JP2000052239A - Wafer polishing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently assure a space required for tool operation above a head body; and to easily rotates and operates a tool without projecting a locking part for holding a carrier to above the head body. SOLUTION: A locking part 60 locking and unlocking with and from a carrier 38 is constituted not to project from the upper surface of a head body 32 at the engaging position and the removing position relative to the carrier 38. The result projects no locking part 60 for holding the carrier 38 to above the head body 32, sufficiently assuring a space required for tool operation above the head body 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a wafer polishing apparatus for polishing a surface of a semiconductor wafer or the like forming an integrated circuit.

[0002]

2. Description of the Related Art A wafer polishing apparatus of this type includes a disk-shaped platen having a polishing pad attached to a surface thereof, and a plurality of wafer polishing apparatuses for holding one surface of a wafer to be polished and bringing the other surface of the wafer into contact with the polishing pad. It is widely known to provide a wafer holding head and perform polishing by supplying a slurry containing abrasive grains between a polishing pad and a wafer while relatively moving these wafer holding heads and the platen. I have.

As one example, there is disclosed a wafer holding head adopting a floating head structure having an advantage that a contact pressure of a wafer against a polishing pad can be made uniform (see Japanese Patent No. 2597449).

As shown in FIG. 5, the wafer holding head includes a hollow head main body 1, a diaphragm 2 stretched horizontally in the head main body 1, and a carrier 3 fixed to the lower surface of the diaphragm 2. The carrier 3 is pressed downward by supplying pressurized air from a pressurized air source 6 through a shaft 5 to an air chamber 4 defined by the diaphragm 2.

[0005] A retainer ring 7 is arranged on the outer periphery of the carrier 3 so that the lower end protrudes below the carrier 3. The retainer ring 7 holds the outer periphery of the wafer attached to the lower surface of the carrier 3, and holds the wafer being polished. A trouble such as detachment from the carrier 3 is prevented.

Further, a fixing ring 8 for fixing the diaphragm 2 on the carrier 3 is mounted on the diaphragm 2, and a flange portion extending outward is formed at the upper end of the fixing ring 8. . A holding member 9 for holding the flange portion of the fixing ring 8 is attached to an upper portion of the head main body 1 in a state where the head main body 1 is inserted. The holding member 9 is screwed into an upper end thereof. The rotation of the nut 10 is adjusted so that the nut 10 can be moved up and down.

Further, a C-type washer 11 is mounted below the nuts 10 of the holding member 9. Then, by removing the C-shaped washer 11, the holding member 9 is lowered, and accordingly, the carrier 3 is lowered together with the fixing ring 8, so that the lower portion of the carrier 3 projects downward from the retainer ring 7, and the lower surface of the carrier 3 The mounted wafer bonding insert is exposed to facilitate replacement.

[0008]

In the conventional wafer holding head constructed as described above, when the head main body 1 is mounted on the shaft 5, a tool inserted into the central portion above the head main body 1 is used. When the is rotated, the upper end of the holding member 9 protrudes upward from the upper surface of the head main body 1, so that there is a problem that the upper end of the holding member 9 hinders the rotation operation of the tool.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to prevent a locking portion for holding a carrier from protruding above a head main body, and to operate a tool above a head main body. It is an object of the present invention to provide a wafer polishing apparatus which can sufficiently secure a space required for the wafer polishing and can easily rotate a tool.

[0010]

According to a first aspect of the present invention, a platen having a polishing pad adhered to a surface thereof and one surface of a wafer to be polished are held, and the other surface of the wafer is brought into contact with the polishing pad. A wafer polishing apparatus comprising one or two or more wafer holding heads, and polishing the other surface of the wafer with the polishing pad by a relative movement between the wafer holding head and the platen, wherein the wafer holding head comprises a head A retainer ring is provided inside the main body so as to be movable along its axis, and a carrier holding one surface of the wafer to be polished is provided inside the retainer ring so as to be movable along its axis, A locking portion for engaging and disengaging the carrier is provided on the head main body by vertically penetrating the head body, and the carrier of the locking portion is provided. In the engaged position and the disengaged position with the upper end of the locking portion is one that is configured so as not to protrude from the upper surface of at least the head body. According to the first aspect of the present invention, the locking portion engaging with and disengaging from the carrier is configured not to protrude from the upper surface of the head main body at the engagement position and the disengagement position with the carrier. Ensuring sufficient space to facilitate tool operation.

According to a second aspect of the present invention, the locking portion is provided on the head body so as to be rotatable around its axis, and a locking claw which engages with and disengages from the carrier is formed at a lower end portion of the locking portion. In addition, an overhang portion is formed at the upper end of the locking portion so as to fit into a recess formed on the upper surface of the head main body. According to the second aspect, by rotating the locking portion about its axis, the locking claw at the lower end portion of the locking portion is engaged with and disengaged from the carrier, and the upper end portion of the locking portion is rotated. By fitting the overhanging portion into the recess on the upper surface of the head main body, the locking portion is prevented from protruding above the head main body.

According to a third aspect of the present invention, when the engaging portion is engaged with and disengaged from the carrier, the projecting portion of the engaging portion is fitted into the recess of the head body. Things. According to the third aspect, when performing the engagement / disengagement operation between the locking portion and the carrier, the projecting portion of the locking portion fitted to the recess on the upper surface of the head main body is pulled up from the recess, The locking portion is rotated about its axis to engage and disengage the locking claw of the locking portion with the carrier, and then the protrusion of the locking portion is fitted into the recess of the head body again.

According to a fourth aspect of the present invention, a direction indicator is provided on the overhanging portion to indicate the direction of the locking claw. According to the fourth aspect, the position of the locking claw of the locking portion is grasped from above the head main body by the overhanging portion provided with the direction indicating portion indicating the direction of the locking claw, and the locking portion and the carrier are connected to each other. Is surely visually confirmed.

[0014]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG. First, the overall configuration will be briefly described with reference to FIGS. In these figures, reference numeral 21 denotes a base, and a disk-shaped platen 22 is horizontally installed at the center of the base 21. The platen 22 is rotated about an axis by a platen drive mechanism (not shown) provided in the base 21, and a polishing pad 23 is attached to the entire upper surface thereof.

Above the platen 22, a plurality of columns 24
The upper mounting plate 25 is installed horizontally via the. A disk-shaped carousel 26 is provided on the lower surface of the upper mounting plate 25. This carousel 26 is
A carousel driving mechanism (not shown) provided on the upper side rotates the lens about an axis. On its lower surface, a total of six wafer holding heads 3 facing the platen 22 are provided.
0 is provided.

These wafer holding heads 30 are shown in FIG.
As shown in FIG. 2, the carousel 26 is arranged at every 60 degrees around the center axis of the carousel 26 at the same distance from the center of the carousel 26, and is rotated in the circumferential direction by a head driving mechanism (not shown). To rotate the planet. The number of the wafer holding heads 30 is not limited to six, and may be 1 to 5
Or seven or more groups.

Next, a wafer holding head 30 according to the present embodiment will be described with reference to FIGS. The wafer holding head 30 has a hollow head main body 32 whose axis is vertically arranged and whose lower end is opened, a first diaphragm 34 and a second diaphragm 36 stretched inside the head main body 32, It has a disc-shaped carrier 38 fixed to the lower surface of one diaphragm 34 and a retainer ring 40 arranged concentrically on the outer periphery of the carrier 38.

The head main body 32 has a disk-shaped top plate 3.
20; a cylindrical peripheral wall portion 321 fixed to the outer periphery of the top plate portion 320; and an adapter 322 attached to the center of the top plate portion 320. The adapter 322 is attached to the shaft of the carousel 26. And are mounted coaxially. The inner peripheral surface of the peripheral wall portion 321 has a mounting portion 323 of an annular step portion projecting radially inward over the entire circumference.
Are formed.

The carrier 38 is formed of a material having high rigidity such as ceramic and has a constant thickness.
No elastic deformation. The retainer ring 40 has a flat annular shape at the lower end surface, is arranged concentrically with a small clearance between the retainer ring 40 and the outer peripheral surface of the carrier 38, and can be vertically displaced independently of the carrier 38.

A retainer 400 is formed on the outer peripheral edge of the upper end of the retainer ring 40 so as to protrude outward in the radial direction. When the wafer retaining head 30 is lifted up from the platen 22 together with the carousel 26, the retainer 400 is provided. 40
0 is held by an annular stopper portion 324 at the lower end of the peripheral wall portion 321. The stopper 324
Is formed so as to protrude radially inward from the lower peripheral edge of the peripheral wall portion 321 and to abut on the outer periphery of the retainer ring 40 or to surround the retainer ring 40 with a slight clearance.

On the upper surface of the carrier 38, the inner edge of the first diaphragm 34 is arranged along the same axis, and on the upper surface of the retainer ring 40, the outer edge of the first diaphragm 34 is arranged. ing. On the upper surface of the inner edge portion of the first diaphragm 34, a first fixing ring 42 is disposed coaxially, and the first fixing ring 42
The first diaphragm 34 is fixed to the carrier 38 while holding the first diaphragm 34 by a number of bolts 44 penetrating the first fixing ring 42 and the first diaphragm 34.

A bottomed cylindrical stopper 46 having a flange 460 at the upper end is provided at a plurality of predetermined positions on the upper surface of the first fixing ring 42 at a plurality of predetermined positions among the mounting portions of the respective bolts 44. It is fixed by bolts 44.
On the upper surface of the outer edge of the first diaphragm 34, a connecting ring 48 is disposed along the same axis, and on the upper surface of the connecting ring 48, the inner edge of the second diaphragm 36 is disposed. .

On the upper surface of the inner edge portion of the second diaphragm 36, a second fixing ring 50
The second fixing ring 50 includes a first diaphragm 34, a connecting ring 48, and a second diaphragm 36.
And a plurality of bolts 5 penetrating the second fixing ring 50
2, the first diaphragm 34 and the second diaphragm 36 are fixed to the retainer ring 40 while sandwiching the first diaphragm 34 and the second diaphragm 36, respectively.

Further, the outer edge of the second diaphragm 36 is placed on the mounting portion 323, and the second diaphragm 3
A third fixing ring 54 is arranged on the upper surface of the outer edge portion 6 along the same axis. The third fixing ring 54 is fixed to the mounting portion 323 while holding the second diaphragm 36 by a plurality of bolts 56 penetrating the second diaphragm 36 and the third fixing ring 54.

The first diaphragm 34 and the second diaphragm 36 are made of an elastic material such as various rubbers, so that the retainer ring 40 can be vertically displaced independently of the peripheral wall 321 of the head main body 32. In addition, the carrier 38 can be vertically displaced independently of the retainer ring 40. Top plate part 32 of the head main body 32
A plurality of stopper screws 58 are provided on the lower surface of the “0” so that the distal ends thereof are opposed to the second fixing ring 50 at predetermined intervals.

Further, the flange portion 4 of the stopper 46
An engaging portion 60 that engages with and disengages from the top 60 is provided to penetrate the top plate portion 320 of the head main body 32 vertically. The locking portion 60 is configured such that the columnar main body portion 600 is
A locking claw 601 that is rotatable around an axis and that can be moved up and down into a cylindrical bush 62 mounted on the main body 600 and that is engaged with and disengaged from the flange 460 of the stopper 46 at the lower end of the main body 600. The protruding portion 602 having a rectangular plate shape is provided on the upper end of the main body 600 so as to protrude outward in the radial direction of the main body 600.
The protrusions 602 are provided on the upper surface of the overhang portion 602 and protrude in the same direction as the locking claws 601. Arrows indicating the direction in which the locking claws 601 protrude. (Direction display section) 603 is formed. A substantially rectangular groove (recess) 621 for fitting the overhang portion 602 is formed on the upper surface of a disk-shaped flange 620 formed at the upper end of the bush 62.

On the other hand, the adapter 322 has a flow path 325.
Is formed, and a fluid chamber 64 defined by the head main body 32, the carrier 38, the first diaphragm 34, and the second diaphragm 36 is connected to a pressurizing means as a pressure adjusting mechanism through a flow path 325. The first pressure is adjusted by adjusting the fluid pressure in the fluid chamber 64 by the pressurizing means.
The diaphragm 34 and the second diaphragm 36 are vertically displaced, so that the pressing force of the carrier 38 on the polishing pad 23 changes. As the fluid, it is generally sufficient to use air, but other types of gas or liquid may be used as needed.

A fluid passage 326 for supplying pure water (cleaning liquid) is formed at the center of the adapter 322. Further, a fluid passage 380 is formed inside the carrier 38 from the center to the outer periphery thereof,
Between the fluid passage 380 and the lower surface of the carrier 38,
A small hole 381 is formed. A tube 66 is connected between the fluid passages 326 and 380.
Further, the retainer ring 40 and the peripheral wall portion 321 of the head main body 32 correspond to the fluid passage 380 of the carrier 38, and respectively correspond to the fluid passages 401 and 327.
Are formed.

In the wafer polishing apparatus configured as described above, when the wafer holding head 30 is separated from the platen 22 together with the carousel 26, the flange portion 460 of the stopper 46 locks the locking portion 60. Nail 60
1, the carrier 38 smoothly moves together with the head main body 32, and the holding portion 400 of the retaining ring 40
By engaging with 24, retainer ring 40 also moves smoothly with head body 32. Therefore, both the carrier 38 and the retainer ring 40 are securely held by the head main body 32.

On the other hand, when the wafer bonding insert (not shown) mounted on the lower surface of the carrier 38 is to be replaced, the locking portion 60 is pulled up and the projecting portion 602 of the locking portion 60 is formed into the groove 621. , And after half-turn, the overhang portion 602 is fitted into the groove portion 621 again.
As a result, the locking claw 601 of the locking portion 60 is
The carrier 38 is disengaged from the flange portion 460 and faces outward of the head main body 32, so that the engagement relationship with the head main body 32 is released. As a result, the wafer bonding insert mounted on the lower surface of the carrier 38 is
The wafer bonding insert can be easily replaced.

As described above, except for the case where the engaging portion 60 is engaged with and disengaged from the carrier 38, the engaging portion 60 is provided with the projecting portion 6 at the engaging position and the disengaging position with the carrier 38.
02 is fitted into the groove 621 without protruding upward from the upper surface of the head main body 32.
When attaching the wafer holding head 30 to the shaft of the carousel 26 or removing the wafer holding head 30 from the shaft, the engaging portion 60 does not hinder the operation of the tool, and the attaching or detaching operation can be completed smoothly.

Since the arrow 603 indicating the direction of the locking claw 601 is formed on the upper surface of the projecting portion 602, the locking claw 60 of the locking portion 60 is located from above the head body 32.
1 is grasped, and the engagement / disengagement relationship between the locking portion 60 and the carrier 38 is reliably visually confirmed.

[0033]

According to the first aspect of the present invention, a retainer ring is provided inside a head body so as to be movable along its axis, and a carrier holding one surface of a wafer to be polished is provided inside the retainer ring. The head body is provided movably along its axis, and the head body is provided with a locking portion that is engaged with and disengaged from the carrier. In the engagement position and the disengagement position, the upper end of the locking portion is configured so as not to protrude at least from the upper surface of the head main body. In the detached position, since the protrusion does not protrude from the upper surface of the head main body, the locking portion for holding the carrier does not protrude above the head main body and does not hinder the work. The space required for the tool operation can be sufficiently secured, it is possible to easily rotate the tool.

According to a second aspect of the present invention, the locking portion is provided on the head main body so as to be rotatable around its axis, and a locking claw which engages with and disengages from the carrier is formed at a lower end portion of the locking portion. At the same time, since an overhanging portion that fits into a recess formed on the upper surface of the head main body is formed at the upper end of the locking portion, the locking portion is rotated around its axis so that the locking portion is rotated. The engaging and disengaging operation of the locking claw at the lower end of the portion and the carrier can be easily performed, and the protrusion of the upper end of the locking portion is fitted into the recess on the upper surface of the head main body, so that the locking portion is formed. The protrusion above the head main body can be prevented, and a sufficient operation space can be secured above the head main body.

According to a third aspect of the present invention, when the engaging portion is engaged with and disengaged from the carrier, the projecting portion of the engaging portion is fitted into the recess of the head body. Therefore, when engaging and disengaging the locking portion and the carrier, the projecting portion of the locking portion fitted into the recess on the upper surface of the head main body is pulled up from this recess, and the locking portion is removed. After rotating around the axis to engage and disengage the locking claw of the locking portion and the carrier, the projecting portion of the locking portion is fitted into the recess of the head body again. Thus, the locking portion does not rotate around its axis except during the engagement / disengagement operation, and the engagement / disengagement relationship between the locking portion and the carrier can be easily maintained.

According to a fourth aspect of the present invention, since the direction indicating portion indicating the direction of the locking claw is provided on the overhanging portion,
An overhanging portion provided with a direction indicating portion indicating the direction of the locking claw allows the position of the locking claw of the locking portion to be grasped from above the head main body, so that the engagement / disengagement relationship between the locking portion and the carrier is internally determined. It is possible to confirm visually from outside without seeing.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a wafer holding head in one embodiment of a wafer polishing apparatus according to the present invention.

FIG. 2 is a plan view of a locking portion.

FIG. 3 is a front view showing the entire configuration of the device.

FIG. 4 is a plan view showing an arrangement state of a wafer holding head and a carousel of the apparatus.

FIG. 5 is a sectional view showing an example of a wafer holding head in a conventional wafer polishing apparatus.

[Explanation of symbols]

 22 Platen 23 Polishing Pad 30 Wafer Holding Head 32 Head Main Body 38 Carrier 40 Retainer Ring 60 Locking Section 601 Locking Claw 602 Overhanging Section 603 Arrow (Direction Displaying Section) 621 Groove (Concave Section)

Continued on the front page (72) Inventor Kazuo Iizuka 1-297 Kitabukuro-cho, Omiya-shi, Saitama Mitsubishi Materials Research Institute (72) Inventor Kenji Fujimoto 985 Ino-no-Ino, Ginya, Ikuno-cho, Asago-gun, Hyogo Prefecture 1 Mitsubishi Materials Corporation Ikuno Works (72) Inventor Hitoshi Adachi 985 Ino, Ginya, Ikuno-cho, Asago-gun, Hyogo Pref.

Claims (4)

[Claims] 1. A platen having a polishing pad affixed to a surface thereof, and one or more wafer holding heads for holding one surface of a wafer to be polished and bringing the other surface of the wafer into contact with the polishing pad. A wafer polishing apparatus for polishing the other surface of the wafer with the polishing pad by a relative movement between the wafer holding head and the platen, wherein the wafer holding head has a retainer ring inside a head body along an axis thereof. A carrier, which is movably provided and holds one surface of the wafer to be polished inside the retainer ring, is movably provided along an axis of the carrier. The stop is
The head body is inserted vertically, and the upper end of the locking portion does not protrude at least from the upper surface of the head body at the engagement position and the disengagement position of the locking portion with the carrier. A wafer polishing apparatus, comprising: 2. A locking portion is provided on the head main body so as to be rotatable around its axis, and a locking claw that engages with and disengages from a carrier is formed at a lower end portion of the locking portion. 2. An overhanging portion is formed at an upper end of the head body so as to fit into a recess formed on an upper surface of the head main body.
A wafer polishing apparatus as described in the above. 3. The protrusion of the locking portion is fitted into a recess of the head main body at a position where the locking portion engages with and disengages from the carrier. Item 3. A wafer polishing apparatus according to Item 2. 4. The wafer polishing apparatus according to claim 2, wherein a direction indicating portion indicating a direction of the locking claw is provided on the overhang portion.