JPH0666869A - Semiconductor tester and judging method of electric continuity of probe needle of the semiconductor tester - Google Patents

Abstract

(57) [Summary] [Object] To provide a semiconductor tester for instantaneously elucidating the cause of electrical contact failure of an element formed on a wafer, and a method for determining electrical continuity of a probe needle of the semiconductor tester. Constitution: An electric insulating film extending in the longitudinal direction of the probe needle 30, and two metallic bodies adjacent to each other and sandwiching the electric insulating film and insulated from each other Check the electrical continuity between the metal bodies. Next, the probe needle 30 is brought into contact with the metal plate 40 to confirm the electrical continuity between the two metal bodies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor tester for determining the quality of all the elements on a wafer after the elements are formed on the wafer, and a method for determining the electrical continuity of a probe needle of the semiconductor tester.

[0002]

2. Description of the Related Art Manufacturing processes of semiconductor devices are roughly classified into a wafer process for forming devices on a wafer and an assembly process for dividing the formed devices into individual chips and packaging each chip. By the way, after the elements are formed on the wafer, a probe test is performed in order to judge the quality of all the elements on the wafer. In this probe test, many thin needles called probe needles connected to the semiconductor tester are set up on the bonding pad and the check pattern portion, and the electrical characteristics of each element are evaluated to determine whether the contact of each element is good or bad. Is determined. This electrical characteristic is evaluated by, for example, applying a voltage to a probe needle standing on a bonding pad, and if a current flows into the semiconductor tester at a predetermined voltage, the element contact is considered to be good, and even if the voltage is increased, the semiconductor tester If no current flows through the device, it is considered that the device has a defective contact.

The cause of this probe test and contact failure will be described with reference to the drawings. FIG. 4 is a perspective view showing a prober of a conventional semiconductor tester, in which a portion provided with a probe needle is shown in an expanded manner. The prober 10 includes a probe needle holder 12 and a plurality of probe needles 14. This probe needle holder 12
4, only one is shown in FIG. 4, but a plurality may be formed. The number of probe needles 14 is determined according to the elements formed on the wafer.

FIG. 5 is an enlarged plan view showing a state where the probe needle 14 is in contact with a predetermined position of the tip 15. Next, the tip of the probe needle 14 and the Al of the element on the wafer are
Various contact states with the pad will be described with reference to FIGS. 6 to 9. FIG. 6 is a sectional view showing a state in which the tip portion of the probe needle and the Al pad 16 are in proper contact with each other. The Al pad 16 is formed so as to be exposed from the opening 20 of the insulating film 18, and is electrically connected to another portion by the Al wiring 22.

FIG. 7 is a cross-sectional view showing a state in which the probe needle 14 is in contact with the Al pad 16 connected to the broken Al wiring portion 24, and a defective contact causes a defective element. FIG. 8 is a cross-sectional view showing a state where the probe needle 14 is in contact with the insulator 18 due to an alignment error, and the contact is defective.

FIG. 9 shows a probe needle 14 and an Al pad 16.
FIG. 6 is a cross-sectional view showing a state in which the attached insulator 26 is interposed between the contact point and the contact point. By the way, in the conventional probe test, it is possible to automatically recognize whether or not the probe needle is in contact with the wafer to be measured by using the touch sensor. However, as shown in FIGS. 6 to 9, it is not possible to automatically recognize whether or not the location where the probe needle is in contact is a bonding pad or the like. Further, it is not possible to automatically recognize whether or not the insulator is attached to the tip of the probe needle.

[0007]

Therefore, for example, as a result of a probe test, when most of the elements have a contact failure and are largely deviated from the normally considered yield range, whether the cause is the wafer or the probe. It is not possible to identify whether it is due to the insulator attached to the tip of the needle or misalignment between the wafer and the probe needle. As a result, the probe test is performed again. For this reason,
There is a problem that re-measurement, analysis, and the like require time, and the throughput of an expensive semiconductor tester (measuring machine) is drastically reduced.

In view of the above circumstances, the present invention provides a semiconductor tester for instantaneously elucidating the cause of electrical contact failure of an element formed on a wafer, and a method for determining electrical continuity of a probe needle of this semiconductor tester. The purpose is to do.

[0009]

A semiconductor tester of the present invention for achieving the above object is configured such that a plurality of electrical conducting portions of an element formed on a wafer are brought into contact with probe needles and a voltage is applied to the probe needles. In a semiconductor tester for measuring the current flowing in an electric conduction portion by applying it and inspecting the electric conduction of an element, a probe needle has an electric insulating film extending in the longitudinal direction of the probe needle and the electric insulating film. It is characterized in that it is composed of two metal bodies that are insulated from each other by sandwiching.

In order to achieve the above object, the method for determining the electrical continuity of the probe needle of the semiconductor tester according to the present invention is such that the electrical insulating film extending in the longitudinal direction and the electrical insulating film are insulated from each other. Check the electrical continuity between the two metal bodies with the probe needle consisting of the two metal bodies floating, and contact the probe needle with the metal plate to make the electrical connection between the two metal bodies. It is characterized in that the electrical continuity is confirmed, and the probe needle is brought into contact with the electrical conduction portion of the element to confirm the electrical conduction between the two metal bodies.

A device for generating an alarm or the like when the electrical continuity is abnormal may be provided in this semiconductor tester.

[0012]

According to the method of determining the electrical continuity of the probe needle of the semiconductor tester of the present invention, the probe is composed of an electrically insulating film extending in the longitudinal direction and two metal bodies insulated from each other with the electrically insulating film interposed therebetween. By confirming the electrical continuity between the two metal bodies with the needle floating, it is determined whether or not a conductive substance is attached to the tip of the probe needle. When there is electrical conduction between these two metal bodies,
The conductive material is attached to the tip of the probe needle.

On the other hand, by bringing the probe needle into contact with the metal plate,
By checking the electrical continuity between the two metal bodies,
It is determined whether or not an electrical insulator is attached to the tip of the probe needle. When there is no electrical conduction between these two metal bodies, it means that an electrical insulator is attached to the tip of the probe needle. When a conductive substance or an electrical insulator is attached to the tip of the probe needle, the tip of the probe needle is cleaned to remove these deposits.

When it is confirmed by the above-mentioned two confirmation methods that the conductor and the electric insulator are not attached to the tip portion of the probe needle, the electrical conduction of the probe needle is normal.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a semiconductor tester of the present invention and a method for determining electrical continuity of a probe needle of this semiconductor tester will be described with reference to the drawings. FIG. 1 is an explanatory view showing a method for judging electrical continuity of a probe needle of a semiconductor tester of this embodiment, FIG. 2 is an enlarged plan view showing a state where the probe needle is in contact with a predetermined place of a chip, and FIG. FIG. 3 is an enlarged cross-sectional view showing a tip end portion of

First, the structure of the probe needle of this embodiment will be described with reference to FIG. The probe needle 30 is composed of an electrically insulating film 32 extending in the longitudinal direction of the probe needle 30, and two metal bodies 34 and 36 which are insulated from each other with the electrically insulating film 32 interposed therebetween. As shown in FIG. 2, the tip portion of the probe needle 30 comes into contact with a predetermined position of the tip 38, but the probe needle 30 has two metal members 3
Both 4, 36 are arranged so as to contact the chip 38.

Next, referring to FIG. 1 and Table 1, a method for determining the electrical continuity of the probe needle 30 will be described. The jig used in the method for determining the electrical continuity of the probe needle 30 includes a metal plate 40 and a tip cleaning plate 42.

[0018]

[Table 1]

First, with the probe needle 30 in a floating state,
Confirm electrical continuity between the metal bodies 34, 36 (see FIG. 3). At this time, if electrical conduction is confirmed by a detector (not shown), it means that a conductive substance is attached to the tip of the probe needle 30. In this case, move the prober 44 to the arrow A
Then, the tip cleaning plate 42 cleans the tip of the probe needle 30. The tip cleaning plate 4
2 may be moved.

Next, after it is confirmed that there is no electrical conduction between the metal bodies 34 and 36, the prober 44 is moved along the arrow B to bring the probe needle 30 into contact with the metal plate 40. Check the electrical continuity between the two metal bodies 34, 36. In this state, if there is no electrical continuity,
The insulator is attached to the tip of the probe needle 30. In this case, the tip cleaning plate 42 cleans the tip of the probe needle 30.

After the electrical connection between the two metal bodies 34 and 36 is confirmed by bringing the probe needle 30 into contact with the metal plate 40, the probe needle 30 is moved to the tip 38 of the chip 38 as shown in FIG. Touch in place. If there is no electrical continuity in this state, the alignment error (see Fig. 8)
it is conceivable that. In this case, the alignment is adjusted to ensure electrical continuity.

In the case of the state shown at the bottom of Table 1, the element is defective and, for example, the Al wiring portion is broken (see FIG. 7). Further, since the above-mentioned continuity confirmation is performed in about several tens of milliseconds, the electrical continuity of the probe needle can be easily and instantly determined, and the cause of the contact failure can be clarified in an instant.

As a result, the time for re-measurement, analysis, etc. is hardly required, so that the throughput of an expensive semiconductor tester (measuring machine) is improved. Further, it is not necessary to prepare a plurality of expensive semiconductor testers. Moreover, the cause of the contact failure can be immediately identified, so that the production line does not stop.

[0024]

As described above in detail, using the semiconductor tester of the present invention, determination of electrical continuity of the probe needle,
When performing a probe test, the cause of the contact failure can be immediately clarified, so that high throughput of the semiconductor tester can be achieved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a method for determining electrical continuity of a probe of a semiconductor tester of this embodiment.

FIG. 2 is an enlarged plan view showing a state in which a probe needle is in contact with a predetermined place of a chip.

FIG. 3 is an enlarged cross-sectional view showing a tip portion of a probe needle.

FIG. 4 is a perspective view showing a prober of a conventional semiconductor tester, in which a portion provided with a probe needle is shown in an enlarged manner.

FIG. 5 is an enlarged plan view showing a state in which the probe needle is in contact with a predetermined location of the chip.

FIG. 6 is a cross-sectional view showing a state where the tip portion of the probe needle and the Al pad are in proper contact with each other.

FIG. 7 shows an Al pad connected to a broken Al wiring,
It is sectional drawing which shows the state which the probe needle is contacting.

FIG. 8 is a cross-sectional view showing a state in which a probe needle is in contact with an insulator due to an alignment error.

FIG. 9 is a cross-sectional view showing a state in which an attached insulator is interposed between a probe needle and an Al pad.

[Explanation of symbols]

 30 probe needle 32 electrical insulating film 34, 36 metal body 40 metal plate 42 tip cleaning plate 44 prober

Claims (2)

[Claims] 1. A probe needle is brought into contact with each of a large number of electrical conducting portions of an element formed on a wafer, and a voltage is applied to the probe needle to measure a current flowing through the electrical conducting portion. In a semiconductor tester for inspecting electrical continuity, the probe needle includes an electrical insulating film extending in a longitudinal direction of the probe needle and two metal bodies adjacent to each other and insulated from each other with the electrical insulating film interposed therebetween. A semiconductor tester characterized in that 2. A method for determining electrical continuity of a probe needle of a semiconductor tester for inspecting electrical continuity of an element formed on a wafer, comprising: an electrical insulating film extending in a longitudinal direction; and the electrical insulating film. In a state in which a probe needle composed of two metal bodies that are adjacent to each other and are insulated from each other is floated, electrical conduction between the two metal bodies is confirmed, and the probe needle is brought into contact with a metal plate, A method for determining electrical continuity of a probe needle of a semiconductor tester, characterized by confirming electrical continuity between the two metal bodies.