JP6424794B2 - Semiconductor device evaluation apparatus and evaluation method - Google Patents

Description

  The present invention relates to an evaluation apparatus and an evaluation method of a semiconductor device provided with an ink hit detection function.

  The electrical characteristics and the like of each of the plurality of semiconductor devices formed on the wafer are evaluated. In this evaluation, the semiconductor device (defective chip) judged to be defective is hit with ink to distinguish it from the semiconductor device (good chip) judged to be good. However, there is no position information (map information) of the defective chip after the defect determination, that is, in the case of purchasing a wafer after the ink is hit. For this reason, in the retest of all the semiconductor devices formed on the wafer, the ink of the defective chip comes in contact with the probe, so that the retest can not be performed. In addition, since the number of non-defective products and the position information are visually obtained, it takes time and erroneous recognition.

  Therefore, it is important to obtain accurate defective chip position information (map information) particularly in retesting. Under such circumstances, as a method of sorting the quality after marking, a method is disclosed in which magnetic ink containing a magnetic material is used as a marking material and sorting of quality is performed by a magnetic sensor (see, for example, Patent Document 1) ). There is also disclosed an apparatus for determining the suitability of a defect mark by a TV camera (see, for example, Patent Document 2).

Japanese Patent Application Laid-Open No. 52-95965 JP-A-62-136041

  However, the method of using a special magnetic ink containing a magnetic material has a problem that the cost increases. And, in retesting of the purchased semiconductor device, since it is necessary to detect the special magnetic ink containing the magnetic material at the purchase source, operation is difficult. Furthermore, it was not easy to divert to the conventional evaluation apparatus.

  Moreover, in the method of using a TV camera, the installation position of the TV camera is unknown, and it is difficult to divert the conventional device. Then, the position and the angle of the TV camera can not be changed to face the semiconductor device to be evaluated, and the device can not cope with a plurality of semiconductor devices.

  The present invention has been made to solve the problems as described above, and an object thereof is to obtain an evaluation device and an evaluation method of a semiconductor device capable of detecting the presence or absence of ink hitting of a semiconductor device at low cost. is there.

An apparatus for evaluating a semiconductor device according to the present invention comprises a chuck stage for fixing a wafer on which a plurality of semiconductor devices are formed, an insulating substrate, a probe fixed to the insulating substrate, and the semiconductor device via the probe. And an ink spot detection unit provided on the insulating substrate and detecting presence or absence of an ink spot of the semiconductor device , the ink spot detection unit includes: The semiconductor device according to the present invention is characterized in that it faces both the semiconductor device in contact with the probe during the evaluation and the semiconductor device adjacent to the semiconductor device .

  In the present invention, the ink hit detection unit is added to the insulating substrate on which the probe is fixed. Thus, since the conventional evaluation apparatus can be diverted, it is possible to detect the presence or absence of the ink hit point of the semiconductor device at low cost.

It is a figure which shows the evaluation apparatus of the semiconductor device concerning Embodiment 1 of this invention. It is a side view for explaining operation of a probe. FIG. 2 is a plan view showing a wafer on which a plurality of semiconductor devices to be evaluated are formed. It is sectional drawing along I-II of FIG. It is a figure which shows the evaluation method of the semiconductor device which concerns on Embodiment 1 of this invention. It is a figure which shows the modification of the evaluation method of the semiconductor device which concerns on Embodiment 1 of this invention. It is a figure which shows the evaluation apparatus of the semiconductor device which concerns on Embodiment 2 of this invention. It is a figure which shows the evaluation apparatus of the semiconductor device concerning Embodiment 3 of this invention. It is a figure which shows the evaluation apparatus of the semiconductor device concerning Embodiment 4 of this invention.

  An evaluation apparatus and an evaluation method of a semiconductor device according to an embodiment of the present invention will be described with reference to the drawings. The same or corresponding components may be assigned the same reference numerals and repetition of the description may be omitted.

Embodiment 1
FIG. 1 is a view showing an evaluation apparatus of a semiconductor device according to a first embodiment of the present invention. The chuck stage 1 fixes the wafer 2. A plurality of semiconductor devices 3 to be evaluated are formed on the wafer 2. The chuck stage 1 is a pedestal that fixes the wafer 2 in contact with the installation surface (rear surface) of the wafer 2. The means for fixing the wafer 2 is, for example, vacuum suction, but is not limited to this and may be electrostatic suction or the like.

  The semiconductor device 3 is a semiconductor device 3 having a vertical structure in which a large current flows in the vertical direction (out-of-plane direction) of the device. However, the present invention is not limited to this, and the semiconductor device 3 may be a semiconductor device having a lateral structure that performs input and output on one surface thereof.

  A plurality of probes 4 are fixed to the insulating substrate 5. The plurality of probes 4 are connected to the connection portion 6 by wiring (not shown) such as a metal plate provided on the insulating substrate 5. The probe base portion 7 is configured by the plurality of probes 4, the insulating substrate 5, the connection portion 6, and the wiring (not shown). The probe base portion 7 can be moved in any direction by the moving arm 8. Here, the configuration is such that the probe base 7 is held by one moving arm 8. However, the present invention is not limited to this, and a plurality of moving arms may be held stably. Also, the chuck stage 1 and the wafer 2 may be moved instead of moving the probe base portion 7.

  In the evaluation of the semiconductor device 3 of vertical structure, the back surface electrode in which the plurality of probes 4 are electrically connected to the front surface electrode provided on the front surface of the semiconductor device 3 and the chuck stage 1 is provided on the back surface of the semiconductor device 3 Electrically connected to

  The connection portion 6 of the insulating substrate 5 is connected to the evaluation / control unit 10 via the signal line 9. The surface of the chuck stage 1 is connected to the evaluation / control unit 10 via a connection portion 11 and a signal line 12 provided on the side surface of the chuck stage 1. The evaluation / control unit 10 applies a current to the semiconductor device 3 through the plurality of probes 4 to evaluate the electrical characteristics of the semiconductor device 3.

  A plurality of evaluation probes 4 are provided on the assumption that a large current (for example, 5 A or more) is applied. It is desirable that the distance between the connection portion 6 of the insulating substrate 5 and the connection portion 11 of the chuck stage 1 be approximately the same regardless of which probe 4 so that the current density applied to each of the probes 4 substantially matches. Therefore, it is desirable that the connection portion 6 and the connection portion 11 be disposed at positions facing each other via the probe 4.

  In the present embodiment, an image processing camera 13 is provided on the insulating substrate 5 as an ink dot detection unit. The image processing camera 13 faces the semiconductor device 3 with which the probe 4 is in contact at the time of evaluation. The image processing camera 13 captures an image of the surface of the semiconductor device 3. The image processing unit 14 performs image processing (for example, comparison by binarization) of this image to detect the presence or absence of the ink spot applied to the surface of the semiconductor device 3 which is an object to be measured. A difference in contrast occurs on the surface of each semiconductor device 3 depending on the presence or absence of the ink spot. Since the difference in contrast can be recognized using, for example, a binarized image processing method, ink dot detection can be performed.

  FIG. 2 is a side view for explaining the operation of the probe. The probe 4 has a tip 4 a in mechanical and electrical contact with the surface electrode 15 of the semiconductor device 3, a barrel 4 b as a base fixed to the insulating substrate 5, and a spring such as a spring incorporated therein. It has a plunger portion 4d including a pressing portion 4c slidable at the time of contact via a member, and an electrical connection portion 4e which is electrically connected to the plunger portion 4d and serves as an output end to the outside.

  The probe 4 is made of a conductive material, for example, a metallic material such as copper, tungsten or rhenium tungsten. However, the present invention is not limited to these, and in particular, the tip portion 4a may be coated with another member such as gold, palladium, tantalum, platinum or the like from the viewpoint of conductivity improvement, durability improvement, and the like.

  When the probe 4 is moved downward toward the semiconductor device 3 from the initial state of FIG. 2A, the surface electrode 15 of the semiconductor device 3 and the tip 4a come in contact as shown in FIG. 2B. . When it is further lowered, as shown in FIG. 2C, the pushing portion 4c is pushed into the barrel portion 4b via the spring member, and the contact with the surface electrode 15 of the semiconductor device 3 is made reliable.

  Here, although the probe 4 incorporates a spring portion having slidability in the Z-axis direction, the present invention is not limited to this, and the spring portion may be provided outside. In addition, although the spring type is used from the viewpoint of discharge suppression, the present invention is not limited to this, and may be a cantilever type, a laminated probe, a wire probe, or the like.

  FIG. 3 is a plan view showing a wafer on which a plurality of semiconductor devices to be evaluated are formed. FIG. 4 is a cross-sectional view taken along line I-II of FIG. An ink hit point 16 is applied to a defective chip among the plurality of semiconductor devices 3. Here, four chips are defective, and the number of ink spots 16 is four.

  In some cases, a good chip and a bad chip may be discriminated on the wafer 2 purchased from the outside. In this case, the marking process of the ink hitting point 16 is performed on the bad chip to distinguish it from the good product. The ink spot 16 is a chip on which the ink is applied and cured on the chip surface by the inker, and although it differs depending on the coating amount, the ink viscosity at the time of coating, etc. .

  Subsequently, a method of evaluating a semiconductor device according to the present embodiment will be described. FIG. 5 is a diagram showing a method of evaluating a semiconductor device according to the first embodiment of the present invention. First, using the image processing camera 13 provided on the insulating substrate 5, the presence or absence of an ink hit point is detected for every one of the plurality of semiconductor devices 3 formed on the wafer 2. At the same time, position information (address) of the semiconductor device 3 on the wafer 2 is acquired. Defective chip position information is formed on the basis of the presence / absence of the ink hit point and the position information. The broken line arrow in the figure indicates the direction in which the probe base 7 moves when ink spot is detected. The detection result is stored in the evaluation / control unit 10 connected to the image processing unit 14. Thereafter, using the probe 4 fixed to the insulating substrate 5, the electrical characteristics of the semiconductor device having no ink dot 16 are evaluated.

  FIG. 6 is a diagram showing a modification of the method of evaluating a semiconductor device according to the first embodiment of the present invention. The presence or absence of an ink hit point is detected for each of the plurality of semiconductor devices 3 one chip at a time. At the same time, the distance of the semiconductor device 3 from the center of the wafer 2 (broken line arrow in the figure) is detected as position information. The position of the ink hit point is superimposed on the wafer map layout to form defective chip position information. The detection result is stored in the evaluation / control unit 10 connected to the image processing unit 14. Thereafter, using the probe 4 fixed to the insulating substrate 5, the electrical characteristics of the semiconductor device having no ink dot 16 are evaluated.

  In addition, the detection of the presence or absence of an ink hit and the evaluation of the electrical characteristics may be performed successively for each semiconductor device. As a result, the number of times the probe base portion 7 moves on the wafer 2 is reduced, so that the process can be shortened.

  As described above, in the present embodiment, the image processing camera 13 which is an ink hit detection unit is added to the insulating substrate 5 (probe card) to which the probe 4 is fixed. Thereby, since the conventional evaluation apparatus can be diverted, the presence or absence of the ink hit point of the semiconductor device 3 can be detected at low cost.

  Further, the image processing camera 13 faces the semiconductor device 3 with which the probe 4 is in contact at the time of evaluation. Thus, immediately before the evaluation, it is possible to detect the presence or absence of the ink hit point of the semiconductor device 3 to be evaluated.

Second Embodiment
FIG. 7 is a view showing an evaluation apparatus of a semiconductor device according to a second embodiment of the present invention. In the first embodiment, the camera 13 for image processing which is an ink spot detection unit faces the semiconductor device 3 with which the probe 4 contacts at the time of evaluation. However, in the present embodiment, the camera 4 for image processing is the probe 4 at the time of evaluation. It faces the semiconductor device adjacent to the contacting semiconductor device. That is, the image processing camera 13 is disposed laterally offset from the probe 4 by one semiconductor device. Since the presence or absence of the ink hit point of the semiconductor device 3 to be evaluated next can be detected in advance, the process can be shortened.

  Note that the image processing camera 13 may face both the semiconductor device 3 with which the probe 4 contacts during evaluation and the semiconductor device 3 adjacent to the semiconductor device 3. Thereby, false detection can be prevented by double check.

  Alternatively, the insulating substrate 5 may be provided with a slit so that the image processing camera 13 can change its position with respect to the insulating substrate 5. Further, the direction in which the image processing camera 13 faces the insulating substrate 5 may be changed by changing the angle with respect to the insulating substrate 5 by a link mechanism or the like. This makes it possible to easily change the range in which the image processing camera 13 can detect the presence or absence of ink spots. Therefore, even if the size of the semiconductor device 3 to be evaluated can be changed, the same probe card can be used, so that the cost is low and the process can be shortened.

  The ink hit detection unit is not limited to the image processing camera 13, and may be an optical distance sensor that measures the distance to the surface of the semiconductor device 3. The light source of the optical distance sensor is, for example, a semiconductor laser or infrared light. The portion with the ink spot is convex compared to the other surface portion of the semiconductor device 3. Therefore, the presence or absence of the ink spot can be easily detected by measuring the distance with the optical distance sensor from the probe card side. Can.

  Further, the ink hit point detection unit may be a distance detection camera. The distance detection camera captures an ink hit point, focuses on the surface of the ink hit point, and measures the distance to the ink hit point, so that the presence or absence of the ink hit point can be easily detected. If it is a camera for distance detection, the conventional apparatus can be diverted, so it is low in cost.

  In addition, the ink hit point detection unit may be a radiation thermometer whose emissivity is fixed. Since the emissivity of the substance differs depending on the material, the emissivity of the conductive material of the connection pad on the surface of the semiconductor device 3 and the ink material of the ink hitting point are different. When the surface temperature is detected by a radiation thermometer, the emissivity is different even if the temperature is the same at the time of detection, so that a difference occurs in the detected temperature. The presence or absence of an ink hit can be easily detected by the change in the detected temperature.

Third Embodiment
FIG. 8 is a view showing an evaluation apparatus of a semiconductor device according to a third embodiment of the present invention. In the first and second embodiments, in order to detect the ink spot without contact, the ink spot detector is recessed in the Z direction from the tip of the probe 4 to avoid the ink spot and the contact with the surface of the semiconductor device. On the other hand, in the present embodiment, the contact sensor 17 facing the semiconductor device 3 is used as the ink dot detection unit. The contact sensor 17 protrudes downward in the Z-axis from the tip of the probe 4.

  Since the ink hit points 16 are convex from the surface of the semiconductor device 3, when the probe base portion 7 is lowered toward the semiconductor device 3 at the time of evaluation, the contact sensor 17 contacts the ink hit points 16 before the evaluation probe 4. If the detection time of the contact by the contact sensor 17 is short, it can be determined that there is an ink hit, so it is possible to detect the presence or absence of the ink hit.

  In addition, as the contact sensor 17, a dummy probe that does not perform electrical evaluation and detects a pressing amount may be used. A difference in push-in amount occurs between the case of contacting the surface of the semiconductor device and the case of contacting the ink spot, so that the presence or absence of the ink spot can be detected. In the case of detecting the pressing amount, the contact sensor 17 may not be protruded with respect to the probe 4.

Fourth Embodiment
FIG. 9 is a view showing an evaluation apparatus of a semiconductor device according to a fourth embodiment of the present invention. A plurality of ink spot detection units 18 are provided. Thus, for example, not only the semiconductor device to be evaluated but also the semiconductor device before one evaluation is subjected to the detection of the presence or absence of the ink hit. False detection can be suppressed by performing detection a plurality of times. The plurality of ink spot detection units 18 are the above-described cameras or sensors, but they are not limited to the same type, and may be different types.

Reference Signs List 1 chuck stage, 2 wafer, 3 semiconductor device, 4 probe, 5 insulating substrate, 10 evaluation / control unit (evaluation unit), 13 image processing camera (ink spot detection unit), 14 image processing unit, 17 contact sensor (ink) Hit point detection unit), 18 Ink hit point detection unit

Claims (11)

A chuck stage for fixing a wafer on which a plurality of semiconductor devices are formed;
An insulating substrate,
A probe fixed to the insulating substrate;
An evaluation unit that evaluates the electrical characteristics of the semiconductor device by supplying a current to the semiconductor device through the probe;
And an ink spot detection unit provided on the insulating substrate for detecting the presence or absence of the ink spot of the semiconductor device .
The apparatus for evaluating a semiconductor device, wherein the ink spot detection unit faces both the semiconductor device with which the probe contacts at the time of evaluation and the semiconductor device adjacent to the semiconductor device. A chuck stage for fixing a wafer on which a plurality of semiconductor devices are formed;
An insulating substrate,
A probe fixed to the insulating substrate;
An evaluation unit that evaluates the electrical characteristics of the semiconductor device by supplying a current to the semiconductor device through the probe;
And an ink spot detection unit provided on the insulating substrate for detecting the presence or absence of the ink spot of the semiconductor device.
The ink RBI detector, the evaluation device of the semi-conductor device you characterized in that it has an optical distance sensor for measuring the distance to the surface of the semiconductor device. A chuck stage for fixing a wafer on which a plurality of semiconductor devices are formed;
An insulating substrate,
A probe fixed to the insulating substrate;
An evaluation unit that evaluates the electrical characteristics of the semiconductor device by supplying a current to the semiconductor device through the probe;
And an ink spot detection unit provided on the insulating substrate for detecting the presence or absence of the ink spot of the semiconductor device.
The ink RBI detecting unit, the semiconductor device evaluation apparatus of semi-conductor devices you further comprising a distance detection camera to measure the distance to the surface of the. A chuck stage for fixing a wafer on which a plurality of semiconductor devices are formed;
An insulating substrate,
A probe fixed to the insulating substrate;
An evaluation unit that evaluates the electrical characteristics of the semiconductor device by supplying a current to the semiconductor device through the probe;
And an ink spot detection unit provided on the insulating substrate for detecting the presence or absence of the ink spot of the semiconductor device.
The ink RBI detector, you characterized by having a radiation thermometer with a fixed emissivity evaluation device of the semi-conductor device. A chuck stage for fixing a wafer on which a plurality of semiconductor devices are formed;
An insulating substrate,
A probe fixed to the insulating substrate;
An evaluation unit that evaluates the electrical characteristics of the semiconductor device by supplying a current to the semiconductor device through the probe;
And an ink spot detection unit provided on the insulating substrate for detecting the presence or absence of the ink spot of the semiconductor device.
The ink RBI detector, the evaluation device of the semi-conductor device you further comprising a contact sensor.   The evaluation apparatus for a semiconductor device according to any one of claims 2 to 5, wherein the ink hit detection unit faces the semiconductor device with which the probe contacts at the time of evaluation.   The evaluation apparatus for a semiconductor device according to any one of claims 2 to 5, wherein the ink hit detection unit faces a semiconductor device adjacent to the semiconductor device with which the probe contacts at the time of evaluation.   The apparatus according to any one of claims 1 to 7, wherein the ink hit detection unit can change a position with respect to the insulating substrate.   The said ink hit point detection part can change an angle with respect to the said insulated substrate, The evaluation apparatus of the semiconductor device in any one of Claims 1-8 characterized by the above-mentioned. Detecting the presence or absence of an ink spot of a plurality of semiconductor devices formed on a wafer using an ink spot detection unit provided on an insulating substrate;
Evaluating the electrical characteristics of the semiconductor device having no ink spot using the probe fixed to the insulating substrate;
After detecting the presence or absence of ink spots and position information for all of the plurality of semiconductor devices, the electrical characteristics of the semiconductor devices without ink spots are evaluated;
Evaluation method of semi-conductor devices you and detects the distance of the semiconductor device from the center of the wafer as the position information. Detecting the presence or absence of an ink spot of a plurality of semiconductor devices formed on a wafer using an ink spot detection unit provided on an insulating substrate;
Evaluating the electrical characteristics of the semiconductor device having no ink spot using the probe fixed to the insulating substrate;
The detection of the presence or absence of the ink spot and the evaluation of the electrical characteristics are continuously performed one by one for each semiconductor device,
Not only the semiconductor device to be evaluated, the evaluation method of the semi-conductor device you comprises carrying out the detection of the presence or absence of the ink RBI also one evaluation before the semiconductor device.

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