JPH1019928A - Cleaning member and cleaning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize easy cleaning by forming an adhesive film having specific viscosity on a semiconductor a semiconductor wafer thereby removing dust efficiently without causing any damage at the forward end part of a probe pin at all. SOLUTION: The cleaning member has such surface shape as touching the line or surface defined by the forward end part of a semiconductor measuring probe simultaneously and generally has a planar shape. An adhesive of various forms is employed as an adhesive substance and an acryl based adhesive is preferably employed in order to avoid so-called residual paste. Dust is left easily when the viscosity (JISZ0237) of an adhesive substance is lower than 100g/25mm, and a paste is left easily on the surface of the semiconductor measuring probe when it exceeds 250g/25mm and thereby the viscosity is preferably set in the range 120g/25mm-200g/25mm. Thickness of the adhesive substance is preferably set in such range as the forward part of a pin is inserted sufficiently without leaving any paste and it is generally set in the range of 10-50μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a cleaning member for removing foreign matter mainly attached to the tip of a semiconductor measuring probe and a cleaning method using the same.

[0002]

2. Description of the Related Art A probe card used for inspecting various electrical characteristics of a semiconductor device at a wafer stage is usually constituted by a probe made of a thin metal wire such as tungsten, which is used for evaluation on a semiconductor wafer. The pad is pressed into contact (hereinafter referred to as overdrive) and inspected.
However, when this inspection is repeated, foreign matter such as metal chips scraped off from the pad adheres to the probe tip and its vicinity. If such foreign matter is left unremoved, conduction failure may occur between the probe and pad, making inspection impossible. In addition, depending on the type of probe, the tip of an adjacent probe may be bridged via foreign matter, or plasticity may occur. Deformation may occur, making it difficult to accurately contact the pad.

In order to prevent the above problem, a method of removing foreign matter by repeating cleaning of the probe tip and the vicinity thereof at predetermined times of inspection has been conventionally performed, and is usually performed on a polishing stage (made of alumina) of a prober. In such a method, the tip of the probe is polished with a probe, or the probe card is removed from the prober and washed with a brush or the like in a solvent to remove foreign matter.

However, in the method using a polishing stage, when cleaning is repeated, a flat polished surface is formed at the tip of the probe, so that it is difficult to make uniform contact every time as compared with before cleaning, and the contact resistance is unstable. And the problem that the amount of metal chips scraped off from the pad at the edge of the polished surface increases. In particular, if the probe
In the case where conductivity is imparted by metallizing the surface of the needle-like single crystal by the LS growth method, if the metal film is scraped off, the life as a probe is greatly shortened and fatal. Further, in the method using a solvent, the setting of the probe card must be performed again each time cleaning is performed, and there is a problem in workability.

In order to avoid the adverse effects of polishing,
As a method of reducing the amount of polishing at the tip of the probe, a cleaning member in which an abrasive is mixed into an elastic base material (Japanese Patent Laid-Open No.
No. 244,074). However, even if cleaning is performed using this cleaning member, it is impossible to eliminate the amount of polishing, and if the metal film is thin, the life of the probe is shortened to a considerable extent. Furthermore, since the polished metal dust is not fixed to the cleaning member, there is a problem that the polished metal dust again adheres to the probe tip.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and it is an object of the present invention to provide a method which does not damage the tip of a probe at all even if cleaning is repeated a plurality of times. Another object of the present invention is to provide a cleaning member and a cleaning method using the same, which can remove foreign matters efficiently and do not shorten the life of the probe.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a cleaning member for removing foreign matter adhering to the tip of a semiconductor measuring probe, wherein the cleaning member has an adhesive substance on its surface. The cleaning member described above, wherein an adhesive film is formed on a semiconductor wafer.

The present invention also provides a semiconductor wafer having the same shape as a semiconductor wafer whose electric characteristics are measured by a semiconductor measuring probe, and an adhesive force (JIS Z) of the adhesive substance.
0237) is 100 g / 25 mm to 250 g / 25 m
m, wherein the cleaning material is m.

Further, the present invention is a cleaning method characterized in that at least a tip portion of a semiconductor measurement probe is cleaned by using the cleaning material, and at least the tip portion of the semiconductor measurement probe is overdriven. The cleaning method described above, wherein at least the tip of the semiconductor measurement probe is inserted a plurality of times, or the load during overdrive is 0.1 to 20 gf / pin.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The cleaning member of the present invention has an adhesive substance on its surface. Regarding its shape, for the purpose of using the cleaning material, it is sufficient that the line or surface formed by the tip of the semiconductor measurement probe has a surface shape that can be touched at once, but in general, it has a planar shape. Having. In particular, a cleaning material having a shape in which an adhesive substance is formed in a film shape on a semiconductor wafer is preferable because a surface having the above-mentioned planar shape can be easily obtained with high flatness. In particular, a semiconductor wafer having the same shape as the semiconductor wafer to be subjected to electrical measurement is mixed in a group of a large number of semiconductor wafers to be inspected, thereby cleaning the semiconductor measurement probe in the prober every predetermined time. This is preferable because it has an effect that the electrical characteristics of the semiconductor wafer can be evaluated without maintenance.

As the pressure-sensitive adhesive of the present invention, various forms of pressure-sensitive adhesive such as a pressure-sensitive adhesive tape, a pressure-sensitive adhesive sheet, or a material obtained by applying a pressure-sensitive adhesive on a substrate such as a semiconductor wafer can be used. Various types of pressure-sensitive adhesives such as acrylic, rubber, and silicone can be used, but for cleaning purposes, the pressure-sensitive adhesive adheres to the probe when foreign matter adheres to the pressure-sensitive adhesive and is removed from the probe. So-called glue residue must be avoided. Therefore, it is more preferable to use an acrylic pressure-sensitive adhesive that has removability and has little adhesive residue, such as that used for dicing tapes for semiconductor production. In addition to the dicing tape, pressure-sensitive adhesive tapes for semiconductor production include polishing cloth fixing, pellicle fixing, and back grinding, depending on the intended use.

In the present invention, the adhesive strength (JI
S Z 0237) is 100 g / 25 mm or more and 250 g
/ 25 mm or less, particularly 120 g
/ 25 mm or more and 200 g / 25 mm or less is more preferable. If the adhesive force is less than 100 g / 25 mm, foreign matter is likely to remain, and if it exceeds 250 g / 25 mm, adhesive residue is likely to occur on the surface of the semiconductor measurement probe.
This is because the probe may sometimes warp or may be damaged in severe cases.
A preferable range is 25 mm or more and 200 g / 25 mm or less. The thickness of the pressure-sensitive adhesive substance is preferably within a range in which the tip of the pin is sufficiently inserted and no adhesive residue is left, and generally about 10 to 50 μm.

In the present invention, the material of the semiconductor measurement probe is not particularly limited. However, when the surface of the needle-like single crystal produced by the VLS growth method is metallized, the probe tip The cleaning member and the cleaning method using the same according to the present invention are more effective because damage to the portion has a large effect on the life of the probe.

Hereinafter, the cleaning method of the present invention will be described with reference to VLS (Vapor-Liquid-Solid).
A semiconductor measurement probe in which the surface of an acicular single crystal produced by a growth method is metallized will be described in detail as an example. The VLS growth method used in the manufacture of semiconductor measurement probes is described in R.S. S. Wagner and W.W. C. Ellis:
Appl. Phys. Letters, 4 (1964)
89. Si with (111) plane on the surface
When an Au bump is placed at a predetermined position on a single crystal substrate and heated above the Au-Si eutectic point in a gas atmosphere such as SiCl ₄ or H ₂ , Si is taken into the Au-Si alloy and Epitaxial growth perpendicular to <111>
A needle-like single crystal is formed in the axial direction.

The needle-like single crystal produced by the VLS growth method can be used as a probe only after the surface is metallized (conducted). For metallization, methods such as a vapor deposition method, a plating method, and a dipping method are employed. Specifically, the needle-like single crystal is plated with a base such as Ni-P, Cr, etc.
The surface layer is plated with a good conductive metal such as u or Cu, and finally plated with Pd, Rh or the like for the purpose of increasing the durability of the probe tip.

In the cleaning method of the present invention, the cleaning member described above is used, and at least the tip of the semiconductor measuring probe exemplified above is brought into contact with the cleaning member, whereby foreign matter existing in the tip of the semiconductor measuring probe and the vicinity thereof is detected. Is removed, and once the foreign matter is removed, the foreign matter adheres to the adhesive substance. Therefore, the foreign matter can be efficiently removed without adhering to the tip of the semiconductor measuring probe or the vicinity thereof again.

Regarding the method of bringing at least the tip of the semiconductor measurement probe into contact with the adhesive substance of the cleaning member, the semiconductor measurement probe may be overdriven, and generally, it is generally used for evaluating the electrical characteristics of a normal semiconductor. Vertical overdrive, which is the same operation as the probing operation, is sufficient. To achieve the overdrive in the vertical direction, the cleaning member is fixed to a flat table that can be moved up and down with a vacuum chuck or a clamp, and the table is moved up and down so that the amount of overdrive that does not damage the probe pins is added. An apparatus having a moving mechanism can be used. Instead of such a device, it can be easily achieved by incorporating the cleaning member of the present invention into a normal prober, and has high reproducibility.
There is an advantage that a simple cleaning method can be achieved.

Although the number of times of overdrive is sufficient even once, it is preferable that the number of times of overdrive be plural depending on the state of adhesion of the foreign matter to the semiconductor measuring probe. This can be easily achieved by the method of incorporating the cleaning member. The amount of overdrive may be such that the semiconductor measurement probe buckles elastically and does not lead to breakage. Usually, this range is 20 to 100 μm. The load applied to the probe pin during overdrive is 0.1 to 20 gf /
It is preferably pin. Load is 0.1gf / pi
If it is less than n, it may not be possible to sufficiently remove the foreign matter, and if it exceeds 20 gf / pin, the reason is unknown. However, a glue residue phenomenon in which a part of the adhesive substance moves to the probe pin side may occur. is there.

[0019]

【Example】

[Examples 1 to 6] <Preparation of Probe for Semiconductor Measurement> As a probe for semiconductor measurement, as shown in FIG. 2, a needle-like single crystal 2 made of Si (diameter 15 μm, length 1600) obtained by VLS growth method
μm) on the surface of Ni plating 3 (0.2 μm thick), Au
Thirteen plating 4 (thickness 1.6 μm) and further Pd plating 5 (thickness 0.5 μm) were prepared. Of these, six were used to measure the adhesive residue, and the remaining seven were probed on the Au-plated Si wafer 300,000 times to make the foreign matter adhere to the tip of the semiconductor measurement probe. Was used as a test piece for the cleaning test.

<Preparation of Cleaning Member> As shown in FIG. 1, a semiconductor wafer was used as a base material 7, and adhesive tapes having various types of adhesive layers 6 were adhered thereon to prepare various cleaning members. In Examples 1 to 4, the acrylic adhesive used for the dicing tape had various adhesive strengths. In Examples 5 and 6, an aluminum vapor-deposited tape, a laminating tape, and a plating mask were used. Among the adhesives used for tapes and the like, a synthetic rubber-based adhesive and a silicone-based adhesive were selected.

<Cleaning Test> As shown in FIG. 1, the cleaning member is fixed to a flat table 10 with a vacuum chuck so that the adhesive layer 6 is on the upper surface. Secure facing. In this state, the specimen is cleaned by moving the table 10 up and down to probe the probe pins 9 on the adhesive layer 6. Probe pin 9 and adhesive layer 6
The contact is made by overdriving the probe. At this time, the overdrive amount was 40 μm and the pin load was 0.5 gf / pin. In the cleaning test, the number of probing was set to 10 times. The specimen before and after the cleaning test was observed by SEM. From the photograph, the number of foreign substances having a size of 1 μm or more existing within a region within 50 μm from the tip of the probe pin was counted. The foreign matter removal rate was calculated by the above. Table 1 shows the results. Foreign matter removal rate = (AB) / A × 100 where A: number of foreign matter before cleaning test B: number of foreign matter after cleaning test

<Measurement of adhesive residue>
except that it is not probed on the i-wafer
Probing under the same conditions as the cleaning test,
The specimen after this treatment was observed with an SEM for the presence of adhesive residue. Table 1 shows the results.

Comparative Example As a comparative example, a method of cleaning the tip of a semiconductor measuring probe with a brush in isopropyl alcohol was evaluated in the same manner as in Examples 1 to 6. The results are shown in Table 1 together with the results of Examples 1 to 6.

[0024]

[Table 1] * 1 According to JIS Z0237. Unit: g / 25mm

[0025]

According to the cleaning member for the tip portion of the probe pin and the cleaning method using the same according to the present invention,
Even if the cleaning is repeated a plurality of times, the foreign matter can be efficiently removed without damaging the tip of the probe pin at all, so that simple cleaning without shortening the life of the probe can be performed.

Further, the cleaning member is formed by forming an adhesive thin film on the wafer, or by forming the cleaning member in the same shape as the semiconductor wafer whose electric characteristics are to be measured by a probe, and then mixing the cleaning member with the semiconductor wafer. Since cleaning can be automatically performed at predetermined times during the operation of the prober, probing without maintenance can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic view illustrating an example of a cleaning member and a cleaning method of the present invention.

FIG. 2 is an explanatory view of a probe pin formed by a VLS growth method with a metallized surface used in an example of the present invention.

[Explanation of symbols]

 1; single crystal substrate 2; needle-like single crystal 3; Ni plating 4; Au plating 5; Pd plating 6; adhesive substance (adhesive) layer 7; base material 8; probe card 9;

Claims (8)

[Claims] 1. A cleaning member for removing foreign matter adhering to a tip of a semiconductor measuring probe, wherein the cleaning member has an adhesive substance on its surface. 2. The cleaning member according to claim 1, wherein an adhesive film is formed on the semiconductor wafer. 3. The cleaning member according to claim 2, wherein the cleaning member has the same shape as a semiconductor wafer whose electric characteristics are measured by the semiconductor measurement probe. 4. The adhesive strength of the adhesive substance (JIS Z 0
237) is 100 g / 25 mm to 250 g / 25 mm.
The cleaning member according to the above. 5. A cleaning method, comprising: cleaning at least the tip of a semiconductor measurement probe using the cleaning member according to claim 1. Description: 6. The cleaning method according to claim 5, wherein at least the tip of the semiconductor measurement probe is overdriven. 7. The cleaning method according to claim 6, wherein at least the tip of the semiconductor measurement probe is inserted a plurality of times. 8. The load at the time of overdrive is 0.1 to 2
8. The cleaning method according to claim 6, wherein the cleaning method is 0 gf / pin.