Abstract:
A probe contactor for testing a semiconductor wafer, a packaged LSI or a printed circuit board is formed on a planar surface of a substrate by a photolithography technology. The contactor is formed of a substrate having an interconnect trace thereon which is an electric conductive path, and a contactor formed on the substrate through a photolithography process. The contactor has a base portion vertically formed on the substrate, a horizontal portion, one end of which is formed on the base portion, and a contact portion formed on another end of the horizontal portion. A spring force of the horizontal portion of the contactor provides a contact force when the probe contactor is pressed against the device to be tested.

Description:
[0001]    This is a continuation-in-part of application Ser. No. 09/099,614, filed Jun. 19, 1998, entitled “PROBE CONTACT FORMED OF PHOTOLITHOGRAPHY PROCESS”, now abandoned. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention relates to probe contactors and production method thereof to establish electrical contact with contact targets such as contact pads or leads of electronic circuits or devices, and more particularly, to probe contactors and production method thereof to be used in a probe card to test semiconductor wafers, semiconductor chips, packaged semiconductor devices or printed circuit boards and the like with an improved frequency bandwidth, density and quality.  
         BACKGROUND OF THE INVENTION  
         [0003]    In testing high density and high speed electrical devices such as LSI and VLSI circuits, high performance probe contactors or test contactors must be used. The probe contactors of the present invention is not limited to the application of testing and burn-in of semiconductor wafers and die, but is inclusive of testing and burn-in of packaged semiconductor devices, printed circuit boards and the like. The probe contactors of the present invention can also be used in more general applications including an IC lead, IC packaging, and other electrical connections. However, for the convenience of explanation, the present invention is described mainly with reference to the semiconductor wafer testing.  
           [0004]    In the case where semiconductor devices to be tested are in the form of a semiconductor wafer, a semiconductor test system such as an IC tester is usually connected to a substrate handler, such as an automatic wafer prober, to automatically test the semiconductor wafer. Such an example is shown in FIG. 1 in which a semiconductor test system has a test head which is ordinarily in a separate housing and electrically connected to the test system with a bundle of cables. The test head and the substrate handler are mechanically connected with one another and the semiconductor wafers to be tested are automatically provided to a test position of the test head by the substrate handler.  
           [0005]    On the test head, the semiconductor wafer to be tested is provided with test signals generated by the semiconductor test system. The resultant output signals from the semiconductor wafer under test are transmitted to the semiconductor test system wherein they are compared with expected data to determine whether IC circuits on the semiconductor wafer function correctly.  
           [0006]    The test head and the substrate handler are connected with an interface component  140  consisting of a performance board  120  which is a printed circuit board having electric circuit connections unique to a test head&#39;s electrical footprint, coaxial cables, pogo-pins and connectors. In FIG. 2, the test head  100  includes a large number of printed circuit boards  150  which correspond to the number of test channels. Each of the printed circuit boards has a connector  160  to receive a corresponding contact terminal  121  of the performance board  120 . A “frog” ring  130  is mounted on the performance board  120  to accurately determine the contact position relative to the substrate handler  400 . The frog ring  130  has a large number of contact pins  141 , such as ZIF connectors or pogo-pins, connected to contact terminals  121 , through coaxial cables  124 .  
           [0007]    [0007]FIG. 2 further shows, in more detail, a structure of the substrate handler  400 , the test head  100  and the interface component  140  when testing a semiconductor wafer. As shown in FIG. 2, the test head  100  is placed over the substrate handler  400  and mechanically and electrically connected to the substrate handler through the interface component  140 . In the substrate handler  400 , a semiconductor wafer  300  to be tested is mounted on a chuck  180 . A probe card  170  is provided above the semiconductor wafer  300  to be tested. The probe card  170  has a large number of probe contactors (such as cantilevers or needles)  190  to contact with circuit terminals or contact targets in the IC circuit of the wafer  300  under test.  
           [0008]    Electrical terminals or contact receptacles of the probe card  170  are electrically connected to the contact pins  141  provided on the frog ring  130 . The contact pins  141  are also connected to the contact terminals  121  of the performance board  120  with coaxial cables  124  where each contact terminal  121  is connected to the printed circuit board  150  of the test head  100 . Further, the printed circuit boards  150  are connected to the semiconductor test system through the cable  110  having several hundreds of inner cables.  
           [0009]    Under this arrangement, the probe contactors  190  contact the surface of the semiconductor wafer  300  on the chuck  180  to apply test signals to the semiconductor wafer  300  and receive the resultant output signals from the wafer  300 . The resultant output signals from the semiconductor wafer  300  under test are compared with the expected data generated by the semiconductor test system to determine whether the semiconductor wafer  300  performs properly.  
           [0010]    [0010]FIG. 3 is a bottom view of the probe card  170  of FIG. 2. In this example, the probe card  170  has an epoxy ring on which a plurality of probe contactors  190  called needles or cantilevers are mounted. When the chuck  180  mounting the semiconductor wafer  300  moves upward in FIG. 2, the tips of the cantilevers  190  contact the pads or bumps on the wafer  300 . The ends of the cantilevers  190  are connected to wires  194  which are further connected to transmission lines (not shown) formed in the probe card  170 . The transmission lines are connected to a plurality of electrodes  197  which contact the pogo pins  141  of FIG. 2.  
           [0011]    Typically, the probe card  170  is structured by a multi-layer of polyimide substrates having ground planes, power planes, signal transmission lines on many layers. As is well known in the art, each of the signal transmission lines is designed to have a characteristic impedance such as 50 ohms by balancing the distributed parameters, i.e., dielectric constant and magnetic permeability of the polyimide, inductances, and capacitances of the signal within the probe card  170 . Thus, the signal lines are impedance matched lines to achieve a high frequency transmission bandwidth to the wafer  300  providing current during steady state and high current peaks generated by the device&#39;s outputs switching. For removing noise, capacitors  193  and  195  are provided on the probe card between the power and ground planes.  
           [0012]    An equivalent circuit of the probe card  170  is shown in FIG. 4 to explain the limitation of bandwidth in the conventional probe card technology. As shown in FIGS. 4A and 4B, the signal transmission line on the probe card  170  extends from the electrode  197 , the strip line (impedance matched line)  196 , the wire  194  and the needle (cantilever)  190 . Since the wire  194  and needle  190  are not impedance matched, these portions function as an inductor L in the high frequency band as shown in FIG. 4C. Because of the overall length of the wire  194  and needle  190  is around 20-30 mm, the significant frequency limitation is resulted in testing a high frequency performance of a device under test.  
           [0013]    Other factors which limit the frequency bandwidth in the probe card  170  reside in the power and ground needles shown in FIGS. 4D and 4E. If the power line can provide large enough currents to the device under test, it will not seriously limit the operational bandwidth in testing the device. However, because the series connected wire  194  and needle  190  for supplying the power (FIG. 4D) as well as the series connected wire  194  and needle  190  for grounding the power and signals (FIG. 4E) are equivalent to inductors, the high speed current flow is seriously restricted.  
           [0014]    Moreover, the capacitors  193  and  195  are provided between the power line and the ground line to secure a proper performance of the device under test by filtering out the noise or surge pulses on the power lines. The capacitors  193  have a relatively large value such as 10 μF and can be disconnected from the power lines by switches if necessary. The capacitors  195  have a relatively small capacitance value such as 0.01 μF and fixedly connected close to the DUT. These capacitors serve the function as high frequency decoupling on the power lines. Thus, the capacitors also limit the high frequency operation of the probe card  170 .  
           [0015]    Accordingly, the most widely used probe contactors as noted above are limited to the frequency bandwidth of approximately 200 MHz, which is insufficient to test recent semiconductor devices. It is considered, in the industry, that the frequency bandwidth be of at least that equal to the IC tester&#39;s capability which is currently on the order of 1 GHz or higher, will be necessary in the near future. Further, it is desired in the industry that a probe card is capable of handling a large number of semiconductor devices, especially memories, such as 32 or more, in parallel (parallel test) to increase test throughput.  
           [0016]    One of new types of probe card having membrane contactors is expected to have a sufficiently high bandwidth because it can incorporate impedance matched transmission lines to the tips of the contactors. However, membrane contactors have a disadvantage in that they are deformed by the temperature change to a degree that the contact performance is no longer available. Another disadvantage of the membrane contactors resides in that only limited number of contactors can be fabricated on the membrane because of the difficulty of providing spring forces to the contactors. One last disadvantage inherent in the technology is the lack of individual compliance in the contactors relative to one another. This is because the contactors are mounted on the common membrane thereby limiting the independent movement of a contactor from the movement of the other. Therefore, the membrane contactors are not suitable for testing a large number of devices in parallel.  
           [0017]    In the conventional technology, the probe card and probe contactors such as shown in FIG. 3 are manually made, resulting in inconsistent quality. Such inconsistent quality includes fluctuations of size, frequency bandwidth, contact force and resistance, etc. In the conventional probe contactors, another factor making the contact performance unreliable is that the probe contactors and the semiconductor wafer under test have different temperature expansion ratios. Thus, under the varying temperature, the contact positions therebetween may vary which adversely affects the contact force, contact resistance and bandwidth.  
         SUMMARY OF THE INVENTION  
         [0018]    Therefore, it is an object of the present invention to provide a contactor for electrically contacting with a contact target which is capable of achieving a high frequency bandwidth, high pin counts and high contact performance as well as high reliability.  
           [0019]    It is another object of the present invention to provide a contact structure such as a probe contactor to establish electrical connection in applications such as testing semiconductor devices and the like, having a very high frequency bandwidth to meet the test requirements in the next generation semiconductor technology.  
           [0020]    It is a further object of the present invention to provide probe contactors to be used in testing a semiconductor wafer, packaged LSI and the like which are suitable for testing a large number of semiconductor devices in parallel at the same time.  
           [0021]    It is a further object of the present invention to provide probe contactors to be used in testing a semiconductor wafer, packaged LSI and the like which are produced through standard semiconductor production process without involving manual assembly or handling, thereby achieving consistent quality.  
           [0022]    It is a further object of the present invention to provide probe contactor to be mounted on a probe card for testing a semiconductor wafer, packaged LSI and the like which are capable of compensating temperature expansion coefficient of a semiconductor wafer under test.  
           [0023]    In the present invention, a probe contactor for establishing an electrical connection with a contact target is formed by a substrate of a planar surface on which a contactor is created by a photolithography process established in the semiconductor technology.  
           [0024]    The probe contactor of the present invention is comprised of a substrate having an interconnect trace thereon which is an electrically conductive path, and a contactor formed on the substrate through a photolithography process wherein the contactor has a base portion vertically formed on the substrate, a horizontal portion, one end of which is formed on the base portion, and a contact portion formed on another end of the horizontal portion, and wherein the horizontal portion of the contactor produces a contact force when the probe contactor is pressed against the device under test.  
           [0025]    Another aspect of the present invention is a process for producing the probe contactor. The method of producing the probe contactor is comprised of the steps of forming an interconnect trace on a silicon substrate either by deposition or plating, and applying photolithography processes for forming a contactor having a base portion vertically formed on the interconnect trace, a horizontal portion one end of which is formed on the base portion and a contact portion formed on another end of the horizontal portion wherein each of the photolithography processes includes steps of photoresist coating, masking, exposure, developing, photoresist stripping and conductive material deposition.  
           [0026]    According to the present invention, the contactor has a very high frequency bandwidth to meet the test requirements in the next generation semiconductor technology. Since the probe contactor is formed through a modern miniaturization technology used in the semiconductor production process, a large number of contactors can be aligned in a small space which is suitable for testing a large number of semiconductor devices at the same time.  
           [0027]    Since the large number of probe contactors are produced at the same time on the substrate with the use of the microfabrication technology without involving manual handling, it is possible to achieve consistent quality, high reliability and long life in the contact performance. Further, because the probe contactors can be fabricated on the same substrate material as that of the device under test, it is possible to compensate the temperature expansion coefficient of the device under test, which is able to avoid positional errors. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0028]    [0028]FIG. 1 is a schematic diagram showing a structural relationship between a substrate handler and a semiconductor test system having a test head.  
         [0029]    [0029]FIG. 2 is a schematic diagram showing an example of detailed structure for connecting the test head of the semiconductor test system to the substrate handler.  
         [0030]    [0030]FIG. 3 is a bottom view showing an example of the probe card having an epoxy ring for mounting a plurality of cantilevers as probe contactors.  
         [0031]    FIGS.  4 A- 4 E are circuit diagrams showing equivalent circuits of the probe card of FIG. 3.  
         [0032]    [0032]FIG. 5A is a schematic cross sectional diagram showing probe contactors of the present invention produced through a photolithography process, and  
         [0033]    [0033]FIG. 5B is a bottom view of the probe contactors of FIG. 5A.  
         [0034]    FIGS.  6 A- 6 C are schematic diagrams showing examples of structure of the probe contactor of the present invention formed on a silicon substrate.  
         [0035]    FIGS.  7 A- 7 R are schematic diagrams showing an example of production process for producing the probe contactor of the present invention.  
         [0036]    [0036]FIG. 8A is a cross sectional front view of another example of probe contactor and  
         [0037]    [0037]FIG. 8B is a top view of the probe contactor of FIG. 8A.  
         [0038]    [0038]FIG. 9A is a cross sectional front view of a further example of probe contactor and  
         [0039]    [0039]FIG. 9B is a top view of the probe contactor of FIG. 9A.  
         [0040]    [0040]FIG. 10A is a cross sectional front view of a further example of probe contactor and  
         [0041]    [0041]FIG. 10B is a top view of the probe contactor of FIG. 10A.  
         [0042]    [0042]FIG. 11A is a cross sectional front view of a further example of probe contactor and  
         [0043]    [0043]FIG. 11B is a top view of the probe contactor of FIG. 11A.  
         [0044]    [0044]FIG. 12A is a cross sectional front view of a further example of probe contactor and  
         [0045]    [0045]FIG. 12B is a top view of the probe contactor of FIG. 12A.  
         [0046]    [0046]FIG. 13A is a cross sectional front view of a further example of probe contactor and  
         [0047]    [0047]FIG. 13B is a top view of the probe contactor of FIG. 13A.  
         [0048]    [0048]FIGS. 14A and 14B are schematic bottom views showing examples of alignment in the probe contactors of the present invention in a manner to change pitches between contact points of the probe contactors to pitches between base ends of the probe contactors. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0049]    The contactors of the present invention will be described with reference to FIGS.  5 - 14 . FIGS. 5A and 5B show an example of contactors  230  of the present invention formed on a substrate  220 . FIGS.  8 - 13  show various other shapes of the probe contactors of the present invention. The substrate  220  is typically a silicon substrate although other materials such as glass fiber, ceramic, alumina or other dielectric materials are also feasible. All of the contactors  230  are produced through the same production process such as a photolithography process on the silicon or dielectric substrate  220 .  
         [0050]    When the semiconductor wafer  300  under test moves upward, the contactors  230  contact corresponding contact targets (electrodes)  320  on the wafer  300 . The pitch between the pads  320  may be as small as 50 μm or less, the contactors  230  can easily be aligned in the same pitch since they are made through the same semiconductor production process as the wafer  300  are made. As shown in the bottom view of FIG. 5B, the probe contactor  230  is rectangular or square shaped in cross section.  
         [0051]    The contactors  230  on the silicon substrate  220  can be directly mounted on a probe card such as shown in FIG. 3, or molded in a package, such as a traditional IC package having leads, so that the package is mounted on a probe card. Since the contactors  230  can be fabricated in a very small size, a frequency bandwidth of a probe card mounting the contactors of the present invention can be easily increased to 2 GHz or higher. Because of the small size, the number of contactors on a probe card can be increased to, for example 2,000, which is able to test as many as 32 or more memory devices in parallel at the same time.  
         [0052]    Furthermore, because the contactors  230  of the present invention are formed on the silicon substrate  220 , environmental changes such as a temperature expansion ratio of the silicon substrate are the same as those of the semiconductor wafer  300  under test. Therefore, the accurate positioning between the contactors  230  and the pads  320  can be maintained throughout the test.  
         [0053]    FIGS.  6 A- 6 C provide more detailed views of the contactor  230  on the silicon substrate  220 . To establish an interconnection with the probe card or the IC package as noted above, the examples of FIGS.  6 A- 6 C show basic three types of electrical path to form such interconnections. FIG. 6A shows an example in which such an electrical connection is established at the top of the substrate. FIG. 6B shows an example in which an electrical connection is established at the bottom of the substrate while FIG. 6 c  shows an example in which an electrical connection is formed at the edge of the substrate. Almost any types of existing IC package design or probe card design can accommodate at least one of the interconnect types of FIGS.  6 A- 6 C.  
         [0054]    The example of FIG. 6A includes an interconnect trace  232  also designated by a and an interconnect pad  233  on the substrate  220 . The interconnect trace  232  establishes an electric path from the contactor  230  to the interconnect pad  233 . The example of FIG. 6B includes an interconnect trace  232 , an interconnect pad  235  via the substrate  220  and an interconnect pad  236  at the bottom of the substrate  220 . In the example of FIG. 6C, the interconnect trace  232  extends to the edge of the substrate  220 . In each of the examples, the interconnect trace  232  also functions to fan-out the small pitch of the contactors  230  to a larger pitch to fit to the probe card or IC package.  
         [0055]    As shown in each of FIGS.  6 A- 6 C, the contactor  230  has vertical portions b and d and a horizontal beam c and a tip portion e. The tip portion e of the contactor  230  is preferably sharpened to achieve a scrubbing effect when pressed against the contact target  320  requiring penetration through a metal-oxide layer. For example, if the target  320  on the wafer  300  has aluminum oxide on its surface, the scrubbing effect is necessary to establish the electric contact with low contact resistance. The spring force of the horizontal beam c provides an appropriate contact force against the contact pad  320 . The elasticity produced by the spring force of the horizontal beam c also functions to compensate the differences in size or the fluctuation of flatness involved in the contactors  230 , the silicon substrate  22 , the contact pad  320  and the wafer  300 .  
         [0056]    An example of material of the contactor  230  includes nickel, aluminum and copper. The tip portion e may be plated by nickel palladium, rhodium, nickel gold, iridium or several other depositable materials. An example of size of the contactor intended for a probe-test application may be 100-400 microns (about 200 μm optimum) in overall height, 50-400 microns (150-200 μm optimum) in horizontal length, and about 30-60 microns in thickness for the pitch of 50 μm between contact targets  320 .  
         [0057]    FIGS.  7 A- 7 R show an example of process for producing the contactors of the present invention through the photolithography technology. In FIG. 7A, a thin metal layer  237  made, for example of copper, is provided on the silicon substrate  220 . The metal layer  237  is to achieve electrical conductivity for forming the interconnect trace  232  and contactor  230  of FIG. 6 through a electroplating process. If the interconnect trace  232  and contactor  230  are formed through other deposition process such as sputtering, the thin metal layer  237  may not be necessary.  
         [0058]    A photoresist layer  242  is formed on the trace layer  232  over which a mask  245  is aligned to be exposed with ultraviolet light as shown in FIG. 7B. If a positive acting resist is used, the photoresist covered by the opaque portions of the mask  245  harden (cure) after exposure. The exposed part of the resist can be dissolved and washed away, leaving a photo mask layer  242  of FIG. 7C. The contactor material such as copper, nickel, aluminum or other metal is deposited in the window of the photo mask  242  to form the interconnect trace  232  as shown in FIG. 7D. The interconnect trace  232  of FIG. 7D corresponds to the portion a shown in FIGS.  6 A- 6 C.  
         [0059]    In the process of FIG. 7E, a thin metal layer  238  is formed by, for example plating, on the interconnect trace  232 . One of the purposes of the metal layer  238  is to protect the interconnect trace  232  from etching. Materials of the metal layer  238  should be different from that of the interconnect trace  232  or thin metal layer  237 . In FIG. 7F, a photo mask layer  243  is formed on the photo mask  242  through the same photolithography process of FIGS. 7B and 7C. In FIG. 7G, the contactor material such as nickel, aluminum and copper is deposited in the window of the photo mask  243  to form the vertical portion b of the contactor  230  shown in FIG. 6. A variety of deposition techniques can be used in this process including vacuum evaporation, cathode sputtering, vapor-phase deposition as well as plating techniques. The overplated portion of FIG. 7G is removed in the grinding (planarizing) process of FIG. 7H.  
         [0060]    The foregoing process will be repeated for forming the other portions of the contactor. In FIG. 7I, using the process of FIG. 7B and 7C, a photo mask layer  244  is created over the photo mask layer  243  to form the horizontal beam c of the contactor  230 . Through the deposition process, the horizontal beam c is formed as shown in FIG. 7J for which a planarizing process is performed to remove the overplated portion as shown in FIG. 7K. On the photo mask  244  and the horizontal beam c, a photo mask layer  246  is provided as shown in FIG. 7L to form the vertical portion d of the contactor  230 . The photo mask  246  is created by the same photolithography process of FIG. 7B and 7C. Thus, after the deposition, the vertical portion d of FIG. 6 is formed in the photo mask layers as shown in FIG. 7M for which a planarizing process is performed to remove the overplated portion as shown in FIG. 7N. FIG. 70 also shows a photo mask  248  to form a tip e of the contactor  230  which is shown in FIG. 7P.  
         [0061]    In FIG. 7Q, the photo masks  242 ,  243 ,  244 ,  246  and  248  are stripped off in a special solvent. An etching process is conducted so that most of the metal layer  237  is removed as shown in FIG. 7R. As in the foregoing, the contactor  230  and the interconnect trace  232  are formed on the silicon substrate  220  by the photolithography technology.  
         [0062]    [0062]FIG. 8A is a cross sectional front view of another example of probe contactor. In this example, the horizonal beam c of the probe contactor  230  is in a diagonal direction as shown in the top view of FIG. 8B. Namely, the horizontal beam c is inclined relative to the direction of the base end a (contract trace  232  of FIG. 6). With use of different angles of diagonal direction, the probe contactors of the present invention can easily change the small pitch between the contact points thereof to a larger pitch between the based ends a thereof which is connected to the contact traces  232  (FIGS.  6 A- 6 C) as shown in FIG. 14A. Other portions of the probe contactor  230  are basically the same as those of the example of FIGS. 5A and 5B. Because the horizonal beam is in the diagonal direction, the contact point scrubs the surface of the contact target in the diagonal direction, resulting in the excellent contact performance.  
         [0063]    [0063]FIG. 9A is a cross sectional front view of a further example of probe contactor. In this example, the horizonal beam c of the probe contactor  230  is curved in a diagonal direction as shown in the top view of FIG. 9B relative to the direction of the base end a. With use of different angles of diagonal direction, the probe contactors of the present invention can easily change the small pitch between the contact points e thereof to a larger pitch between the based ends a thereof which is connected to the contact traces  232  (FIGS.  6 A- 6 C) as shown in FIG. 14B. Other portions of the probe contactor  230  are basically the same as those of the example of FIGS. 5A and 5B. Because the horizonal beam is in the diagonal direction, the contact point scrubs the surface of the contact target in the diagonal direction, resulting in the excellent contact performance.  
         [0064]    [0064]FIG. 10A is a cross sectional front view of a further example of probe contactor. In this example, the horizonal beam c of the probe contactor  230  is curved in a manner shown in the top view of FIG. 10B. FIG. 11A is a cross sectional front view of a further example of probe contactor. In this example, the base end a and vertical beam b have a larger width than that of the horizontal beam c and top beam d, and horizontal beam is extended in the diagonal direction as shown in the top view of FIG. 11B. is a top view of the probe contactor of FIG. 11A.  
         [0065]    [0065]FIG. 12A is a cross sectional front view of a further example of probe contactor. In this example, the horizontal beam c is bent in the manner shown in the top view of FIG. 12B. FIG. 13A is a cross sectional front view of a further example of probe contactor. In this example, the vertical and horizontal are circular in cross section, and the horizontal beam c is extended in the diagonal direction as shown the top view of FIG. 13B.  
         [0066]    [0066]FIG. 14A is a schematic bottom view showing an example of alignment in the probe contactors of the present invention in a manner to change pitches between contact points of the probe contactors to pitches between base ends of the probe contactors. This example involves different angles of diagonal direction using the probe contactors of FIGS. 8A and 8B to change the small pitch between the contact points e thereof to a larger pitch between the based ends a thereof.  
         [0067]    [0067]FIG. 14B is a schematic bottom view showing another example of alignment in the probe contactors of the present invention in a manner to change pitches between contact points of the probe contactors to pitches between base ends of the probe contactors. This example involves different angles of diagonal direction using the probe contactors of FIGS. 9A and 9B to change the small pitch between the contact points e thereof to a larger pitch between the based ends a thereof.  
         [0068]    According to the present invention, the probe contactor has a very high frequency bandwidth to meet the test requirements of next generation semiconductor technology. Since the probe contactor is formed through a modern miniaturization technology used in the semiconductor production process, a large number of contactors can be aligned in a small space which is suitable for testing a large number of semiconductor devices at the same time. The contact structure of the present invention can also be used in more general applications including an IC lead, IC packaging, and other electrical connections.  
         [0069]    Since the large number of probe contactors are produced at the same time on the substrate with the use of the microfabrication technology without involving manual handling, it is possible to achieve consistent quality, high reliability and long life in the contact performance. Further, because the probe contactors can be fabricated on the same substrate material as that of the device under test, it is possible to compensate the temperature expansion coefficient of the device under test, which is able to avoid positional errors.  
         [0070]    Although only a preferred embodiment is specifically illustrated and described herein, it will be appreciated that many modifications and variations of the present invention are possible in light of the above teachings and within the purview of the appended claims without departing the spirit and intended scope of the invention.