JPH05175286A - Method for inspecting semiconductor pellet - Google Patents

Abstract

PURPOSE:To provide an inspecting method by which semiconductor pellets on a semiconductor wafer can be highly efficiently and highly reliably inspected for electrical characteristics without employing a large-sized device. CONSTITUTION:A probe grinding surface 4 composed of a nitride film, etc., is provided in the peripheral section of a semiconductor wafer 1 and semiconductor pellets 2 on the wafer 1 are continuously inspected with the probes 3 of a probe card 6 by bringing the probes 3 into contact with the surface 4 and grinding the front ends of the probes 3 so as to remove contaminants, oxide films, etc., adhering to the front ends of the probes 3 while the pellets 2 are inspected with the probes 3. The surface 4 can also be formed of an alumina film, etc., welded to the wafer 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor pellet inspection method for sequentially inspecting the electrical characteristics of a plurality of semiconductor pellets formed on a semiconductor wafer.

[0002]

2. Description of the Related Art As a method for inspecting the electrical characteristics of a plurality of semiconductor pellets (hereinafter referred to simply as "pellets") formed in a lattice on a semiconductor wafer, a probe (probe) of a probe card is brought into contact with an electrode of the pellet to conduct electricity. There is a way. This inspection method is the method shown in FIGS.

The inspection apparatus shown in FIGS. 5 and 6 is provided with a probe card (6) and a movable inspection stage (7) which are vertically opposed to each other, and the semiconductor wafer (1) is positioned on the inspection stage (7). It will be installed. A plurality of pellets (2) are formed on the semiconductor wafer (1) in a grid-like arrangement. The probe card (6) has a plurality of probes (3) in a hole (8) formed at the center of the tip.

The inspection stage (7) performs an intermittent operation in the XY direction of the pellet arrangement direction of the semiconductor wafer (1) and in the vertical direction, so that each pellet (2) is inspected at the inspection position where the probe (3) is present. Automatically move to. And FIG.
As shown in, at the inspection position, the electrode (5) of the pellet (2) is pressed against and brought into contact with the tip of the probe (3),
The electrical properties of one element compartment, the pellet (2), are examined. The probe (3) is connected to an external tester (not shown) via a probe card (6), and the tester measures the electrical characteristics of the pellet (2) to determine whether it is a good product or a defective product.

The inspection order of the pellets (2) on the semiconductor wafer (1) is determined, for example, as shown by the broken line arrow in FIG. Each row of pellets (2) arranged in the X direction of the semiconductor wafer (1) is divided into a first pellet row N ₁ from the end,
If the second pellet row N ₂ , ..., First, the pellets (2) of the first pellet row N ₁ are sequentially inspected from right to left in FIG. When the inspection of the first pellet row N ₁ is completed, the inspection of the pellets (2) of the second pellet row N ₂ is performed from the left to the right in FIG. 8. Thereafter, the inspection of all the pellets (2) is similarly performed in the alternate direction.

By the way, in the above-mentioned pellet inspection method, accurate inspection may not be able to be continued due to contamination or oxidation of the tip of the probe (3). That is, when the tip of the probe (3) is brought into contact with the electrode (5) of the pellet (2), impurities contained in the electrode (5) and impurities attached to the surface are contaminated at the tip of the probe (3). May adhere. In addition, it is the current situation that oxidation of the tip of the probe (3) is unavoidable. Although this type of contamination and oxidation is slight, it causes an erroneous inspection in which the contact resistance between the probe (3) and the electrode (5) is increased, and the pellet having good characteristics is judged to be defective according to the inspection result.

Contamination of the probe (3) is caused by the semiconductor wafer (1)
When it occurs in one pellet of one pellet row, all the pellets after this pellet may be determined to be defective. This is because the dirt and oxide film on the probe (3) cannot be easily removed.

The erroneous inspection due to the dirt on the tip of the probe (3) is conspicuously generated in a compound semiconductor wafer or the like in which gallium arsenide is remarkable. This is because many of the electrodes of the pellet of the compound semiconductor wafer are soft metals such as gold-plated electrodes and gold bump electrodes, and the probe bites into contact with it, so that impurities easily attach to the probe.

In order to solve such a problem, for example, as shown in FIG. 9, there is an inspection apparatus in which a polishing stage (9) is arranged beside the inspection stage (7). Polishing stage (9)
Has a ceramic plate (10) for needle polishing fixed to the upper surface.

When the probe (3) of the probe card (6) inspects some of the pellets (2) of the semiconductor wafer (1), the probe card (6) and the polishing stage (9) are moved relative to each other, The tip of the probe (3) is pressed against the ceramic plate (10). Then, the tip of the probe (3) is polished by the ceramic plate (10), and the dirt and oxide film at the tip are removed by the ceramic plate (10). Inspection of the pellet (2) is continued with the polished probe (3).

[0011]

As the number of times the tip of the probe is polished by the ceramic plate as described above is increased, the number of pellets in which a good product is erroneously determined as a defective product is reduced, and the reliability of the inspection is improved. Become. However, the distance between the inspection position of the semiconductor wafer and the polishing position where the ceramic plate is present cannot be ignored, and it takes time to polish the probe once. Therefore, the inspection time for one semiconductor wafer was long and the work efficiency was poor. Further, there is also a problem that the entire inspection apparatus is expensive and large in size, such as requiring an elaborate drive system for accurately moving the probe between the distant inspection position and the polishing position.

Therefore, it is an object of the present invention to provide a pellet inspection method capable of polishing a probe with high efficiency without increasing the cost and size of the inspection apparatus.

[0013]

SUMMARY OF THE INVENTION According to the present invention, a needle polishing surface for removing dirt and oxide film adhering to a probe when a pellet characteristic inspection probe comes into contact is formed on at least half of the peripheral portion of a wafer. Every time, a plurality of pellets of a semiconductor wafer are inspected by a probe in a predetermined order, the probe is brought into contact with the needle polishing surface for polishing, and the pellet is continuously inspected by the probe. The inspection method achieves the above objectives.

It is desirable in manufacturing that the needle-polished surface of the semiconductor wafer is an exposed surface of a nitride film or an oxide film formed in the semiconductor wafer manufacturing process.

[0015]

[Function] When the probe is applied to the pellet of the semiconductor wafer and the characteristics are inspected, when the probe is brought into contact with the needle polishing surface around the semiconductor wafer and polished, dirt and oxide film on the probe are removed, and the probe is removed. The next pellet inspection by can be performed with high accuracy.

When the probe is inspected by relatively moving the probe vertically and horizontally with respect to the semiconductor wafer, the probe is polished when the probe relatively moves to the needle polishing surface in the peripheral portion of the semiconductor wafer. The pellet inspection and probe polishing can be performed continuously and efficiently by using the existing inspection device with only the pellet inspection function.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A concrete embodiment of the method of the present invention and an example of its operation will be described with reference to FIGS. The same parts as those in FIGS. 5 to 7 of the embodiment shown in FIG.

According to the present invention, as shown in FIG. 1, a needle-polished surface (4) is formed on the peripheral portion of a semiconductor wafer (1), and the needle-polished surface (4) is used to form a probe (6) of a probe card (6). 3) is appropriately polished, and the pellet (2) is inspected as in the conventional case.

In the present invention, a semiconductor wafer (1)
The existing small and inexpensive inspection device may be used as it is as the inspection device equipped with the movable inspection stage (7) and the probe card (6). In this case, only the operation program of the existing inspection device is partially changed as described later.

Needle-polished surface (4) of semiconductor wafer (1)
When the tip of the probe (3) is pressed, the probe (3)
It has a hardness and surface quality that removes the dirt and oxide film on the tip of the film by rubbing it off, and an exposed surface such as a nitride film, an oxide film, a silicon film, or an alumina film is suitable. In particular, it is desirable to form the needle-polished surface (4) with a nitride film for the following reason.

Most semiconductor wafer (1) manufacturing processes include a nitride film forming step. Further, even if pellets are formed on the peripheral portion of the semiconductor wafer (1), it becomes a defective product and is highly likely to be discarded. Therefore, the peripheral portion of the semiconductor wafer (1) is left as a surplus portion and finally discarded. It

Therefore, in the nitride film forming step of the manufacturing process of the semiconductor wafer (1), a nitride film is also formed on the peripheral portion of the semiconductor wafer (1). Then, as shown in FIG.
Electrodes (5) on each pellet (2) of semiconductor wafer (1)
And the nitride film (4 ′) in the peripheral portion of the semiconductor wafer (1) is exposed and left. By forming the needle-polished surface (4) of the nitride film (4 ′) in this manner, a special manufacturing process for forming the needle-polished surface (4) is not required,
It is advantageous in manufacturing process.

The nitride film (4 ') is substantially flush with the end of the plurality of pellets (2) formed in a lattice pattern in a predetermined portion of the semiconductor wafer (1) excluding the peripheral portion. To do. The nitride film (4 ′) may be formed in the final manufacturing process of forming the pellet (2) on the semiconductor wafer (1).

The electrical characteristics inspection of the pellet (2) of the semiconductor wafer (1) having the nitride film (4 ') on the peripheral portion may be performed using an existing inspection apparatus as follows.

For example, as shown in FIG. 4, the inspection of the pellets (2) of the semiconductor wafer (1) is performed in the same manner as in the case of FIG. 8 from the first pellet row N ₁ to the second pellet row N ₂ arranged in the X direction. , The third pellet row N ₃ , ... And the inspection direction is reversed for each row. Then, the circled portion P ₁ in FIG.
P _2, ... the probe (3) is contacted as rubbed against the needle polishing surface (4).

That is, first, each probe (2) in the first pellet row N ₁ is sequentially inspected by the probe (3), and when the inspection of the last pellet (2) in this row is completed, this pellet (2) The probe (3) is moved by one pitch relative to the polishing portion P ₁ of the needle polishing surface (4) of the nitride film (4 ′) adjacent to, and brought into contact therewith. This contact may be performed with the same force as the probe (3) makes contact with the electrode (5) of the pellet (2) for inspection. When the tip of the probe (3) contacts the needle polishing surface (4), the tip of the probe (3) is polished, and even if the tip of the probe (3) has dirt or an oxide film, These are rubbed against the needle polishing surface (4) and removed.

[0027] When the inspection and the probe polishing in the first pellet row N ₁ is finished, the probe (3) is relatively moved up to the first pellet to the second pellet column N ₂ (2), second pellet column N ₂ Conduct an inspection. In this case, the tip of the probe (3) is already polished, so that the inspection is performed with high reliability. When the inspection of the second pellet row N ₂ is completed, the probe (3) is moved to the needle polishing surface (4).
The tip of the probe (3) is polished again by moving it relative to the polishing point P ₂ of. Thereafter, similarly, the third pellet row N ₃ ,
The inspection is continued with the fourth pellet row N ₄ , ....

In all the steps of the above inspection, the relative movement distance between the semiconductor wafer (1) and the probe (3) for the characteristic inspection and the probe polishing is almost the same as the shortest movement distance only for the inspection. And the probe polishing can be performed with high efficiency. This is because the final pellet (2) in each row to be inspected and the needle polishing surface (4) are adjacent to each other, so that the probe (3) is moved to the pellet (2) in the next row.
This is because the probe polishing can be executed during the relative movement at the shortest distance.

Further, for example, the second pellet row N₂With 1
Tip of probe (3) at the stage of inspecting two pellets (2 ')
If dirt adheres to the second pellet row N₂Pellets of
The pellet (2) after (2 ') may be erroneously inspected.
is there. However, the second pellet row N ₂At the end of the inspection
Since the probe polishing is performed, the third pellet row N₃Up to
There is no impact of the inspection.

The probe polishing using the above nitride film can be accomplished by the present inventor based on the following experience.

The present inventor examined the inspection data of a certain semiconductor wafer and found that non-defective product data existed continuously among the continuous data determined to be defective products. Then, when the pellet of the semiconductor wafer corresponding to the first data of continuous non-defective data was examined, there was a nitride film at a portion corresponding to the electrode of this pellet, the probe was polished by this nitride film, and the subsequent pellet It was found that the examination of 1. was performed normally. After that, it was found by experiments that, in addition to the nitride film, an oxide film formed by chemical vapor deposition on a semiconductor wafer, an alumina film formed by welding, or a ceramic film is also effective for probe polishing, and the present invention was completed. It was possible.

The inventor of the present invention inserts the semiconductor wafer into a ceramic ring having the same inner diameter as the outer diameter of the semiconductor wafer and the same thickness, and inspects one row of the pellets of the semiconductor wafer with the probe, and then the probe. Attempts were made to contact and polish the ceramic ring. In this case, the polishing of the probe is performed well, but when the probe relatively moves from the semiconductor wafer to the ceramic ring or in the opposite direction, the probe malfunctions due to the gap between the semiconductor wafer and the ceramic ring. Sometimes. Further, it was found that a large number of ceramic rings had to be prepared according to the size of the semiconductor wafer, and the maintenance thereof was troublesome, and the present invention was devised while considering the correction of the defect.

In the present invention, the needle-polished surface in the peripheral portion of the semiconductor wafer is not limited to being provided all around the periphery of the semiconductor wafer, but may be formed at least in a half circumference portion of the periphery of the semiconductor wafer. In the case of this half-round needle-polished surface, the probe is polished on the needle-polished surface immediately before or after the inspection of each row of pellets.

[0034]

According to the present invention, characteristics are inspected by sequentially applying a probe to the pellets of a semiconductor wafer, and when the probe comes to the peripheral portion of the semiconductor wafer, the probe is attached to the needle polishing surface of the peripheral portion of the semiconductor wafer. By contacting with, the dirt and oxide film at the tip of the probe are removed, the next pellet inspection can be performed with high accuracy, and as a result, the inspection reliability of all pellets of the semiconductor wafer is improved.

Further, since the probe polishing and the pellet inspection can be simultaneously performed on one semiconductor wafer, the time loss for the probe polishing is small and the pellet inspection can be performed with high efficiency.

Furthermore, since it is only necessary to move the probe relatively on the semiconductor wafer, it is possible to use an existing inspection device having only a pellet inspection function, and it is possible to provide a pellet inspection device which is advantageous in terms of capital investment. is there.

[Brief description of drawings]

FIG. 1 is a plan view of a main part of an inspection device for carrying out the method of the present invention.

2 is a partially enlarged side view of the apparatus of FIG.

FIG. 3 is a side view of the apparatus of FIG. 2 when polishing a probe.

FIG. 4 is a plan view for explaining a procedure for inspecting a semiconductor wafer in the apparatus shown in FIG.

FIG. 5 is a plan view of a main part of an inspection apparatus according to a conventional inspection method

6 is a partial side view of the device of FIG.

7 is a partially enlarged side view of the apparatus of FIG. 5 during a pellet inspection.

8 is a plan view for explaining a semiconductor wafer inspection procedure in the apparatus of FIG.

FIG. 9 is a side view showing an outline of an inspection apparatus for explaining another conventional inspection method.

[Explanation of symbols]

 1 semiconductor wafer 2 semiconductor pellet 3 probe 4 needle polished surface

Claims (2)

[Claims] 1. An inspection method for inspecting electrical characteristics by sequentially contacting a plurality of semiconductor pellets formed on a semiconductor wafer with a probe, wherein the probe is in contact with at least half of a peripheral portion of a semiconductor wafer. Then, a needle-polished surface that removes dirt and oxide film attached to the probe is formed, and the probe is polished with the needle-polished surface in the middle of several times in which a plurality of semiconductor pellets are inspected by the probe in a predetermined order. A method for inspecting a semiconductor pellet, comprising: 2. The semiconductor pellet inspection method according to claim 1, wherein the needle-polished surface is an exposed surface of a nitride film or an oxide film formed on the semiconductor wafer.