JPH0837211A - Testing equipment of semiconductor device - Google Patents

Abstract

PURPOSE:To increase the positioning accuracy of a probe and the work efficiency and provide a method for detecting the life of a probe card. CONSTITUTION:This equipment is provided with an image pick-up means or a camera 14 which picks up an image of a probe 6a on a wafer stage 7 from downward, an image processing mechanism 15 which preliminarily stores the position on the wafer stage of an electric pad which a probe test is to be made for and displays simultaneously the image information about the probe 6a which the camera picks up the image of and the position of the electric pad, and a setup control mechanism which moves the wafer stage and corrects the position of the electric pad when it receives the detected numerical information about the deviation in position between the probe 6a and the electrode pad.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of semiconductor device manufacturing, and is particularly effective when applied to semiconductor device testing technology.

[0002]

2. Description of the Related Art A so-called prober is used when testing the electrical characteristics of a semiconductor device at the stage when a circuit is formed on a semiconductor wafer. The prober contacts the external connection electrodes (electrode pads) provided on the individual semiconductor chips formed on the semiconductor wafer with the needle-shaped or bump-shaped probe electrodes, and automatically connects the semiconductor chips with the tester. It is a facility for testing.

The mechanism of the prober is roughly classified into a loader section, an alignment section, a probing section, and a control section. The semiconductor wafer set on the wafer supply loader is transferred to the alignment unit by the wafer transfer belt or the like and positioned. After that, the probe electrode, for example, a probe needle is brought into contact with the electrode pad of each semiconductor chip by moving to the probing portion, and the electrical characteristics of the probe electrode are measured by a tester working in conjunction with the prober. Conventionally, as shown in FIG. 6, a setup for contacting a probe needle is performed by attaching a needle mark 27 to an aluminum dummy wafer 24 on which the same chip pattern 25 and pad pattern 26 as the wafer to be actually probed are drawn. The operator visually confirms and corrects the deviations in the X, Y, Z, and θ directions by moving the wafer stage.

Further, regarding the detection of the life of the probe card, the operator is expected to predict the amount of wear and replace the probe card.

Regarding the prober, for example, Japanese Patent Laid-Open No.
It is described in Japanese Patent Publication No. 1-131541.

[0006]

As semiconductor devices become more multifunctional and miniaturization progresses year by year, the number of pins increases and the area of electrode pads decreases, so does the number of probe needles in a probe card for wafer testing. It is increasing. However, in the above method, since the position of the probe needle is indirectly confirmed by using the dummy wafer, it is becoming difficult to improve the accuracy of alignment, and it is difficult to improve the work efficiency. Further, regarding the detection of the life of the probe card, in the above method, the prediction of the operator is not constant, and in the worst case, there is a problem that the life of the probe card is discovered only due to the yield abnormality at the time of inspection.

Therefore, an object of the present invention is to improve the accuracy of alignment of the probe needle and the work efficiency.

Another object of the present invention is to provide a method for detecting the life of a probe card. The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0009]

The outline of the representative one of the inventions disclosed in the present application will be briefly described as follows. That is, a tester for measuring the electrical characteristics of a semiconductor device, a wafer stage on which a semiconductor wafer is placed and movable in the X direction, Y direction, Z direction, and θ direction, connected to the tester, and connected to the semiconductor wafer. By contacting the electrode pads of the formed individual semiconductor chips,
A semiconductor device inspection apparatus comprising a tester and a probe card having a probe electrode for electrically connecting the semiconductor chip, wherein the probe electrode provided on the wafer stage is imaged from below. Image pickup means, and image processing means capable of simultaneously displaying the image information of the probe electrodes picked up by the image pickup means and the position on the wafer stage of the electrode pad of the wafer to be subjected to electrical measurement stored in advance. Is provided.

[0010]

According to the above means, the image pickup means and the image processing means can simultaneously display the image information of the probe electrode and the position on the wafer stage of the electrode pad of the wafer to be subjected to the electrical measurement stored in advance. The amount of positional deviation between the probe electrode and the electrode pad can be corrected while directly checking the image. Therefore, the accuracy of alignment of the probe electrodes and the work efficiency can be improved.
Further, since the wear amount of the probe electrode can be directly confirmed by the image every time the probe electrode is aligned, the life of the probe card can be easily detected. Further, the foreign matter attached to the needle tip can be easily found by the image.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows an outline of a prober 1 of the present invention, and FIG. 2 shows an enlarged view of a probing section 2. The prober 1 is roughly divided into a loader unit 3, an alignment unit 4, a probing unit 2, and a control unit (not shown). In the loader unit 3, the wafer 5 is transferred from the wafer supply loader 10 to the probing unit 2 and the wafer 5 after the probe test is completed.
The wafer is stored in the wafer storage loader 11. The alignment unit 4 performs pre-alignment for detecting the orientation flat of the wafer 5 and determining the direction thereof, and fine alignment for performing parallel alignment of the wafer 5 for probing with higher positional accuracy. Probing section 2
Then, in order to test the individual semiconductor chips in the wafer 5, the movement of the wafer in the Z / Y axis direction and the contact between the electrode pads in the semiconductor chip and the probe electrodes are automatically performed for all the chips. The probing unit 2 mainly includes a wafer stage 7 and a tester measurement system 13, and the tester measurement system 13
A probe card 6 in which a probe electrode, for example, a probe needle 6a made of tungsten steel is erected is set corresponding to the electrode pad of the semiconductor chip to be measured.

In the present invention, the image pickup means for picking up the image of the probe needle 6a on the wafer stage 7 from below, that is, the camera 1
4 and the position of the electrode pad of the wafer to be subjected to the probe test on the wafer stage in advance, and an image processing mechanism 15 capable of displaying the image information of the probe needle 6a captured by the camera 14 at the same time, and an image. There is provided a setup control mechanism for correcting the position by moving the wafer stage by inputting the numerical information of the positional deviation between the probe needle 6a and the electrode pad detected by the processing mechanism 15. The camera 14 is provided inside through a small window provided on the surface of the wafer stage 7, and is connected to an image processing mechanism 15 provided outside the wafer stage 7. The image processing mechanism 15 has a function of displaying image information captured by the camera 14, a function of previously storing the position of the electrode pad of the wafer to be subjected to the probe test on the wafer stage 7, and image information of the probe needle 6a. And a function of simultaneously displaying the position of the electrode pad and the numerical information of the positional deviation thereof. Further, the image processing mechanism 15 includes a wafer stage control mechanism 1 for controlling the movement of the wafer stage 7.
6 is linked. That is, the image processing mechanism 15 inputs the positional deviation amount of each direction component of the probe needle 6a and the electrode pad to the wafer stage control mechanism 16 so that the wafer stage control mechanism 16 causes the wafer stage 7 to move for each direction component. Move the position shift amount of. By this method, the setup can be automated.

The present invention is also provided with a sensor capable of detecting the life of the probe needle 6a by wear, that is, a wear detecting groove 6b. As shown in FIG. 4, the wear detecting groove 6b is provided at the tip of the probe needle 6a ((a)), and when the probe needle 6a is worn ((b)), a groove cross section appears on the worn surface. ((C) a cross-sectional view as seen from the worn surface). By providing the wear detecting groove 6b, the wear degree of the probe needle 6a can be confirmed by the camera 14 and the image processing mechanism 15 for each setup.

Next, a setup method using the prober 1 of the present invention will be described. First, the image processing mechanism 15
Then, the size of the chip to be aligned on the wafer stage 7 of the wafer to be subjected to the probe test and the position information of the electrode pad are input and stored. Next, the tip of the probe needle 6a is imaged by the camera 14, and image data is displayed on the monitor screen of the image processing mechanism 15 together with the contour of the tip and the position of the electrode pad 19, as shown in FIG.
At this time, if there is a deviation between the position of the electrode pad 19 and the position of the probe needle 6a, the position of the electrode pad 19 is corrected on the screen of the monitor. In conjunction with this, the wafer stage 7 moves and the setup is completed. When performing the setup automatically, for example, two electrode pads and probe needles for position alignment are arbitrarily set in advance, and the amount of displacement of each is detected on the coordinates, and the amount of displacement is set to 0. Then, the wafer stage control mechanism 16 is operated. As a result, the setup can be automated.

The operation and effect of the present invention will be described below.

(1) Image pickup means provided on the wafer stage for picking up an image of the probe electrode from below, and image information of the probe electrode picked up by the image pickup means and the electrode pad of the wafer for preliminarily stored electric measurement. By providing the image processing means capable of displaying the position on the wafer stage at the same time, the image information of the probe electrode and the electrode of the wafer on which the electrical measurement stored in advance is to be performed by the imaging means and the image processing means. Since the position of the pad on the wafer stage can be displayed at the same time, the amount of positional deviation between the probe electrode and the electrode pad can be corrected while directly checking the image. Therefore, the accuracy of alignment of the probe electrodes and the work efficiency can be improved. Further, since the wear amount of the probe electrode can be directly confirmed by the image every time the probe electrode is aligned, the life of the probe card can be easily detected. Further, the foreign matter attached to the needle tip can be easily found by the image.

(2) The image processing means takes in the image information of the probe electrode and arbitrarily stores the position of the electrode pad of the wafer on the wafer stage on which the electrical measurement is prestored and the probe electrode. Since the positional deviation amount between the points can be displayed numerically, the positional deviation can be corrected by the numerical correction, so that the accuracy of the probe electrode alignment can be further improved.

(3) Since the image processing means is connected to the setup control means for moving the wafer stage and correcting the position by inputting the positional deviation amount, the setup can be automated.

(4) Since the probe electrode is provided with a sensor capable of detecting the life of the probe electrode due to wear, the life of the probe card can be easily detected.

Although the present invention has been concretely described based on the embodiments by the present inventor, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, in the above embodiment, the camera directly images the probe needle, but as shown in FIG.
Images may be taken from another angle by using the mirror 22 or the prism 23 as shown in (b). Also,
A pad may be provided on the wafer stage to electrically store the contact point by bringing the probe needle into contact. In this case, the pad surface can be realized by forming a sensing means formed in a matrix, for example, a plurality of arranged switches.

[0023]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

That is, the image pickup means provided on the wafer stage for picking up an image of the probe electrode from below, and the image information of the probe electrode picked up by the image pickup means and the electrode pad of the wafer for preliminarily stored electric measurement By providing the image processing means capable of displaying the position on the wafer stage at the same time, the image information of the probe electrode and the electrode of the wafer on which the electrical measurement stored in advance is to be performed by the imaging means and the image processing means. Since the position of the pad on the wafer stage can be displayed at the same time, the amount of positional deviation between the probe electrode and the electrode pad can be corrected while directly checking the image. Therefore, the accuracy of alignment of the probe electrodes and the work efficiency can be improved. Also,
Since the wear amount of the probe electrode can be directly confirmed by the image every time the probe electrode is aligned, the life of the probe card can be easily detected. Further, the foreign matter attached to the needle tip can be easily found from the image.

[0025]

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a prober 1 which is an embodiment of the present invention.

FIG. 2 is a diagram showing an enlarged view of a probing unit 2 included in a prober 1 according to an embodiment of the present invention.

FIG. 3 is a diagram showing a state of a monitor screen showing a positional relationship between image data of a probe needle and an electrode pad in a setup method which is an embodiment of the present invention.

FIG. 4A is a diagram showing a tip portion of a probe needle of the present invention. (B) is a figure which shows the state where the front-end | tip part of the probe needle of (a) was worn. (C) is the figure which looked at the worn state from the lower part.

FIG. 5A is a diagram showing a wafer stage using a mirror in the probing part of the present invention. (B) is a diagram showing a wafer stage using a prism in the probing part of the present invention.

FIG. 6 is a diagram showing a conventional probe setup method.

[Explanation of symbols]

1 ... prober, 2 ... probing part, 3 ... loader part, 4 ... alignment part, 5 ... wafer, 6 ... probe card, 6a ... probe needle, 7 ... wafer stage, 8 ... alignment Optical system, 9 ... Tester, 10 ...
... Wafer supply loader, 11 ... Wafer storage loader,
12 ... Wafer transport belt, 13 ... Tester measurement system, 1
4 ... Camera, 15 ... Image processing mechanism, 16 ... Wafer stage control mechanism, 17 ... Wafer stage operating mechanism,
18 ... small window, 19 ... electrode pad position, 20 ... angle shift display, 21 ... position shift display, 22 ... mirror, 2
3 ... Prism, 24 ... Dummy wafer, 25 ... Chip pattern, 26 ... Pad pattern, 27 ... Needle trace

Claims (4)

[Claims] 1. A tester for measuring electrical characteristics of a semiconductor device, a wafer stage on which a semiconductor wafer is placed, and which is movable in X, Y, Z, and θ directions, connected to the tester, and An inspection device for a semiconductor device, comprising: a tester and a probe card having a probe electrode for electrically connecting the semiconductor chip to an electrode pad of an individual semiconductor chip formed on a semiconductor wafer. An image pickup means provided on the wafer stage for picking up an image of the probe electrode from below, and image information of the probe electrode picked up by the image pickup means and an electrode pad of a wafer on which electric measurement stored in advance is to be performed. And an image processing unit capable of simultaneously displaying the position on the wafer stage and the inspection device for a semiconductor device. 2. The image processing means captures image information of the probe electrode, and stores the position of the electrode pad of the wafer on the wafer stage on which the electrical measurement is to be performed, which is stored in advance, and the probe electrode. 2. The position shift amount between any two points can be displayed numerically.
A semiconductor device inspection apparatus as described above. 3. The image processing means is connected to a setup control means for moving the wafer stage and correcting the position by inputting a positional deviation amount. Semiconductor device inspection equipment. 4. The inspection device for a semiconductor device according to claim 1, wherein the probe electrode is provided with a sensor capable of detecting a life of the probe electrode by abrasion. .