JPH11330173A - Semiconductor-wafer prober device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform evaluation of electrical characteristics in a state in which various bending stresses are applied on a semiconductor wafer, by providing the rod-shaped push rod that can be freely lifted and lowered in the inside of a stage, lifting up a pushing die from the lower part of the stage, lifting up the push rod and deforming the semiconductor wafer as the shape of the pushing die. SOLUTION: The inside of a stage is made to be a completely sealed state tightly by a wafer 1 at the upper surface and a pushing-die holding stage 7 at the lower surface, and vacuum chucking is performed. The semiconductor wafer 1 is brought into complete tight contact with an annular stage and fixed. Thereafter, when the pushing-die holding stage 7 is lifted up, a pushing die 8 is brought to the lower part of a pushing rod 5 that is freely lifted and lowered. The pushing rod 5 is lifted as the shape of the pushing die 8. The upper part of the lifted pushing rod 5 lifts the semiconductor wafer 1 and deforms the wafer. Since both the end parts of the pushing rod 5 have a hemispherical shape, the shape of the pushing die 8 can be accurately transferred to the semiconductor wafer 1. In this state, a probe 11 is applied on an electrode pad from the upper part of the semiconductor wafer 1, and the test for electrical characteristics is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prober for a semiconductor wafer which is used when inspecting and testing elements formed on a semiconductor wafer.

[0002]

2. Description of the Related Art The quality before dicing is checked by measuring the electrical characteristics of an IC formed on a semiconductor wafer, so that unnecessary work in a post-process is omitted.
For this purpose, as shown in FIG. 5, the semiconductor wafer 1 is placed on a horizontal stage 12, and the semiconductor wafer 1 is evacuated and fixed by suction through small holes 9 provided on the stage 12, and the probe 11 is placed on the wafer 1 from above. The electrical characteristics are evaluated by contacting the electrodes. As described above, in order to place the wafer 1 on the horizontal stage 12 and perform vacuum suction, the wafer 1 is fixed horizontally and the electrical characteristics are measured.

[0003] However, a change in electrical characteristics with respect to bending stress has become a problem as in recent IC cards and the like, and it is necessary to evaluate electrical characteristics due to bending stress at the wafer level. As an example of the experimental results, a 6-inch wafer was measured with a junction leak measurement pattern in a state where the center was raised by 300 μm. As a result, the leak current value was 1
From × 10 ^-12 A order to 1 × 10 ^-9 A order 3
Digit up was observed. As is clear from this experimental example, even a chip determined to be good in a test in which normal stress is not applied may become defective due to stress applied after shipment.

Japanese Patent Application Laid-Open No. 7-161785 describes that a semiconductor device on a wafer is measured while the bent wafer is kept bent, that is, the measurement is performed while the warpage of the wafer is fixed without extending. ing.

SUMMARY OF THE INVENTION An object of the present invention is to provide a prober device for a semiconductor wafer capable of evaluating electrical characteristics due to bending stress at a wafer level.

[0006]

According to a first aspect of the present invention, there is provided a semiconductor wafer prober apparatus for measuring electrical characteristics of elements formed on a semiconductor wafer, wherein at least a wafer end is held on a stage upper surface. Holding means, a plurality of rod-shaped push rods which are provided inside the stage and are vertically movable to face the wafer, a push die which pushes up the plurality of push rods from below into a desired shape, and a vertical movement of the push die And a semiconductor wafer prober device.

According to a second aspect of the present invention, there is provided the semiconductor wafer prober device according to the first aspect, wherein the inside of the stage is evacuated to hold the semiconductor wafer on the stage.

The invention according to claim 3 is the semiconductor wafer prober device according to claim 1, wherein the wafer holding means comprises a rotatable ring-shaped stage.

According to a fourth aspect of the present invention, there is provided the semiconductor wafer prober device according to the first aspect, wherein the pressing die is replaceable with the elevating means.

According to a fifth aspect of the present invention, the pressing die is
5. The semiconductor wafer prober device according to claim 4, wherein the semiconductor wafer prober device includes at least a downward bending type, a twist bending type, and an upward bending type pressing die.

According to a sixth aspect of the present invention, the size of the pressing die includes a plurality of types.
2. A semiconductor wafer prober device according to item 1.

[0012]

An embodiment of the present invention will be described below with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description.

FIG. 1 is a sectional view showing the structure of this embodiment, and FIG.
Is a plan view of the stage.

In this embodiment, the wafer stage is
A ring-shaped stage 2 is provided at a position in contact with the periphery of the wafer 1.
Is a structure that can be rotated by an uneven fitting mechanism between them. A ring-shaped rubber wafer stopper 3 is arranged on the upper surface of the stage, and can be attached and detached by bolts 4. The push rods 5 are rod-shaped and rounded at both ends. These push rods 5 are held in a suspended state inside the upper part of the stage by a push rod holder 6 having a disk-shaped hard hole attached to the stage 2. I have.

At the lower part of the stage, there is provided a press-type holding table 7 having a circular press-type 8 which is in close contact with the inner wall of the ring-shaped stage 2 and is connected to a screw-type device 10 and can be moved up and down. There is a small hole at the center of the surface of the press-type holding table 7, and the vacuum suction 9 is possible. Further, the upper surface of the press die holding base 7 can be attached to the press die 8 with the bolt 4 so as to be attachable / detachable. The press die 8 has a hollow inside, and has many small holes formed on the surface. When the press die 8 is attached to the press die holder 7, it can be vacuum-sucked through the small holes on the surface of the holder 7. Various types of stamping die 8 are prepared in advance, and can be replaced with the stamping die holder 7 as needed.

The procedure for conducting an electrical property evaluation test on a wafer is as follows.

First, the pressing die holder 7 at the lower part of the stage is lowered to a state where the pressing die 8 can be removed, and the pressing die 8 of the type in which the wafer is desired to be deformed is mounted.
Then, the press-type holding table 7 is raised until it enters the ring-shaped stage 2 to some extent. At this time, the inner wall of the ring-shaped stage 2 and the periphery of the pressing die holder 7 are in close contact.

Next, the semiconductor wafer 1 is placed on the ring-shaped stage 2 with the ring-shaped wafer stopper 3 on the upper surface of the stage removed, and then the wafer stopper 3 is mounted with bolts 4. The wafer stopper 3 is positioned close to the periphery of the semiconductor wafer 1. Next, vacuum suction 9 is performed from the pressing die holding table 7. At this time, since the inside of the stage is completely sealed by the wafer 1 on the upper surface and the press holding table 7 on the lower surface, the semiconductor wafer 1 is sucked by vacuum suction.
Is completely adhered and fixed to the ring-shaped stage 2. Here, since the ring-shaped stage 2 is of a rotary type, the positioning of the angle of the semiconductor wafer 1 can be adjusted.

After the adjustment of the wafer angle, the pressing die holder 7 is raised. When the pressing die holding table 7 is raised, as shown in FIG. 3, the pressing die 8 comes into close contact with the lower part of the vertically movable push rod 5, and the push rod rises according to the shape of the die 8. The upper part of the raised push rod raises and deforms the semiconductor wafer 1. Since both end portions of the push rod 5 have a hemispherical shape, the mold of the push die 8 can be accurately transferred to the semiconductor wafer 1. The pressing die 8 is prepared in a concave type, a convex type, a twist type, a corrugated type, or the like, and is mounted as necessary. In addition, when the size of the amount of warpage or the like is clarified when the pressing die is formed, the amount of warpage or the like of the wafer can be quantified. In this state, the probe 11 is placed on the electrode pad from above the semiconductor wafer 1 and an electrical property test is performed.

The vacuum suction may be performed by vacuum suction 9 'from the stage holder 13 as shown in FIG. 4. In this case, the ring-shaped stage 2 and the press-type holder 7 are used for vacuum suction of the entire stage. It is not necessary to consider the adhesiveness with the device.

The following is still more useful.

In a semiconductor wafer prober apparatus, an electric characteristic test is performed in a state where a torsion bending stress is applied to a semiconductor wafer by making a pressing die a torsion bending type. In addition, a semiconductor prober device that performs an electrical characteristic test in a state in which a semiconductor wafer is subjected to a bending stress according to the pressing die by providing one pressing die with a special bending type such as upward, downward, or twisting is also useful.

Further, in the semiconductor wafer prober apparatus, by preparing various sizes of the pressing die, an electrical characteristic test can be performed in a state where bending stress of any size is applied to the semiconductor wafer. In addition, the bending stress of the semiconductor wafer can be quantitatively determined by clarifying the size of the pressing die.

[0024]

As described above, the prober device for a semiconductor wafer according to the present invention is provided with a rod-shaped push rod which can be moved up and down inside the stage, and the push die is raised by raising the press die from the lower part of the stage. Semiconductor wafer that has been vacuum-sucked into the mold can be deformed according to the shape of a pressing mold. Therefore, it is possible to perform an electrical property test in a state where various bending stresses are applied to the semiconductor wafer.

Although a push rod is used as a means for contacting the wafer, the push rod has the advantage of equalizing the load on the wafer and is useful. Further, by holding the wafer in a vacuum in the stage, it is possible to easily cope with the deformation to the concave shape in particular. Further, by setting the stage as a rotatable ring-shaped stage, the angle of the wafer can be easily determined.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a semiconductor wafer prober device according to the present invention.

FIG. 2 is a plan view of the stage of FIG.

FIG. 3 is a cross-sectional view showing a state where stress is applied to a wafer in the apparatus of FIG. 1;

FIG. 4 is a sectional view showing another embodiment of the semiconductor wafer prober device of the present invention.

FIG. 5 is a sectional view showing a conventional semiconductor wafer prober device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor wafer 2 Ring stage 3 Wafer stopper 5 Push bar 6 Push bar holding stand 7 Push type holding stand 8 Push type 9 Vacuum suction 9 'Vacuum suction 11 Probe 13 Stage holding stage

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hironori Matsumoto 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka

Claims (6)

[Claims] 1. A semiconductor wafer prober device for measuring electrical characteristics of elements formed on a semiconductor wafer, a wafer holding means for holding at least a wafer end portion on a stage upper surface, and a wafer holding means inside the stage and having A semiconductor wafer prober, comprising: a plurality of rod-shaped push rods provided to be vertically movable so as to face each other; a push die for pushing up the plurality of push rods to a desired shape from below; and a vertically moving means of the push die. apparatus. 2. The semiconductor wafer prober device according to claim 1, wherein the inside of said stage is evacuated to hold said semiconductor wafer on said stage. 3. The semiconductor wafer prober apparatus according to claim 1, wherein said wafer holding means comprises a rotatable ring-shaped stage. 4. The semiconductor wafer prober device according to claim 1, wherein said pressing die is replaceable with said elevating means. 5. The semiconductor wafer prober device according to claim 4, wherein said pressing die includes at least a downward bending type, a twist bending type, and an upward bending type. 6. The semiconductor wafer prober device according to claim 4, wherein said press die includes a plurality of sizes.