JP2011017654A - Manufacturing method of amorphous carbon film-coated member, and probe pin for semiconductor inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method useful for manufacturing amorphous carbon film-coated members having both electrical conductivity and durability and capable of prolonging its life by reducing the attachment/adhesion of a material on the other side (especially Sn contained in solder) as much as possible and to provide a probe pin made of such an amorphous carbon film-coated member for semiconductor inspection devices.SOLUTION: When an amorphous carbon film-coated member having a substrate surface coated with a tungsten-containing amorphous carbon film is to be manufactured, the substrate surface is alternately treated a plurality of times, with two evaporation atmospheres formed separately from a solid carbon target 3 and a solid tungsten target 2. Operations and settings are made, in such a way that the amount of tungsten vapor-deposited per treatment may correspond to 0.40×10m or greater and smaller than 2.74×10m.

Description

  The present invention comprises a useful method for producing an amorphous carbon film-coated member coated with an amorphous carbon film having both conductivity and durability, and such an amorphous carbon film-coated member. The present invention relates to a probe pin for a semiconductor inspection apparatus.

  Semiconductor elements (elements using semiconductors) such as integrated circuits (ICs), large-scale integrated circuits (LSIs), and light emitting diodes (LEDs) are inspected for electrical characteristics by bringing probe pins into contact with the electrodes of the semiconductor elements. . The probe pin used in such an inspection apparatus (semiconductor inspection apparatus) has low contact resistance (good conductivity) and, of course, does not cause wear or damage due to multiple contact with the electrode. It is required to have excellent durability.

  As a technique for reducing contact resistance of a probe pin for a semiconductor inspection apparatus and improving durability, for example, Patent Document 1 proposes a probe pin (contact probe) in which a gold plating film is applied to the surface of a base material. In this technique, the durability of the probe pin is improved by setting the hardness of the gold plating to 160 Hv or more in terms of Vickers hardness.

  However, gold plating basically has a low hardness, and sufficient durability cannot be imparted to the probe pin.

On the other hand, in Patent Document 2, a film having a high Young's modulus and a specific resistance of 1 × 10 ⁻⁴ Ω · cm or less is formed on the probe pin surface (base material surface) as a first layer ( A technique for forming a film having low cohesion on the outermost surface has been proposed. In this technique, carbon containing a metal element is exemplified as a film formed on the outermost surface, and tungsten or an alloy thereof is exemplified as a film material formed in the first layer.

  With this technique, low contact resistance can be realized and excellent durability can be achieved, but the adhesion of the mating material (electrode material) may deteriorate. In other words, the “coating with low cohesiveness” formed on the outermost surface by this technology is intended to reduce adhesion and adhesion to solder and gold. In some cases, the suppression of adhesion and adhesion of Sn) is insufficient. If the adhesion / adhesion suppression of the mating material is insufficient, the mating / adhering mating material (especially Sn) will oxidize, leading to an increase in electrical resistance, resulting in defects during inspection. Service life is shortened.

JP 2007-187580 A JP 2003-57311 A

  The present invention has been made paying attention to the above-mentioned circumstances, and its purpose is to have both conductivity and durability, and to reduce adhesion / adhesion of the counterpart material (particularly Sn contained in the solder) as much as possible. And a probe pin for a semiconductor inspection apparatus to which such an amorphous carbon film covering member is applied, and a useful method for manufacturing the amorphous carbon film covering member capable of extending the life. It is in.

The method for producing an amorphous carbon film-coated member of the present invention, which has solved the above problems, is a solid material for producing an amorphous carbon film-coated member in which a tungsten-containing amorphous carbon film is coated on a substrate surface. In the two evaporation atmospheres formed separately from the carbon target and the solid tungsten target, the surface of the base material is alternately processed a plurality of times, and the amount of tungsten deposited by one processing has a theoretical thickness of 0.40. It has a gist in that it is set and operated so as to correspond to × 10 ⁻¹⁰ m or more and less than 2.74 × 10 ⁻¹⁰ m.

As a more specific method of the present invention, in producing an amorphous carbon film covering member in which a tungsten-containing amorphous carbon film is coated on the surface of a base material, an independent carbon target and a solid tungsten target are provided. Using a device including two evaporation sources and a rotating body having a rotating surface orthogonal to the front of these evaporation sources, a substrate is placed on the rotating surface of the rotating body, and the rotating body is rotated to rotate the rotating member. The surface is sequentially directed to the front of the target a plurality of times, and the amount of tungsten deposited in each treatment is 0.40 × 10 ⁻¹⁰ m or more and less than 2.74 × 10 ⁻¹⁰ m in theoretical thickness. You may make it set and operate so that it may correspond.

  In the method of the present invention, the film formation amount of tungsten (same for amorphous carbon described later) for each treatment may not be reflected as the layer thickness as it is after the formation. “Theoretical thickness” (equivalent amount of theoretical thickness) is adopted.

  A probe pin for a semiconductor inspection apparatus that exhibits the desired characteristics can be obtained by applying the above-described methods and using a core material as a base material and coating the core material with a tungsten-containing amorphous carbon film. When used as a probe pin for a semiconductor inspection apparatus, the tungsten-containing amorphous carbon film preferably has a thickness of 0.1 to 1 μm.

  In the method of the present invention, amorphous carbon and tungsten are alternately deposited on the surface of the substrate by two independent evaporation sources each having a solid carbon target and a solid tungsten target, and per rotation of the substrate. By appropriately setting the amount of tungsten deposited on the substrate, an amorphous carbon film in which tungsten is uniformly dispersed can be coated on the substrate surface. It has both conductivity and durability, and has reduced the adhesion and adhesion of the mating material (particularly Sn contained in the solder) as much as possible, and is extremely useful as a material for probe pins for semiconductor inspection devices.

It is a schematic explanatory drawing which shows the example of an apparatus structure for implementing this invention.

  Since the amorphous carbon film has low conductivity, a metal element is contained in the amorphous carbon film. Various methods are conceivable for the metal-containing method, but a method for improving durability as well as conductivity has not been established.

  The inventors of the present invention have clarified the relationship between the metal element content method, conductivity, and durability of the amorphous carbon film as described above, and are suitable as a material for probe pins for semiconductor inspection devices. In order to realize a carbon film covering member, examination was performed from various angles. In particular, from the standpoint of extending the life, Sn, which is the main component of solder, adheres to and adheres to the contact portion of the probe pin in contact with the solder, which is the main counterpart material during semiconductor inspection (hereinafter simply referred to as “simple”) (Sometimes referred to as “adhesion”), the oxidized Sn is oxidized, resulting in an increase in contact resistance, which hinders inspection. In order to solve these problems, the present inventors have realized the development of an amorphous carbon film that exhibits low electrical resistance and is excellent in Sn adhesion resistance.

  In the amorphous carbon film covering member of the present invention, an amorphous carbon film is used as a basic film material. Since the carbon film, particularly the amorphous carbon film, has a property that it is hardly dissolved in Sn or the like, adhesion of the counterpart material (especially Sn contained in the solder) can be suppressed.

  In the present invention, tungsten (W) is selected as the metal element contained in the amorphous carbon film. Since tungsten has a property that it is difficult to dissolve in Sn and lead (Pb) as compared with other metal elements, it is expected to suppress adhesion of the counterpart material (particularly Sn contained in the solder). it can. Tungsten has a greater conductivity imparting effect on the amorphous carbon film than iron or the like. However, since the tungsten film formed by sputtering does not cause Sn adhesion at all, it is not sufficient to simply contain tungsten.

  As a method of adding a metal element to a carbon film, a conventionally known film forming method includes a method of arranging a metal element chip on a carbon target (that is, a method of arranging a metal element in association with the carbon target). Generally, it is adopted (for example, Patent Document 2). In such a method, the amount of metal element relative to carbon can be precisely controlled as a whole by adjusting the amount of metal element chip, but when viewed microscopically, the metal element or its carbide is uniformly dispersed in the carbon film. This can cause a bias in the metal element or its carbide. Therefore, the counterpart material (especially Sn contained in the solder) easily adheres to the tungsten or carbide particles aggregated on the surface.

  On the other hand, in the present invention, when the tungsten-containing amorphous carbon film as described above is formed, the solid tungsten target and the solid carbon target are provided as two independent evaporation sources, and the vapor atmosphere from each evaporation source is provided. Then, the substrate surface is alternately processed a plurality of times (a film is formed by a rate-controllable vacuum deposition method or sputtering method).

  In this way, by depositing tungsten and carbon from independent targets, the deposition conditions can be controlled for each component, and the tungsten-containing amorphous carbon film has the required characteristics such as probe pins. It can form in the state which can respond | correspond appropriately. The tungsten-containing amorphous carbon film thus obtained has a granular structure in which tungsten (or tungsten carbide) particles are appropriately dispersed in amorphous carbon, and has a layered structure of tungsten / amorphous carbon. In addition, the tungsten particles are not connected from the base material side to the surface. The tungsten-containing amorphous carbon film obtained by the present invention has the above-described structure, and as a result, Sn adhesion can be remarkably suppressed.

  The tungsten-containing amorphous carbon film of the present invention does not have a layered structure of tungsten / amorphous carbon as described above, and tungsten (or tungsten carbide) particles are appropriately dispersed in the amorphous carbon. It has a granular structure. A film having such a structure can be formed by alternately treating the substrate surface a plurality of times in a vapor atmosphere from two independent evaporation sources. As described above, tungsten or amorphous material is used for each treatment. Since the amount of carbonaceous film formed cannot be directly reflected as the layer thickness after the formation, the theoretical thickness (the equivalent amount of the theoretical thickness) was adopted as a measure of the amount for each treatment. The theoretical thickness deposited for each treatment is calculated by dividing the thickness of the formed layer by the number of treatments after processing multiple times and actually forming either tungsten or amorphous carbon alone. Can be sought.

The amount of film formation (theoretical thickness) of tungsten or amorphous carbon for each treatment is the voltage (or power) applied to each target (solid tungsten target or solid carbon target), substrate bias voltage, substrate and each It can be controlled by the processing cycle with the evaporation source (corresponding to the rotation speed of the base material when a structure for rotating the base material as shown in FIG. 1 is employed). The theoretical thickness for each process (per one time) does not reflect the actual thickness as described above, but also includes the meaning of the apparent layer thickness. For example, the atomic diameter of tungsten is 2.74 × 10 ⁻¹⁰ m, and this value is the minimum value of the thickness of the tungsten layer. However, in the present invention, when a complete layer of tungsten is not formed by one treatment, There is. Therefore, the “theoretical thickness” is used as the thickness for each process.

And from the viewpoint of imparting conductivity, the amount of tungsten to be deposited in the process per once must be at a theoretical thickness of 0.40 × 10 ^-10 m or more, 1.00 × 10 ^- It is preferably ¹⁰ m or more, more preferably 1.50 × 10 ⁻¹⁰ m or more, and further preferably 2.00 × 10 ⁻¹⁰ m or more. As described above, the upper limit of the amount of tungsten deposited by one treatment is less than 2.74 × 10 ⁻¹⁰ m in terms of the theoretical thickness because of the atomic diameter of tungsten.

On the other hand, the amount of the amorphous carbon film deposited by one treatment is not particularly limited, but the theoretical thickness is 1. in terms of the bond distance of carbon atoms (diamond: 1.57 × 10 ⁻¹⁰ m). It is preferably 57 × 10 ⁻¹⁰ m or more, and more preferably 2.00 × 10 ⁻¹⁰ m or more. However, if the thickness (theoretical thickness) of the amorphous carbon film per one time is too thick, the conductivity deteriorates due to the relationship with the amount of tungsten, so that it is 2.00 × 10 ⁻⁹ m or less (20.0 × 10 ⁻¹⁰ m or less), preferably 1.00 × 10 ⁻⁹ m or less (10.0 × 10 ⁻¹⁰ m or less).

  In carrying out the method of the present invention, the arrangement configuration (device configuration) of the two evaporation sources composed of the respective targets (solid carbon target and solid tungsten target) is not particularly limited. For example, FIG. An apparatus as shown in FIG. In this apparatus, two evaporation sources 2 and 3 (in the figure, 2 indicates a solid tungsten target and 3 indicates a solid carbon target) are arranged so that directions perpendicular to the respective target surfaces serving as evaporation sources are orthogonal to each other. In addition, a rotating body 4 (base material stage) having a rotation surface orthogonal to the front surface of each of these evaporation sources is provided in the vacuum chamber 1, and a substrate holder 5 is interposed on the rotation surface of the rotation body. The base 6 is placed.

  Then, by rotating the rotating body 4, the surface of the substrate 6 is processed a plurality of times so as to be sequentially directed to the front surface of the solid tungsten target 2 and the solid carbon target 3, whereby two targets (solid tungsten target 2) are processed. The components from the solid carbon target 3) are alternately deposited, and a tungsten-containing amorphous carbon film is formed on the surface of the substrate 6. Although not shown, the inside of the vacuum chamber 1 is configured to be evacuated by a vacuum pump and to introduce various film forming gases. Each target (solid tungsten target or solid carbon target) is configured to be able to apply a bias voltage to the substrate while applying electric power during film formation.

  By adopting and operating the apparatus configuration as described above, a tungsten-containing amorphous carbon film can be continuously formed. In the case of adopting such a configuration, the processing per one time corresponds to “per one rotation of the base material”. In addition, the amount of tungsten or carbon deposited by the process per rotation of the substrate corresponds to the above-described process amount per time.

  The apparatus configuration for carrying out the method of the present invention is not limited to that shown in FIG. 1, but other configurations can be adopted. In short, a solid tungsten target and a solid carbon target are provided as two independent evaporation sources. It is only necessary that the substrate surface can be alternately processed a plurality of times in a vapor atmosphere from each evaporation source.

The tungsten-containing amorphous carbon film formed as described above is useful as a material for a probe pin for a semiconductor inspection apparatus, but when used in such applications, an Fe alloy, Ni alloy, Cu alloy, Al alloy, W, W-Re, Mo, Ti or the like may be used as a core material, and the core material may be covered with a tungsten-containing amorphous carbon film by the method of the present invention. In the case of constituting such a probe pin for a semiconductor inspection apparatus, the thickness (total thickness) of the tungsten-containing amorphous carbon film is 0.1 μm (1000 × 10 ^-10 m) or more is preferable. However, if this film thickness becomes too thick, it becomes easy to peel off due to the influence of film stress, so it is preferable to set it to 1 μm (10000 × 10 ⁻¹⁰ m) or less.

  However, the material of the base material used in the present invention is not limited to the above-described materials when applied to applications other than the probe pins for semiconductor inspection devices (for example, sliding members and electronic parts that dislike static electricity), such as glass SUS, silicon wafer, etc. can also be applied as a substrate.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention.

[Example 1]
A tungsten-containing amorphous carbon film was formed using an unbalanced magnetron sputtering apparatus (Kobe Steel Corporation: UBM202) equipped with a solid carbon target and a solid tungsten target as an evaporation source. The outline of the apparatus configuration used at this time is as shown in FIG. 1, and will be described with reference to FIG. The solid carbon target 3 and the solid tungsten target 2 were disposed so that their mutual positions were in the direction of 90 °, and the rotating body 4 (base material stage) placed around the base material 6 was rotated. A glass substrate was used as the substrate 6.

After introducing the substrate 6 into the chamber 1, the substrate 6 was evacuated to 1 × 10 ⁻³ Pa or less, and film formation was performed in an Ar (argon) gas atmosphere (film formation pressure: 0.6 Pa). At this time, the tungsten layer thickness (theoretical thickness) per rotation was controlled by setting the input power to the solid tungsten target 2 to 0.12 kW. The input power to the solid carbon target 3 was fixed at 2.0 kW. At the time of film formation, a bias voltage of −100 V was applied to the substrate 6, and the rotation speed of the rotating body 4 (substrate stage) was 5 rpm. A sample was prepared under the above film forming conditions (Sample No. 2 in Table 1 below).

  The obtained sample was evaluated for conductivity by measuring an electric resistance value (specific resistance) by a four-probe method. The film thickness (total film thickness) is determined by applying a correction liquid to the glass substrate (base material 6) in advance, and then stripping the correction liquid and the film with ethanol after film formation so that the level difference of the film can be measured with a surface roughness meter. It was measured. In addition, each layer thickness (theoretical thickness of each layer formed per rotation) is the same as the actual film formation conditions for tungsten-containing amorphous carbon film. The thickness formed per time was calculated from the film speed.

  Moreover, Sn adhesion was evaluated about the obtained sample by implementing the sliding test using Sn ball | bowl. For the sliding test, a rotating sliding test was performed using a ball-on-disk test apparatus (manufactured by CMS: Tribometer). At this time, the rotation radius was 1.5 mm, the rotation speed was 0.2 cm / second, the load was 0.2 N, and the ball was SUJ2 (diameter: 9.5 mm) with 10 μm Sn plated. The sliding distance was fixed at 300 m, and the Sn adhesion amount after the sliding test was used as an index for Sn adhesion. For the Sn adhesion amount, three points on the sliding circumference were measured with a surface roughness meter, the adhesion cross-sectional area of each part was obtained, and the average value of the three points was obtained. A value of 0 at this time (sample No. 2 in the following table) indicates that no Sn adhesion occurred.

  The results (specific resistance, Sn adhesion amount) are shown in Table 1 below together with the metal content in the film. Table 1 below also shows the results due to the difference in film formation technique and added metal species. That is, a target using an Fe target instead of a solid tungsten target (target 1) (target 2 is a solid carbon target: sample No. 3), and a tungsten wire (W line) arranged on a solid carbon target. The film (sample No. 1) is also shown. At this time, the applied voltage to the solid carbon target (including the one in which the W line is arranged on the solid carbon target) was 2.0 kW, and the applied voltage to the Fe target was 0.06 kW (for the number of rotations, Same as).

The theoretical film thicknesses of the tungsten layer, the Fe layer, and the carbon layer formed per rotation of the substrate under the above conditions are 2.35 × 10 ⁻¹⁰ m, 2.17 × 10 ⁻¹⁰ m, and 3.51 ×, respectively. 10 ⁻¹⁰ m. In addition, the film formation time was controlled so that the film thickness (total thickness) of each film was 0.2 μm (2000 × 10 ⁻¹⁰ m).

  From this result, it can be considered as follows. First, in the composite film (sample No. 1), although the specific resistance is low, it can be seen that Sn adhesion occurs. On the other hand, when a solid tungsten target and a solid carbon target were formed by providing two independent evaporation sources (Sample No. 2: Example of the present invention), the specific resistance was low, and Sn was adhered. It can be seen that no problem has occurred. In addition, when the metal species to be contained is changed to Fe (sample No. 3), the specific resistance is relatively low, but it is higher than that of tungsten, and Sn adhesion also occurs. I understand.

[Example 2]
Next, in order to evaluate the specific resistance and Sn adhesion property due to the difference in the layer thickness of tungsten, the applied power of the solid carbon target is kept constant at 2.0 kW, and the applied power of the tungsten target is set between 0.02 and 0.00. By changing the thickness to 25 kW, the tungsten layer thickness was changed to form a tungsten-containing amorphous carbon film (other conditions are the same as in Example 1). Therefore, the theoretical thickness of the carbon layer per revolution is 3.51 × 10 ⁻¹⁰ m.

  Applied power to tungsten target (W applied power), tungsten thickness at that time (theoretical thickness per rotation: W layer thickness), specific resistance and Sn of tungsten-containing amorphous carbon film formed under each condition The adhesion amount (measurement method is the above) is shown in Table 2 below (Sample No. 9 in Table 2 corresponds to Sample No. 2 in Table 1).

From the results in Table 2, it can be considered as follows. First, when the W applied power is 0.02 kW, the W layer thickness is 0.32 × 10 ⁻¹⁰ m, and it can be seen that the specific resistance value is relatively large. This is presumably because the amount of tungsten contained was reduced. On the other hand, when the W applied power is 0.04 to 0.12 kW (sample Nos. 5 to 9), the W layer thickness is 0.56 to 2.35 (× 10 ⁻¹⁰ m), which is a tungsten having a granular structure. It is presumed that the amorphous carbon film is contained, and it can be seen that the specific resistance is small and no Sn adhesion occurs. However, when the W layer thickness is 3.26 × 10 ⁻¹⁰ m or more (Sample Nos. ^{10 to} 14), it is understood that Sn adhesion occurs although the specific resistance is small. This is because, under the film forming conditions where the W layer thickness is 3.26 × 10 ⁻¹⁰ m or more, the tungsten particles are coarsened, so that the specific resistance is lowered, but the proportion of tungsten existing on the film surface is increased. By doing so, it was thought that Sn adhesion occurred.

1 Vacuum chamber 2 Solid tungsten target 3 Solid carbon target 4 Rotating body (base stage)
5 Base material holder 6 Base material

Claims (4)

In manufacturing an amorphous carbon film-coated member in which a tungsten-containing amorphous carbon film is coated on the surface of the substrate, the surface of the substrate is divided into two evaporation atmospheres separately formed from the solid carbon target and the solid tungsten target. The amount of tungsten deposited in each treatment is set so that the theoretical thickness corresponds to 0.40 × 10 ⁻¹⁰ m or more and less than 2.74 × 10 ⁻¹⁰ m. A method for producing a tungsten-containing amorphous carbon film-coated member, wherein the tungsten-containing amorphous carbon film-coated member is operated. In manufacturing an amorphous carbon film-coated member in which a tungsten-containing amorphous carbon film is coated on the surface of a substrate, two independent evaporation sources each having a solid carbon target and a solid tungsten target, and the front surfaces of these evaporation sources Using a device equipped with a rotating body having a rotating surface orthogonal to the substrate, the substrate is placed on the rotating surface of this rotating body, and the rotating member is rotated so that the surface of the substrate is sequentially directed to the front of the target multiple times. At the same time, the amount of tungsten deposited per treatment should be set so that the theoretical thickness is equivalent to 0.40 × 10 ⁻¹⁰ m or more and less than 2.74 × 10 ⁻¹⁰ m. A method for producing a tungsten-containing amorphous carbon film-coated member.   A probe pin for a semiconductor inspection apparatus obtained by coating the core material with a tungsten-containing amorphous carbon film by the method according to claim 1.   4. The probe pin for a semiconductor inspection device according to claim 3, wherein the tungsten-containing amorphous carbon film has a thickness of 0.1 to 1 [mu] m.

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