US20060201816A1

US20060201816A1 - Semiconductor manufacturing apparatus

Info

Publication number: US20060201816A1
Application number: US11/371,928
Authority: US
Inventors: Kakushi Kamada; Hiroshi Ashida; Naoki Torazawa
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp
Priority date: 2005-03-11
Filing date: 2006-03-10
Publication date: 2006-09-14
Also published as: JP2006249533A

Abstract

A semiconductor manufacturing apparatus includes: a disk-shaped holding part for holding a semiconductor substrate with its fist surface; a rotation shaft having an end placed at a second surface of the holding part; a rotatable terminal provided at the other end of the rotation shaft and rotating with the holding part; a fixed terminal for applying current or a voltage to the semiconductor substrate through the rotatable terminal, the fixed terminal being in contact with the rotatable terminal to form a sliding surface perpendicularly to the rotation shaft and electrically connected to a power supply; and a sensor part for detecting a rotational state of the rotation shaft. Protection means for protecting the sensor part against fine particles produced at an interface between the fixed terminal and the rotatable terminal is provided between the sliding surface and the holding part.

Description

CROSS-REFERENCE TO RELATED APPLICATION

The disclosure of Japanese Patent Application No. 2005-69750 filed on Mar. 11, 2005 including specification, drawings and claims is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to semiconductor manufacturing apparatus including a rotating and grinding part.
In recent years, electrolytic plating processes are adopted in forming interconnections of semiconductor devices. In general electrolytic plating, an anode electrode and a semiconductor wafer are immersed in a plating solution containing copper sulfate as a main component and current is caused to flow between the anode electrode and the semiconductor wafer so that copper is deposited by reduction on the surface of the semiconductor wafer and a recess in the surface of the semiconductor wafer is filled with copper.
In view of this, a semiconductor manufacturing apparatus for use in an electrolytic plating process needs a current introducing terminal for causing current to flow while holding a wafer. To uniformly fill the recess in the electrolytic plating process, the semiconductor wafer needs to be rotated in the plating solution. Therefore, the current introducing terminal is formed by a fixed terminal fixed to the body of the apparatus and a rotatable terminal for introducing current to the wafer in the state of being in contact with the fixed terminal and for rotating the wafer while supporting the wafer, and includes a rotating and grinding part (see, for example, Japanese Unexamined Patent Publication No. 2001-32098). It is also necessary to control the rotational position of the wafer and the number of revolutions, for example. Therefore, sensors such as an index sensor and an encoder are provided.
When the rotatable terminal is rotated under the state of being in contact with the fixed terminal, the fixed terminal and the rotatable terminal are grinded in the sliding surface by rolling friction so that shavings, i.e., fine particles, are produced. As the number of processed wafers increases, the amount of shavings increases, and the shavings are scattered inside the semiconductor manufacturing apparatus to adversely affect sensors or other components which are precision parts provided in the semiconductor manufacturing apparatus. For example, there occurs an error in which shavings are scattered around an encoder and an index sensor so that an index (a robot origin) is not detected.
In this manner, to suppress the influence of the shavings, exchange and cleaning, for example, of the fixed current terminal, which is particularly worn to a great extent, need to be frequently performed, resulting in that frequency of maintenance of a semiconductor manufacturing apparatus increases and productivity deteriorates.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a semiconductor manufacturing apparatus in which influence of fine particles produced at a current introducing terminal including a rotating and grinding part on, for example, sensors which are precision parts is reduced and whose availability and productivity are enhanced.
To achieve the object, a semiconductor manufacturing apparatus according to the present invention includes protection means for protecting sensors provided in the apparatus against fine particles.
Specifically, a semiconductor manufacturing apparatus according to the present invention includes: a disk-shaped holding part having a first surface and a second surface, a semiconductor substrate being held with the fist surface; a rotation shaft having an end placed at the second surface of the holding part; a rotatable terminal provided at the other end of the rotation shaft and rotating with the holding part; a fixed terminal for applying current or a voltage to the semiconductor substrate through the rotatable terminal, the fixed terminal being in contact with the rotatable terminal to form a sliding surface perpendicularly to the rotation shaft and electrically connected to a power supply; a sensor part for detecting a rotational state of the rotation shaft; and protection means for protecting the sensor part against fine particles produced at an interface between the fixed terminal and the rotatable terminal, the protection means being provided between the sliding surface and the holding part.
In the semiconductor manufacturing apparatus of the present invention, fine particles produced at the sliding surface are less likely to reach the sensor part. Accordingly, malfunction of the sensor part is less frequently caused by fine particles. As a result, frequency of maintenance of the semiconductor manufacturing apparatus is reduced and production efficiency is enhanced.
In the semiconductor manufacturing apparatus of the present invention, the protection means is preferably a plate-shaped member provided between the sliding surface and the sensor part and blocks a scattering path of the fine particles. The protection means may be a film member provided between the sliding surface and the sensor part and blocks a scattering path of the fine particles. In this case, the film member preferably has an adhesive property. With this configuration, fine particles produced at the sliding surface are trapped by the film member, thereby ensuring protection of the sensor part and enabling prevention of contamination of the substrate.
The protection means may be a C-shaped member having a substantially C-shaped cross section and provided around the rotation shaft to surround the sliding surface. With this configuration, scattering of fine particles produced at the sliding surface into the apparatus is suppressed, thereby ensuring protection of the sensor part. It is also possible to prevent contamination of the substrate by the fine particles.
In the semiconductor manufacturing apparatus of the present invention, the protection means is preferably a suction mechanism for sucking the fine particles. Preferably, in this case, the suction mechanism has an inlet, and the inlet is placed to face the sliding surface. With this configuration, fine particles generated at the sliding surface are removed by suction, thereby protecting the sensor part and enabling prevention of contamination of the substrate.
In the semiconductor manufacturing apparatus of the present invention, the protection means preferably has a nozzle placed near the sensor part and causes a jet of gas from the nozzle. In this case, the nozzle preferably has a tip facing the sensor part. The gas is preferably nitrogen gas. This configuration ensures prevention of fine particles from reaching the sensor part.
In the semiconductor manufacturing apparatus of the present invention, it is preferable that the sensor part includes: a disk-shaped index wheel mounted on the rotation shaft; and an index sensor for detecting a position of the index wheel, and the protection means is a first brush member provided for the index sensor and used for cleaning an upper face of the index wheel. Preferably, in this case, the index sensor is an optical sensor having a light-emitting portion and a light-receiving portion, and the protection means includes a second brush member provided for the index wheel and used for cleaning at least one of the light-emitting portion and the light-receiving portion. This configuration allows the sensor part to be always subjected to cleaning, and reduces the influence of the fine particles on the sensor part.
In the semiconductor manufacturing apparatus of the present invention, it is preferable that the sensor part includes a disk-shaped index wheel mounted on the rotation shaft and an index sensor for detecting a position of the index wheel, and the protection means is an index-sensor covering member covering the index sensor.
In the semiconductor manufacturing apparatus of the present invention, it is preferable that the protection means includes a flame member surrounding the fixed terminal, the rotatable terminal and the rotation shaft, using the rotation shaft as a center, and the sensor part includes a disk-shaped index wheel mounted on the rotation shaft and an index sensor which is a proximity sensor provided outside the flame member and used for detecting a position of the index wheel. With this configuration, the mechanism for detecting the sensor part and the source of the fine particles are completely separated from each other, so that the influence of the fine particles on the sensor part is suppressed.
In the semiconductor manufacturing apparatus of the present invention, the fixed terminal preferably has a recess with which the rotatable terminal is jointed. With this configuration, a scattering path of fine particles produced at the sliding surface is extended, so that the scattering of fine particles into the apparatus is suppressed. In addition, the fixed terminal and the rotatable terminal are in uniform contact with each other, thereby preventing uneven grinding and eccentricity of the fixed terminal. Accordingly, reduction of frequency of maintenance is enabled.
In the semiconductor manufacturing apparatus of the present invention, the fixed terminal and the rotatable terminal preferably contain tough pitch copper. With this configuration, durability against wear of the fixed terminal and the rotatable terminal are enhanced and the conductivities thereof are increased. Accordingly, frequency of maintenance of the fixed terminal and the rotatable terminal is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view illustrating a semiconductor manufacturing apparatus according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view illustrating a semiconductor manufacturing apparatus according to a first modified example of the first embodiment.
FIG. 3 is a cross-sectional view illustrating a current introducing terminal used in a semiconductor manufacturing apparatus according to a second modified example of the first embodiment.
FIG. 4 is a cross-sectional view illustrating a semiconductor manufacturing apparatus according to a second embodiment of the present invention.
FIG. 5 is a cross-sectional view illustrating a semiconductor manufacturing apparatus according to a third embodiment of the present invention.
FIG. 6 is a cross-sectional view illustrating a semiconductor manufacturing apparatus according to a fourth embodiment of the present invention.
FIG. 7 is a cross-sectional view illustrating a semiconductor manufacturing apparatus according to a fifth embodiment of the present invention.
FIG. 8 is a cross-sectional view illustrating a semiconductor manufacturing apparatus according to a sixth embodiment of the present invention.
FIG. 9 is a graph showing correlations between conductivities and tensile strengths of materials for an electrode in a semiconductor manufacturing apparatus according to a seventh embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiment

1

A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 illustrates a cross-sectional configuration of a main portion of a plating apparatus as a semiconductor manufacturing apparatus according to the first embodiment.
As illustrated in FIG. 1, the plating apparatus of this embodiment includes; a current introducing terminal 3; a plating bath 11 for storing a plating solution 12; an anode electrode 10 which is an anode placed in the plating bath 11; a holding disk 15 provided to face the anode electrode 10 and to hold and rotate a wafer 7; cathode electrodes 5 electrically connected to the wafer 7 held by the holding disk 15 and rotating together with the wafer 7; and a contact seal 8 for preventing the plating solution from entering the cathode electrodes 5. The anode electrode 10 is electrically connected to an anode terminal of a power supply 9 through a wire 22.
The current introducing terminal 3 includes; a fixed current terminal 1 electrically connected to the power supply 9; a rotatable current terminal 2 electrically connected to the cathode electrodes 5; a rotation shaft 27 for rotating the rotatable current terminal 2 and the holding disk 15; a housing member 4 for housing, for example, a motor for driving the rotation shaft 27; an encoder 25 serving as a sensor for rotation control and provided around the rotation shaft 27; an index wheel and an index sensor (not shown) serving as sensors for detecting the position of the origin; and a scattering protection member 31 provided to the housing member 4. The scattering protection member 31 herein is protection means of the present invention.
The fixed current terminal 1 is made of a cylindrical conductive material and is electrically connected to a cathode terminal of the power supply 9 through a wire 23. The rotatable current terminal 2 is made of a conductive member in the shape of a disk and is electrically connected to the cathode electrodes 5 with a wire 24. The bottom face of the fixed current terminal 1 and the upper face of the rotatable current terminal 2 are in contact with each other, so that current flows between the fixed current terminal 1 and the wafer 7 held by the holding disk 15 through the rotatable current terminal 2 and the cathode electrodes 5. The rotation of the rotation shaft 27 causes the rotatable current terminal 2 and the holding disk 15 provided at respective ends thereof to rotate accordingly, so that it is possible to perform plating while rotating the wafer 7 held by the holding disk 15.
The rotatable current terminal 2 rotates in the state of being in contact with the fixed current terminal 1, so that the surface of the fixed current terminal 1 is particularly grinded by friction at the interface between the fixed current terminal 1 and the rotatable current terminal 2 and shavings 60 which are fine particles are produced. However, in the semiconductor manufacturing apparatus of this embodiment, the disk-shaped scattering protection member 31 for blocking scattering paths of the shavings 60 is provided between the encoder 25 and the interface between the fixed current terminal 1 and the rotatable current terminal 2.
Since the scattering of shavings 60 produced during rotation of the current introducing terminal 3 is blocked by the scattering protection member 31, it is possible to prevent the shavings 60 from scattering all over the apparatus and the index sensor and the encoder 25 are protected against the shavings 60. Accordingly, occurrence of errors in the index sensor and encoder 25 caused by shavings 60 is prevented and contamination of the wafer 7 is also prevented.
The scattering protection member 31 is preferably as large as possible to block scattering paths of the shavings 60 in the maximum range.

Modified Example 1 of Embodiment 1

Now, a first modified example of the first embodiment will be described with reference to the drawings. FIG. 2 illustrates a cross-sectional configuration of a main portion of a plating apparatus as a semiconductor manufacturing apparatus according to this modified example. In FIG. 2, components also shown in FIG. 1 are denoted by the same reference numerals and description thereof will be omitted.
As illustrated in FIG. 2, the semiconductor manufacturing apparatus of this modified example includes, as the scattering protection member 31, a disk-shaped film member provided between the holding disk 15 and the interface between the fixed current terminal 1 and the rotatable current terminal 2, placing the rotation shaft 27 at the center. The film member is made of, for example, vinyl chloride and has a disk-shaped structure completely covering the interface between the fixed current terminal 1 and the rotatable current terminal 2.
In this configuration, shavings 60 produced at the interface by rolling friction are caught by the scattering protection member 31, thus preventing the shavings 60 from reaching the wafer 7.
The scattering protection member 31 only needs to cover at least an index wheel 17 and preferably has a radius equal to or larger than the scattering radius of the shavings 60. The larger the radius of the scattering protection member 31 is, the more the effect thereof is. Accordingly, the radius of the scattering protection member 31 may be approximately equal to or larger than that of the holding disk 15. The shape of the scattering protection member 31 is not limited to a disk, and the scattering protection member 31 may be, for example, a flat plate having a flat rectangular shape.
The film may have a bowl shape about the rotation shaft. In such a case, the produced shavings 60 are more effectively caught.
In this modified example, the scattering protection member 31 may be formed by an adsorptive or adhesive film. Alternatively, an adsorptive or adhesive coating may be applied to the film. In such a case, shavings 60 are adsorbed or adhered to the film to be effectively collected, thereby preventing scattering of the shavings 60 in the apparatus.
As described above, in this modified example, the scattering protection member 31 made of a film is provided as a member for blocking scattering paths of shavings 60, so that precision parts such as the encoder 25 and the index sensor 16 in the semiconductor manufacturing apparatus are protected. In addition, shavings 60 less affect the wafer 7 and productivity of the semiconductor manufacturing apparatus is enhanced.

Modified Example 2 of Embodiment 1

Now, a second modified example of the first embodiment will be described with reference to the drawings. FIG. 3 illustrates a cross-sectional configuration of a current introducing terminal used in a semiconductor manufacturing apparatus according to this modified example in an enlarged manner. In FIG. 3, components also shown in FIG. 1 are denoted by the same reference numerals and description thereof will be omitted.
As illustrated in FIG. 3, in this modified example, a scattering protection member 32 has a substantially C shape in cross section and surrounds the interface between the fixed current terminal 1 and the rotatable current terminal 2. Since the source of shavings 60 is surrounded in this manner, the shavings 60 are kept in the scattering protection member 32 and scattering thereof in the apparatus is prevented. Accordingly, precision parts such as the encoder 25 in the apparatus are protected and contamination of the wafer 7 by the shavings 60 is also prevented. As a result, frequency of maintenance such as cleaning of the apparatus and exchanges of parts is reduced and, in addition, the yield is enhanced.
In this modified example, a recess is formed in an end portion of the fixed current terminal 1 in contact with the rotatable current terminal 2 such that the fixed current terminal 1 and the rotatable current terminal 2 are joined together at this recess and the fixed current terminal 1 covers the upper face and part of the side face of the rotatable current terminal 2.
As described above, the fixed current terminal 1 partly covers the side face of the rotatable current terminal 2, so that shavings 60 produced at the interface in which the bottom of the recess of the fixed current terminal 1 is in contact with the upper face of the rotatable current terminal 2 are not scattered directly to the inside of the apparatus. In this manner, scattering paths of the shavings 60 are extended, so that it is possible to greatly suppress scattering of the shavings 60 in the apparatus. Accordingly, though the yield is enhanced even without the scattering protection member 32, the scattering protection member 32 enables further reduction of scattering of the shavings 60.
In this modified example, instead of, or in addition to, the scattering protection member 32, the disk-shaped scattering protection member described in the first embodiment or the scattering protection member made of the film member described in the first modified example may be provided.
The fixed current terminal 1 and the rotatable current terminal 2 are joined together using a recess in the manner described above, the fixed current terminal 1 and the rotatable current terminal 2 are in uniform contact with each other, thereby preventing uneven grinding and eccentricity of the fixed current terminal 1. In this manner, the cycle of maintenance is prolonged.

Embodiment 2

Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 4 illustrates a cross-sectional configuration of a main portion of a plating apparatus as a semiconductor manufacturing apparatus according to the second embodiment. In FIG. 4, components also shown in FIG. 1 are denoted by the same reference numerals and description thereof will be omitted.
As illustrated in FIG. 4, the semiconductor manufacturing apparatus of this embodiment is characterized in that brushes 34 are provided at the upper and lower faces of an index sensor 16. In this manner, shavings 60 deposited on a rotatable index wheel 17 are removed by the brushes 34, so that a reading error of the index sensor 16 caused by the shavings 60 is prevented.
Since one of the brushes 34 is placed at the upper face of the index wheel 17, shavings 60 sticking to a light-emitting portion of the index sensor 16 are removed when the brush 34 passes the index sensor 16. In addition, since another brush 34 is provided at the lower face of the index wheel 17, shavings 60 sticking to a light-receiving portion of the index sensor 16 are removed. In actual application, the brushes 34 are provided in two places, i.e., the upper face of either the index sensor 16 or the index wheel 17 and the lower face of either the index sensor 16 or the index wheel 17. The brushes 34 may be provided only in one place out of the upper and lower faces of the index sensor 16 and the upper and lower faces of the index wheel 17. In such a case, it is possible to suppress a reading error of the index sensor 16 caused by shavings 60.
In this embodiment, as described in the modified examples of the first embodiment, a recess may be provided in the fixed current terminal 1 so that the fixed current terminal 1 and the rotatable current terminal 2 are joined together or a substantially C-shaped scattering protection member 32 may be additionally provided.

Embodiment 3

Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. FIG. 5 illustrates a cross-sectional configuration of a main portion of a plating apparatus as a semiconductor manufacturing apparatus according to the third embodiment. In FIG. 5, components also shown in FIG. 1 are denoted by the same reference numerals and description thereof will be omitted.
As illustrated in FIG. 5, the semiconductor manufacturing apparatus of this embodiment is characterized by including an interface cover 35 having such a shape that covers the interface between a fixed current terminal 1 and a rotatable current terminal 2 and an index sensor cover 36 covering an index sensor 16. In this embodiment, the index sensor cover 36 has an opening only in a portion associated with an index wheel 17.
The index sensor cover 36 is provided for the index sensor 16 susceptible to the influence of shavings 60 produced at the interface between the fixed current terminal 1 and the rotatable current terminal 2 in this manner, so that sticking of the shavings 60 is prevented. Accordingly, the origin is accurately read out.
In addition, the interface between the fixed current terminal 1 and the rotatable current terminal 2 is covered with the interface cover 35, so that scattering of the shavings 60 in the apparatus is prevented, thus reducing frequency of maintenance and enhancing productivity.
As described in the modified example of the first embodiment, a recess may be provided in the fixed current terminal 1 so that the fixed current terminal 1 and the rotatable current terminal 2 are joined together.

Embodiment 4

Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 6 illustrates a cross-sectional configuration of a main portion of a plating apparatus as a semiconductor manufacturing apparatus according to the fourth embodiment. In FIG. 6, components also shown in FIG. 1 are denoted by the same reference numerals and description thereof will be omitted.
As illustrated in FIG. 6, the semiconductor manufacturing apparatus of this embodiment is characterized in that a suction mechanism 41 for removing shavings 60 by suction is provided near the interface between a fixed current terminal 1 and a rotatable current terminal 2.
The suction mechanism 41 is formed by, for example, a dust collecting motor and a suction nozzle 42 connected to the dust collecting motor. The dust collecting motor may be provided with a dust collecting filter. The suction mechanism 41 has the same configuration as that of a member forming a general vacuum cleaner.
Shavings 60 produced at the interface are sucked and removed by the suction mechanism 41 in the manner described above, so that it is possible to prevent the shavings 60 from reaching an index sensor 16, the upper surface of a wafer 7 and other precision parts in the apparatus. Accordingly, the influence of the shavings 60 on the apparatus is suppressed, and frequency of maintenance is reduced.
In addition, the suction nozzle 42 is provided near the index sensor 16, so that occurrence of errors in reading the origin is prevented. The suction nozzle 42 may be provided near the interface opposite to the index sensor 16.
In this embodiment, the number of suction mechanisms 41 is not necessary one, and two or more suction mechanisms 41 may be provided in plural places. The inlet may be movable to any direction. This allows shavings 60 to be removed more effectively.

Embodiment 5

Hereinafter, a fifth embodiment of the present invention will be described with reference to the drawings. FIG. 7 illustrates a cross-sectional configuration of a main portion of a plating apparatus as a semiconductor manufacturing apparatus according to the fourth embodiment. In FIG. 7, components also shown in FIG. 1 are denoted by the same reference numerals and description thereof will be omitted.
As illustrated in FIG. 7, in the semiconductor manufacturing apparatus of this embodiment, a gas introducing mechanism 43 for introducing nitrogen gas, for example, is provided near an index sensor 16.
In this embodiment, the gas introducing mechanism 43 includes: a vinyl tube 44 having an inside diameter of 1 mm to 2 mm; and a blow-off nozzle 45 attached to the tip of the vinyl tube 44.
In this manner, the gas introducing mechanism 43 allows shavings 60 produced at the interface to be blown off with an inert gas. Accordingly, shavings 60 are blown off before reaching the index sensor 16 and an index wheel 17, for example, and shavings 60 deposited on (sticking to) the index sensor 16 and the index wheel 17, for example are blown off to be removed. As a result, shavings 60 less affect the apparatus, and productivity is enhanced.
In this embodiment, the number of gas introducing mechanisms 43 is not necessary one, and two or more gas introducing mechanisms 43 may be provided in plural places. The nozzle 45 may be movable to any direction. This allows shavings 60 to be removed more effectively.
As a gas introduced by the gas introducing mechanism 43, an inert gas containing nitrogen, argon, neon or helium, for example, may be used. Alternatively, oxygen or other elements may also be used.

Embodiment 6

Hereinafter, a sixth embodiment of the present invention will be described with reference to the drawings. FIG. 8 illustrates a cross-sectional configuration of a main portion of a plating apparatus as a semiconductor manufacturing apparatus according to the sixth embodiment. In FIG. 8, components also shown in FIG. 1 are denoted by the same reference numerals and description thereof will be omitted.
As illustrated in FIG. 8, in the semiconductor manufacturing apparatus of this embodiment, an index sensor 19 is placed outside a casing 51 surrounding a current introducing terminal. The casing 51 also covers the entire surface (back surface) of a holding disk 15 opposite to the surface thereof with which a wafer 7 is held.
An index wheel 17 has a diameter substantially equal to the inside diameter of the casing 51. The index sensor 19, which is a proximity sensor placed outside the casing 51 with the side wall of the casing 51 sandwiched therebetween, detects the position of the index wheel 17.
In this manner, a rotatable part including the interface between a fixed current terminal 1 and a rotatable current terminal 2 is entirely housed in the casing 51, so that shavings 60 produced in the casing 51 do not reach the index sensor 19. Accordingly, frequency of maintenance of the apparatus is reduced.
In addition, since the diameter of the index wheel 17 is substantially equal to that of the wafer 7, an advantage in which shavings 60 produced at the interface between the fixed current terminal 1 and the rotatable current terminal 2 do not reach the wafer 7 below the index wheel 17 is achieved. Accordingly, the influence of shavings 60 on the wafer 7 is suppressed.
At least one of the scattering protection member, the suction mechanism and the gas introducing mechanism described in the first through sixth embodiments and the modified examples may be additionally provided. In such a case, scattering of shavings 60 produced at the interface between the fixed current terminal 1 and the rotatable current terminal 2 is more effectively prevented.

Embodiment 7

Hereinafter, a seventh embodiment of the present invention will be described with reference to the drawings. FIG. 9 shows relationships between conductivities and tensile strengths of various conductive materials for a fixed current terminal and a rotatable current terminal. In FIG. 9, the abscissa represents the conductivities of the materials and the ordinate represents the tensile strengths of the materials. In the graph, the maximum value and the minimum value of each material are plotted.
The present inventors studied a relationship between the type of each conductive material for the fixed current terminal and the rotatable current terminal in a current introducing terminal and scattering of shavings from experiments, to find that the use of a material having a high wear resistance and a high conductivity for the current introducing terminal is effective for preventing scattering of shavings.
First, a relationship between a tensile strength (N/mm²) and a conductivity (conductivity in the International Annealed Copper Standard: % IACS) was examined with respect to seven materials described in JIS standard: A1050 (pure aluminum, purity: 99.5%), A2024 (super duralumin, Al—Cu-based alloy), A5052 (aluminum material, Al—Mg-based alloy), C1100 (tough pitch copper), C2700 (brass), C5191 (phosphor bronze) and Z3234 (chromium copper).
As shown in FIG. 9, chromium copper (represented by ⊚: double circles) exhibits the highest tensile strength in the range from 450 N/mm²to 540 N/mm², i.e., is the hardest, and pure aluminum (represented by ∇: inverse triangles) exhibits the lowest tensile strength in the range from 59 N/mm²to 147 N/mm², i.e., is the softest. This supports the experimental result that an aluminum (Al)-based alloy generally used for a fixed current terminal and a rotatable current terminal is soft so that the fixed current terminal is likely to be worn by friction between the fixed terminal and the rotatable current terminal and production of shavings is facilitated.
Even in the case of using a hard material having a high tensile strength for a current terminal, if this material has a low conductivity, a heat value in an energized state is large, so that the current terminal is more likely to be softened to be worn. Accordingly, a material suitable for the current terminal preferably has a high conductivity. However, only two materials, i.e., tough pitch copper (represented by ●: closed circles) and chromium copper, have conductivities of 80% IACS or more. In an actual wearing test, the uses of tough pitch copper and chromium copper having high conductivities greatly suppressed production of shavings at the interface. This shows that a material having a conductivity of 80% IACS or more and a tensile strength of 195 N/mm²or more is preferably used for the current terminal.
In a case where tough pitch copper is used for the fixed current terminal 1 and the rotatable current terminal 2 of the semiconductor manufacturing apparatus of the first modified example of the first embodiment, the amount of worn of the fixed current terminal 1 is reduced to about one seventh of that in the case of using a conventional Al-based alloy, and the amount of shavings 60 is greatly reduced.
The use of tough pitch copper for the fixed current terminal 1 and the rotatable current terminal 2 of the semiconductor manufacturing apparatus greatly suppresses the influence of shavings 60 on the apparatus. In addition, in a conventional apparatus, the fixed current terminal 1 which is greatly worn by rotation needs to be frequently removed from the apparatus for replacement. However, this replacement timing is prolonged in the apparatus of the present invention. For example, in a case where the number of revolutions is 500 RPM, maintenance needs to be performed after every 200 wafer processes in a conventional apparatus. However, in the semiconductor manufacturing apparatus of this embodiment, it is sufficient to perform maintenance after every 1200 wafer processes.
In the semiconductor manufacturing apparatus of the first through seventh embodiments, if tough pitch copper is used for the fixed current terminal 1 and the rotatable current terminal 2, the same advantages are also obtained.
In the foregoing embodiments, plating apparatus for use in forming interconnections is described as an example of a semiconductor manufacturing apparatus. However, the present invention is applicable to other apparatuses such as an ion implantation apparatus and a coating apparatus including introduction terminals having rotatable parts.
As described above, the semiconductor manufacturing apparatus according to the present invention is implemented as a semiconductor manufacturing apparatus in which fine particles produced from a current introducing terminal including a rotating and grinding part less affect sensors, which are precision parts, and other components, and whose availability and productivity are enhanced. The present invention is useful for a semiconductor manufacturing apparatus including a rotating and grinding part.

Claims

1. A semiconductor manufacturing apparatus, comprising:

a disk-shaped holding part having a first surface and a second surface, a semiconductor substrate being held with the fist surface;

a rotation shaft having an end placed at the second surface of the holding part;

a rotatable terminal provided at the other end of the rotation shaft and rotating with the holding part;

a fixed terminal for applying current or a voltage to the semiconductor substrate through the rotatable terminal, the fixed terminal being in contact with the rotatable terminal to form a sliding surface perpendicularly to the rotation shaft and electrically connected to a power supply;

a sensor part for detecting a rotational state of the rotation shaft; and

protection means for protecting the sensor part against fine particles produced at an interface between the fixed terminal and the rotatable terminal, the protection means being provided between the sliding surface and the holding part.

2. The apparatus of claim 1, wherein the protection means is a plate-shaped member provided between the sliding surface and the sensor part and blocks a scattering path of the fine particles.

3. The apparatus of claim 1, wherein the protection means is a film member provided between the sliding surface and the sensor part and blocks a scattering path of the fine particles.

4. The apparatus of claim 3, wherein the film member has an adhesive property.

5. The apparatus of claim 1, wherein the protection means is a C-shaped member having a substantially C-shaped cross section and provided around the rotation shaft to surround the sliding surface.

6. The apparatus of claim 1, wherein the protection means is a suction mechanism for sucking the fine particles.

7. The apparatus of claim 6, wherein the suction mechanism has an inlet, and

the inlet is placed to face the sliding surface.

8. The apparatus of claim 1, wherein the protection means has a nozzle placed near the sensor part and causes a jet of gas from the nozzle.

9. The apparatus of claim 8, wherein the nozzle has a tip facing the sensor part.

10. The apparatus of claim 8, wherein the gas is nitrogen gas.

11. The apparatus of claim 1, wherein the sensor part includes: a disk-shaped index wheel mounted on the rotation shaft; and an index sensor for detecting a position of the index wheel, and

the protection means is a first brush member provided for the index sensor and used for cleaning an upper face of the index wheel.

12. The apparatus of claim 11, wherein the index sensor is an optical sensor having a light-emitting portion and a light-receiving portion, and

the protection means includes a second brush member provided for the index wheel and used for cleaning at least one of the light-emitting portion and the light-receiving portion.

13. The apparatus of claim 1, wherein the sensor part includes a disk-shaped index wheel mounted on the rotation shaft and an index sensor for detecting a position of the index wheel, and

the protection means is an index-sensor covering member covering the index sensor.

14. The apparatus of claim 1, wherein the protection means includes a flame member surrounding the fixed terminal, the rotatable terminal and the rotation shaft, using the rotation shaft as a center, and

the sensor part includes a disk-shaped index wheel mounted on the rotation shaft and an index sensor which is a proximity sensor provided outside the flame member and used for detecting a position of the index wheel.

15. The apparatus of claim 1, wherein the fixed terminal has a recess with which the rotatable terminal is jointed.

16. The apparatus of claim 1, wherein the fixed terminal and the rotatable terminal contain tough pitch copper.