JPH08274133A - Semiconductor wafer prober - Google Patents

Abstract

PURPOSE: To provide a semiconductor wafer prober which automatically recognizes and informs the defect of a device when no defect mark is added. CONSTITUTION: A semiconductor wafer prober is constituted of a wafer chip measuring means, marking means, marking error detecting means, and means which informs that the results of second marking are not recognized for a prescribed number of times when such case occurs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer measuring apparatus in a semiconductor wafer manufacturing process, and more particularly to a semiconductor wafer prober.

[0002]

2. Description of the Related Art Conventionally, hundreds of conventional semiconductor wafer chips are usually formed on one wafer at the same time, and they are individually cut off after completion of measurement. Among the separated chips, only good chips are taken out and packaged to complete an integrated circuit (IC) product.

To explain this in more detail, in the process of measuring the electrical characteristics of the chips in the wafer, an input signal is sent to the chips from a device usually called a tester for judging whether the chips are good or bad, and the testers are The output signal from the chip is received and the output signal is determined to determine whether the chip is a good product or a defective product.

Usually, the above-mentioned input / output signals are sent from the tester by a stylus (hereinafter referred to as a probe card needle) arranged on the probe card so as to match the position of an electrode (hereinafter referred to as a pad) provided on the chip, Or sent to a tester. The tester receives a signal from the chip to determine whether it is a non-defective product or a defective product, and if it is a defective product, sends a defective signal to the semiconductor wafer prober. The semiconductor wafer prober operates a device called a marker (marker) for marking the chip surface according to the above-mentioned defective signal, and adds a mark to the surface of the defective wafer chip.

Conventionally, such an inker is one in which one or a plurality of needle portions are provided in the center of a semiconductor wafer prober. At that time, the tester adds the mark to the surface of the chip which is determined to be defective, firstly when the measurement is performed for one chip immediately, and secondly, when the chip determined to be defective is mapped. (Hereinafter referred to as “mapping”) and stored in a storage area (hereinafter referred to as “wafer map”), and when all the chips have been measured, they are collectively marked at a different location at a chip judged to be defective. There are cases when

Further, as the mechanism of the above inker, there are a type in which ink is adhered to the chip surface by a needle portion, and a type in which the tip surface is hit with a hard needle to cause damage.
There is a type in which the chip surface is irradiated with laser light to melt the chip surface.

[0007]

In any of the above-mentioned three types of marks to be added, when the inker hits the needle part toward the chip during marking, it is one of the functions of the semiconductor wafer prober. Since an electric current passes through and becomes an electromagnet, the operation of the inker due to energization can be grasped.
However, since it is not confirmed whether or not the mark is actually added, if the inker is operated with the ink running out, the mark may not be added. Therefore, even a defective chip will be judged as a good product. In addition, regarding a type in which the tip surface is hit with a hard needle to damage the chip, even when the tip needle is broken and cannot reach the wafer chip, the defective chip is also judged to be a good product. The same applies to the case of the type of irradiating the chip surface with the laser light to melt the chip surface, and the laser light may not be emitted due to the breakage of the tip portion where the laser light is emitted.
Therefore, even this defective chip is determined to be a good product.

An object of the present invention is to automatically solve the problems when the tester determines that the defective wafer chip is a defective wafer chip and the defective wafer chip is not marked with a defective mark in the inker. It is an object of the present invention to provide a semiconductor wafer prober capable of recognizing and notifying a defect.

[0009]

SUMMARY OF THE INVENTION The present invention comprises means for measuring each wafer chip provided on a semiconductor wafer, means for marking a defective chip based on the measurement result measured by this means, and the above marking. A means for recognizing a mark, a means for detecting a marking error by comparing the mark recognition result with the measurement result, and a notification when the result of remarking by the marking means cannot be recognized a predetermined number of times. And a semiconductor wafer prober.

[0010]

According to the present invention, when the state where the result of re-marking cannot be recognized a predetermined number of times continues, the notifying means operates to notify that the defective mark is not added.

[0011]

EXAMPLE An example of the present invention will be described below.
FIG. 1 is a block diagram showing an outline of a semiconductor wafer prober of the present invention, FIG. 2 is a plan view showing the surface of a semiconductor wafer, and FIG. 3 is a wafer map diagram.

The semiconductor wafer prober of the present invention is
A semiconductor wafer, which is an object to be measured, is mounted on a mounting table and is vacuum-adsorbed and fixed. This mounting table has horizontal X-axis and Y-axis directions,
It is automatically operated by a drive mechanism that moves in the vertical Z-axis direction. The probe card needle is brought into contact with the pad of the chip on the wafer positioned at a predetermined position for measurement. This probe card needle is connected to a tester to make a good wafer,
It has a measuring mechanism for measuring defects. This tester measures individual wafer chips through a mechanism such as positioning of a semiconductor wafer prober, and has a judgment function of judging whether the electrical characteristics of the obtained wafer chips are good or bad according to the measurement result. .

The result of the tester measurement thus determined is displayed on the wafer by a marking mechanism which adds a defective mark by a defective signal from the tester. After that, while recognizing the defective mark shape of the whole wafer added to this wafer by the recognition device,
The measurement result of the wafer chips in this wafer is stored as a wafer map. Each such mechanism is controlled by the control mechanism as a whole. Needless to say, each known mechanism can be used as each individual mechanism itself.

In the semiconductor wafer prober of the present invention, the address signals in the X-axis and Y-axis directions in the driving mechanism and the good and bad signals in the chip measurement results by the tester are measured in correspondence with each chip and address. Information is stored in a storage area of a control mechanism called a wafer map, and the defective chip 8 in the wafer 1 is stored as shown in FIG.
Is displayed by the defective signal of the tester and is mapped to the addresses in the X-axis and Y-axis directions. Based on the information stored in the wafer map, the inker is operated on the surface of the defective wafer chip in the wafer to add a mark.
Up to this step is performed by a conventional technique.

When the added defective mark is recognized by the recognition device, the information obtained by the recognition may be mistaken for dust. Therefore, the wafer prober itself stores the shape of the defective mark in advance. Is called a basic defect mark. The basic defective mark and the added defective mark are compared, and if the shape is in accordance with the basic defective mark, it is a defective wafer chip corresponding to the measurement result by the tester, and the defective mark is added to the surface of the wafer chip. It becomes clear. Also, this defect mark is automatically recognized after the measurement of the chip in the wafer by the semiconductor wafer prober,
Although there is a process of assembling only good wafer chips, in this case as well, it is often judged by the size of the defective mark (which means the area), so the size of the defective mark is also automatically detected in the wafer probing process. Recognition is extremely useful.

If the measurement result indicated by the wafer map is a defective wafer chip and the result recognized by the recognition device is not recognized by the defective mark, the defective mark is added to the surface of the defective wafer chip by the defective signal again. It After that, the defective mark is recognized again by the recognition device, and as a result, the defective mark is recognized.

Further, if the above-mentioned state in which the recognition cannot be performed continues for several times, for example, if a function for notifying the operator is attached, the defective mark is always added only to the defective wafer chip by the ink filling by the operator. And complete the work of the whole process of the semiconductor wafer prober.

[0018]

Since the present invention is constituted as described above, the marking error can be detected by the notifying means, and all the defective wafer chips except the good wafer chip of the semiconductor wafer can be accurately marked with the defective mark. Since it can be added, and the sorting operation is performed by using the defective mark as a mark at the time of sorting the wafer chips, a highly reliable product as a semiconductor wafer chip can be obtained. It is also very effective in automation.

[0019]

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a semiconductor wafer prober according to the present invention.

FIG. 2 is a plan view showing an example of a defective wafer chip on the wafer surface.

FIG. 3 is a schematic diagram for explaining a wafer map.

[Explanation of symbols]

 1 semiconductor wafer 8 defective wafer chip

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[Procedure amendment]

[Submission date] September 21, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Delete

Claims (1)

[Claims] 1. A means for respectively measuring a wafer chip provided on a semiconductor wafer, a means for marking a defective chip based on a measurement result measured by this means, a means for recognizing a mark by the marking, It is provided with means for detecting a marking error by comparing the mark recognition result with the measurement result, and means for notifying the result of re-marking by the marking means when it cannot be recognized a predetermined number of times. Semiconductor wafer prober.