, q + 3)... Switch, corresponding to each coaxial probe needle unit 9 (p, q), 9 (p, q + 1), 9 (p, q + 2), 9 (p, q + 3)... are changeover switches S (p, q), S (p, q + 1), S, respectively. It is connected to the tester device 4 via (p, q + 2), S (p, q + 3). 5 is a switching device, and each of the changeover switches S (p, q), S (p, q + 1), S (p, q + 2), S (p, q + 3). Has a function to turn off. In the drawing, two probe needles are in contact with one semiconductor element D (n, m) from above and below so as to make a Kelvin contact, but one semiconductor element D One (1) probe needle may be in contact with (n, m) from above and below, and in some cases, three or more probe needles may be in contact with each other.

  Next, the operation of the semiconductor measurement apparatus of the present invention and the semiconductor measurement method of the present invention will be described with reference to FIGS. First, the test target wafer Wn separately pre-aligned is placed on the support surface of the chuck top 6 at the suction position, and the support surface W is sucked to the negative pressure via the suction groove 12 to thereby test the wafer Wn. Is supported on the support surface of the wafer chuck 2, that is, the support surface of the chuck top 6. In this state, the XYZθ stage 3 is driven to perform accurate alignment between the test target wafer Wn and the probe card 7 or the probe needles 8 and 8. When the alignment is completed, the chuck top 6 is moved to the measurement position, and the coaxial probe needle units 9 (p, q + 1), 9 (p, q + 1), 9 (p, q + 2), 9 (p, q + 3) is brought into contact with the back electrode B of the wafer to be tested Wn.

  In this state, the XYZθ stage 3 is driven to move the wafer chuck 2 in the horizontal direction. For example, when the semiconductor element D (n, m) is a test semiconductor element, the electrode T is connected to the probe needle 8. , 8 is moved to the measurement position immediately below, and at the same time, the selector device S (p, q) and S (p, q + 1) are turned on by the switching device 5 to the semiconductor element D (n, m). Corresponding coaxial probe needle units 9 (p, q), 9 (p, q + 1) are connected to the tester device 5. When the wafer chuck 2 is raised in this state, the probe needles 8 and 8 and the electrode T of the test semiconductor element D (n, m) come into contact, and the measurement of the semiconductor element D (n, m) is performed. . When the measurement is completed, the wafer chuck 2 is lowered and the contact between the probe needles 8 and 8 and the electrode T of the test semiconductor element D (n, m) is released.

  When the measurement of the semiconductor element D (n, m) is completed and the next test semiconductor element is the semiconductor element D (n, m + 1), the XYZθ stage 3 is driven, and the wafer chuck 2 is moved to the semiconductor element. The electrode T of D (n, m + 1) is moved to the measurement position immediately below the probe needles 8 and 8, and the selector switch S (p, q), S (p, q + Instead of 1), the selection switches S (p, q + 2) and S (p, q + 3) are turned ON, and the coaxial probe needle unit 9 (p) corresponding to the semiconductor element D (n, m + 1) , q + 2) and 9 (p, q + 3) are connected to the tester device 5. When the wafer chuck 2 is raised in this state, the probe needles 8 and 8 and the electrode T of the test semiconductor element D (n, m + 1) are in contact with each other, and the measurement of the semiconductor element D (n, m + 1) is performed. It will be. By repeating this in sequence, each semiconductor element on the test target wafer Wn is measured, and when all of the measurement is completed, the suction support of the test target wafer Wn by the chuck top 6 is released, and the test target wafer Wn is moved outside. Take it out.

  As described above, according to the semiconductor measuring apparatus of the present invention, even when the semiconductor elements to be measured are sequentially switched, it is not necessary to move the coaxial probe needle unit 9 that is the lower probe needle just below the back surface electrode. Since only the selection switch S needs to be switched, the apparatus is simplified, and the time required for the movement of the lower probe needle is not required. Therefore, there are advantages that the measurement can be performed efficiently and quickly.

  The selection of the lower probe needle corresponding to the test semiconductor element is preferably performed automatically by the switching device 5 as follows. That is, a storage device (not shown) is attached to the semiconductor measurement device 1 or the switching device 5, and a coaxial probe needle unit 9 that is a plurality of lower probe needles held by the wafer chuck 2 of the semiconductor measurement device 1 is attached to the storage device. Information about the positions 9, 9... Is input and stored in advance, and specification information about each wafer to be tested, that is, the size of the wafer, the semiconductor element formed on the wafer, and so on. Information on the number, size, arrangement, etc. and / or information on the size, position, etc. of the electrodes of each semiconductor element formed on the wafer are input and stored via appropriate means prior to measurement. Let Further, the movement of the XYZθ stage 3 from the reference position obtained when accurate alignment with the probe card 7 or the probe needles 8 and 8 is performed on the wafer to be tested that is sucked and supported on the support surface of the chuck top 6. The amount is stored in the storage device as a displacement amount from the reference position of the wafer under test.

  Based on the information stored in these storage devices, the switching device 5 uses, for each of the semiconductor elements formed on the wafer to be tested, a coaxial probe that is closest to or directly below the formed electrode T. The needle unit 9 is indexed, and the determined coaxial probe needle unit 9 is made to correspond to each semiconductor element as a coaxial probe needle unit 9 to be electrically connected to the tester device 4 when measuring each semiconductor element. And stored as a correspondence between each semiconductor element and the coaxial probe needle unit. The index of the coaxial probe needle unit 9 that is directly below or closest to the electrode T that is formed is determined based on the size and position information about each semiconductor element and / or the electrode T that is formed on each semiconductor element. And the positional information of the plurality of coaxial probe needle units 9 held on the wafer chuck 2 and the amount of positional deviation from the reference position of the wafer under test obtained at the time of alignment. It can be carried out. When one coaxial probe needle unit 9 is brought into contact with the back electrode B, the one closest to the bottom of the electrode T, and when two coaxial probe needle units 9 are brought into contact with the back electrode B, The one closest to the electrode T and the one closest to the next may be selected as the lower probe needle to be connected to the tester device 4.

  When the new semiconductor element moves to a position immediately below the probe needles 8, 8, that is, to the measurement position based on the correspondence obtained as described above, the switching device 5 selects the coaxial probe needle unit 9 ( p, q) and 9 (r, s) are selected, and the corresponding selection switches S (p, q) and S (r, s) are turned ON. Information about which semiconductor element is at the measurement position can be obtained from a control device (not shown) incorporated in the semiconductor measurement device 1. The above correspondence between each semiconductor element D and the coaxial probe needle unit 9 may be obtained in advance for all formed semiconductor elements before the measurement of the test target wafer is started. You may make it obtain | require, whenever the test semiconductor element used as a measuring object switches.

  As described above, according to the semiconductor measuring apparatus and the semiconductor measuring method of the present invention, the lower probe needle electrically connected to the tester apparatus is switched by the selection switch even when the wafer to be tested and the semiconductor element to be measured are switched. This eliminates the need for a moving mechanism for moving the lower probe needle directly below the semiconductor element to be measured, and also eliminates the time required for the movement, making it possible to perform inexpensive and efficient measurement. In addition, according to the semiconductor measuring apparatus and the semiconductor measuring method of the present invention, even when various types of wafers having different sizes and numbers of semiconductor elements formed and different arrangements are to be tested, they are within the support surface of the chuck top. The lower probe needle can be used as the lower probe needle by selecting the one closer to the upper electrode of the semiconductor element to be measured from among the plurality of lower probe needles arranged in a matrix in the vertical and horizontal directions. There is an advantage that a high versatility can be obtained without a specific arrangement according to each wafer to be tested.

  As described above, according to the semiconductor measuring device and the semiconductor measuring method of the present invention, it is possible to perform measurement with low cost and high efficiency. Therefore, semiconductor devices, particularly power semiconductor devices for which further expansion of applications is expected in the future. It greatly contributes to the improvement of the quality and performance, and has a great industrial applicability. In addition, the coaxial probe needle unit of the present invention has a simple structure, is easy to handle, and is excellent in measurement signal transmission, so that it exhibits great convenience when used in semiconductor measurement devices and semiconductor measurement methods. There is also a great deal of industrial applicability.

DESCRIPTION OF SYMBOLS 1 Semiconductor measuring device 2 Wafer chuck 2a Chuck body 2b Outer ring 2c Housing 2d Chuck base 3 XYZθ stage 4 Tester device 5 Switching device 6 Chuck top 7 Probe card 8 Probe needle 9 Coaxial probe needle unit 10 Signal line 11 Heater 12 Suction groove 13 Lifting guide pin 14 Cam follower 15 Cam groove 16 Suction tube 17 Bearing 18 Slip ring W Wafer D Semiconductor element T Electrode S Selection switch

Claims (8)

A semiconductor measuring apparatus for testing characteristics of a semiconductor element by contacting a probe needle with each electrode of a plurality of semiconductor elements formed on a wafer and a back electrode of the wafer, and supporting a wafer to be tested A wafer chuck having a surface; a moving mechanism for moving the wafer chuck in a vertical direction and a horizontal direction relative to an upper probe needle located at an upper portion of the wafer chuck; and an upper tip of the wafer chuck; A plurality of lower probe needles which are in contact with electrodes and are held by the wafer chuck and arranged in a matrix in the vertical and horizontal directions within the support surface; electrically connected to the upper probe needles And a tester device electrically connected to each of the plurality of lower probe needles via a selection switch; to a test semiconductor element at a measurement position And a switching device for switching the selection switch to lower the probe needle is connected to the tester device electrically to respond, the switching device, information on the size and position of each semiconductor device on the test target wafer And / or information on the size and position of the electrodes of each semiconductor element, information on the positions of the plurality of lower probe needles held by the wafer chuck, and a test target wafer supported on the support surface of the wafer chuck Based on the information on the deviation from the reference position, the correspondence between each of the semiconductor elements on the wafer to be tested and the lower probe needle to be electrically connected to the tester device when measuring each semiconductor element is obtained. And a lower probe needle corresponding to the semiconductor element at the measurement position is electrically connected to the tester device based on the correspondence relationship. Semiconductor measuring device comprises means for switching the selection switch. The wafer chuck includes a chuck top having a support surface that supports a wafer to be tested, and a chuck body that holds the plurality of lower probe needles, and the support surface of the chuck top includes the plurality of lower probes. A through-hole through which at least the upper end of the needle is slidably penetrated is provided, and a suction groove for sucking and supporting the wafer to be tested by negative pressure is provided. An elastic means for urging the needle in the direction of the wafer under test supported on the support surface, and the chuck top has an upper end of the plurality of lower probe needles in an unloaded state, A support unit is movably supported with respect to the chuck body between a measurement position located above the support surface and a suction position located below the support surface. 1 semiconductor measuring device according. The lower probe needle has a coaxial structure having a conductive core wire , an insulator that covers at least the upper end of the core wire and covers an outer periphery thereof, and a conductive sheath that covers the outer periphery of the insulator. 2. The semiconductor measuring apparatus according to 2 . The semiconductor measurement apparatus according to claim 3, wherein the lower probe needle has an insulating sleeve on an outer periphery of an upper end of the core wire that is not covered with the insulator. The lower probe needle further comprises a stopper projecting radially in the vicinity of the upper part of the outer skin, and a coil spring fitted into the outer periphery of the outer skin with the upper end abutted against the stopper. 4. The semiconductor measuring apparatus according to 4. The semiconductor measuring device according to claim 1, heating means for heating the supporting surface of the wafer chuck is provided. A semiconductor measuring method for testing characteristics of a semiconductor element by contacting a probe needle with each electrode of a plurality of semiconductor elements formed on a wafer and a back electrode of the wafer, and supporting a wafer to be tested A step of supporting a test wafer on a wafer chuck having a surface; a plurality of lower probes arranged in a matrix in the vertical and horizontal directions within the support surface on a back electrode of the test wafer supported on the wafer chuck A step of bringing a needle into contact; a step of moving the wafer chuck relative to an upper probe needle located above the wafer chuck in a horizontal direction to move a semiconductor element to be measured to a measurement position; Selecting a lower probe needle corresponding to the semiconductor element from the plurality of lower probe needles; Step hermetically connected; comprising the step of contacting the electrode and the upper probe of the test semiconductor device is moved relative vertical direction with respect to the upper probe the wafer chuck, a semiconductor measurement method. The step of selecting the lower probe needle corresponding to the semiconductor element moved to the measurement position from the plurality of lower probe needles includes information on the size and position of each semiconductor element on the wafer to be tested and / or each semiconductor element. Information on the size and position of the electrodes, information on the positions of the plurality of lower probe needles held by the wafer chuck, and deviation from the reference position of the wafer to be tested supported on the support surface of the wafer chuck Obtaining a correspondence relationship between each semiconductor element on the wafer to be tested and a lower probe needle to be electrically connected to the tester device when measuring each semiconductor element based on the information; and the semiconductor moved to the measurement position Based on the information about the element and the correspondence, the lower probe needle corresponding to the semiconductor element moved to the measurement position is changed to the plurality of lower probe needles. Semiconductor measuring method according to claim 7, wherein is intended to include the step of selecting from among.

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