Probing device and alignment method

Abstract

This invention provides a probing device that prevents misalignment by maintaining atmospheric pressure on the probe side of the semiconductor wafer. [Solution] The system comprises a base plate, a top plate, an alignment stage provided on the base plate on which a semiconductor wafer is mounted, one or more suction parts provided on the base plate, and a probe card provided on the top plate. The base plate is provided parallel to the top plate and is movable in a direction that changes the distance between the base plate and the top plate, the wafer chuck of the alignment stage is capable of adsorbing the semiconductor wafer, adsorbing to the base plate, and floating away from the base plate, and the suction parts are capable of adsorbing to the top plate.

Description

Technical Field

[0001] This invention relates to a probing device and an alignment method used for testing the electrical characteristics of semiconductor chips formed on a semiconductor wafer.

Background Art

[0002] A large number of semiconductor chips are formed on a single semiconductor wafer. In an electrical characteristic test for inspecting the electrical characteristics of semiconductor chips, a probing device is used to contact the electrodes of the semiconductor chips with the electrodes of a probe card.

[0003] Generally, in an electrical characteristic test using this probing device, the semiconductor wafer is fixed and mounted on a wafer stage by vacuum adsorption. When conducting the test, although it is common to mechanically move the semiconductor wafer closer until it adheres to the probe card, here, a method of evacuating the internal space containing the probe card and the semiconductor wafer to bring them into contact is used.

[0004] In this method, after the semiconductor wafer mounted on the wafer stage and the probe card included in the probing device are aligned, the internal space containing the probe card and the semiconductor wafer is evacuated. By evacuating this internal space, the wafer stage is attracted towards the probe card. As a result, the semiconductor chips of the semiconductor wafer mounted on the wafer stage come into contact with the probes included in the probe card, and an electrical characteristic test can be performed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005] [[ID=XX]] [[ID=XX]]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the technology disclosed in Patent Document 1 mentioned above, the semiconductor wafer is contained within the internal space that is subjected to reduced pressure. As a result, both the front side (probe card side) and the back side (wafer stage side) of the semiconductor wafer become vacuum. Consequently, the semiconductor wafer is not properly vacuum-adhered to the wafer stage. This can lead to misalignment of the semiconductor wafer, potentially preventing the probe card and the semiconductor wafer from making proper contact.

[0007] This invention has been made in view of the above-mentioned problems. The object of this invention is to provide a probing apparatus and alignment method that prevent misalignment by maintaining atmospheric pressure on the probe side of a semiconductor wafer. [Means for solving the problem]

[0008] To solve the above-mentioned problems, the probing apparatus of this invention comprises a base plate, a top plate, an alignment stage provided on the base plate on which a semiconductor wafer is mounted, one or more suction units provided on the base plate, and a probe card provided on the top plate.

[0009] The base plate is provided parallel to the top plate and is movable in a direction that changes the distance between the base plate and the top plate; the wafer chuck of the alignment stage is capable of adsorbing the semiconductor wafer, adsorbing to the base plate, and floating away from the base plate; and the adsorption portion is capable of adsorbing to the top plate.

[0010] Furthermore, according to the preferred embodiment of the probing apparatus described above, the wafer chuck of the alignment stage has an upper opening and a lower opening, the upper opening is connected to an exhaust pump, the lower opening is switchably connected to an exhaust pump and an intake pump, and the adsorption section has an adsorption opening, the adsorption opening is connected to an exhaust pump.

[0011] Furthermore, according to another preferred embodiment of the probing device described above, the suction portion is formed of a material that does not deform in shape, the suction portion is provided with an suction opening, and an O-ring is provided around the suction opening on the surface of the suction portion that contacts the top plate when the suction portion is adsorbed to the top plate.

[0012] Furthermore, according to another preferred embodiment of the probing device described above, the base plate is provided on the bottom surface of the housing via a lift mechanism.

[0013] In this case, a pressurizing mechanism may be provided between the bottom surface of the housing and the base plate at the planar position where the suction portion is provided.

[0014] Furthermore, the configuration may include a load cell for pressure detection between the base plate and the alignment stage.

[0015] Furthermore, the alignment method of this invention is an alignment method performed using the above-described probing apparatus, and comprises the steps of: adsorbing and fixing a semiconductor wafer to the wafer chuck; floating the wafer chuck away from the base plate and performing alignment; adsorbing and fixing the aligned wafer chuck to the base plate; moving the base plate to bring the probe provided on the probe card into contact with the semiconductor wafer; and exhausting the inside of the adsorption opening to adsorb and fix the base plate and the top plate.

[0016] Furthermore, according to a preferred embodiment of the alignment method described above, the method includes the steps of: adsorbing and fixing a semiconductor wafer to the wafer chuck; floating the wafer chuck away from the base plate and performing alignment; adsorbing and fixing the aligned wafer chuck to the base plate; moving the base plate to bring the probe provided on the probe card into contact with the semiconductor wafer; exhausting the inside of the adsorption opening to adsorb and fix the base plate and the top plate; and applying pressure to the top plate side relative to the base plate using the pressurizing mechanism. [Effects of the Invention]

[0017] In the probing apparatus and alignment method according to this invention, the semiconductor wafer is fixed to the wafer chuck by suction while the upper side is at atmospheric pressure and the lower side is under reduced pressure, such as a vacuum. The wafer chuck is also fixed to the base plate by suction while the upper side is at atmospheric pressure and the lower side is under reduced pressure, such as a vacuum.

[0018] Therefore, when the base plate and top plate are fixed by suction, misalignment of the semiconductor wafer and wafer chuck can be prevented.

[0019] Furthermore, during alignment, the wafer chuck is slightly elevated from the base plate. This makes it easier to align the wafer chuck. [Brief explanation of the drawing]

[0020] [Figure 1] This is a schematic diagram (1) illustrating the probing device of this invention. [Figure 2] This is a schematic diagram (2) illustrating the probing device of this invention. [Figure 3] This is a schematic diagram (3) illustrating the probing device of this invention. [Figure 4]It is a schematic diagram for explaining an alignment stage included in the probing device of this invention. [Figure 5] It is a schematic diagram for explaining contact pressure. [Figure 6] It is a schematic diagram (1) for explaining the alignment procedure. [Figure 7] It is a schematic diagram (2) for explaining the alignment procedure. [Figure 8] It is a schematic diagram (3) for explaining the alignment procedure. [Figure 9] It is a schematic diagram (4) for explaining the alignment procedure. [Figure 10] It is a schematic diagram (5) for explaining the alignment procedure.

Embodiments for Carrying Out the Invention

[0021] Hereinafter, embodiments of this invention will be described with reference to the drawings. However, the shapes, sizes, and arrangement relationships of the respective components are merely schematically shown to the extent that this invention can be understood. Note that illustration and description of some components may be omitted.

[0022] Also, hereinafter, preferred configuration examples of this invention will be described. However, the materials, numerical conditions, etc. of the respective components are merely preferred examples. Therefore, this invention is not limited to the following embodiments, and many changes or modifications can be made without departing from the scope of the configuration of this invention and achieving the effects of this invention.

[0023] The probing device of this invention will be described with reference to FIGS. 1 to 4. FIGS. 1 to 3 are schematic diagrams for explaining the probing device of this invention. FIG. 1 is a schematic plan view of the probing device as seen from above. FIGS. 2 and 3 are diagrams showing the cut end faces of the probing device shown in FIG. 1 along lines A-A and B-B, respectively. Further, FIG. 4 is mainly a schematic diagram for explaining an alignment stage included in the probing device.

[0024] The probing device comprises a base plate 100 and a top plate 200. The base plate 100 and the top plate 200 are arranged parallel to each other. The top plate 200 is positioned above the base plate 100.

[0025] The base plate 100 is attached to a lift mechanism 310 provided on the bottom surface 300 of the housing. The base plate 100 can move up and down by the drive of the lift mechanism 310. Both the bottom surface 300 and the top plate 200 are fixed to the side surface 350 of the housing. For example, an air cylinder can be used as the lift mechanism 310.

[0026] In this explanation, the base plate 100 and the top plate 200 are provided parallel to the XY plane, and the base plate 100 is provided so as to be movable in the Z direction.

[0027] To prevent the base plate 100 from shifting position or rotating in the XY plane when it moves up and down due to the drive of the lift mechanism 310, it is advisable to provide a movement / rotation prevention guide. The movement / rotation prevention guide is configured, for example, with a guide support part 312 fixed to the bottom surface 300 of the housing or the lift mechanism 310, and a guide movement part 314 attached to the lower surface of the base plate 100. A scale for detecting the exact amount of movement may also be implemented on the movement / rotation prevention guide. This scale, along with the pressure detection load cell 180 described later, enables precise control of load and position.

[0028] The guide support portion 312 and the guide movement portion 314 can be configured in any suitable shape. For example, the guide movement portion 314 can be formed in the shape of a cylinder (or rod), and the guide support portion 312 can be formed in the shape of a hollow cylinder, so that the guide movement portion 314 can move along the axis of the guide support portion 312.

[0029] An alignment stage and a suction unit 130 are provided on the upper surface of the base plate 100. The alignment stage can be a UVW stage that achieves motion in the X, Y, and θ directions by operating the U, V, and W axes. Here, an example is described in which the UVW stage, which is the alignment stage, is equipped with a wafer chuck 110 and four axis drive units 120. Note that there may be three axis drive units.

[0030] The wafer chuck 110 has an adhesive structure on both sides.

[0031] The wafer chuck 110 has an upper opening 111 on its upper side. The upper opening 111 is connected to an upper piping 112 that extends from the inside of the wafer chuck 110 to the outside of the wafer chuck 110. An upper exhaust pump 113 is also connected to the upper piping 112.

[0032] By operating the upper exhaust pump, the wafer chuck 110 vacuum-adsorbs the semiconductor wafer 500 mounted on its upper surface.

[0033] The wafer chuck 110 has a bottom opening 115 on its lower side. The bottom opening 115 is connected to a bottom piping 116 that extends from the inside of the wafer chuck 110 to the outside of the wafer chuck 110. A bottom exhaust pump 117 and a bottom intake pump 118 are also connected to the bottom piping 116. Between the bottom piping 116, the bottom exhaust pump 117, and the bottom intake pump 118, for example, a three-way valve 119 is provided to switch between intake and exhaust to the bottom piping 116.

[0034] By operating the lower exhaust pump 117, the wafer chuck 110 is fixed to the base plate 100 by suction. On the other hand, by operating the lower intake pump 118, the wafer chuck 110 is slightly lifted from the base plate 100. This makes it easy to align the wafer chuck 110.

[0035] Furthermore, as long as exhaust can be performed from the upper piping 112 and intake and exhaust from the lower piping 116, the configuration of the pump and valves is not limited to the above example and can be any suitable configuration.

[0036] The wafer chuck 110 can be made of ceramic or stainless steel with a thickness of 10 to 15 mm. This provides a rigid wafer chuck. Alternatively, the base plate 100 and top plate 200 may be made of lighter carbon fiber reinforced plastics (CFRP).

[0037] Multiple suction units 130 are arranged at equal intervals around the alignment stage on the upper surface of the base plate 100. Here, we show an example where the base plate 100 is square-shaped and the suction units 130 are provided at the four corners of the base plate 100. Suction openings 132 are provided on the upper side of the suction units 130.

[0038] The suction portion 130 can be made of a material that does not deform when the suction opening 132 is evacuated, for example, the same material as the wafer chuck 110. An O-ring 134 is provided around the suction opening 132 on the upper surface of the suction portion 130 that contacts the top plate 200.

[0039] When the O-ring 134 on the upper surface of the suction pad 130 and the lower surface of the top plate 200 are in contact, and the inside of the suction opening 132 is evacuated, the top plate 200 and the suction pad 130 are vacuum-adsorbed. As a result, the top plate 200 and the base plate 110 on which the suction pad 130 is mounted are fixed to each other. At this time, the semiconductor wafer 500 mounted on the base plate 100 comes into contact with the probe card 210 provided on the lower surface of the top plate 200.

[0040] The configuration for exhausting the inside of the adsorption opening 132 can be the same as the configuration for exhausting the inside of the upper opening 111 and lower opening 115 of the wafer chuck 110 described above, so the illustration and detailed explanation are omitted here.

[0041] The suction part 130 has, for example, an area of ​​100 cm² on its upper surface. 2 It is equipped with an adsorption opening 132 of a certain degree, and by exhausting the air from inside this adsorption opening 132, the base plate 100 and the top plate 200 are vacuum-adsorbed. If, for example, four adsorption units 130 are evenly arranged around the wafer chuck 110, an adsorption capacity of about 300 kgf can be obtained.

[0042] Here, an example has been described in which the adsorption section 130 is configured as an adsorption pocket that does not deform when the adsorption opening 132 is vented, but the system is not limited to this. If an adsorption pad is used as the adsorption section 130, it may deform when the adsorption opening is vented, reducing the contact area with the top plate 200, and potentially preventing the desired adsorption capacity from being obtained. For this reason, it is preferable to use an adsorption pocket to ensure the desired adsorption capacity is obtained. However, if the desired adsorption capacity can be expected, an adsorption pad that may deform when vented can also be used.

[0043] The base plate 100 can be configured to include a pressurizing mechanism 360 between the housing bottom surface 300 and the base plate 100 at the planar position where the suction portion 130 is located, when viewed from above. With the pressurizing mechanism 360, if the contact between the probe card 210 and the semiconductor wafer 500 is insufficient due to suction by the suction portion 130, the contact pressure between the probe card 210 and the semiconductor wafer 500 can be increased by applying auxiliary pressure.

[0044] The contact pressure between the probe card 210 and the semiconductor wafer 500 will be explained with reference to Figure 5. Figure 5 is a schematic diagram illustrating the contact pressure between the probe card 210 and the semiconductor wafer 500. In Figure 5, the horizontal axis represents the position of the semiconductor wafer in the Z direction, and the vertical axis represents the pressure (contact pressure).

[0045] When the semiconductor wafer moves in the Z direction, the contact pressure is 0 kgf until the probe on the probe card 210 makes contact with the semiconductor wafer. The probe and semiconductor wafer are not in contact at the point when the base plate is moved by the lift mechanism until the top plate and the upper O-ring of the adsorption part make contact. After the top plate and the O-ring make contact, the top plate and the adsorption part are adsorbed by exhausting air from the adsorption opening, but the distance the base plate, i.e., the semiconductor wafer moves at this time is, for example, about 50 μm. In this case, sufficient contact pressure may not be obtained, so it is preferable to apply pressure using a pressurizing mechanism.

[0046] In this case, it is preferable to install a pressure-sensing load cell 180 between the base plate 100 and the wafer chuck 110. By measuring the contact pressure using this pressure-sensing load cell 180, it is possible to confirm whether the contact between the semiconductor wafer 500 and the probe on the probe card 210 is appropriate. Furthermore, the pressure applied by the pressure-sensing mechanism 360 can be appropriately controlled.

[0047] In particular, proper control of contact pressure is extremely important for multi-pin probe cards. In the example shown earlier, the contact pressure changes by approximately 300 kgf for a 50 μm travel distance on the semiconductor wafer. Therefore, if the pressure value is not monitored and controlled by the pressurization mechanism 360, there is a risk of irreversibly damaging the very expensive probe card.

[0048] Furthermore, although detailed explanations and illustrations are omitted here, a pressure detection load cell may be provided on the portion of the top plate 200 that contacts the upper surface of the adsorption portion 130 in order to confirm whether the parallelism between the semiconductor wafer 500 and the probe card 210 is maintained.

[0049] Refer to Figures 6-10 to explain the alignment procedure. Figures 6-10 are schematic diagrams illustrating the alignment process.

[0050] First, in the first step, the semiconductor wafer 500 is placed on the wafer chuck 110, and the opening 111 on the upper side of the wafer chuck 110 is evacuated. This causes the semiconductor wafer 500 to be adsorbed and fixed onto the upper surface of the wafer chuck 110 (Figure 6). At this time, a vertical imaging microscope (hereinafter simply referred to as a microscope) 600 capable of imaging both above and below may be inserted between the semiconductor wafer and the probe card to check and correct wafer misalignment.

[0051] Next, in the second step, air is sent to the lower opening 115 of the wafer chuck 110. As the air sent to this lower opening 115 is blown out from the lower side of the wafer chuck 110, the pressure of this air causes the wafer chuck 110 to lift slightly above the base plate 100. Alignment is then performed with the wafer chuck 110 in this lifted position above the base plate 100 (Figure 7).

[0052] Next, in the third step, the opening 115 on the lower side of the wafer chuck 110 is evacuated. This causes the aligned wafer chuck 110 to be adsorbed and fixed onto the upper surface of the base plate 100 (Figure 8).

[0053] Next, in the fourth step, the base plate 100 is lifted by the base lift 310 provided on the underside of the base plate 100 to a position where the semiconductor wafer 500 and the probe provided on the probe card 210 come into contact. At this time, the upper surface of the suction pad provided on the base plate comes into contact with the lower surface of the top plate (Figure 9).

[0054] Next, in the fifth step, the exhaust pump for the suction pad is activated. This causes the base plate 100 and the top plate 200 to be adsorbed and fixed together while the semiconductor wafer 500 and the probe are in contact (Figure 10).

[0055] In this case, the semiconductor wafer 500 is fixed to the wafer chuck 110 by suction, with the upper side (probe card 210) at atmospheric pressure and the lower side (wafer chuck 110) under reduced pressure, such as a vacuum. Similarly, the wafer chuck 110 is fixed to the base plate 100 by suction, with the upper side (probe card 210) at atmospheric pressure and the lower side (base plate 100) under reduced pressure, such as a vacuum.

[0056] Therefore, when the base plate 100 and the top plate 200 are adsorbed and fixed together, misalignment of the semiconductor wafer 500 and the wafer chuck 110 can be prevented.

[0057] Furthermore, in the probing apparatus of this invention described above, an alignment stage is mounted on the base plate 100. Therefore, by inserting a microscope capable of imaging both vertically and horizontally between the semiconductor wafer and the probe card, it becomes possible to check and correct wafer misalignment while the semiconductor wafer is fixed to the wafer chuck 110, unlike in conventional technology. For this reason, even in so-called multi-probers with multiple measurement units, position correction can be performed simply by inserting the microscope as needed. [Explanation of symbols]

[0058] 100 base plate 110 Wafer Chuck 111 Top side opening 112 Top side piping 113 Top-mounted exhaust pump 115 Bottom side opening 116 Bottom side piping 117 Bottom exhaust pump 118 Bottom intake pump 119 Three-way valve 120 Axis drive unit 130 Adsorption part 132 Adsorption opening 134 O-rings 180 Pressure detection load cell 200 Top Plate 210 Probe Card 300 Bottom of the enclosure 310 Lift Mechanism 312 Guide support section 314 Guide movement section 350 Side view of the enclosure 360 Pressurization Mechanism 500 semiconductor wafers 600 Microscopes

Claims

1. base plate and Top plate and An alignment stage is provided on the base plate on which a semiconductor wafer is mounted, A plurality of adsorption units are provided on the base plate and arranged around the alignment stage, The probe card provided on the top plate and Equipped with, The base plate is provided parallel to the top plate and is movable in a direction that changes the distance between the base plate and the top plate. The wafer chuck of the alignment stage is capable of adsorbing the semiconductor wafer when the upper surface of the semiconductor wafer is at atmospheric pressure, is capable of adsorbing the semiconductor wafer to the base plate when the upper surface of the semiconductor wafer is adsorbed at atmospheric pressure, and is capable of floating away from the base plate when the upper surface of the semiconductor wafer is adsorbed at atmospheric pressure. The adsorption portion is capable of adsorbing to the top plate when the upper surface of the semiconductor wafer is at atmospheric pressure, the semiconductor wafer is adsorbed to the wafer chuck, and the wafer chuck is adsorbed to the base plate. Probing device.

2. The wafer chuck of the alignment stage is provided with an upper opening and a lower opening. The aforementioned upper opening is connected to the exhaust pump. The aforementioned lower opening is switchably connected to an exhaust pump and an intake pump. The adsorption portion is equipped with an adsorption opening, The aforementioned adsorption opening is connected to the exhaust pump. The probing apparatus according to claim 1.

3. The adsorption part is, It is made of a material that does not deform, The adsorption portion is equipped with an adsorption opening, The adsorption opening is connected to an exhaust pump, and The adsorption portion is provided with an O-ring around the adsorption opening on the surface that contacts the top plate when adsorbed to the top plate. The probing apparatus according to claim 1.

4. The base plate is provided on the bottom surface of the housing via a lift mechanism. The probing apparatus according to claim 1.

5. A pressurizing mechanism is provided between the bottom surface of the housing and the base plate at the planar position where the suction portion is provided. The probing apparatus according to claim 4.

6. A load cell for pressure detection is provided between the base plate and the alignment stage. The probing apparatus according to claim 5.

7. An alignment method performed using a probing device according to any one of claims 1 to 6, The steps include: adsorbing and fixing a semiconductor wafer to the wafer chuck, The steps include lifting the wafer chuck from the base plate and aligning it, The steps include: fixing the aligned wafer chuck to the base plate by suction; The steps include moving the base plate to bring the probe provided on the probe card into contact with the semiconductor wafer, The steps of adhering and fixing the base plate and the top plate together. An alignment method comprising [a specific feature / feature].

8. An alignment method performed using the probing device described in claim 5 or 6, The steps include: adsorbing and fixing a semiconductor wafer to the wafer chuck, The steps include lifting the wafer chuck from the base plate and aligning it, The steps include: fixing the aligned wafer chuck to the base plate by suction; The steps include moving the base plate to bring the probe provided on the probe card into contact with the semiconductor wafer, The steps include: fixing the base plate and the top plate by suction, The pressurizing mechanism applies pressure to the base plate toward the top plate, and An alignment method comprising [a specific feature / feature].

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