JP2017084958A - Evaluation device and evaluation method for semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaluation device and an evaluation method for a semiconductor device capable of detecting presence or absence of an ink dot on a semiconductor device at low cost.SOLUTION: A wafer 2 on which a plurality of semiconductor devices 3 are formed is fixed by a chuck stage 1. A probe 4 is fixed to an insulation substrate 5. An evaluation unit 10 applies a current to each semiconductor device 3 via the probe 4 to evaluate electric characteristics of the semiconductor device 3. An ink dot detector 13 for detecting presence or absence of an ink dot on the semiconductor device 3 is provided on the insulation substrate 5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an evaluation apparatus and an evaluation method for a semiconductor device having an ink dot detection function.

  Electrical characteristics and the like are evaluated for each of a plurality of semiconductor devices formed on the wafer. In this evaluation, the semiconductor device (defective chip) determined to be defective is marked with ink, and distinguished from the semiconductor device (non-defective chip) determined to be good. However, there is no position information (map information) of defective chips after defect determination, that is, when a wafer is purchased after ink has been hit. For this reason, in the retest of all the semiconductor devices formed on the wafer, since the ink of the defective chip comes into contact with the probe, the retest cannot be performed. Moreover, since the number of non-defective products and position information are obtained by visual inspection, it takes time and is misrecognized.

  For this reason, it is important to acquire accurate position information (map information) of defective chips particularly in retesting. Under such circumstances, as a quality screening method after marking, a method is disclosed in which magnetic ink containing a magnetic material is used as a marking material, and quality screening is performed with a magnetic sensor (see, for example, Patent Document 1). ). In addition, an apparatus for determining whether a defect mark is appropriate or inappropriate by a TV camera is also disclosed (for example, see Patent Document 2).

JP-A-52-95965 JP-A-62-136041

  However, the method using a special magnetic ink containing a magnetic material has a problem that the cost increases. In the retest of the purchased semiconductor device, it is difficult to operate because it is necessary to detect special magnetic ink containing a magnetic material at the purchase source. Furthermore, it cannot be easily applied to a conventional evaluation apparatus.

  Further, in the method using the TV camera, the installation position of the TV camera is unknown, and it is difficult to divert the conventional apparatus. Further, the position and angle of the TV camera cannot be changed so as to face the semiconductor device to be evaluated, and it has not been possible to deal with a plurality of semiconductor devices.

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

  An evaluation apparatus for a semiconductor device according to the present invention includes 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. An evaluation unit that evaluates the electrical characteristics of the semiconductor device by passing an electric current, and an ink hit point detection unit that is provided on the insulating substrate and detects the presence or absence of an ink hit point of the semiconductor device.

  In the present invention, an ink spot detection unit is added to the insulating substrate to which the probe is fixed. Thereby, since the conventional evaluation apparatus can be diverted, it is possible to detect the presence / absence of an ink dot of the semiconductor device at low cost.

It is a figure which shows the evaluation apparatus of the semiconductor device which concerns on Embodiment 1 of this invention. It is a side view for demonstrating operation | movement of a probe. It is a top view which shows the wafer in which the several semiconductor device used as evaluation object was formed. FIG. 4 is a cross-sectional view taken along I-II in FIG. 3. 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 which concerns on Embodiment 3 of this invention. It is a figure which shows the evaluation apparatus of the semiconductor device which concerns on Embodiment 4 of this invention.

  A semiconductor device evaluation apparatus and an evaluation method according to embodiments of the present invention will be described with reference to the drawings. The same or corresponding components are denoted by the same reference numerals, and repeated description may be omitted.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a semiconductor device evaluation apparatus according to Embodiment 1 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 for fixing the wafer 2 in contact with the installation surface (back 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 lateral type semiconductor device that performs input / 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. A plurality of probes 4, an insulating substrate 5, connection portions 6, and wiring (not shown) constitute a probe base portion 7. The probe base 7 can be moved in any direction by the moving arm 8. Here, the probe base portion 7 is held by the single moving arm 8, but the present invention is not limited to this, and it may be stably held by a plurality of moving arms. Further, instead of moving the probe base 7, the chuck stage 1 and the wafer 2 may be moved.

  When evaluating the semiconductor device 3 having the vertical structure, the plurality of probes 4 are electrically connected to the surface electrode provided on the surface of the semiconductor device 3, and the chuck stage 1 is provided on the back surface of the semiconductor device 3. Is electrically connected.

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

  Note that a plurality of evaluation probes 4 are installed 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 is substantially the same through any probe 4 so that the current densities applied to the probes 4 are substantially the same. Therefore, it is desirable that the connecting portion 6 and the connecting portion 11 are disposed at positions facing each other with the probe 4 interposed therebetween.

  In the present embodiment, an image processing camera 13 is provided on the insulating substrate 5 as an ink hitting point detection unit. The image processing camera 13 faces the semiconductor device 3 with which the probe 4 contacts during evaluation. The image processing camera 13 photographs the surface of the semiconductor device 3. The image processing unit 14 performs image processing (for example, binarization) on the image to detect the presence / absence of an ink spot applied to the surface of the semiconductor device 3 that is the object to be measured. A difference in contrast occurs on the surface of each semiconductor device 3 depending on the presence or absence of ink dots. The difference in contrast can be recognized using, for example, a binarized image processing technique, so that it is possible to detect ink dots.

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

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

  When the probe 4 is lowered below the Z-axis toward the semiconductor device 3 from the initial state of FIG. 2A, first, as shown in FIG. 2B, the surface electrode 15 and the tip portion 4a of the semiconductor device 3 come into contact with each other. . When further lowered, the pushing portion 4c is pushed into the barrel portion 4b via the spring member as shown in FIG. 2C, and the contact with the surface electrode 15 of the semiconductor device 3 is ensured.

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

  FIG. 3 is a plan view showing a wafer on which a plurality of semiconductor devices to be evaluated are formed. 4 is a cross-sectional view taken along the line I-II in FIG. Of the plurality of semiconductor devices 3, ink dots 16 are given to defective chips. Here, four chips are defective, and there are four ink dots 16.

  In some cases, a good chip and a defective chip are already determined on the wafer 2 purchased from the outside. In that case, in order to distinguish the defective chip from the non-defective product, the marking process of the ink dot 16 is performed on the defective chip. The ink hitting point 16 is obtained by applying ink to the chip surface by an inker and curing, and varies depending on the application amount, ink viscosity at the time of application, etc., but is in a convex state of about several hundred μm with respect to the surface of the semiconductor device. .

  Subsequently, a method for evaluating a semiconductor device according to the present embodiment will be described. FIG. 5 is a diagram showing a method for 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 hitting point is detected for each of the plurality of semiconductor devices 3 formed on the wafer 2 for each chip. In accordance with this, position information (address) of the semiconductor device 3 on the wafer 2 is acquired. Defective chip position information is formed based on the presence / absence of ink hit points and position information. A broken line arrow in the figure indicates a direction in which the probe base portion 7 moves when an ink hit point is detected. The detection result is stored in the evaluation / control unit 10 connected to the image processing unit 14. Thereafter, the electrical characteristics of the semiconductor device having no ink spot 16 are evaluated using the probe 4 fixed to the insulating substrate 5.

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

  Further, detection of the presence or absence of ink dots and evaluation of electrical characteristics may be successively performed for each semiconductor device. As a result, the number of times the probe base 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 that is an ink spot 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, it is possible to detect the presence or absence of an ink dot on the semiconductor device 3 at a low cost.

  Further, the image processing camera 13 faces the semiconductor device 3 with which the probe 4 contacts during evaluation. Thereby, it is possible to detect the presence or absence of an ink hit point of the semiconductor device 3 to be evaluated immediately before the evaluation.

Embodiment 2. FIG.
FIG. 7 is a diagram showing a semiconductor device evaluation apparatus according to Embodiment 2 of the present invention. In the first embodiment, the image processing camera 13 that is the ink spot detection unit faces the semiconductor device 3 with which the probe 4 contacts at the time of evaluation. However, in this embodiment, the image processing camera 13 has the probe 4 at the time of evaluation. The semiconductor device is adjacent to a semiconductor device adjacent to the contacting semiconductor device. That is, the image processing camera 13 is shifted from the probe 4 by one semiconductor device in the lateral direction. Accordingly, it is possible to detect in advance the presence or absence of an ink hit point of the semiconductor device 3 to be evaluated next, so that 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 at the time of evaluation and the semiconductor device 3 adjacent to the semiconductor device 3. Thereby, erroneous detection can be prevented by double check.

  Further, a slit may be provided in the insulating substrate 5 so that the position of the image processing camera 13 with respect to the insulating substrate 5 can be changed. In addition, the image processing camera 13 may change the angle with respect to the insulating substrate 5 by using a link mechanism or the like so that the facing direction can be changed. Thereby, the range in which the image processing camera 13 can detect the presence or absence of ink dots can be easily changed. Therefore, even if the size of the semiconductor device 3 to be evaluated changes, the same probe card can be used, so that the cost is low and the process can be shortened.

  Further, the ink spot detection unit is not limited to the image processing camera 13, but 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. Since the portion having the ink hitting point is convex as compared with the other surface portion of the semiconductor device 3, the presence or absence of the ink hitting point can be easily detected by measuring the distance from the probe card side with the optical distance sensor. Can do.

  The ink hit point detection unit may be a distance detection camera. The distance detection camera captures an ink hit point and focuses the surface to measure the distance to the ink hit point, thereby easily detecting the presence or absence of the ink hit point. Since a conventional device can be used for a distance detection camera, the cost is low.

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

Embodiment 3 FIG.
FIG. 8 is a diagram showing an evaluation apparatus for a semiconductor device according to the third embodiment of the present invention. In the first and second embodiments, since the ink hitting point is detected in a non-contact manner, the ink hitting point detection unit is recessed in the Z direction from the tip of the probe 4 to avoid contact with the ink hitting point and 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 hitting point detection unit. The contact sensor 17 projects downward from the tip of the probe 4 in the Z-axis direction.

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

  As the contact sensor 17, a dummy probe that detects the pushing amount without performing electrical evaluation may be used. Since there is a difference in the amount of pressing between the case of contacting the surface of the semiconductor device and the case of contacting the ink hitting point, the presence or absence of the ink hitting point can be detected. When detecting the push-in amount, the contact sensor 17 may not protrude from the probe 4.

Embodiment 4 FIG.
FIG. 9 is a diagram showing a semiconductor device evaluation apparatus according to Embodiment 4 of the present invention. A plurality of ink spot detection units 18 are provided. Thereby, for example, the presence / absence of an ink hit point is detected not only for the semiconductor device to be evaluated but also for the semiconductor device before one evaluation. By detecting multiple times, it is possible to suppress erroneous detection. The plurality of ink spot detection units 18 are the above-described cameras or sensors, but are not limited to the same type, and may be different types.

DESCRIPTION OF SYMBOLS 1 Chuck stage, 2 Wafer, 3 Semiconductor device, 4 Probe, 5 Insulating substrate, 10 Evaluation / control part (evaluation part), 13 Image processing camera (ink dot detection part), 14 Image processing part, 17 Contact sensor (ink) Dot spot detector), 18 Ink spot detector

Claims (16)

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 section that evaluates the electrical characteristics of the semiconductor device by passing a current through the semiconductor device via the probe;
An evaluation apparatus for a semiconductor device, comprising: an ink dot detection unit that is provided on the insulating substrate and detects the presence or absence of an ink dot of the semiconductor device.   The semiconductor device evaluation apparatus according to claim 1, wherein the ink dot detection unit faces a semiconductor device with which the probe contacts during evaluation.   The semiconductor device evaluation apparatus according to claim 1, wherein the ink dot detection unit faces a semiconductor device adjacent to the semiconductor device with which the probe contacts during evaluation.   2. The evaluation apparatus for a semiconductor device according to claim 1, wherein the ink spot detection unit faces both the semiconductor device with which the probe contacts during evaluation and a semiconductor device adjacent to the semiconductor device.   5. The evaluation apparatus for a semiconductor device according to claim 1, wherein a position of the ink spot detection unit can be changed with respect to the insulating substrate. 6.   The semiconductor device evaluation apparatus according to claim 1, wherein the ink spot detection unit can change an angle with respect to the insulating substrate.   The ink spot detection unit includes an image processing camera that captures the surface of the semiconductor device, and an image processing unit that performs image processing on an image captured by the image processing camera. The evaluation apparatus for a semiconductor device according to any one of the above.   The semiconductor device evaluation apparatus according to claim 1, wherein the ink spot detection unit includes an optical distance sensor that measures a distance to the surface of the semiconductor device.   The semiconductor device evaluation apparatus according to claim 1, wherein the ink hitting point detection unit includes a distance detection camera that measures a distance to the surface of the semiconductor device.   The semiconductor device evaluation apparatus according to claim 1, wherein the ink spot detection unit includes a radiation thermometer with a fixed emissivity.   The evaluation apparatus for a semiconductor device according to claim 1, wherein the ink hit point detection unit includes a contact sensor. Detecting the presence or absence of ink spots on a plurality of semiconductor devices formed on a wafer using an ink spot detection unit provided on an insulating substrate; and
And a step of evaluating electrical characteristics of the semiconductor device having no ink spot using a probe fixed to the insulating substrate.   13. The method of evaluating a semiconductor device according to claim 12, wherein after detecting presence / absence and position information of an ink hit point for all of the plurality of semiconductor devices, an electrical characteristic of the semiconductor device having no ink hit point is evaluated.   The semiconductor device evaluation method according to claim 13, wherein a distance of the semiconductor device from the center of the wafer is detected as the position information.   13. The method for evaluating a semiconductor device according to claim 12, wherein the detection of the presence or absence of the ink spot and the evaluation of the electrical characteristics are successively performed for each semiconductor device.   16. The method of evaluating a semiconductor device according to claim 15, wherein the presence or absence of the ink hitting point is detected not only for the semiconductor device to be evaluated but also for the semiconductor device before one evaluation.

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