JPH11257496A - Flow passage structure of rotary coupling for fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a two-system fluid passage at the internal part of a rotary coupling without the occurrence of a trouble on the function of the rotary coupling to realize simplification of a device. SOLUTION: In a rotary coupling 101 for fluid, a seal member 31 descendingly energized relatively non-rotatably with a fixed joint body 1 and a seal support part 30 arranged at a rotary joint body 2 are brought into relative rotary contact, and a seal mechanism 3 for a fluid passage 3a in a seal and an external region is provided. This flow passage structure comprises a polishing liquid route A formed such that the passage 3a in the seal mechanism 3 and passages 60 and 61 formed in two joint bodies 1 and 2 are intercommunicated, a pressure air route B consisting of a passage 70 on the input side on the side of the fixed joint body 1, and a passage 71 on the take-out side of the second joint body 2, and a cooling liquid route C to cool the seal mechanism 3 by water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CMP (Kle) used for wafer polishing in a semiconductor manufacturing process.
medical-Mechanical Plishin
g) A flow path structure of a fluid rotary joint of a top ring in the apparatus.

[0002]

2. Description of the Related Art The above-described CMP apparatus, which is one method of planarization (a process of smoothing the surface with reference to the wafer surface), is applied to polishing of all kinds of materials.・ It is used to mean a device that performs a process.
The CMP apparatus has a structure including a mechanism for rotating the surface plate and a polishing head mechanism for rotating and pressing the wafer against a polishing pad laid on the surface of the surface plate, and a wafer supported on the upper surface of the rotating surface plate. Then, there is a polishing head mechanism having a polishing head mechanism provided with a polishing pad that is rotated by being pressed against the upper surface of the wafer.

As an example, as shown in FIG. 4, a rotary table 102 which rotates around a vertical axis, a pad support 103 which can move horizontally and vertically and move up and down, and a pad support 103 which rotates around the vertical axis. There is a CMP apparatus having a polishing pad 104 rotatably supported, and polishing the upper surface of a wafer 109 supported by a rotary table 102 with the polishing pad 104 moving forward and backward while rotating. The polishing pad 104 is supported by the pad support 103 via the rotary joint 101, and a slurry (a mixture of a liquid such as a chemical agent and particles = polishing liquid) supplied from the support pad side passes through the passage of the polishing pad 104. Through the rotary joint 101 to feed the wafer through
08 is provided.

[0004] As shown in FIG.
Reference numeral 1 denotes a fluid passage 60 formed in the first joint body 1 on the fixed side and a fluid passage 61 formed in the second joint body on the rotating side.
Air for pressing and removing the wafer by air pressure from a single fluid passage 61 provided on the rotation axis Q is arranged so that it is relatively rotatable by being arranged on the upper side. Alternatively, it has been configured to pass a polishing liquid or the like.

[0005]

However, at the time of actual wafer polishing, both of the polishing liquid and the pressurized air for widely dispersing the polishing liquid on the wafer surface while flowing the polishing liquid between the wafer and the polishing pad. Since it is necessary, equipment to supply pressurized air or polishing liquid to the polishing location is required separately,
There has been a tendency for the CMP apparatus to be complicated. SUMMARY OF THE INVENTION An object of the present invention is to form two fluid passages inside a rotary joint without impairing the function of the rotary joint in order to simplify the apparatus.

[0006]

According to a first aspect of the present invention, a first joint body on a fixed side and a second joint body on a rotating side are connected so as to be relatively rotatable and relatively immovable in the direction of the rotation axis. In the fluid rotary joint flow path structure, a seal mechanism in which one of the two joint bodies cannot rotate relative to the other, and contacts the other while rotating relative to each other, and has a passage formed therein along the rotation axis. And a polishing liquid path formed by communicating the passage of the seal mechanism with the passage formed in each of the joint bodies, and the second joint body in a state of being fitted inside the outer cylindrical portion of the first joint body. , And an air path comprising an intake side passage formed in the outer cylinder portion in an arrangement state communicating with the extraction side passage.

According to a second aspect of the present invention, in the first aspect, one of the two joint bodies is provided with a seal member which is not rotatable relative to the joint body, is relatively movable in the direction of the axis of rotation, and has a passage. A seal mechanism that is provided with a seal receiving portion that is capable of contacting with the seal member while rotating relative to the seal member and that has a passage, and that presses and biases the seal member toward the seal receiving portion. An outer region of the seal mechanism formed by the two joint bodies, and a coolant passage for supplying and discharging a seal coolant formed in the first joint body in a state of being communicated with the outer region. And

According to the structure of the first aspect, both the polishing liquid path and the air path are provided in the rotary joint, and both the polishing liquid necessary for polishing the wafer and the pressurized air for dispersing the polishing liquid are provided. Since the supply can be performed through a single rotary joint, it is not necessary to separately provide a polishing liquid or pressurized air supply device as in the related art, and the structure can be simplified accordingly.

In addition, a polishing liquid, which is disadvantageous to air in terms of abrasion of the seal portion due to sliding contact, flows through a passage penetrating the inside of the seal mechanism along the axis of rotation. When the polishing liquid flows through the joint outer cylinder part where the effect of the joint is reduced and the centrifugal force acts greatly, that is, the path (air path referred to in claim 1) on the side of the joint where the two joint bodies are in contact with each other on the peripheral surface. Is more advantageous in terms of sealing properties and durability.

According to the second aspect of the present invention, the sealing mechanism is
The seal member provided on one joint body has a mechanical seal structure that presses and urges the seal receiving section provided on the other joint body so as to be relatively rotatable. Can be brought into strong pressure contact, and an effective sealing function can be exhibited even under a high load. Since the seal member is pressed and urged by the urging mechanism, the seal member can be continuously used even if the seal portion is slightly worn, so that the continuous use time of the seal can be extended and the durability can be improved.

Since the seal mechanism can be externally cooled by the cooling liquid flowing through the cooling liquid path, frictional heat due to a strong contact pressure between the seal member and the seal receiving portion can be easily removed by the cooling liquid, and the overheating can be achieved. Disadvantages such as roughening of the sealing surface and deterioration of the sealing function can be prevented, and sufficient durability can be obtained. Also, since the cooling fluid path for that is formed in the rotary joint without preparing separately,
The above-described effective operation of “simplification of the structure” can be obtained as it is.

[0012]

According to the channel structure according to claim 1 or 2,
It is possible to form two passages for the polishing liquid and the air in the rotary joint, so that an effective polishing operation of the wafer can be obtained without causing a complicated structure, and a fluid rotary joint suitable for a CMP apparatus is provided. We were able to.

[0013] In the flow path structure of the fluid rotary joint according to the second aspect, a high-performance sealing mechanism suitable for flowing the polishing liquid,
By forming the coolant passage inside the joint, the continuous use time is increased without complicating the apparatus, and there is an advantage that the durability is excellent.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 and FIG.
A model of a CMP apparatus for performing the surface polishing of No. 09 is shown. The CMP apparatus includes a rotary table 102 that is driven and rotated around a vertical rotation axis P, a pad support 103 that moves horizontally (reciprocates), and a polishing pad that is driven and rotated while being supported by the pad support 103. 104, a supply / discharge path 105 formed in the pad support 103, a supply / discharge mechanism 107 for the polishing liquid 106 connected to the supply / discharge path 105,
The polishing pad 104 is provided with a supply / discharge path 108 formed in the polishing pad 104 so as to penetrate the rotation axis P and open downward at the center of the pad portion 104a at the lower end. In addition, polishing liquid 1
As an example of 06, a slurry obtained by adding isopropyl alcohol to a silica slurry containing KOH as an alkaline component can be given.

Also, in order to blow down the pressurized air from the pressurizing device 6 such as an air pump from the pad portion 104a,
The air passages 105 and 108B formed in the pad support 103 and the polishing pad 104 are configured to pass therethrough.
Then, in order to support the polishing pad 104 on the pad support 103 so as to be rotatable around the vertical rotation axis Q, the polishing pad 104 is interposed between the two, 104 and 103, and the supply and discharge passages 105 and 108, And both air paths 105a, 108
A rotary joint (rotary joint) 101 is provided for connecting the respective parts a so as to be relatively rotatable.

According to this CMP apparatus, first, the silicon wafer 109 is placed and held on the rotary table 102 such that the wafer surface 109a is on the top, and then the polishing pad 1
04, the pad portion 104a at the lower end is
Lower until it contacts 9a. Next, the positive pressure operation of the supply / discharge mechanism 107 (discharge operation of the polishing pump) causes the pad unit 1 to operate.
Polishing liquid (slurry) 106 between wafer 04 and wafer 109
And the pressurized air 106a, while the polishing pad 10
The wafer surface 109a is polished by reciprocating forward and backward while rotating the wafer 4.

The pad 104a has a pressurized air 106a
Are formed, and the pressurized air 106 jetted from the air path B is formed.
As a result, the polishing liquid 106 jetted between the pad portion 104a and the wafer 109 can be quickly and uniformly dispersed, and the residual polishing liquid can be quickly removed from between the two. After the polishing is completed, the supply / discharge mechanism 107 is switched to a negative pressure operation (a suction operation of the polishing pump), and the polishing liquid 106 remaining in the supply / discharge paths 105 and 108 is suctioned and discharged so as not to drop on the wafer surface 109a. It is.

Next, the rotary joint 101 will be described.
As shown in FIG. 1, a fixed-side first joint body 1 attached to a pad support 103, a rotating-side second joint body 2 attached to a polishing pad 104, and an interposition between the joint bodies 1 and 2. First to third sealing mechanisms 3, 4,
The rotary joint 101 is composed of the polishing liquid path A, the air path B, and the like extending over the joint body 1 and the joint bodies 1 and 2.

The first joint body 1 includes upper and lower cylindrical portions 10.
a and 10c, and a cylindrical side wall 10 composed of an intermediate cylinder 10b interposed between the cylindrical portions 10b and 10c, and a disk-shaped end wall 11, and the side wall 10 Is
It is formed of a metal material such as stainless steel (SUS304). Since the fluid passages 60 through which the polishing liquid 106 flows are formed in the end wall 11, PEEK (excellent in dimensional stability and heat resistance by processing without generating particles due to contact of abrasive grains) is provided. PES or PC may be used)
And other plastics for mechanical parts.

The second joint body 2 has a cylindrical main body 2.
0, a holding portion 21 formed at an upper end thereof, a disk-shaped flange portion 22 formed at a lower end of the main body 20,
The main body 20 includes a cylindrical lid 23 that is externally fitted to the main body 20, and portions other than the lid 23 are integrally formed.
Since the fluid passage 61 through which the polishing liquid 106 flows is formed in the second joint body 2, like the end wall 11, portions other than the lid 23 are formed of plastic for mechanical parts such as PEEK. The lid 23 is made of a metal material such as stainless steel.

The second joint body 2 is rotatably fitted in the first joint body 1 by interposing a bearing 13 between the lower end portion of the end wall 11 and the lid portion 23, and has a flange portion 23. Only the first joint body 1 is configured to be exposed to the outside.

The first seal mechanism 3 includes the first joint body 1
A seal member 31 which is not rotatable relative thereto and is relatively movable in the direction of the rotation axis Q;
A seal receiving portion 30 provided on the second joint body 2 in a state where the seal receiving portion 30 can be brought into contact with the second joint body 2 while rotating relative to the first joint member 1.
Mechanism 3 for stopping the rotation of the first joint body 1 with respect to the first joint body 1
2 and an urging mechanism 33 for urging the seal member 31 toward the seal receiving portion 30.

The seal receiving portion 30 has an annular main body portion 30.
a and a silicon-made fixing portion 30 b made of silicon carbide, and the fixing portion 30 b is externally fitted to the holding portion 21 of the second joint body 2. The upper surface of the main body 30a is formed as a smooth seal surface 30c suitable for contact with the seal member 31. The fitting portion between the fixing portion 30b and the holding portion 21 is secondarily sealed by the O-ring 24. A fluid passage 30d communicating with the fluid passage 61 is formed on the rotation axis Q inside the fixed portion 30b.

The sealing member 31 has an annular main body 31a.
And a cylindrical holding portion 31b having a smaller diameter than the above. The holding portion 31b is fitted in a holding hole 11a formed in the end wall 11 so that the holding portion 31b is fitted in the direction of the rotation axis Q. It is slidably supported. The holding hole 11a and the holding portion 31b are secondarily sealed by an O-ring 14. The outer periphery of the main body portion 31a has a tapered surface of
In addition, the inner peripheral surface is formed on a downwardly expanding tapered surface, respectively, and forms a pointed seal portion 31c concentrically annularly in contact with the seal surface 30c of the seal receiving portion 30. . A fluid passage 3 a communicating with the fluid passage 60 is formed on the rotation axis Q inside the seal member 31.

The locking mechanism 32 has a locking pin 32a protruding downward from a low surface portion of the end wall 11, which is an outer peripheral region of the holding hole 11a, and seals an engaging recess 32b into which the locking pin 32a enters. The sealing member 31 is formed on the main body 31a of the member 31, and the sealing member 31 is moved in the direction of the rotation axis Q with respect to the first joint body 1 by engaging the locking pin 32a with the engaging recess 32b. And, and
Relative rotation is disabled.

The biasing mechanism 33 includes a plurality of winding springs 33a interposed between the upper end of the main body 31a of the seal member 31 and the lower end of the end wall 11 opposed thereto. , The sealing member 31 is urged downward to
This is to make a zero-contact.

With the above configuration, the first seal mechanism 3 exhibits the same sealing performance as the mechanical seal of the end face contact type, and the inside of the seal face 30c and the seal portion 31c accompanying the rotation of the second joint pair 2. A good seal is provided between the area 3a and the outer area 3b. The dimensions of each part are set such that the good sealing function is maintained even when the polishing liquid path A is switched to the negative pressure or the dry mode.

The second and third seal mechanisms 4 and 5 shown in FIGS. 1 to 3 have basically the same structure, and have a lid 23 which is an outer peripheral portion of the second joint pair 2 and an intermediate cylinder of the joint body 1. 10b and are mounted in parallel along the rotation axis Q direction. The second sealing mechanism 4 includes a side wall 10 and a lid 23.
Since the lower end of the outer region 3b of the first seal mechanism 3 is sealed, the outer region 3b is configured as a cooling liquid path 3a to be described later. is there. The third sealing mechanism 5 seals the air path B. Next, the structure of the second seal mechanism 4 will be described. still,
Reference numerals in parentheses indicate those of the third seal mechanism 5.

As shown in FIGS. 1 to 3, a stationary ring 43 (53) fixedly held inside by an O-ring 42 (52) on the inner periphery of the side end portion 10 and an O Ring 44 (5
4) a rotary seal ring 45 (55) held movably in the direction of the rotation axis Q via the spring retainer 46 fixed to the lid 23, and a disc spring 47 (57). Due to the relative rotational sliding action of the sealing rings 43 (53) and 45 (55), the outer regions 4 of the second and third sealing mechanisms 4 and 5 are formed.
a and the coolant passage 3a, and the outer region 4a
Seal with the lower end.

The rotary seal ring 45 (55) is engaged with the engagement protrusion 46a of the spring retainer 46 in an engagement groove 45a (55a) formed on the outer periphery thereof, so that the rotation seal ring 45 (55) can freely rotate in the rotation axis Q direction. And it is held by the second joint body 2 so as not to rotate relatively. Thus, the cooling water (an example of the cooling liquid) 8 discharged from the water cooling mechanism 15 such as a water pump and supplied from the supply hole 11b formed in the side wall 11 of the first joint body 1 is supplied to the outer region. 3b, the liquid is discharged from a not-shown discharge hole (the same one as the supply hole 11b is provided on the opposite side) through a cooling liquid path C,
The first seal mechanism 3 can be cooled from the outside.

The compressed air 10 from the pressurizing device 6
6a can be ejected downward from the flange portion 22 through the air path B including the passage 70, the outer region 4a, the opening passage 71d, the annular passage 71a, the communication passage 71c, and the annular passage 71b of the intermediate cylinder 10b. . The polishing liquid 106 from the supply / discharge mechanism 107 is ejected downward from the flange portion 22 through the polishing liquid path A including the fluid passage 60, the fluid passage 3a, the fluid passage 30d, and the fluid passage 61. Can be.

As described above, the rotary joint 101 includes the polishing liquid path A through which the polishing liquid 106 passes, the air path B through which pressurized air passes, and the cooling liquid path C through which the cooling water of the first seal mechanism 3 passes. Three paths are formed, and the structure as a CMP apparatus can be simplified as compared with the conventional case where the polishing liquid path A or the air path B is separately provided.
Compactness is also possible.

The present invention can be applied to a rotary joint 101 having no coolant path C for the first seal mechanism 3 and a simple structure such as an O-ring for the first seal mechanism 3.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure of a rotary joint.

FIG. 2 is an enlarged sectional view showing a structure of a first seal mechanism.

FIG. 3 is an enlarged cross-sectional view showing a structure of a second and third seal mechanisms.

FIG. 4 is a principle view schematically showing a CMP apparatus.

FIG. 5 is an operation diagram showing a state in which a polishing liquid and pressurized air are supplied to a wafer.

FIG. 6 is a sectional view showing a main part of a conventional rotary joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st joint body 2 2nd joint body 3 Seal mechanism 3a, 30d Passage 3b External area 10b Outer cylinder part 30 Seal receiving part 31 Seal member 33 Energizing mechanism 60, 61 Passage 70 Intake passage 71 Extraction passage A polishing liquid Route B Air route C Coolant route

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[Procedure amendment]

[Submission date] March 11, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Flow path structure of rotary joint for fluid

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CMP (Cheap) used in wafer polishing in a semiconductor manufacturing process.
mechanical-Mechanical Polish
g) A flow path structure of a fluid rotary joint of a top ring in the apparatus.

[0002]

2. Description of the Related Art The above-described CMP apparatus, which is one method of planarization (a process of smoothing the surface with reference to the wafer surface), is applied to polishing of all kinds of materials.・ It is used to mean a device that performs a process.
The CMP apparatus has a structure including a mechanism for rotating the surface plate and a polishing head mechanism for rotating and pressing the wafer against a polishing pad laid on the surface of the surface plate, and a wafer supported on the upper surface of the rotating surface plate. Then, there is a polishing head mechanism having a polishing head mechanism provided with a polishing pad that is rotated by being pressed against the upper surface of the wafer.

As an example, as shown in FIG. 4, a rotary table 102 which rotates around a vertical axis, a pad support 103 which can move horizontally and vertically and move up and down, and a pad support 103 which rotates around the vertical axis. There is a CMP apparatus having a polishing pad 104 rotatably supported, and polishing the upper surface of a wafer 109 supported by a rotary table 102 with the polishing pad 104 moving forward and backward while rotating. The polishing pad 104 is supported by the pad support 103 via the rotary joint 101, and a slurry (a mixture of a liquid such as a chemical agent and particles = polishing liquid) supplied from the support pad side passes through the passage of the polishing pad 104. A slurry passage 108 is provided in the rotary joint 101 so that the slurry is supplied to the wafer through the rotary joint 101.

[0004] As shown in FIG.
Reference numeral 1 denotes a fluid passage 60 formed in the first joint body 1 on the fixed side and a fluid passage 61 formed in the second joint body on the rotating side.
Air for pressing and removing the wafer by air pressure from a single fluid passage 61 provided on the rotation axis Q is arranged so that it is relatively rotatable by being arranged on the upper side. Alternatively, it has been configured to pass a polishing liquid or the like.

[0005]

However, at the time of actual wafer polishing, both of the polishing liquid and the pressurized air for widely dispersing the polishing liquid on the wafer surface while flowing the polishing liquid between the wafer and the polishing pad. Since it is necessary, equipment to supply pressurized air or polishing liquid to the polishing location is required separately,
There has been a tendency for the CMP apparatus to be complicated. SUMMARY OF THE INVENTION An object of the present invention is to form two fluid passages inside a rotary joint without impairing the function of the rotary joint in order to simplify the apparatus.

[0006]

A fluid rotary joint according to the present invention is a fluid rotary joint used in a chemical mechanical polishing apparatus, comprising: a fixed-side first joint body; A polishing liquid path for passing the polishing liquid and an air path for passing the pressurized air are respectively formed in the second joint body rotatably fitted in the first joint body, and the polishing liquid paths of both joint bodies are formed. While communicating with each other through a seal mechanism provided on the rotation axis, each air path of both joint bodies is provided via a seal mechanism provided between the inner peripheral surface of the first joint body and the outer peripheral surface of the second joint body. A seal member that is not rotatable relative to one joint body and is relatively movable in the direction of the rotation axis, and the seal member is provided in the other joint body. And a cooling liquid supply hole, which is formed by a mechanical seal mechanism having a biasing mechanism for pressing and biasing toward the socket receiving portion, and which communicates with the first joint body from an outer surface thereof to a space between the two seal mechanisms. And a discharge hole is formed to form a coolant passage.

[0007] According to the above configuration, both the polishing liquid path and the air path are provided in the rotary joint, and both the polishing liquid necessary for polishing the wafer and the pressurized air for dispersing the polishing liquid are provided in a single unit. Since the supply can be performed via the rotary joint, it is not necessary to separately provide a polishing liquid or pressurized air supply device as in the related art, and the structure can be simplified accordingly.

In addition, since the polishing liquid, which is disadvantageous to air in terms of abrasion of the seal portion due to sliding contact, flows through the seal mechanism along the axis of rotation, the influence of centrifugal force due to rotation is small. In comparison with the case where the polishing liquid is caused to flow through a joint outer cylinder portion where a large centrifugal force acts, that is, a path (air path referred to in claim 1) on a joint side where the two joint bodies contact each other on the peripheral surface. It is advantageous in sealing performance and its durability.

Further, since the seal mechanism has a mechanical seal structure, the sealing member and the seal receiving portion can be brought into contact with each other with a strong pressure by the urging mechanism, so that an effective sealing function can be exhibited even under a high load. become. Since the seal member is pressed and urged by the urging mechanism, the seal member can be continuously used even if the seal portion is slightly worn, so that the continuous use time of the seal can be extended and the durability can be improved.

[0010] Since the seal mechanism can be externally cooled by the cooling liquid flowing through the cooling liquid path, frictional heat due to strong contact pressure between the seal member and the seal receiving portion can be easily removed by the cooling liquid, and the overheating can be achieved. Disadvantages such as roughening of the sealing surface and deterioration of the sealing function can be prevented, and sufficient durability can be obtained. Also, since the cooling fluid path for that is formed in the rotary joint without preparing separately,
The above-described effective operation of “simplification of the structure” can be obtained as it is.

[0011]

According to the flow path structure of the present invention, two paths for the polishing liquid and the air can be formed in the rotary joint, and an effective polishing operation of the wafer can be obtained without complicating the structure. As a result, a fluid rotary joint suitable for a CMP apparatus could be provided.

Further, by providing a high-performance sealing mechanism suitable for the flow of the polishing liquid and forming the cooling liquid passage inside the joint, the continuous use time can be increased without complicating the apparatus, and the durability is improved. There are excellent advantages.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 and FIG.
A model of a CMP apparatus for performing the surface polishing of No. 09 is shown. The CMP apparatus includes a rotary table 102 that is driven and rotated around a vertical rotation axis P, a pad support 103 that moves horizontally (reciprocates), and a polishing pad that is driven and rotated while being supported by the pad support 103. 104, a supply / discharge path 105 formed in the pad support 103, a supply / discharge mechanism 107 for the polishing liquid 106 connected to the supply / discharge path 105,
The polishing pad 104 is provided with a supply / discharge path 108 formed in the polishing pad 104 so as to penetrate the rotation axis P and open downward at the center of the pad portion 104a at the lower end. In addition, polishing liquid 1
As an example of 06, a slurry obtained by adding isopropyl alcohol to a silica slurry containing KOH as an alkaline component can be given.

Further, in order to blow down the pressurized air from the pressurizing device 6 such as an air pump from the pad portion 104a,
It is configured to pass through an air path B formed in the pad support 103 and the polishing pad 104. Then, in order to support the polishing pad 104 on the pad support 103 so as to be rotatable about the vertical rotation axis Q,
4, 103, and both supply and discharge paths 105, 1
08 and a rotary joint (rotary joint) 101 for communicating and connecting the air path B so as to be relatively rotatable.

According to this CMP apparatus, first, the silicon wafer 109 is placed and held on the turntable 102 such that the wafer surface 109a is on the top, and then the polishing pad 1
04, the pad portion 104a at the lower end is
Lower until it contacts 9a. Next, the supply / discharge mechanism 107
Of the polishing liquid (slurry) 10 between the pad portion 104a and the wafer 109 by the positive pressure operation (discharge operation of the polishing pump).
6 and the pressurized air 106a,
The wafer surface 109a is polished by reciprocating forward and backward while rotating the wafer 04.

The pad 104a has a pressurized air 106a
Are formed. A plurality of air paths 108a for ejecting the polishing liquid are formed, and the polishing liquid 106 ejected between the pad portion 104a and the wafer 109 is quickly and uniformly dispersed by the pressurized air 106a ejected from the air paths 108a. At the same time, the polishing residual liquid can be quickly removed from between the both 104a and 109. After the polishing is completed, the supply / discharge mechanism 107 is switched to a negative pressure operation (a suction operation of the polishing pump), and the polishing liquid 106 remaining in the supply / discharge paths 105 and 108 is suctioned and discharged so as not to drop on the wafer surface 109a. It is.

Next, the rotary joint 101 will be described.
As shown in FIG. 1, a fixed-side first joint body 1 attached to a pad support 103, a rotating-side second joint body 2 attached to a polishing pad 104, and an interposition between the joint bodies 1 and 2. First to third sealing mechanisms 3, 4,
The rotary joint 101 is composed of the polishing liquid path A, the air path B, and the like extending over the joint body 1 and the joint bodies 1 and 2.

The first joint body 1 includes upper and lower cylindrical portions 10.
a and 10c, and a cylindrical side wall 10 composed of an intermediate cylinder 10b interposed between the cylindrical parts 10a and 10c, and a disk-shaped end wall 11; Is
It is formed of a metal material such as stainless steel (SUS304). Since the fluid passages 60 through which the polishing liquid 106 flows are formed in the end wall 11, PEEK (excellent in dimensional stability and heat resistance by processing without generating particles due to contact of abrasive grains) is provided. PES or PC may be used)
And other plastics for mechanical parts.

The second joint body 2 has a cylindrical main body 2.
0, a holding portion 21 formed at an upper end thereof, a disk-shaped flange portion 22 formed at a lower end of the main body 20,
The main body 20 includes a cylindrical lid 23 that is externally fitted to the main body 20, and portions other than the lid 23 are integrally formed.
Since the fluid passage 61 through which the polishing liquid 106 flows is formed in the second joint body 2, like the end wall 11, portions other than the lid 23 are formed of plastic for mechanical parts such as PEEK. The lid 23 is made of a metal material such as stainless steel.

The second joint body 2 is rotatably fitted in the first joint body 1 by interposing a bearing 13 between the lower end portions of the side wall 10 and the lid 23, and has a flange portion. Only the structure 22 is exposed from the first joint body 1 to the outside.

The first seal mechanism 3 includes a first joint body 1
A seal member 31 which is not rotatable relative thereto and is relatively movable in the direction of the rotation axis Q;
A seal receiving portion 30 provided on the second joint body 2 in a state where the seal receiving portion 30 can be brought into contact with the second joint body 2 while rotating relative to the first joint member 1.
Mechanism 3 for stopping the rotation of the first joint body 1 with respect to the first joint body 1
2 and an urging mechanism 33 for urging the seal member 31 toward the seal receiving portion 30.

The seal receiving portion 30 has an annular main body portion 30.
a, and a fixed portion 30 b on a cylinder, which is made of silicon carbide, and the fixed portion 30 b is externally fitted to the holding portion 21 of the second joint body 2. The upper surface of the main body 30a is formed as a smooth seal surface 30c suitable for contact with the seal member 31. The fitting portion between the fixing portion 30b and the holding portion 21 is secondarily sealed by the O-ring 24. A fluid passage 30d communicating with the fluid passage 61 is formed on the rotation axis Q inside the fixed portion 30b.

The seal member 31 has an annular main body 31a.
And a holding portion 31b on a cylinder having a smaller diameter than the above, and is made of silicon carbide. By fitting the holding portion 31b into a holding hole 11a formed in the end wall 11, it is possible to move the holding portion 31b in the rotation axis Q direction. It is slidably supported. The holding hole 11a and the holding portion 31b are secondarily sealed by an O-ring 14. The outer periphery of the main body portion 31a has a tapered surface of
In addition, the inner peripheral surface is formed on a downwardly expanding tapered surface, respectively, and forms a pointed seal portion 31c concentrically annularly in contact with the seal surface 30c of the seal receiving portion 30. . A fluid passage 3 a communicating with the fluid passage 60 is formed on the rotation axis Q inside the seal member 31.

The locking mechanism 32 has a locking pin 32a protruding downward from the bottom surface of the end wall 11, which is an outer peripheral area of the holding hole 11a, and seals an engaging recess 32b into which the locking pin 32a enters. The sealing member 31 is formed on the main body 31a of the member 31, and the sealing member 31 is moved in the direction of the rotation axis Q with respect to the first joint body 1 by engaging the locking pin 32a with the engaging recess 32b. And, and
Relative rotation is disabled.

The biasing mechanism 33 includes a plurality of winding springs 33a interposed between the upper end of the main body 31a of the seal member 31 and the lower end of the end wall 11 opposed thereto. , The sealing member 31 is urged downward to
This is to make a zero-contact.

With the above configuration, the first seal mechanism 3 exhibits the same sealing performance as the mechanical seal of the end face contact type, and the inside of the seal surface 30c and the seal portion 31c accompanying the rotation of the second joint body 2. A good seal is provided between the area 3a and the outer area 3b. The dimensions of each part are set such that the good sealing function is maintained even when the polishing liquid path A is switched to the negative pressure or the dry mode.

The second and third seal mechanisms 4 and 5 shown in FIGS. 1 to 3 have basically the same structure, and the lid 23 which is the outer peripheral portion of the second joint body 2 and the first joint body 1 have the same structure. It is provided in parallel with the intermediate cylinder 10b along the rotation axis Q direction. The second sealing mechanism 4 includes a side wall 10 and a lid 2.
3 is an end face contact type mechanical seal interposed between
Since the lower end of the outer region 3b of the first seal mechanism 3 is sealed, the outer region 3b is thereby configured as a cooling liquid path described later. The third sealing mechanism 5 seals the air path B. Next, the structure of the second seal mechanism 4 will be described. The reference numerals in parentheses indicate those of the third seal mechanism 5.

As shown in FIGS. 1 to 3, a stationary ring 43 (53) fixedly held on an inner fitting via an O-ring 42 (52) on the inner periphery of the side wall 10 and an O Ring 44 (5
The stationary ring includes a rotary seal ring 45 (55) held movably in the direction of the rotation axis Q via the component 4), a spring retainer 46 fixed to the lid 23, and a disc spring 47 (57). By the relative rotational sliding action between the rotary seal 43 (53) and the rotary seal ring 45 (55), the seal between the outer region 4a of the second and third seal mechanisms 4, 5 and the coolant path 3b, and the lower end of the outer region 4a. And seal.

The rotary seal ring 45 (55) is engaged with the engaging projection 46a of the spring retainer 46 in an engaging groove 45a (55a) formed on the outer periphery thereof, so that the rotary seal ring 45 (55) can freely rotate in the rotation axis Q direction. And it is held by the second joint body 2 so as not to rotate relatively. Thus, the cooling water (an example of the cooling liquid) 8 discharged from the water cooling mechanism 15 such as a water pump and supplied from the supply hole 11b formed in the side wall 10 of the first joint body 1 is supplied to the outer region. 3b, the liquid is discharged from a not-shown discharge hole (the same one as the supply hole 11b is provided on the opposite side) through a cooling liquid path C,
The first seal mechanism 3 can be cooled from the outside.

The compressed air 10 from the pressurizing device 6
6a can be ejected downward from the flange portion 22 through the air path B including the passage 70, the outer region 4a, the opening passage 71d, the annular passage 71a, the communication passage 71c, and the annular passage 71b of the intermediate cylinder 10b. . The polishing liquid 106 from the supply / discharge mechanism 107 is ejected downward from the flange portion 22 through the polishing liquid path A including the fluid passage 60, the fluid passage 3a, the fluid passage 30d, and the fluid passage 61. Can be.

As described above, the rotary joint 101 has a polishing liquid path A through which the polishing liquid 106 passes, an air path B through which pressurized air passes, and a cooling liquid path C through which the cooling water of the first seal mechanism 3 passes. Three paths are formed, and the structure as a CMP apparatus can be simplified as compared with the conventional case where the polishing liquid path A or the air path B is separately provided.
Compactness is also possible.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure of a rotary joint.

FIG. 2 is an enlarged sectional view showing a structure of a first seal mechanism.

FIG. 3 is an enlarged cross-sectional view showing a structure of a second and third seal mechanisms.

FIG. 4 is a principle view schematically showing a CMP apparatus.

FIG. 5 is an operation diagram showing a state in which a polishing liquid and pressurized air are supplied to a wafer.

FIG. 6 is a sectional view showing a main part of a conventional rotary joint.

[Description of Signs] 1 First joint body 2 Second joint body 3 First seal mechanism 3a, 30d Fluid passage 3b Outer area 30 Seal receiver 31 Seal member 33 Urging mechanism 60, 61 Passage A Polishing liquid path B Air Route C Coolant route

Claims (2)

[Claims] 1. A flow path of a fluid rotary joint in which a first joint body on a fixed side and a second joint body on a rotating side are connected so as to be relatively rotatable and relatively immovable in a direction of a rotation axis. A seal mechanism in which one of the two joint bodies is not rotatable relative to the other, and is in contact with the other while relatively rotating, and a passage is formed therein along the rotation axis, A polishing liquid path formed by communicating a path of a mechanism with a path formed in each of the two joint bodies, and a polishing liquid path formed in the second joint body in a state of being fitted inside the outer cylindrical portion of the first joint body. A flow path structure for a fluid rotary joint, comprising: a take-out side passage formed in the outer cylinder portion; and an air path formed by the take-out side passage formed in the outer cylindrical portion in a state of communication with the take-out side passage. 2. One of the two joint bodies includes a seal member that is not rotatable relative to the joint member and is relatively movable in the direction of the rotation axis, and includes the passage. The seal mechanism comprises a seal receiving portion provided with a seal receiving portion provided with the passage, and a pressing member for pressing the seal member toward the seal receiving portion. An outer region of the seal mechanism formed by the two joint bodies; and a coolant passage for supplying and discharging a seal coolant formed in the first joint body in a state of being communicated with the outer region. The flow path structure of the fluid rotary joint according to claim 1.