JP5022408B2 - Element inspection method for electrical contact structure - Google Patents

Description

  The present invention relates to an electrical contact structure that contacts an electrode (pad or bump) of an LSI (Large Scale Integration) or a bare LSI (bare chip) that is a semiconductor device, and in particular, the electrode material has an oxide film and the electrode pitch is narrow. The present invention relates to an electrical contact structure of an inspection probe suitable for LSI or bare chip inspection, a method for forming the same, and an element inspection method.

  Conventionally, a semiconductor device is inspected by bringing a probe of an inspection substrate into contact with an external terminal electrode of a semiconductor device to be inspected to obtain electrical contact between the semiconductor device and the inspection substrate. As the probe, a metal lead supported on a flexible substrate, a metal lead supported on a rigid substrate, a pin obtained by plating a silicon whisker, a metal pin, or the like is used. A membrane sheet system with a metal lead (TAB), a metal lead system supported on a rigid substrate, and a system using silicon whiskers have been proposed. These will be described.

(1) Membrane sheet system with metal lead (TAB) Patent Documents 1-4 describe. These are probe structures using a flexible substrate having a metal lead at a position facing an external electrode of a semiconductor device. As a representative example, FIG. 17 shows a structure diagram of a probe card of Patent Document 1. A desired inspection circuit pattern and probe pins 1 are formed on one side of the flexible film 30, and the probe pins 1 are in contact with the external electrodes of the semiconductor device 10.

  Since the flexible substrate 7 is thin, a desired contact force cannot be obtained by itself, so the clamper 32 and the support 36 that support both surfaces of the flexible substrate 7 are provided. Thereby, the structure which obtains a desired contact as the probe pin 1 is taken.

(2) Metal lead system supported on rigid substrate. These are probe structures using a rigid substrate having a metal lead at a position facing an external electrode of a semiconductor device. As a representative example, FIGS. 18 and 19 show structural diagrams of the probe unit and the manufacturing method thereof in Patent Documents 6 and 7, respectively. FIG. 18 shows the overall structure of the probe unit. Rigid substrate (Glass substrate, synthetic resin plate, ceramic plate, silicon laminated with insulating material, metal plate, etc. are described as substrate materials in column 4, lines 40 to 44 of Patent Document 8) Desired on one side A protrusion 39 is formed on the lead 3 and the arc-shaped probe pin 1 or the arc-shaped top, and the probe pin 1 is in contact with the external electrode of the semiconductor device.

  The probe pin itself has elasticity, and adopts a structure in which contact is made with the electrode of the semiconductor device by a push amount and a load within a predetermined elastic deformation region.

  FIG. 19 shows the shape of the tip of the probe pin that becomes a contact portion with the semiconductor electrode. The tip portion is composed of a spire-shaped or knife-edge-shaped protrusion 41, 43, 45 and a protrusion support 40, 42, 44 that supports the protrusion.

(3) System using silicon whisker It is described in Patent Documents 9-11. As a typical example, FIG. 25 shows a structural diagram of a probe pin of Patent Document 9 and a contactor having the probe pin. These are probe structures using a probe pin 1 having a structure in which a Ni base film 54, an Au film 55, and a Pd film 56 are formed on the tip of a silicon needle-like single crystal 53 grown. A needle-like single crystal 53 of silicon can be formed by arranging Au seeds on the silicon substrate 52 and performing VLS growth. The probe for semiconductor measurement is provided with a conductive film on the surface, and has a probe pin structure in which only the tip is covered with a contact material.

(4) Method Using Metal Pin The probe device of Patent Document 12 is shown in FIG. This is a probe structure in which a wire probe needle 57 and a crystal probe needle 60 in which a metal pin such as tungsten is processed into an ultrathin wire are used in combination, and has a structure having both a narrow pitch and a low cost. For example, a wire probe needle 57 made of tungsten is provided on a portion of the printed circuit board 34 where the electrode pitch of the semiconductor device 10 is wide (300 to 400 μm pitch), and a portion where the electrode pitch of the semiconductor device 10 is narrow (45 to 65 μm pitch) is quartz. A probe needle 60 is used. The crystal probe needle 60 is configured by forming an electrode pattern by etching the tip of the crystal plate 58 and performing gold plating on the surface thereof. Since the quartz probe needle 60 is used, it is possible to cope with a fine pitch of 40 μm pitch level, and by using different probes according to the electrode pitch, the cost can be reduced as compared with the case of using a full-face quartz probe. .

JP-A-6-334006 JP-A-6-334005 JP-A-6-331655 JP-A-6-324081 JP 2002-286755 A JP 2002-286758 A JP 2003-185664 A JP 2003-121466 A Japanese Patent Laid-Open No. 10-038918 Japanese Patent Laid-Open No. 2002-257859 JP-A-5-198636 JP-A-6-140482 JP 2003-207521 A JP 2003-322664 A

  Since the probe card of Patent Document 1 has a configuration using a film-like flexible material as a base material, (1) due to the thermal history of the film substrate manufacturing process, in the case of a fine pitch of 40 μm pitch or less, the metal lead pitch direction It is difficult to control the position accuracy to a desired value (± 1.0 μm or less). (2) When performing a high temperature inspection at 80 to 100 ° C. in a wafer state, the thermal expansion coefficient (several tens of ppm) of the film material is larger than the thermal expansion coefficient (2 to 3 ppm) of silicon of the semiconductor device material. Misalignment occurs between the metal lead and the electrode of the semiconductor device. Furthermore, as an important issue, the probe pin is formed of a single material that is a metal material having elasticity, and (3) good contact characteristics when the semiconductor electrode is a material having an oxide film such as aluminum or copper. It is difficult to obtain. There is a problem.

  Since the probe unit and the manufacturing method thereof in Patent Document 6 use glass, a synthetic resin plate, a ceramic plate, silicon laminated with an insulating material, a metal plate, or the like as a substrate material, the material excluding the synthetic resin plate is relatively hot. Since the expansion coefficient is close to that of silicon, accuracy degradation due to thermal history during manufacturing and occurrence of misalignment during high temperature testing are not very small and problematic, and are described in (1) and (2) described in Patent Document 1. The problem is solved.

  Further, the protrusion formed on the arcuate top described in Patent Document 6 and the spire-shaped or knife-edge-shaped protrusion described in Patent Document 7 are not oxidized even when the semiconductor electrode is made of a material having an oxide film. Has the effect of breaking through the membrane.

However, in order to break through the oxide film, the spire-shaped or knife-edge-shaped protrusion needs to have a curvature radius of a certain level or less. In particular, when the pitch of the semiconductor electrode is an ultra-fine pitch of 40 μm or less, the probe pin itself is reduced in size, so the probe pin does not plastically deform (the amount by which the probe is pushed into the electrode: hereinafter referred to as the OD amount) The force that can be applied to the contact portion becomes very small. Therefore, (1) a control of a small curvature radius, that is, a manufacturing technique is required more than in the past, and when manufacturing a probe pin that satisfies this, the manufacturing cost increases significantly. Furthermore, (2) in order to form a spire-shaped or knife-edge-shaped protrusion, a certain area is required from the end of the knife-edge portion, and a spire-shaped or knife-edge-shaped protrusion is formed as the final shape. The area has a thinner material thickness than the other parts. There is a problem that stress at the time of contact is concentrated in the thin portion, and plastic deformation occurs at the base of the thin portion. These problems will be described with specific examples. FIG. 20 shows an SEM photograph of the tip of the probe pin with a pitch of 20 μm. Further, FIG. 21 shows the contact characteristic measurement results when this probe pin is used. Although all pin continuity can be obtained with an OD amount of 50 μm or more, it can be seen that there are high resistance portions. The portion where the high resistance portion is generated has a rounded shape 49 as shown in FIG. Accordingly, it can be presumed that high resistance is generated because slipping occurs on the surface of the semiconductor electrode, and an oxide film is interposed at the contact portion between the electrode surface and the probe. In order to solve this, it is necessary to control the knife-edge-like protrusion to a tip radius of 0.36 μm or less, which is the same level as the low resistance portion 48. FIG. 23 shows an observation photograph and a cross-sectional dimension in the vicinity of the tip of the probe, and FIG. 24 shows a photograph of a contact state when the probe is used. As can be clearly seen from FIG. 23, it can be seen that there is a thin portion between the knife-edge portion and the base material portion, and deformation has occurred from the base of the thin portion. Eventually, plastic deformation occurred from this portion due to several times of contact, resulting in a problem that the function of the probe pin was impaired. Although this problem can also reduce the distance of a thin part by improving the process before forming a knife edge-like part, it is impossible to make it zero. In addition, when the distance between the thin portions is minimized, it is inevitable that the manufacturing cost is significantly increased.

  According to this example, the two problems described in Patent Document 6 and Patent Document 7 can be easily and clearly understood.

  Since Patent Document 9 has a structure in which contact with an external electrode of a semiconductor device is performed by a pin obtained by plating a silicon needle-like single crystal, a diameter suitable for a pitch of 40 μm or less, for example, a pin diameter of 10 μm if the pitch is 20 μm. If a pin of a certain size is formed, the technology to mount gold bumps on the Si mesa before the pin growth becomes extremely difficult, the stress when applying the metal film and the damage caused by the tip trimming process after pin formation Therefore, (1) it is difficult to ensure position accuracy corresponding to the electrode pitch of the semiconductor device. (2) Since the pin diameter is a very thin wire, the pin breaks due to insufficient pin strength when overdrive is applied. In addition, a metal film is formed on the entire surface of the Si pin to obtain conduction, and a metal film is further formed on the tip, and (3) there is a problem that the cost is increased.

  Patent Document 12 is a structure in which a tungsten wire probe pin and a quartz probe are used in combination with an external electrode of a semiconductor device in accordance with the size of the electrode pitch. When the electrode pitch is small, for example, 40 μm pitch or less, the wire Since the probe pin diameter needs to be 20 μm or less, (1) production is very difficult. Even if it can be manufactured, it is difficult to accurately arrange the pins. Furthermore, there is a problem that the durability of the pin is insufficient. Similarly to the silicon pin of Patent Document 9, it is difficult to ensure the positional accuracy corresponding to the electrode pitch of the semiconductor device due to the stress when the metal film is applied to the crystal probe. (3) Since the pin diameter is an extra fine wire, the pin breaks due to insufficient pin strength when overdrive is applied. Further, when the crystal probe is used on the entire surface, (4) there is a problem that the cost is increased. Further, as a problem common to Patent Document 9, there is a problem that (5) durability at a practical level cannot be ensured even when used in an overdrive in which pin destruction does not occur.

  Therefore, an object of the present invention is to provide an electrical contact structure of a practical inspection probe suitable for inspection of a semiconductor device having an external terminal of a material that forms a narrow pitch and an oxide film, a method for forming the inspection contact method, and an inspection method. is there.

  The present invention employs the following means in order to solve the above problems.

  When obtaining contact between the probe pin 1 and the electrode 11 of the semiconductor device 10, the probe pin contacts the electrode of the semiconductor device and vibrates either the probe pin or the semiconductor device when a desired push is applied. An element inspection method having an electrical contact structure in which an oxide film on an electrode of the semiconductor device is removed by applying energy to obtain electrical contact between the probe pin and the electrode of the semiconductor device.

  As is apparent from the description of the specification, the present invention has the following effects.

  1. According to the electrical contact structure of the present invention, good contact characteristics between the probe pin and the semiconductor device electrode can be obtained.

  2. The durability of the probe pin is improved.

  3. The electrical contact structure, its formation method, and element inspection method have a simple configuration and are easy to operate.

  4). The electrical contact structure and the method for forming the electrical contact structure are inexpensive.

It is Example 1 (electrical contact structure) of this invention, and the test probe structure example 1 which applied this. It is the structure of the probe tip structure and wiring layer of Example 2 of this invention. It is an electrical contact structure (shape of fine unevenness) of the present invention. It is the fine unevenness | corrugation (Example 1) of the electrical contact part of this invention. It is the fine unevenness | corrugation (Example 2) of the electrical contact part of this invention. It is inspection probe structure example 2 to which the present invention is applied. It is inspection probe structure example 3 to which the present invention is applied. It is a probing schematic diagram of the present invention. This is the amount of scrub during probing according to the present invention. It is the electrical contact formation method 1 of this invention. It is the electrical contact formation method 2 of this invention. It is a material used for electrical contact formation of this invention. It is a probe manufacturing method of the first example to which the present invention is applied and a fine unevenness forming stage. It is a probe manufacturing method of the second example to which the present invention is applied and a fine unevenness forming stage. It is an inspection method flowchart of the present invention. It is an inspection method embodiment of the present invention. It is a 1st example of a prior art. It is 1 of the 2nd example of a prior art. It is 2 of the 2nd example of a prior art. It is a specific example of the 2nd example of a prior art. It is a basic performance measurement result of the specific example of the second example of the prior art. It is a state observation figure after contact of the example of the 2nd example of conventional technology. It is a probe pin front-end | tip external view of the specific example of the 2nd example of a prior art. It is the probing state of the specific example of the 2nd example of a prior art. It is a 3rd example of a prior art. It is a 4th example of a prior art. It is a graph of the contact characteristic measurement result of a prior art and this invention. It is a graph of the contact characteristic measurement result of a prior art and this invention. It is the graph which confirmed the influence of the sulfuric acid perwater treatment time of this invention.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an example of a cross-sectional view showing a first embodiment of the electrical contact structure of the present invention, an external SEM photograph of fine irregularities formed at the tip of a probe to be an electrical contact portion, and an inspection probe to which this is applied. Details of the inspection probe are disclosed in Patent Document 13 and Japanese Patent Application No. 2003-109843. As shown in the lower side of FIG. 1, the probe structure having the electrical contact structure according to the embodiment of the present invention extends the probe pin 1 that contacts the external terminal electrode 11 of the semiconductor device 10 as an object to be inspected and the electrode pitch. Substrate 2 based on ceramics, glass ceramics, glass having a wiring layer 3, glass or silicon coated with an insulating material, etc., backup plate 9 on which the base material is installed, inspection substrate 8 and flexibility based on polyimide FPC (Flexible Printed Circuit) 7 having

  The configuration of the probe pin 1 and the pitch expansion wiring layer 3 will be described using the upper side of FIG. The probe pin 1 and the pitch extension wiring layer 3 are simultaneously formed by electroplating with an elastic metal layer (for example, nickel, nickel / iron alloy, nickel / cobalt alloy, nickel / manganese alloy) A metal layer 5 (for example, a gold / palladium alloy) having a low specific resistance value is formed by electroplating or sputtering method.

  Thereafter, after the step of forming the metal layer 2 shown in FIGS. 13 and 14, a wrapping sheet (abrasive paper) having fine metal particles shown in FIG. 12, a ceramic substrate having an appropriate porosity, and appropriate irregularities are formed in advance. Fine tips 6 are formed by pressing and pressing the tip of the probe pin 1 against the silicon substrate, or by moving in the front-rear, left-right, and diagonal directions in a pressurized state.

  In addition, although the process of forming this fine unevenness | corrugation is explained in full detail by the below-mentioned manufacturing method, after the resist removal process shown in FIG.13, FIG.14, after removing from the surface plate shown in FIG.14, inspection shown in FIG.13,14 It can be formed at any stage after the substrate is attached.

  For example, when the contact object has a pitch of 20 μm and an electrode size of 12 μm, the contact angle of the inspection probe is 15 °, and the OD amount is 70 μm, the longitudinal direction of the probe pin 1 is the scrub amount (probe to the electrode). Of 14 μm), the electrode size (12 μm), the positional tolerance of the probe pin 1 in the longitudinal direction (± 5 μm), and the positional tolerance of the electrode 11 of the semiconductor device 10 (± 1 μm), ie, a length of 38 μm or more is required. Become. The width direction is preferably equal to the width of the probe pin 1.

  Each of the lengths required in the longitudinal direction will be described. FIG. 9 shows a view of the contact point and the state of the electrode 11 and the probe pin 1 of the semiconductor device 10 having an OD amount of 70 μm as viewed from the side. As can be seen from the figure, the scrub amount is an amount by which the probe pin 1 moves while rubbing on the electrode after the probe pin 1 contacts the electrode 11. The electrode size is a portion that contacts the probe pin 1 at the end of OD (inspection time). The tolerances between the longitudinal position of the probe pin 1 and the electrode position must be considered in order to maintain the initial positional relationship between the electrode 11 and the probe pin 1. Of course, considering the positional accuracy of the probe pin 1 in the longitudinal direction, the probe pin 1 can be protruded from the beginning by about half (6 μm) of the electrode.

  The contact angle of the inspection probe can be in the range of 0-90 °.

  After the fine irregularities 6 are formed in the above-described area, the noble metal layer 4 is formed on this portion by plating or sputtering. The low resistance metal layer 5 on the pitch extended wiring layer 3 can be formed at any stage before or after the formation of the fine irregularities 6. Further, the noble metal layer 4 and the low resistance metal layer 5 formed on the pitch expansion layer 3 at the fine irregularities 6 at the tip of the probe pin may be made of the same material or different materials. For example, it is possible to form pure gold (99.99% gold) on the low resistance metal layer 5 on the pitch extension wiring layer 3 and to form a gold alloy on the fine irregularities 6. It is also possible to form a gold alloy on both of the wiring layers 3.

  Needless to say, when the same material is used, the noble metal layer 4 and the low resistance metal layer 5 can be formed simultaneously as shown in FIG. In the case of using a different material, it is possible to divide the noble metal layer 4 formation area and the low resistance metal layer 5 formation area as shown in FIG. 2, and this is considered easier to manufacture.

  The thickness of the noble metal layer on the fine irregularities 6 needs to be formed at a level at which the irregular shape is inherited and does not disappear, and is preferably formed between 0.05 and 3 μm. FIG. 4 shows the result of measuring the fine irregularities of the electrical contact structure shown in FIG. The measurement was carried out by scanning the area within the square with a non-contact three-dimensional laser measuring machine in 0.1 μm steps in both the X and Y directions. Although 84 points are extracted, it can be seen that they have fine irregularities of 0.01 to 0.67 μm. FIG. 5 shows the measurement results of the fine irregularities formed on the tip of the probe for 20 μm pitch. It turns out that it has the fine unevenness | corrugation of 0.04-0.62 micrometer. Thus, in the case of the copper electrode processed by CMP after electrolytic plating used in this measurement, the oxide film thickness is 46 mm, and in this case, the uneven size of 1 μm or less is appropriate. Naturally, although the dimensional appropriate value of the fine unevenness varies depending on the thickness and property of the oxide film formed on the electrode, it is considered that the fine unevenness 10 times the oxide film thickness is appropriate as a guide.

  As shown in FIG. 3, the fine concavo-convex shape is a type that is formed in the same direction as the scrub direction, a type that is formed in the direction perpendicular to the scrub direction, a type that is formed by combining both in the vertical direction, and a combination file in the oblique direction. It is possible to adopt various shapes such as a type that is formed in an eye shape and a type that is formed randomly. In consideration of the generation of electrode debris after contact between the semiconductor electrode and the electrical contact portion of the present invention, the type formed in the same direction as the scrubbing direction is considered most preferable.

  Next, the effect of the precious metal layer 4 coating with the electrical contact portion at the tip of the probe pin as the fine irregularities 6 and the effectiveness of the semiconductor electrode cleaning process will be described using experimental results.

  First, the probing mechanism will be described with reference to the schematic diagram of probing in FIG. The left side of FIG. 8 is a side view and a top view before and after probing when the metal projection electrode 11 is a contact target, and the right side is a perspective view. When the probe pin 1 is subjected to an OD amount (push-in), the pin itself is elastically deformed and scrubbing is generated on the metal protruding electrode 11 to obtain electrical contact.

  FIG. 27 shows the measurement result of the contact resistance value with respect to the OD amount when the semiconductor device electrode material uses copper having an oxide film in the probe structure that obtains contact by such a mechanism. The left side of the figure is a measurement result when using a conventional electrical contact (a flat shape of the base material of the probe pin). Although continuity can be obtained when the OD amount is 60 μm or more, the absolute value of the resistance value is 10 to 40Ω, and it is clear that the contact state has a large variation and is unstable. The center of the figure is the measurement result of the contact resistance value of the probe in which the fine irregularities of the present invention are formed on the base material of the probe pin 1. Conductivity can be obtained when the OD amount is 40 μm or more, and stable contact of 1Ω or less is obtained. The right side of the figure shows the experimental results when the fine concavo-convex structure of the present invention and the cleaning process of the semiconductor electrode are performed, and the probe used is one in which the fine concavo-convex is formed on the base material described above. Conductivity is obtained when the OD amount is 20 μm or more, and stable contact properties of 0.4Ω are exhibited when the OD amount is 60 μm or more. FIG. 28 shows the experimental results when the probe having the electrical contact structure of the present invention (fine irregularities are formed on the probe pin base material and gold alloy plating is formed) and the cleaning process conditions of the semiconductor electrode are optimized. . It can be seen that a very good and stable contact of 0.3Ω is realized at an OD amount of 20 μm or more. The cleaning process condition will be described later in the item of the inspection method.

  As shown in the above experimental results, a probe having an electrical contact structure in which an appropriate fine concavo-convex shape is formed at the tip portion of the probe pin and one or more noble metal layers are arranged in this portion can provide stable contact of 1Ω or less. Furthermore, by cleaning the semiconductor electrode, it is possible to realize a very good contact characteristic of 0.3Ω with an OD amount of 20 μm or more. Therefore, a probe electrode having an electrical contact structure in which fine irregularities and a noble metal layer are formed on the tip portion of the probe pin is cleaned and combined with the semiconductor electrode, and a great effect can be obtained.

  FIG. 6 is a second example of an inspection probe structure to which the electrical contact structure of the present invention is applied. Details of this probe structure are also disclosed in Patent Document 14. In the case of the first embodiment, when assembling the structure shown in FIG. 1, it is necessary to align the positions of the four substrates with high accuracy, and the backup plate 9 needs very high accuracy. Therefore, by adopting the structure shown in the second embodiment, it is possible to further improve the contact reliability and facilitate the assembly of the structure of the first embodiment. Further, the accuracy of the backup plate 9 can be reduced, and the cost can be reduced. Of course, the structure of the tip portion of the probe pin 1 and the low resistance metal layer 5 is the same as that of the first embodiment.

  The difference in configuration from the first embodiment is disclosed in detail in Japanese Patent Application Laid-Open No. 2004-228620, and will be briefly described here. A substrate 2 having probe pins 1 with a peripheral arrangement is manufactured in a lump, the substrate 2 is thinned to about 100 μm, a support substrate 13 is attached to the outer periphery thereof with an adhesive 12, and this is attached to an inspection substrate 8. A convex support plate 15 is attached to the central portion of the inspection substrate 8 and is supported by this end face. With this support point and the bending start point of the probe substrate 2, the angle of the probe pin 1 with respect to the electrode 11 of the semiconductor device 10 can be adjusted to obtain a desired value. Unlike the first embodiment, the probe pins 1 are collectively formed on the four sides and mounted on the inspection board 8, so that the positional accuracy of the assembled probe pins 1 can be increased, and the probe pins 1 are damaged. If this occurs, the entire probe board 2 can be exchanged and has an advantage such as excellent repairability.

  By applying the electrical contact structure and the semiconductor device electrode cleaning process of the present invention to this probe structure, an electrode material having an oxide film (for example, aluminum, copper, aluminum / silicon / copper alloy, etc.) can be used for the superposition of the peripheral arrangement. Further excellent contact performance can be ensured for the fine pitch electrode.

  FIG. 7 shows a third example of the inspection probe structure to which the electrical contact structure of the embodiment of the present invention is applied. A similar structure is also disclosed in Patent Document 6 for this probe structure. However, this structure is an improvement of the probe structure shown in Example 2 and is different from Patent Document 6. That is, a through-electrode hole is formed in the outermost peripheral portion of the substrate 2 having the pitch-extended wiring layer with the pitch extended by using a laser to form a desired shape (for a pitch of 250 μm, a hole with a diameter of about 100 μm to 150 μm. The bumps 17 are formed on the back surface of the through electrodes 16 and connected to the connection pads of the inspection substrate, or an anisotropic conductive sheet is sandwiched between the upper and lower surfaces. A mechanism that can be held by pressure is provided.This structure is advantageous in terms of signal transmission characteristics in a high-frequency region because short-distance wiring is possible, and the FPC 7 is unnecessary, so that the manufacturing cost can be reduced. It has the merit that.

(About micro unevenness formation method and formation stage)
Next, the manufacturing method of the electrical contact structure of the present invention shown in FIGS. 1 to 5 will be described in detail with reference to FIGS.

  There are two types of methods for manufacturing the electrical contact structure of the present invention. In the first method, as shown in FIG. 10, a probe pin base material formed is mounted on the suction stage 18, and the materials 20, 21, 22 having irregularities on the surface shown in FIG. In this state, pressurization is performed in a state where the projections 20, 21, and 22 are transferred to a desired area at the tip of the probe pin 1. Of course, it is also possible to move the collet 19 in the forward / backward, left / right, and oblique directions after pressurization.

  Next, it will be described at which stage of the probe manufacturing process this process is performed. FIG. 13 shows a series of manufacturing steps, which will be briefly described. A counterbore 23 is formed on the substrate 2, a copper sacrificial layer is filled in the counterbore 23 by electroplating, a seed layer is formed by sputtering, and resist coating and pattern formation are performed. Thereafter, the base material of the probe pin 1 is formed by electroplating, and the low resistance metal layer 5 is formed on the wiring layer portion of the substrate 2 by electrolytic or electroless plating and sputtering. Then, resist removal and sacrificial layer removal are performed by wet etching, and the outer shape is cut. At this stage, one unit having the probe pin 1 on one side is completed. With the FPC 7 connected to this unit, four units are attached to the inspection board 8 to complete the entire process.

  In this process, it is optimal that the surface of the probe pin base material is exposed and the sacrificial layer is present, that is, after metal layer formation, metal layer formation 2, and resist removal. In the step of adding the fine unevenness to the tip of the probe pin in the manufacturing process of the probe structure of FIG. 6 (FIG. 14), the surface of the probe pin base material is exposed and a sacrificial layer is present as in FIG. In view of this stage, it is optimal to carry out after metal layer formation, metal layer formation 2, and resist removal. Furthermore, in the present probe structure, the stage after the substrate backside thinning process and removal from the surface plate are also suitable.

  The second forming method is a method of forming fine irregularities when the probe card structure is completed. This will be described with reference to FIG. After the probe card is completed, a material having fine irregularities on the surface shown in FIG. 12 is fixed to the suction stage 18 and brought into contact with the probe pin as shown in the right of FIG. In this state, the unevenness is mechanically formed by reciprocating the suction stage 18 back and forth, right and left, and obliquely. For example, when the # 2000 wrapping sheet shown in FIG. 12A) is fixed to the suction stage 18 and a 20 μm pitch probe is loaded with a 70 μm overdrive, the probe pin is reciprocated 50 times in the longitudinal direction of the probe pin with a movement amount of 300 μm. Thus, the fine unevenness shown in FIG. 5 can be formed. The formation of the noble metal layer after forming the fine irregularities has an effect of preventing oxidation on the surface of the probe base material. Therefore, the noble metal layer is formed with a thickness of one layer or more and 0.01 μm or more by electroless or electrolytic plating or sputtering.

(About inspection method)
Next, the element inspection method of the present invention will be described with reference to FIGS. FIG. 15 shows four specific examples of the device inspection method of the present invention shown in flowcharts. FIG. 16 is a cross-sectional view of a technique for applying vibration energy when using the inspection probe shown in the second embodiment to which the electrical contact structure of the present invention is applied.

  Each of the four examples will be described with reference to FIG. A (upper left in the figure) is a flow when the probe having the electrical contact structure of the present invention is simply used. This is a flow in which a probe in which an electrical contact according to the present invention is formed in advance is attached to an inspection device (prober), probed to a semiconductor device electrode to perform an electrical inspection, and after completion, the probe is separated from the electrode of the semiconductor device. . B (lower left in the figure) is a flow in which an electrical inspection is carried out by making a contact with the probe having the electrical contact structure of the present invention after cleaning the electrodes of the semiconductor device in advance. As an example of the surface cleaning method at this time, it is conceivable to use sulfuric acid / hydrogen peroxide. For example, after immersing in a mixed solution of sulfuric acid having a concentration of 96%, hydrogen peroxide solution having a concentration of 30 to 35.5% and pure water at a volume ratio of 1: 1: 100 at room temperature for 5 minutes, The surface is cleaned and blown with dry air or nitrogen gas. The volume ratio can be in the range of 1: 1: 100-1000. This method is based on the principle that copper, which is a stable metal, is melted simultaneously with an oxide film to add one thin skin by adding hydrogen peroxide having oxidizing power to sulfuric acid. Formulas (1) to (4) show chemical reaction formulas occurring in each step.

Oxidizing power of hydrogen peroxide: H2O2 → H2O + (O) ... Formula (1)
Copper is oxidized ... Cu + (O)-> CuO ... Formula (2)
Neutralization reaction ・ ・ ・ CuO + H2SO4 → CuSO4 + H2O ・ ・ ・ ・ ・ ・ ・ ・ Formula (3)
CuO + H2SO4 + H2O2 → CuSO4 + 2H2O ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Formula (4)

  C (upper right in the figure) is a flow when vibration energy is applied. As shown in FIG. 16, after using a semiconductor inspection apparatus (prober) incorporating a vibration energy generator and probing a probe having an electrical contact structure of the present invention to a semiconductor device electrode, any of left, right, front, back, and diagonal directions This is a mechanism in which the semiconductor device electrode is vibrated in the left-right, front-back, and diagonal directions by propagating such vibration to the semiconductor device, and the oxide film is broken by the fine unevenness of the present invention. Considering the arrangement of the probe pins and the electrode shape, it is optimal to operate in an oblique direction. D (lower right in the figure) is a flow in which vibration energy is applied after the semiconductor electrode is cleaned in advance and contacted using a probe having the electrical contact structure of this structure.

  If the electrode pitch of the semiconductor device is at a level of 20 μm, it is considered that good contact can be realized with the flow of B, but it can be an effective means in a further fine pitch region of 20 μm pitch or less.

  FIG. 29 shows confirmation data of the influence of the sulfuric acid / hydrogen peroxide treatment time. It was confirmed by experiments that 1 to 10 minutes for sulfuric acid / hydrogen peroxide treatment and 5 seconds to 3 minutes for washing with pure water were appropriate.

DESCRIPTION OF SYMBOLS 1 Probe pin 2 Board | substrate 3 Pitch expansion wiring layer 4 Noble metal layer 5 Metal layer 6 Fine unevenness 7 FPC
DESCRIPTION OF SYMBOLS 8 Inspection board 9 Backup board 10 Semiconductor device 11 External terminal electrode 12 Adhesive layer 13 Support board 14 Through-hole 15 Support plate 16 Through-electrode 17 Bump 18 Adsorption stage 19 Collet 20 Lapping sheet (abrasive paper)
DESCRIPTION OF SYMBOLS 21 Alumina ceramics 22 Silicon processed substrate 23 Counterbore 24 Sacrificial layer 25 Seed layer 26 Resist 27 Wax 28 Surface plate 29 Vibration energy generator 30 Film 31 Insulation sheet 32 Clamper 33 Bolt 34 Printed circuit board 35 Reinforcement plate 36 Support body 37 Metal 38 Conduction Hole 39 Protrusion 40, 42, 44 Protrusion support portion 41, 43, 45 Protrusion portion 46 Knife edge portion 47 Thin portion 48 Probe pin tip at low resistance location 49 Probe pin tip at high resistance location 50 Scrub mark on semiconductor device electrode ( Low resistance location)
51 Scrubbing mark (high resistance point) on semiconductor device electrode
52 Silicon substrate 53 Needle-shaped single crystal 54 Ni base film 55 Au film 56 Pd film 57 Wire probe needle 58 Crystal plate 59 Viewing window 60 Crystal probe needle 61 Contact pin 62 Y-axis adjustment section

Claims (6)

When obtaining contact between the probe pin and the electrode of the semiconductor device, vibration energy is applied to either the probe pin or the semiconductor device when the probe pin comes into contact with the electrode of the semiconductor device and gives a desired push. An element inspection method with an electrical contact structure that removes an oxide film on the electrode of the semiconductor device and obtains electrical contact between the probe pin and the electrode of the semiconductor device ,
When obtaining contact with the electrode of the semiconductor device using an inspection probe having fine irregularities at the tip of the probe pin, the electrode part of the semiconductor device is cleaned in advance,
A method for inspecting an element of an electrical contact structure characterized in that, as a method for cleaning an electrode of the semiconductor device, a sulfuric acid / hydrogen peroxide treatment is performed for a time required for removing an oxide film, and then a pure water cleaning process and a dry air or nitrogen gas blow are performed. .   2. The element inspection method for an electrical contact structure according to claim 1, wherein a direction in which vibration energy is applied is 0, 45, or 90 degrees with respect to the probe pin.   3. The element inspection method for an electric contact structure according to claim 1, wherein vibration energy is applied to the semiconductor device side using an inspection probe.   4. The element inspection method for an electrical contact structure according to claim 1, wherein the vibration energy is ultrasonic vibration. The composition of the SPM is sulfuric acid: hydrogen peroxide: water = 1: 1: device testing method of electrical contact structure of claim 1, wherein it is a volume ratio of 100-1000. 6. The element inspection method for an electrical contact structure according to claim 5, wherein the sulfuric acid / hydrogen peroxide treatment and the pure water cleaning time are 1 to 10 minutes and 5 seconds to 3 minutes, respectively.