JPH07140168A - Semiconductor probe - Google Patents

Abstract

PURPOSE:To prevent misjudgment at the time of wafer test, for example, due to the increase of contact resistance caused by adhesion of dust particles by employing a mixture of tungsten particles and different metal particles falling between the tungsten particles as a material for semiconductor probe. CONSTITUTION:A mixture of tungsten particles 2 and different metal particles 3 filling between the tungsten particles is employed as a material of a probe 1. The main material of the probe 1, i.e., the tungsten particle 2, has particle size from several hundreds Angstrom to several mum and the different metal particle 3 filling between the tungsten particles 2 is excellent in the weldability and electric characteristics. The different metal 3 includes gold, silver, copper, rhenium, etc., and a rhenium particle having substantially same size as the tungsten particle is excellent in the matching with the tungsten particle. Since no dust particle adheres to the point even after repetitive contact with a semiconductor wafer 4 to be tested, service life of the probe can be prolonged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor probe used in a semiconductor device measuring apparatus, and more particularly to an improved probe for preventing foreign matter from adhering to the probe when it contacts a test object.

[0002]

2. Description of the Related Art A semiconductor device measuring apparatus transmits a test signal generated by a test signal generator to a probe card,
A large number of probes provided on the probe card are brought into contact with the electrodes of the semiconductor element that is the actual test object to supply a test signal, and the response signal of the semiconductor element to this test signal is sent via this probe and the probe card. That is, the quality of the semiconductor element is determined by comparing the expected value prepared in advance with the test signal generator.

As described above, the semiconductor probe contacts the electrode formed on the semiconductor element, which is the device under test, supplies a test signal to the electrode, and extracts the response signal of the semiconductor element to the test signal. There are BeCu (beryllium kappa) and W (tungsten) products, but the beryllium kappa product has a short life because it is soft, and the tungsten product has strength (hardness). And elasticity) is excellent.

FIG. 4 shows a conventional tungsten probe for semiconductors. In the figure, 10 is a probe formed by using tungsten as a material, 2 is the probe 10, and the particle size is several hundreds. Tungsten particles having a size of angstrom or several μm, 4 are semiconductor wafers to be subjected to a wafer test by the probe 10,
Reference numeral 5 is an Al electrode formed for each chip on the semiconductor wafer 4, and 6 is a glass coat film formed on the entire surface of each chip except the electrode portion.

FIG. 5 shows a process of manufacturing this conventional semiconductor probe. In FIG. 5, tungsten powder (step S21), which is a raw material for the probe, is pressed (step S22) and sintered (step S23) to produce an ingot (step S24).

Next, swaging is performed (step S2).
5) After heat treatment (step S26), swaging is performed again (step S27), and wire drawing is performed (step S28) to obtain a thick line (step S29).
Then, this thick line is drawn (step S3
0), the center line is obtained (step S31). The middle wire is drawn (step S32) to obtain a thin wire (step S33), and the thin wire is further drawn (step S34) to obtain an ultrafine wire (step S3).
5).

Then, the needle tip is aligned with the fine wire so that the needle tip uniformly contacts the pad of the semiconductor chip (step S36), and finally a hard powder such as walnut powder is sprayed on the needle tip. It causes unevenness and the contact resistance is 0.
It is set to 5Ω or less (step S37).

Next, the method of use will be described by taking a wafer test as an example. The wafer test is an electrical test in which a semiconductor chip is formed on the semiconductor wafer 4 and is not diced into individual chips, and the electrical test is performed on the Al electrode 5 of each semiconductor chip as described above. Contact the probe 1 made by
Test signals are input to and output from the probe from the probe to test individual chips. Then, all the semiconductor chips formed on the wafer are tested by repeating this contact for each chip.

[0009]

The conventional probe is completed by importing a probe that has already been processed into a needle shape by the process shown in FIG. 5, aligning the needle tips in Japan, and working to reduce the contact resistance. Although the product is obtained, foreign matter, that is, Al2 O3 (this is Al when contact is made on the Al electrode during the wafer test, at the grain boundary of the tungsten particles of several hundred angstroms or several μm forming the probe during use. Al2 O3 formed on the electrode is attached to the probe so as to be scraped off, and its size varies from several μm to 50 μm), and the contact resistance increases. This contact resistance is initially 0.5Ω
It is as follows, but as the foreign matter adheres, it increases from 6 Ω to 10 Ω or more, so once the foreign matter adheres, the rate at which a chip that is actually a good product is mistakenly determined as a defective product increases. This is one of the factors that reduce the yield in the wafer test. Further, in order to remove foreign matter attached to the needle tip, the needle tip was polished and reused with glass or the like, but by performing this polishing, the probe needle is more likely to be broken, and the durability of the probe needle is increased. There was a problem that it was bad.

The present invention has been made in order to solve the above-mentioned problems of the conventional ones, and can prevent foreign matter from adhering to the probe, eliminating the need to polish the probe needle and adhering foreign matter. Therefore, it is an object of the present invention to obtain a semiconductor probe capable of preventing an erroneous determination from occurring during a test such as a wafer test due to an increase in contact resistance.

[0011]

In the semiconductor probe according to the present invention, tungsten, which is the material of the semiconductor probe made of tungsten, is mixed with a dissimilar metal for filling the interparticles. It is a thing. Further, in the probe for semiconductors according to the present invention, a dissimilar metal layer is formed on the surface of the probe body made of tungsten as a material to prevent foreign matter from biting between the tungsten particles.

[0012]

According to the present invention, as described above, since the probe is mixed with a different kind of metal having a good matching with the tungsten particles as the main material, the different kind of metal enters the tungsten grain boundary and is formed on the semiconductor chip. It is possible to prevent foreign matter from penetrating into the grain boundaries during contact with the electrodes, and to prevent foreign matter from adhering to the grain boundaries of the tungsten particles during repeated contact.

Further, in the present invention, as described above, since the dissimilar metal layer is formed on the surface of the probe body made of tungsten, the dissimilar metal coated on the surface of the probe is subjected to the wafer test. It prevents foreign matter from digging into the tungsten grain boundaries and prevents foreign matter from adhering to the grain boundaries of the tungsten particles during repeated contact.

[0014]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a semiconductor probe according to a first embodiment of the present invention. In the figure, 1 is a probe using a mixture of tungsten and a different metal filling the space between the particles of tungsten as a material, 2 is the main material of the probe 1, and the particle size is several hundred angstroms to several μm. Of the tungsten particles, 3 fills the spaces between the tungsten particles 2, different metal particles having excellent weldability and electrical characteristics, 4 is a semiconductor wafer on which a wafer test is performed by the probe 1, and 5 is a semiconductor wafer 4. An Al electrode formed on each chip, and 6 is a glass coat film formed on the entire surface of each chip excluding the electrode portion.

FIG. 2 shows a process of manufacturing this semiconductor probe. In FIG. 2, a mixture (step S1) of tungsten powder as a raw material of the probe and a dissimilar metal powder for filling particles is pressed (step S2),
An ingot (step S4) is produced by sintering (step S3).

Next, swaging is performed (step S
5) After heat treatment (step S6), swaging is performed again (step S7), and wire drawing is performed (step S8) to obtain a thick line (step S9).

Then, the thick line is drawn (step S10) to obtain the center line (step S11). The middle wire is drawn (step S12) to obtain a thin wire (step S13), and the thin wire is further drawn (step S14) to obtain an ultrafine wire (step S15).

Then, with respect to this ultrafine wire, the needle tip is aligned so that the needle tip uniformly contacts the pad of the semiconductor chip (step S16), and finally a hard powder such as walnut powder is sprayed on the needle tip. It causes unevenness and the contact resistance is 0.
It is set to 5Ω or less (step S17).

Next, the operation and effect will be described. In this embodiment, as shown in FIG. 1, the probe 1 is prepared by mixing the dissimilar metal 3 for filling the interparticles, which has excellent weldability with tungsten and electrical characteristics, so that the wafer test is repeated. Also in the above, it is possible to prevent foreign matter from adhering to the grain boundaries of the tungsten particles. Therefore, it is possible to omit the work of polishing the needle tip, which was conventionally performed to remove the foreign matter attached to the needle tip, and the durability of the probe is improved. Further, it is possible to prevent the contact resistance of the needle tip from increasing due to the adhesion of foreign matter, and it is possible to prevent the yield of the semiconductor chips from decreasing during the wafer test.

The different metals suitable for filling the space between the tungsten particles include gold, silver, copper, rhenium (Re) and the like. Among them, particularly, the same particle size as the tungsten particles is used. The rhenium that it has has excellent matching properties with the tungsten particles, and by using this, a good probe can be obtained.

When rhenium is mixed in the range of 0.1 to 5.0% with respect to tungsten (W), the most excellent effect can be obtained. The reason for this is that when rhenium is mixed in an amount of 0.1% or less with respect to tungsten, the penetration into the tungsten grain boundaries is not sufficient and no remarkable effect appears. Further, when rhenium is mixed with tungsten in an amount of 5.0% or more, the mechanical properties inherent to tungsten are impaired, and problems such as strength occur. The most preferable range of the mixing ratio is when rhenium is mixed with tungsten in an amount of 0.3% to 3.0%, and at that time, as shown in FIG. Since the gap can be filled and the foreign matter can be prevented from penetrating into the grain boundary, the above-described effect can be optimally obtained.

Example 2. FIG. 2 shows a semiconductor probe according to a second embodiment of the present invention. In the figure, 10 is a probe formed only of tungsten, 2 is the probe 10 and tungsten particles having a particle size of several hundred angstroms to several μm, and 7 are formed on the surface of the probe 10. A foreign metal layer, which is formed by coating a dissimilar metal by a general vapor deposition method or the like. Reference numeral 4 denotes a semiconductor wafer on which a wafer test is performed by the probe having the dissimilar metal layer thus formed, and 5 denotes A formed on the semiconductor wafer 4.
1 electrode, 6 is a glass coat film formed on the entire surface of each chip except the electrode portion. As the dissimilar metal coated on the probe 10, gold is most suitable because it has excellent workability and electrical characteristics.

Next, the operation and effect will be described. In the present embodiment, as shown in FIG. 2, the surface of the probe 10 is coated with the dissimilar metal layer 7, so that the grain boundaries of the tungsten particles on the surface of the probe are covered with the dissimilar metal. Therefore, it is possible to prevent the foreign matter from biting into the grain boundary of the tungsten particle by making contact with the semiconductor chip, and the foreign matter adheres to the grain boundary of the tungsten particle during repeated contact with the semiconductor chip during the wafer test. Can be prevented.

As described above, in the second embodiment, the surface of the probe made of tungsten is coated with gold, which is most suitable as the dissimilar metal for coating, as described above, so that the foreign matter penetrates into the grain boundaries. Since it is possible to improve the durability of the probe, it is possible to prevent the contact resistance of the needle tip from increasing due to the adhesion of foreign matter, it is possible to prevent the decrease in the yield of semiconductor chips during wafer testing. The same effect as the first embodiment can be obtained.

[0025]

As described above, according to the semiconductor probe of the present invention, a semiconductor probe prepared only from tungsten is used as a mixture of different metals for filling tungsten particles. By using it as a material, the semiconductor probe is configured so that foreign matter does not adhere to the needle tip even after repeated contact with the test object, so that the durability of the semiconductor probe can be extended and further, such as in wafer test. There is an effect that it is possible to prevent a decrease in holding during the test.

Further, according to the semiconductor probe of the present invention, the semiconductor probe is formed by forming a dissimilar metal layer on the surface of the probe body made of tungsten as a material for preventing foreign matter from biting between the tungsten particles. Since the foreign matter does not adhere to the needle tip even after repeated contact with the test object, it is possible to extend the durability of the semiconductor probe and to prevent a decrease in holding during a test such as a wafer test. The effect is that you can do it.

[Brief description of drawings]

FIG. 1 is a sectional view of a semiconductor probe according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a manufacturing process of the semiconductor probe according to the first embodiment of the present invention.

FIG. 3 is a sectional view of a semiconductor probe according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of a conventional tungsten probe for semiconductors.

FIG. 5 is a flowchart showing a manufacturing process of a conventional tungsten probe for semiconductors.

[Explanation of symbols]

 1 probe 2 tungsten particles 3 dissimilar metal 7 dissimilar metal layer 10 probe

Claims (2)

[Claims] 1. A probe for semiconductors, wherein a mixture of tungsten and a dissimilar metal for filling the spaces between the tungsten particles is used as a material. 2. A semiconductor probe main body made of tungsten as a material, and a dissimilar metal layer formed on the surface of the semiconductor probe main body for preventing foreign matter from biting between the tungsten particles. A semiconductor probe.