JPH01262635A - Method of marking semiconductor chip - Google Patents

Abstract

PURPOSE:To mark only a semiconductor chip decided to be a defective positively by marking a blackened mark on the surface of the defective semiconductor chip by discharge between a discharge needle and a semiconductor wafer. CONSTITUTION:When semiconductor chips 3 formed to a semiconductor wafer 2 are electrically inspected, the electrode needles 4 of a probing card 1 are abutted against the specified electrode layers of the semiconductor chips 3 and electric characteristics are inspected. When the electric characteristics of the semiconductor chip 3 are normal at that time, the next semiconductor chip 3 is inspected similarly. When the electric characteristics of the semiconductor chip 2 are decided to be defective ones, high voltage is applied in a clearance L between the tip of a discharge needle 5 fitted to the probing card 1 and the defective semiconductor chip 3, the surface of the chip 2 is burnt and scorched by heat generated by discharge, and a blackened mark M is marked. Accordingly, the semiconductor chip decided to be defective can be identified positively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for marking semiconductor chips formed on a semiconductor wafer that are determined to be defective in an electrical property test.

[Prior Art] Conventionally, the following three types of methods have been known as methods for marking semiconductor chips determined to be defective by electrical property testing.

As shown in FIG. 2, the first method is to eject a marking liquid 100, such as red liquid ink, from the tip of a marker 101 to form a red mark on the surface of a defective chip 102, thereby making it normal. This is to distinguish it from a semiconductor chip.

The second method is to form scratches on the surface of the semiconductor chip with a needle-like object (not shown) with a hardened tip.
This distinguishes it from normal semiconductor chips.

The third method is to irradiate the surface of a semiconductor chip with a laser beam, and the heat generated during this process melts or discolors a portion of the surface of the semiconductor chip, thereby distinguishing it from a normal semiconductor chip.

[Problems to be Solved by the Invention] However, in the first method of discharging the red marking liquid, when marking a small semiconductor chip of 11 sides or less, the marking liquid is forcefully pushed out from the tip of the marker 10117). 100 is a defective chip 102
There is a problem in that not only do they adhere to the surface of the chip, but they also rebound due to recoil, and in some cases, they even fly off and adhere to adjacent normal semiconductor chips. This poses a problem because a normal semiconductor chip is erroneously determined to be defective. Furthermore, even when forming scratches on the surface as in the second method, there is a problem in that it is difficult to see the scratches on small semiconductor chips, making it difficult to distinguish them from defective semiconductor chips. . Furthermore, when a laser beam is irradiated as in the third method, steam is generated when the surface of the semiconductor chip is melted, and the rapid expansion of the steam causes the melted semiconductor chip material to fly over the surrounding normal semiconductor chips. Problems have arisen in which semiconductor chips, which should normally be good, are turned into defective ones, and on top of that,
None of these methods is satisfactory as a method for distinguishing between a semiconductor chip determined to be defective and a normal semiconductor chip.

Means for Solving the Problems] The present invention, which has been made to solve the above problems, brings the tip of a discharge needle close to the surface of a semiconductor chip formed on a semiconductor wafer, and creates a gap between the discharge needle and the semiconductor chip. It is characterized in that marking is performed by applying a high voltage to and causing a discharge between the two.

[Operation of the invention] As described above, when the tip of the discharge needle is brought close to the surface of the semiconductor chip and a high voltage is applied between the discharge needle and the semiconductor wafer to generate a discharge between them, the semiconductor chip is The surface becomes charred and has dark markings.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing an inspection device used in a semiconductor chip marking method according to an embodiment of the present invention.
In the figure, 1 is a blow card for testing the electrical characteristics of a semiconductor chip 3 formed on a semiconductor wafer 2; This is used to test electrical characteristics.

Reference numeral 5 denotes a discharge needle attached to the probe card 1, and when the electrode needle 4 of the probe card 1 comes into contact with the electrode layer of the semiconductor chip 2, the tip of the discharge needle 5 is located approximately at the center of the surface of the semiconductor chip 3. The present invention provides an external power source between the discharge needle 5 and the support substrate 6 on which the semiconductor wafer 2 is supported. 7, a high voltage is applied and a discharge is caused between the semiconductor chip 3 determined to be defective, thereby burning the surface of the semiconductor chip and marking a dark mark M.

That is, when testing the electrical characteristics of the semiconductor chip 3 formed on the semiconductor wafer 2, first the electrode needles 4 of the probe card 1 are brought into contact with a predetermined electrode layer of the semiconductor chip 3 to test the electrical characteristics. At this time, if the electrical characteristics of the semiconductor chip 3 are normal, the next semiconductor chip 3 is inspected in the same manner as described above.

When the electrical characteristics of the semiconductor chip 2 are determined to be defective, a high voltage is applied to the gap between the tip of the discharge needle 5 provided on the probe card 1 and the defective semiconductor chip 3, and a discharge occurs. The heat generated burns the surface of the semiconductor chip 2 and marks a dark mark M.

In this way, we sequentially inspect the electrical characteristics of semiconductor chips,
If it is determined to be defective, it is marked with a mark M to distinguish it from a normal half-quad chip in the next process.

Here, the voltage applied between the discharge needle 5 and the defective semiconductor chip 2 may be approximately 4 kV for a period of several tens to several hundred milliseconds, and even if the semiconductor chip 2 is small with an angle of less than the IN angle, Since the size of the mark M can be easily adjusted by adjusting the applied voltage, the mark M can be formed in a size that is most easily identified. Further, since the discharge needle 5 does not generate and scatter vapor, etc., and since the tip of the discharge needle 5 is placed close to the semiconductor chip 3 to be inspected, the discharge needle 5 is not disposed between it and the adjacent normal semiconductor chip 3. , there is no fear that this normal semiconductor chip 3 will be marked.

Further, in the above embodiment, the tip of the discharge needle 5 is placed near the center of the probe card 3, but the tip of the discharge needle 5 is not limited to this. Marking may be performed in the same manner as described above by applying a high voltage after bringing the tips of the discharge needles 5 close to each other.

[Effects of the Invention] As is clear from the above description, in the semiconductor chip marking method of the present invention, a dark mark is marked on the surface of a defective semiconductor chip by the discharge between the discharge needle and the semiconductor wafer. , it becomes easy to distinguish between normal semiconductor chips and normal semiconductor chips. Furthermore, since the distance between the tip of the discharge needle and the semiconductor chip is close, there is no fear that discharge will occur between adjacent semiconductor chips and the semiconductor chip will be marked. Therefore, it is possible to reliably mark only semiconductor chips determined to be defective.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an apparatus used in a semiconductor chip marking method according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing an example of a conventional marking method. 2... Semiconductor wafer 3... Semiconductor chip 5... Discharge needle.

Claims (1)

[Claims] (1) Marking is performed by bringing the tip of a discharge needle close to the surface of a semiconductor chip formed on a semiconductor wafer and applying a high voltage between the discharge needle and the semiconductor chip to generate a discharge between them. A semiconductor chip marking method characterized by: