JPH04286140A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To conduct a marking of a defective chip in a wafer decided to be defective in a probe test and to easily recognize a mark in a method of marking the defective chip. CONSTITUTION:An indicator pad 4 to be isolated from a circuit and discolored by energizing is provided on each chip 1 in a wafer, and the pad 4 of the chip 1 decided to be defective in a probe test is discolored by energizing to mark the defective chip. Magnesium is used as a material of the pad 4.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing semiconductor devices, and more particularly to a method for marking defective chips in a wafer that are determined to be defective in a probe test.

In manufacturing semiconductor devices, a plurality of chip circuits are assembled on a wafer, and individual chips are cut out by scribing. Since there may be some defective chips among the chips cut out, normally a probe test is performed before scribing, and the defective chips in the wafer that are determined to be defective are marked. Makes selection easy.

0003

2. Description of the Related Art Conventionally, defective chips within a wafer have been marked using the following method.

1) A scratch pad is provided on each chip within a wafer, and a scratch marker is used to scratch the scratch pad of a defective chip. 2) Apply ink approximately in the center of the defective chip using an ink marker.

[0005]

[Problems to be Solved by the Invention] However, these marking methods require a large number of man-hours because they are performed in a separate process from the probe test using the scratch marker or ink marker mentioned above. It is necessary to accurately manage each wafer between markings, which poses many problems in terms of both man-hours and management. Further, when using a scratch marker, there is a problem that the scratches made as marks cannot be easily read by an automatic recognition device.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a marking method that enables marking of defective chips in a wafer in a probe test, and also allows the marks to be easily recognized.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the marking method of the present invention provides marking pads on each chip in a wafer that are separated from circuits and change color when energized. The marking pad of the chip determined to be defective is changed in color by applying electricity to mark the defective chip.

[0008]

According to this structure, marking of a defective chip is performed in a probe test, and since the discolored marking pad serves as a mark of a defective chip, the mark can be easily recognized.

[0009]

Embodiments Examples of the present invention will be described below with reference to FIGS. 1 to 3. 1 and 2 are partial plan views of a chip for explaining the first and second embodiments, and FIG. 3 is a plan view of the chip for explaining the third embodiment.

In FIG. 1 or 2, 1 is a chip, 2
3 is a pad connected to the circuit, 3 is a pad separated from the circuit, 4 is a label pad, and 5 is a probe needle. Figure 1
The difference between the first embodiment and the second embodiment shown in FIG. In the example, marker pad 4 is located in the same row as pads 2 and 3.

The indicator pad 4 is made of a material such as magnesium (Mg) that changes color when energized, and is interposed between the wiring connecting the ground line of the chip 1 and the pad 3 to apply voltage or current to the pad 3. This causes discoloration. When the material is Mg, the color changes from white to black.

In the probe test, the probe needle 5 is brought into contact with the pads 2 and 3, and the quality of the chip 1 is determined by applying current from the probe needle 5 which is brought into contact with the pad 2. When the chip 1 is determined to be defective, the probe needle 5
A voltage or current is applied from the probe needle 5a touching the pad 3 in the marking pad 4 to change color, thereby marking a defective chip. Discolored sign pad 4
marks a defective chip.

[0013] Therefore, the above-mentioned marking, which was conventionally performed in a separate process from the probe test, is performed in the probe test, and the above-mentioned problems in terms of man-hours and management are solved. Since the mark is a discolored marking pad 4, it can be easily read by an automatic recognition device.

By the way, in the probe test, measurements may be performed two or more times to determine the quality of the chip. Figure 3
The third embodiment shows a case where the measurement is performed twice. That is, two marker pads 4a and 4b similar to the marker pad 4 described above.
, and two pads 3a and 3b similar to the pad 3 described above are provided accordingly.

When the first measurement is determined to be defective, the marking pad 4a is changed in color by applying electricity from the probe needle 5a touching the pad 3a in the probe needle 5, and the second measurement is performed. When it is determined that the marking pad 4b is defective, the marking pad 4b is changed in color by applying electricity from the probe needle 5b that touches the pad 3b in the probe needle 5.

[0016] In this way, when measurements are made twice or more in a probe test, marking pads similar to the marking pad 4 are provided for a number equal to or more than the number of measurements, thereby marking defects for each measurement in the probe test. Can be done.

[0017]

As explained above, according to the present invention, regarding a method for marking defective chips in a wafer determined to be defective in a probe test, the marking can be performed in the probe test, and the marks can be A marking method is provided that makes the marking easy to recognize, and has the effect of overcoming the conventional man-hour and management difficulties associated with the marking.

[Brief explanation of the drawing]

FIG. 1 is a partial plan view of a chip for explaining a first embodiment.

FIG. 2 is a partial plan view of a chip for explaining a second embodiment.

FIG. 3 is a chip plan view for explaining a third embodiment.

[Explanation of symbols]

1 Chip 2 Pads 3, 3a, 3b connected to the circuit Pads 4, 4a separated from the circuit
, 4b Marking pad 5 Probe needle

Claims (1)

[Claims] [Claim 1] On each chip (1) in the wafer, there is a marking pad (4) that is separated from the circuit and changes color when energized.
A method for manufacturing a semiconductor device, characterized in that the marking pad (4) of a chip (1) determined to be defective in a probe test is discolored by applying electricity to mark the defective chip.