JP4936707B2 - Prober - Google Patents

Description

  The present invention relates to a prober for connecting a die electrode to a tester in order to perform electrical inspection of a plurality of semiconductor chips (die) formed on a semiconductor wafer, and in particular, heating and cooling a wafer chuck holding the wafer. It is related to a prober that can be inspected in high and low temperature environments.

  In the semiconductor manufacturing process, various processes are performed on a thin disk-shaped semiconductor wafer to form a plurality of chips (dies) each having a semiconductor device (device). Each chip is inspected for electrical characteristics, then separated by a dicer, and then fixed to a lead frame and assembled. The inspection of the electrical characteristics is performed by a wafer test system composed of a prober and a tester. The prober holds the wafer on the stage and brings the probe into contact with the electrode pad of each chip. The tester supplies power and various test signals from the terminals connected to the probe, and analyzes the signals output to the electrodes of the chip with the tester to check whether it operates normally.

  Semiconductor devices are used in a wide range of applications, and there are also semiconductor devices (devices) that are used in low temperature environments such as -50 ° C and high temperature environments such as 150 ° C. It is required that the inspection can be performed. Therefore, a wafer temperature adjusting means for changing the surface temperature of the wafer chuck such as a heater mechanism, a chiller mechanism, and a heat pump mechanism is provided under the wafer mounting surface of the wafer chuck for holding the wafer in the prober. Heating or cooling the wafer held thereon is performed.

  FIG. 1 is a diagram showing a schematic configuration of a wafer test system including a prober having a wafer temperature adjusting means. As shown, the prober 10 includes a base 11, a moving base 12, a Y-axis moving table 13, an X-axis moving table 14, a Z-axis moving unit 15, and a Z-axis moving table provided thereon. 16, θ rotation unit 17, wafer chuck 18, wafer alignment camera 19, support columns 20 and 21, head stage 22, card holder 23 provided on the head stage 22, and probe attached to the card holder 23. Card 24. The probe card 24 is provided with a cantilever type probe 25. The movement base 12, the Y-axis movement table 13, the X-axis movement table 14, the Z-axis movement unit 15, the Z-axis movement table 16, and the θ rotation unit 17 move the wafer chuck 18 in the three-axis direction and the Z-axis direction. It constitutes a moving / rotating mechanism that rotates around the center. Since the moving / rotating mechanism is widely known, the description thereof is omitted here. The probe card 24 has a probe 25 arranged according to the electrode arrangement of the device to be inspected, and is exchanged according to the device to be inspected. A needle alignment camera 19 for detecting the position of the probe and a cleaning mechanism for cleaning the probe are provided, but are omitted here.

  The tester 30 includes a tester body 31 and a contact ring 32 provided on the tester body 31. The probe card 24 is provided with a terminal connected to each probe, and the contact ring 32 has a spring probe arranged so as to contact the terminal. The tester body 31 is held with respect to the prober 10 by a support mechanism (not shown). The prober 10 performs measurement in cooperation with the tester 30 in the wafer test, but its power supply system and mechanism are independent from the tester body and the test head.

  When performing the inspection, the tip position of the probe 25 is detected by a needle alignment camera (not shown). Next, with the wafer W to be inspected held by the wafer chuck 18, the Z-axis moving table 16 is moved so that the wafer W is positioned under the wafer alignment camera 19, and the electrode pads of the semiconductor chips on the wafer W are moved. The position of is detected. It is not necessary to detect the positions of all the electrode pads of one chip, and the positions of several electrode pads may be detected. Further, it is not necessary to detect the electrode pads of all the chips on the wafer W, and the positions of the electrode pads of several chips are detected.

  After detecting the position of the probe 25 and the position of the electrode on the wafer W, the wafer chuck 18 is rotated by the θ rotating unit 17 so that the arrangement direction of the electrode pads of the chip matches the arrangement direction of the probe 25. Then, after moving so that the electrode pad of the chip to be inspected on the wafer W is positioned below the probe 25, the wafer chuck 18 is raised and the electrode pad is brought into contact with the probe 25. Then, a power source and a test signal are supplied from the tester main body 31 to the electrode via the contact ring 32, and a signal output to the electrode is detected to check whether it operates normally.

  The above is the schematic configuration of the wafer test system. In the prober that can inspect the wafer W held by heating or cooling the wafer chuck at a high temperature or low temperature, the heater 26 and the coolant path 27 are provided in the wafer chuck 18. Provided. A cooling liquid flows from the cooling liquid source 28 to the cooling liquid path 27 via the path 29 to cool the surface of the wafer chuck 18 holding the wafer W. The heater 26 generates heat to heat the surface of the wafer chuck 18 that holds the wafer W.

  In addition, a vacuum path or the like for vacuum-sucking the wafer W is provided in the wafer chuck 18, and there are various modified examples of the arrangement of the heater 26, the coolant path 27, and the vacuum path in the wafer chuck 18. . In the following description, the heating mechanism including the heater 26 and the cooling mechanism including the coolant path 27, the coolant source 28, and the path 29 are collectively referred to as wafer temperature adjusting means. Therefore, the wafer temperature adjusting means may have only one of a cooling mechanism and a heating mechanism. The wafer temperature adjusting means can also be realized by a heat pump mechanism or the like.

  When the inspection is performed at a predetermined temperature, the wafer temperature adjusting means is controlled so that the wafer chuck 18 reaches a predetermined temperature while the wafer W is held on the wafer chuck 18. The wafer chuck 18 is made of a material such as a metal such as aluminum or copper or a ceramic having good thermal conductivity.

  Since the configuration of the prober and wafer test system described above is widely known, further description is omitted here.

  The wafer temperature adjusting means can set the wafer W held on the wafer chuck 18 to an arbitrary temperature from −55 ° C. to + 200 ° C., for example. Only the wafer chuck 18 and the wafer W held thereon need to be changed in temperature for inspection. If the heat capacity of the portion where the temperature is changed is large, it takes a long time to change the temperature to a desired temperature, and it is necessary to increase the capability of the wafer temperature adjusting means, resulting in an increase in cost. Further, the temperature of the wafer chuck 18 is changed, and the heat base 12, the Y-axis moving table 13, the X-axis moving table 14, the Z-axis moving unit 15, and the Z-axis moving are configured. When heat is transferred to the base 16 and the θ rotation unit 17 and the temperature of these parts changes, the movement and rotation accuracy of the movement / rotation mechanism decreases, and the positional accuracy of bringing the probe 25 into contact with the electrode decreases. Produce.

  In order to solve such a problem, Patent Document 1 describes a heat insulation mechanism for a wafer chuck, and Patent Document 2 describes a mechanism for reducing heat transfer between the wafer chuck and a moving part.

JP 2003-59985 A (Overall) JP 2003-59986 A (Overall)

  On the other hand, the number of probes in the probe card tends to increase for improving inspection throughput, and the contact pressure of the entire probe is very large. For example, even if the contact pressure of each probe is 5 g, if the number of probes is 1000, the total contact pressure is 5 kg. For this reason, the wafer chuck is not only required to have a very small deformation even when the probe contacts the wafer electrode held by the wafer chuck, but also when the probe is brought into contact with the periphery of the wafer. Is required to have a very small inclination. For this purpose, in the configuration of FIG. 1, not only the wafer chuck 18 itself has sufficient rigidity, but also the structure for supporting the wafer chuck 18 (the θ rotating portion 17 in FIG. 1) must not be deformed. For this purpose, it is desirable to support the wafer chuck 18 over the entire back surface.

  However, if the entire back surface of the wafer chuck 18 is supported, the area of the heat transfer path with respect to the support portion is widened, and the temperature of the rotation / movement mechanism that is the support portion changes to cause a problem that the movement and rotation accuracy is reduced. .

  Patent Document 1 describes a configuration in which a heat insulating member is provided between the wafer chuck 18 and a rotation / movement mechanism that is a supporting portion. However, the heat insulating member is difficult to process with high accuracy, has insufficient rigidity, and costs are low. There is a problem that it is expensive.

  Patent Document 2 has a configuration in which an intermediate member is provided between the wafer chuck 18 and the rotation / movement mechanism that is the support portion, so that the heat dissipation efficiency of the intermediate member is increased and the heat of the wafer chuck 18 is not transmitted to the support portion. Although described, since the heat capacity of the wafer chuck 18 is substantially increased, it takes a long time to change to the desired temperature as described above, and it is necessary to increase the capability of the wafer temperature adjusting means. There is a problem that the cost increases.

  SUMMARY OF THE INVENTION The present invention solves the above-described problems, and an object of the present invention is to realize a wafer chuck having a simple configuration, a substantially low heat capacity, and small deformation and inclination even when a probe is brought into contact with the wafer.

  In order to achieve the above object, the prober of the present invention is provided with a wafer chuck support part for supporting a wafer chuck on a moving / rotating table that moves and rotates, and the wafer chuck support part is provided on the wafer chuck for holding a wafer. The wafer chuck is supported around a diameter portion of 75% to 85% of the circular range. Here, it is assumed that the probe contacts the entire range of the wafer and a contact pressure is applied to the entire range of the wafer. However, when the contact pressure is not applied to the entire range of the wafer, the range in which the contact pressure is applied is a circular range. And

  That is, the prober of the present invention includes a probe card having a probe that contacts an electrode of a semiconductor device formed on a wafer and connects the electrode to a terminal of a tester, a wafer chuck that holds the wafer, A temperature adjusting means for adjusting the temperature; and a moving rotation mechanism for moving and rotating the wafer chuck. In order to inspect a plurality of semiconductor devices formed on the wafer with a tester, each terminal of the tester is A prober connected to the electrode of the semiconductor device, wherein the moving and rotating mechanism is a moving and rotating table that moves and rotates, and a wafer chuck support that is provided on the moving and rotating table and supports the wafer chuck, The wafer chuck support portion is centered on a diameter portion of 75% to 85% of a circular range on the wafer chuck holding the wafer. Characterized by supporting the wafer chuck Te.

  The inventor of the present application provides a wafer chuck support unit on a moving / rotating table that moves and rotates to support the wafer chuck. If the wafer chuck support unit supports any part of the wafer chuck, We simulated whether the deformation and tilt were small even when the probe was touched. As a result, if the wafer chuck is supported around a diameter portion of 75% to 85% of the circular range on the wafer chuck holding the wafer, the deformation and inclination of the wafer chuck when the probe is brought into contact with the wafer are the smallest. I found out. In addition, the inventors have found that even if the area of the portion where the wafer chuck support portion contacts the wafer chuck is small, the deformation and the inclination do not change. Accordingly, the contact area between the wafer chuck and the support portion can be made very narrow to reduce the area of the heat transfer path, so that the heat capacity of the wafer chuck does not substantially increase and includes a moving / rotating table due to a temperature change of the wafer chuck. The temperature change of the rotation / movement mechanism can also be reduced.

  The wafer chuck support portion can have various shapes. For example, even in the case of a ring shape having a diameter of 75% to 85% of the circular range for holding the wafer on the wafer chuck, a plurality of independent support members are used. Each support member may support the wafer chuck at a portion having a diameter of 75% to 85% of the circular range.

  In order to reduce heat transfer from the wafer chuck to the moving / rotary table, including heat transfer through the wafer chuck support and heat radiation from the back surface of the wafer chuck and heat transfer through gas (air), It is desirable to blow air to the back surface of the wafer chuck. For this reason, it is desirable to provide a vent hole in the moving / rotating table so as to communicate with the space between the lower surface of the wafer chuck. Further, when the wafer chuck support portion is ring-shaped, it is desirable to provide a vent hole in the wafer chuck support portion. When the wafer chuck support part is composed of a plurality of independent support members, ventilation is possible as it is.

  The wafer chuck support is preferably made of a material having good thermal insulation.

  The temperature adjusting means for adjusting the temperature of the wafer chuck can be provided at least partially inside the wafer chuck as shown in FIG. 1, but may be attached to the lower part of the wafer chuck, for example.

  According to the present invention, even when a probe is brought into contact with a wafer, the deformation and inclination of the wafer chuck are small even when the probe is brought into contact with the wafer chuck, and the heat capacity of the wafer chuck is not substantially increased. Temperature changes of the rotation / movement mechanism including the turntable can also be reduced. As a result, a prober capable of positioning with high accuracy and setting the inspection temperature in a short time can be realized at low cost.

  2A and 2B are views showing the configuration of the wafer chuck portion of the prober according to the first embodiment of the present invention. FIG. 2A is a side sectional view and FIG. 2B is a top view. . The parts other than the illustrated part are the same as the conventional example shown in FIG.

  As shown in the figure, the wafer chuck 51 is supported by eight support members 53 on a moving / rotating table 54 that can be moved in three axial directions by a moving / rotating mechanism and that can rotate around the Z axis. The moving / turning table 54 is made of metal and is supported by a member 56 of the θ rotating portion. The wafer chuck 51 is made of, for example, a metal such as aluminum or copper, or a highly rigid high thermal conductive ceramic such as aluminum nitride or silicon carbide. The illustrated example is made of aluminum and has a diameter of 320 mm or more and a thickness of 20 mm so that a wafer having a diameter of about 305 mm (12 inches) can be held. The support member 53 is made of, for example, a material having low thermal conductivity such as alumina ceramic, zirconia, or steatite, and, as shown in FIG. The wafer chuck 51 is supported at the location.

  Although not shown, a vacuum path for vacuum-sucking the wafer W is provided inside the wafer chuck 51.

  On the lower surface of the wafer chuck 51 other than the portion supported by the support member 53, temperature adjusting means 52 is provided to make the wafer chuck 51 high and / or low. The temperature adjusting means 52 includes the heater 26 and / or the coolant path 27 shown in FIG. 1, and coolant is supplied to the coolant path from a coolant source (not shown) provided at a distant position. It is also possible to configure the temperature adjusting means 52 by other means such as a heat pump. By providing the temperature adjusting means 52 externally, maintenance and the like are facilitated as compared with the case where the temperature adjusting means is provided inside as shown in FIG.

  A hole 57 is provided in the member 56 of the θ rotation section, and a hole 55 is provided in the moving / rotation table 54. The temperature of the lower surface of the wafer chuck 51 is adjusted via the holes 57 and 55 by a blower mechanism (not shown). A gas at normal temperature is blown to the lower surface of the means 52 so that the gas is removed from between the support members 53 to the outside. Thereby, since the lower surface of the temperature adjustment means 52 approaches normal temperature, the amount of heat transfer to the moving / rotary table 54 including heat transfer through heat radiation and gas (air) can be reduced.

  As shown in FIG. 2B, the position of the wafer chuck 51 supported by the support member 53 is a portion having a diameter φA from the center of the wafer chuck 51, and φA is 75 to 85% of the diameter φB of the wafer W. Value. The inventor of the present application simulated the deformation and inclination when the probe is brought into contact with the wafer with the configuration as shown in the figure, and as a result, when such a condition is satisfied, the deformation and inclination of the wafer chuck 51 are minimized. I found it.

  The wafer chuck of the first embodiment is small in deformation and inclination when the probe is brought into contact with the wafer as described above, has a small contact area with the wafer chuck of the support member, and the support member has low thermal conductivity. Since it is made of a material, even if the temperature of the wafer chuck is changed, the change is not transmitted to the movement / rotation table 54 and the movement / rotation mechanism below it, and the movement and rotation accuracy is low.

  FIG. 3 is a cross-sectional view showing the configuration of the wafer chuck portion of the prober according to the second embodiment of the present invention. The portions other than the illustrated portion are the same as those in the first embodiment shown in FIG. It is the same. In the second embodiment, the temperature adjusting means 62 is provided in the wafer chuck 61 as in the conventional example shown in FIG. The support member 63 has a ring shape and is provided with ventilation holes 64 at a plurality of locations. The moving / rotating table 65 is provided with ventilation holes 66 at a plurality of locations other than the center. Thereby, the member of the θ rotating portion can support the central portion of the moving / rotating table 65.

  As shown in the figure, in the second embodiment, the diameter φA of the center of the support portion of the ring-shaped support member 63 is 75 to 85% of the diameter φB of the wafer W.

  Since the features of the second embodiment are the same as those of the first embodiment, further explanation is omitted.

  Although the embodiments of the present invention have been described above, it goes without saying that various modifications can be made to the present invention as described in the description. In addition to those described above, for example, when it is not necessary to rotate the wafer chuck around the Z axis, the moving / rotating table does not need to rotate.

  The present invention is applicable to any prober having a temperature-adjustable wafer chuck.

It is a figure which shows schematic structure of a wafer test system provided with the prober which has a wafer temperature adjustment mechanism. It is a figure which shows the structure of the part of the wafer chuck | zipper of the prober of 1st Example of this invention. It is a figure which shows the structure of the part of the wafer chuck | zipper of the prober of 2nd Example of this invention.

Explanation of symbols

51 Wafer chuck 52 Temperature adjusting means 53 Support member 54 Moving / rotating table W Wafer

Claims (5)

A probe card having a probe that contacts an electrode of a semiconductor device formed on a wafer and connects the electrode to a terminal of a tester;
A wafer chuck for holding the wafer;
Temperature adjusting means for adjusting the temperature of the wafer chuck;
A prober for connecting each terminal of the tester to an electrode of the semiconductor device in order to inspect a plurality of semiconductor devices formed on the wafer with a tester. Because
The moving and rotating mechanism includes a moving / rotating table that moves and rotates, and a ring-shaped wafer chuck support portion that is provided on the moving / rotating table and supports the wafer chuck,
A wafer chuck supporting portion that supports the wafer chuck around a diameter portion of 75% to 85% of a circular mounting range of the circular wafer on the wafer chuck holding the wafer ;
The prober characterized in that the ring-shaped wafer chuck support portion has a vent hole .   The prober according to claim 1, wherein the wafer chuck support portion is made of a material having good thermal insulation.   The prober according to claim 1, wherein the moving / turning table has a vent hole communicating with a space between the wafer chuck and a lower surface of the wafer chuck.   The prober according to claim 1, wherein at least a part of the temperature adjusting means is provided inside the wafer chuck.   The prober according to claim 1, wherein the temperature adjusting unit is attached to a lower portion of the wafer chuck.

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