JP5535131B2 - Probe pin for semiconductor inspection apparatus and manufacturing method thereof - Google Patents

Description

  The present invention relates to a probe pin for a semiconductor inspection apparatus including a conductive base material and a tungsten-containing carbon film, and a method for manufacturing the same.

  The probe pin for a semiconductor inspection device repeatedly comes into contact with a metal terminal portion or solder that is a mating material of the probe pin in semiconductor inspection. At that time, the film surface of the probe pin is worn, and eventually the film disappears, and the semiconductor inspection may not be performed stably. For this reason, the abrasion of the film not only causes the lifetime of the probe pin to be shortened, but also causes a decrease in the productivity of the semiconductor.

  As a prior art that focuses on the film on the tip side of the probe pin, for example, in Patent Document 1, from the viewpoint of conductivity and aluminum adhesion resistance, the tungsten content is 1 to 50% by weight (0. However, the detailed structure of the film is not described. Further, Patent Document 2 discloses that the life of the contact probe is extended by making the hardness of the base material steel equal to or higher than HRC40, but the conductive film on the surface is described from the viewpoint of extending the life. Has not been made.

JP 2001-289874 A JP 7-248337 A

  From the viewpoint of extending the life of the probe pins for semiconductor inspection devices, it is necessary that the electrical resistance is low and the durability is excellent. However, the proposals made so far have not been satisfactory.

  In particular, in order to improve the durability, it is necessary to improve the hardness of the probe pin surface to increase the wear resistance. However, the surface hardness of the conventional probe pin is not sufficient.

  The present invention has been made in view of such a problem, and is a probe pin for a semiconductor inspection apparatus in which a conductive hard film is formed on the surface of a conductive base material, the semiconductor having improved surface hardness. An object is to provide a probe pin for an inspection apparatus.

  In the process of studying the relationship between the surface properties of the film formed on the surface of the probe pins for semiconductor inspection equipment and the durability, the present inventors paid attention to the effect of the properties of the conductive film on the durability and used the film It has been found that the hardness is improved by selecting tungsten-containing carbon having a specific crystal structure as a material to be obtained, and the present invention has been achieved.

  That is, the first subject of the present invention is a probe pin for a semiconductor inspection apparatus including a conductive base material and a tungsten-containing carbon film, and the tungsten-containing carbon film is X-ray diffraction in 2θ-θ mode. In the analysis, a probe for a semiconductor inspection apparatus is characterized in that one diffraction peak observed in an angle 2θ in a range of 30 ° ≦ 2θ ≦ 50 ° is one in an angle 2θ in a range of 37 ° ≦ 2θ ≦ 40 °. It is a pin.

  According to such a configuration, the conductive film formed on the surface of the conductive base material can remarkably improve the durability of the conductive film, thereby causing a failure of the probe pin for the semiconductor inspection apparatus. It can be reduced to increase the life, and the probe replacement frequency can be reduced.

  The ratio of the number of tungsten atoms to the total number of tungsten and carbon atoms in the tungsten-containing carbon film is preferably 40.0 to 65.0 atomic%.

  According to such a configuration, the durability of the conductive film can be further improved.

  In the probe pin for a semiconductor inspection apparatus, it is preferable that the film thickness of the film is 0.05 to 3.00 μm.

  According to such a configuration, the surface roughness can be further reduced, and the durability of the conductive film can be further improved.

  A method of manufacturing a probe pin for a semiconductor inspection apparatus, wherein the tungsten-containing carbon film is preferably formed on a conductive substrate by performing sputtering in an argon gas using a cemented carbide target. It is.

  According to such a manufacturing method, the durability of the conductive film can be improved, and an amorphous tungsten-containing carbon film having excellent durability can be effectively applied to the contact probe pin base material for a semiconductor inspection apparatus. Can be formed easily and easily.

  In the manufacturing method, it is preferable that the sputtering is unbalanced magnetron sputtering.

  According to such a configuration, a tungsten-containing carbon film having a smooth surface property of the tungsten-containing carbon film can be formed on the substrate.

  According to the present invention, the conductive film formed on the surface of the conductive substrate of the probe pin for a semiconductor inspection apparatus can remarkably improve the durability of the probe pin film when the probe pin comes into contact with the solder. . As a result, it is possible to reduce the occurrence of defects in the probe pins for the semiconductor inspection apparatus, thereby extending the life, and to reduce the probe replacement frequency.

It is a mimetic diagram of a probe pin for semiconductor inspection devices concerning this embodiment. It is a schematic diagram which shows the structure in the chamber for forming the electroconductive film concerning this embodiment on a substrate surface by a sputtering method. It is an X-ray analysis figure of the electroconductive film formed into a film by each manufacturing method.

[Probe pins for semiconductor inspection equipment]
A first subject of the present invention is a probe pin for a semiconductor inspection apparatus including a conductive substrate and a tungsten-containing carbon film.

  Hereinafter, the present invention will be described with reference to the drawings according to an embodiment.

  FIG. 1 is a schematic diagram of a probe pin for a semiconductor inspection apparatus. The probe pin 10 includes a conductive substrate 11 and a tungsten-containing carbon film 12. The tip of the probe pin is brought into contact with the solder 20 connected to the substrate 21 to confirm the operation of the semiconductor element.

  The conductive substrate 11 is covered with a tungsten-containing carbon film 12.

  The solder 20 is not particularly limited as long as it is a known solder material, but generally a solder material having a BGA (ball grid array) configuration or the like is used.

(Conductive substrate)
The material of the conductive base material is not particularly limited, but the base material is preferably one having a high hardness, and even when the surface of the base material is plated, it is preferably hard plating. Generally, as the metal, a copper alloy such as beryllium copper, tungsten, rhenium tungsten, steel, etc., which is hard and elastic, is used. Moreover, the surface of the base material may be plated. As the plating, for example, one containing one type of pure metal or two or more types of alloys selected from the group consisting of chromium, cobalt, nickel, rhodium, palladium, gold and the like can be used.

  In FIG. 1, the tip of the probe pin has a simple point shape, but the shape of the tip can be arbitrarily applied to a crown shape, a triangular pyramid shape, a conical shape, etc., depending on the object to be inspected. Is not to be done.

(Tungsten-containing carbon film)
In the X-ray diffraction analysis in the 2θ-θ mode, the tungsten-containing carbon film has a diffraction peak observed in the range of 30 ° ≦ 2θ ≦ 50 ° at an angle 2θ of 37 ° ≦ 2θ ≦ 40 ° at an angle 2θ. Have only one. In this case, the hardness of the tungsten-containing carbon film is particularly improved.

For example, even if the ratio of the number of tungsten atoms to the total number of tungsten and carbon atoms in the tungsten-containing carbon film is substantially the same, two peaks appear in the vicinity of 36 ° and 40 °. In some cases, the hardness decreases. It is considered that the peaks at 2θ around 36 ° and around 40 ° are diffraction lines from the β-tungsten layer, respectively, and the hardness decreases due to the precipitation of a soft tungsten layer in the amorphous structure. Because it is considered. On the other hand, a structure in which only one broad peak is observed at 2θ from 37 ° to 40 ° indicates an amorphous or ultrafine crystal structure of the WC _1-x layer, which is considered to improve the hardness.

  Also, a tungsten-containing carbon coating that uses a cemented carbide target, which will be described later, and the ratio of the number of tungsten atoms to the total number of tungsten and carbon atoms in the tungsten-containing carbon coating is 40.0 to 65.0 atomic percent. By doing, what has sufficient hardness and a smaller electrical resistance is obtained. In addition, since the electrical resistance value with a tungsten ratio of 10.0 atomic% or less is high, it cannot be applied as an inspection apparatus. Further, when the ratio of the number of tungsten atoms is more than 10.0 atom% and less than 40.0 atom%, the resistance value is decreased, but it is not sufficient, and the film hardness is not sufficient, which is satisfactory. There is a tendency that abrasion resistance cannot be obtained. On the other hand, when the tungsten composition is increased, the hardness tends to improve according to the composition, but when the proportion of the number of tungsten atoms is more than 65.0 atomic%, the hardness tends to decrease. This is considered to be because pure tungsten having a low hardness is likely to precipitate in the cemented carbide structure.

  Here, in the conventional probe pin for a semiconductor inspection apparatus, the film surface of the probe pin is worn by repeated contact with metal or solder connected to the semiconductor element during semiconductor inspection. As a result, the film eventually disappears, and stable inspection cannot be performed. Therefore, it is necessary to replace the probe itself frequently, which is a problem.

  In view of these problems, the present inventors have studied a coating that is highly durable and excellent in low electrical resistance for the purpose of reducing the frequency of probe pin replacement. As a result, it was found that the tungsten-containing carbon film described above can provide a film with high hardness, and as a result, it is possible to obtain a probe pin with a lower replacement frequency compared to the prior art.

  The tungsten-containing carbon film is preferably a vapor deposition method from the viewpoint that an amorphous structure that is a metastable phase is easily obtained. Examples of the vapor deposition method include methods such as vacuum deposition, arc ion plating, and sputtering. Tungsten-containing carbon produced by these methods can obtain a coating with a smooth surface in a wide composition range.

  In the probe pin for a semiconductor inspection apparatus according to the present invention, the film thickness of the tungsten-containing carbon film to be coated varies depending on the shape of the probe pin, the type of the conductive base material, etc., and is 0.05 to 3.00 μm. It is preferable that it is 0.10-2.50 micrometers. When the film thickness is larger than 3.00 μm, the roughness of the surface of the probe pin may increase or the film thickness may be inferior. On the other hand, when the thickness is smaller than 0.01 μm, durability may be lowered because the film is thin.

  The tungsten-containing carbon film is formed by, for example, a method described later, and includes, in addition to tungsten and a carbon component, other element components contained in the cemented carbide, an argon component that is a sputtering gas, and the like. When the total amount of tungsten and carbon components is 90 atomic% or more, the influence of these other elements is small, so that the tungsten composition is obtained only from tungsten and carbon components. As other components, there is a hydrogen component derived from a hydrocarbon gas during film formation, but in the present invention, the hydrogen content does not contribute to the film quality and can be removed. SEM-EDX is preferably used for composition analysis from the viewpoint of simplicity.

(Middle layer)
The tungsten-containing carbon film may be formed on the base material through an intermediate layer between the contact probe pin and the base material. An intermediate | middle layer has a role which strengthens the adhesiveness to the base-material surface of a tungsten containing carbon membrane. The intermediate layer may include tungsten and carbon, and may have a gradient composition in which the ratio of the number of tungsten atoms to carbon decreases in the thickness direction from the substrate surface toward the tungsten-containing carbon film.

  The intermediate layer may be a layer made of a pure metal such as chromium, titanium, tungsten, or aluminum, or may be a combination of a layer made of a pure metal and a layer having a gradient composition. The thickness of the intermediate layer is preferably 5 to 5000 nm, and more preferably 500 to 3000 nm.

  When the substrate is soft, it is preferable to add an intermediate layer having a hardness higher than that of the substrate for the purpose of preventing plastic deformation of the substrate. In this case, the thickness of the intermediate layer should be 500 to 5000 nm or more. It ’s fine. By setting the thickness to 5000 nm or less, it is possible to prevent the electrical resistance value from increasing.

  As a method for forming the intermediate layer on the probe pin substrate, it is preferable to use a sputtering method, particularly an unbalanced magnetron sputtering method. In that case, an intermediate layer can be formed on the conductive substrate first, and then a tungsten-containing carbon film can be formed on the intermediate layer.

[Production method]
A second subject of the present invention is a method for producing a tungsten-containing carbon film on a substrate of a probe pin for a semiconductor inspection device, wherein the tungsten-containing carbon film is used in argon gas or argon gas using a target. It is formed on a base material by performing sputtering in a mixed gas of hydrogen and hydrocarbon gas.

  The sputtering can be performed, for example, with a film forming apparatus 30 as shown in FIG. Specifically, first, the glass substrate 36 is placed on the substrate holder 35 placed in parallel with the sputtering target. Next, after the vacuum chamber 31 is evacuated, the surface of the substrate 36 is covered and formed with a sputtering target 32 adjusted to a predetermined ratio. The substrate stage 35 may be fixed in parallel with the sputtering target, or may be formed while being rotated (revolution or rotation + revolution).

  In the present invention, it is preferable to use a cemented carbide target as the sputtering target. With respect to the cemented carbide target, only one film may be formed, or from the viewpoint of improving productivity, two or more cemented carbide targets (for example, cemented carbide targets 32 and 33) are used for rotational film formation. (Revolution or self-revolution) is also possible. The probe pin of the present invention can be manufactured by performing a coating operation of tungsten-containing carbon with such an apparatus.

  In the case of these methods, the tungsten content of the tungsten-containing carbon film can be controlled by controlling the amount ratio of the mixed gas of argon gas and hydrocarbon gas. Alternatively, the tungsten content of the tungsten-containing carbon film can be controlled by controlling the tungsten content of the cemented carbide target.

  As for the film thickness, any method can be used to form a tungsten-containing carbon film having an arbitrary film thickness by controlling the film formation time and the power applied to the target.

(target)
The target used for the sputtering method according to the present invention is a cemented carbide target. That is, by performing sputtering using a cemented carbide target, it is possible to easily add a metal and form a film having a desired hardness.

  As a method for forming a tungsten-containing carbon-based film, a sputtering method using a solid carbon source is generally used, and film formation by a composite target in which a pure tungsten chip is placed on a carbon target or pure tungsten is embedded is performed. Although widely used, it is difficult to obtain a film having high hardness by these methods.

  As the cemented carbide target, a general cemented carbide can be used. For example, various cemented carbides defined in JIS H 5501-1996 can be used. In particular, G type and D type of JIS H5501-1996 are preferable because they substantially contain no Ti and an amorphous tungsten-containing carbon film is suitably formed. The various cemented carbides specified in JIS H 5501-1996 include those containing 2 atomic% or less of other elements other than tungsten, cobalt, and carbon. It is also possible to control the tungsten content of the tungsten-containing carbon film by controlling the target content of the cemented carbide target.

(Process gas)
In the sputtering method according to the present invention, argon gas or a mixed gas of argon gas and hydrocarbon gas is used as a process gas. As hydrocarbon gas, gas, such as methane, acetylene, benzene, toluene, can be used. That is, a tungsten-containing carbon film is formed by introducing argon gas or a mixed gas of argon gas and hydrocarbon gas into a vacuum chamber and performing sputtering under predetermined conditions.

(Sputtering)
In the present invention, the tungsten-containing carbon film is formed on the contact probe pin base material by performing sputtering in argon gas or a mixed gas of argon gas and hydrocarbon using a cemented carbide target.

  As sputtering, from the viewpoint of smoothing the surface properties of the tungsten-containing carbon film, magnetron sputtering is preferable, and unbalanced magnetron sputtering is more preferable.

  According to this method, since the plasma space can be expanded to the vicinity of the substrate, it is possible to irradiate the base material with Ar ions. The kinetic energy of Ar ions due to Ar ion irradiation contributes to the improvement of thermal energy of sputtered particles that have reached the substrate. By improving the thermal energy of the sputtered particles, the movement of the particles on the substrate is facilitated, and the film becomes dense and a smooth film can be obtained. In order to further increase these effects, the energy of Ar ions can be controlled by applying a bias to the substrate, and the hardness can be further increased.

(Formation of tungsten-containing carbon film)
When the manufacturing method of the present invention is used, a tungsten-containing carbon film having high hardness can be imparted on the base material of the contact probe pin. As a result, the probe pin replacement frequency can be significantly reduced.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to these examples.

(Formation of conductive film)
Film formation was performed using an unbalanced magnetron sputtering (UBMS202) apparatus manufactured by Kobe Steel.

  As types of film formation, (A) a composite film formed by placing a pure tungsten wire on a carbon target, adjusting the number of wires, and forming the film in argon gas to control the tungsten content; (B) tungsten Film formation in which the tungsten content is adjusted by adjusting the flow rates of argon gas and hydrocarbon gas using a target (purity 99.9%), or (C) a cemented carbide target (manufactured by Allied Materials, Inc .; as a binder) Three types of film formation, in which the tungsten content is adjusted by adjusting the flow rates of argon gas and hydrocarbon gas using cobalt), were performed.

  The substrate was placed in parallel with the target. The base material was implemented using the glass substrate.

After introducing the base material into the apparatus, the film was evacuated to 1 × 10 ⁻³ Pa or less, and film formation was performed. Argon gas and hydrocarbon gas (CH ₄ ) were used as the process gas, and only a mixed gas of argon gas and hydrocarbon gas or argon gas was introduced into the chamber.

  The gas pressure during film formation was 0.6 Pa, and the substrate applied bias during film formation was constant at −100V. The tungsten content in the film was controlled by changing the mixed gas ratio during film formation. The deposition time was adjusted so that the input power to the carbon composite target, tungsten target or cemented carbide target was 2.0 kW, and the film thickness was constant at about 200 nm.

  Table 1 shows samples (sample numbers 1 to 10) formed at different tungsten ratios by the above-described film formation methods (A) to (C), and the tungsten ratio, specific resistance, hardness, The measurement result by X-ray measurement was described.

  In addition, although elements other than tungsten and carbon components were also detected for the above film, since the total amount of tungsten and carbon was 90 atomic% or more, the value calculated to be 100% with two elements of tungsten and carbon was calculated. Using.

(Tungsten ratio)
The tungsten ratio in the film was determined by analysis using a scanning electron microscope SEM-EDX with an energy dispersive X-ray analyzer.

(Measurement of specific resistance)
The specific resistance was measured by measuring electric resistance by a four-probe method.

  In addition, the film thickness of a tungsten containing carbon film is required for calculation of specific resistance. In this film thickness measurement, the correction liquid is applied on the substrate before film formation, and the base material of the correction liquid application part is exposed by removing the correction liquid after film formation, and the level difference between the film and the base material is measured. The film thickness obtained in this way was used.

(Measurement of hardness)
The hardness was measured with a Hystron nanoindenter device incorporated in an AFM apparatus (SPI4000 manufactured by SII). The measurement load was measured at 10 points in the range from 100 μN to 2000 μN, and the average value was obtained.

(X-ray diffraction measurement)
For X-ray diffraction, 2θ-θ measurement was carried out using a RINT ULTIMA-PC apparatus manufactured by Rigaku.

  FIG. 1 shows X-ray diffraction patterns of films having different compositions with a composition around 60.0 atomic%.

(A) in FIG. 1 is a composite film formed by placing a pure tungsten wire on a carbon target, (b) is a film formed from a pure tungsten target in methane gas, (c) A cemented carbide target is formed with argon gas. The respective tungsten contents were (a) 60.2 atomic%, (b) 58.1 atomic%, and (c) 59.6 atomic%. In FIGS. 1A and 1B, two peaks are observed when 2θ is around 37 ° and around 41 °, and these are considered to be diffraction lines from the β-tungsten layer, and are soft in the amorphous structure. It is considered that a tungsten layer is deposited. On the other hand, in FIG. 1C, a single broad peak is observed when 2θ is around 39 °, which is considered to be a peak due to an amorphous or microcrystalline WC _1-x structure.

(result)
The results are shown in Table 1. (A), (b), and (c) in FIG. 1 correspond to Samples 2, 4, and 10 in Table 1, respectively.

From the results shown in Table 1, the specific resistance of all the films was 1 × 10 ⁻³ Ω · cm or less. Regarding hardness, Samples 1 and 2 obtained by composite film formation (A) in which a tungsten wire is set on a carbon target, and Sample 3 obtained by film formation of tungsten in a hydrocarbon gas (B) 3 No. 5 could not achieve a hardness higher than about 23 GPa.

  On the other hand, samples 8 to 10 obtained by using a cemented carbide target in a composite gas of hydrocarbon gas and argon gas or only with argon gas (C) have a tungsten content of 40 atoms. When the percentage was not less than%, the hardness exceeded 25 GPa. In particular, the sample 10 formed only with argon gas showed a hardness exceeding 30 GPa.

  Further, the peak position obtained from the X-ray diffraction results (the peak position was obtained from the result of the fitting by the Voigt function and the two peaks overlapped by the peak fitting) was determined. Except for the case where the film was formed with the target, two peaks appeared as shown in FIGS. From these results, it was suggested that the hardness is lowered by the precipitation of a tungsten layer having a low hardness. Table 1 lists the peak positions thus obtained. In the cemented carbide film formation (C), only a single peak was obtained with any tungsten composition, and the peak position shifted to 37 ° or less when the composition was 40.0 atomic% or less.

  On the other hand, in a film formed using a tungsten target in a hydrocarbon gas or a film formed using a composite target in which a tungsten wire is disposed on a carbon target, two peaks appeared in all the films. In particular, in the pure tungsten film of Sample 5, two peaks appeared and a decrease in hardness was observed, suggesting that the hardness decreased due to the precipitation of the tungsten phase.

DESCRIPTION OF SYMBOLS 10 Probe pin 11 Conductive base material 12 Tungsten containing carbon film 20 Solder 21 Substrate 30 Film-forming apparatus 31 Vacuum chamber 32 Sputter target 33 Sputter target 34 Base stage 35 Base material holder 36 Base material

Claims (4)

A probe pin for a semiconductor inspection device comprising a conductive substrate and a tungsten-containing carbon film,
In the X-ray diffraction analysis in the 2θ-θ mode, the tungsten-containing carbon film has a diffraction peak observed in the range of 30 ° ≦ 2θ ≦ 50 ° at an angle 2θ of 37 ° ≦ 2θ ≦ 40 ° at an angle 2θ. Have only one in the range ,
The probe pin for a semiconductor inspection apparatus , wherein a ratio of the number of tungsten atoms to the total number of tungsten and carbon atoms in the tungsten-containing carbon film is 40.0 to 65.0 atomic% . 2. The probe pin for a semiconductor inspection apparatus according to claim 1, wherein the tungsten-containing carbon film has a thickness of 0.05 to 3.00 μm. A method of manufacturing the probe pin for a semiconductor inspection device according to claim 1,
The tungsten-containing carbon film is formed on a conductive substrate by performing sputtering in a argon gas or a mixed gas of an argon gas and a hydrocarbon gas using a cemented carbide target. Manufacturing method of probe pin for inspection device. The manufacturing method according to claim 3 , wherein the sputtering is unbalanced magnetron sputtering.

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