JPH0927467A - Polisher - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the structure of a polisher head by constituting an air feeder to feed air to a top plate pressing air cylinder so that it can be connected onto a loader while stopping, using a check valve attached to joint mounted on the top plate. SOLUTION: A polisher head 13 comprises a top plate base 22 coupled with the top end of a rotary shaft 16, top plate mounted tightly on the base 22 to rotate together, and air cylinder 35 for pressing the top plate having a wafer sucking surface at the lover face. An air passage 38 for feeding air to the air cylinder 35 is formed on the base 22 and check valve attached to joint 40 is mounted in an entrance opened at the outer surface of the base 22. On a loader an air feeder is disposed which is removably connectable to this joint 40 when the head 13 moves.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polishing apparatus,
Particularly, in the field of semiconductor device processing, the present invention relates to a polishing apparatus used for polishing processing for finishing the surface of a wafer to be smooth.

[0002]

2. Description of the Related Art In recent years, the chemical mechanical polishing process, which is being considered for use in the manufacture of semiconductor devices, presses a wafer against a polishing cloth at a constant pressure while performing a relative rotational movement between the wafer and the polishing cloth. This is a process of polishing while supplying a polishing liquid while supplying it.

A polishing apparatus used for this kind of chemical mechanical polishing process holds a surface plate having a polishing cloth fixed to the surface thereof with an adhesive such as a double-sided tape, and a semiconductor wafer which is a material to be polished. The polishing head includes a polishing head, a polishing agent supply device that supplies a polishing material onto a polishing cloth, and a loader device that temporarily mounts a wafer to attach and detach the wafer to and from the polishing head.

The polishing head presses the surface of the held wafer against the surface of the polishing cloth on the surface plate while rotating the held wafer, and moves in the radial direction of the surface plate. At this time, the polishing agent is supplied from the polishing agent supply device to polish the wafer.

In this type of polishing apparatus, as a method for mounting a wafer on the lower surface of the polishing head, a waxless pad method such as vacuum suction or water sticking is adopted for automation. In this case, in order to rotate the wafer integrally with the polishing head, it is necessary to firmly mount the wafer, therefore, a vacuum suction method is often adopted, and in this vacuum suction method, during polishing, The wafer is constantly vacuumed.

By the way, recently, with the progress of miniaturization of patterns, it has been particularly required to carry out polishing processing of a wafer while maintaining a high degree of flatness. Therefore, it is indispensable to uniformly press the wafer adsorbed by the polishing head over the entire surface thereof against the polishing cloth on the surface plate.

Conventionally, a polishing head is generally provided with a mechanism for uniformly pressing a wafer.
Examples thereof include those disclosed in Japanese Patent Laid-Open No. 0-201174 and Japanese Patent Laid-Open No. 4-201174.

[0008]

However, as in Japanese Utility Model Laid-Open No. 64-16260, a polishing head incorporating an air cylinder for ensuring a high degree of flatness of the wafer sucks the wafer. In addition to the passage for evacuation, the passage for supplying air to the air cylinder is required.

Since the polishing head is constantly rotating during the polishing process, conventionally, two through-holes are provided in the rotary shaft of the polishing head, and these are used as a passage for the evacuation and pressing air. In addition, it is necessary to use these passages and to provide two passages to the tip of the polishing head through a rotary joint for two passages, which complicates the structure of the polishing head and requires a rotating shaft more than necessary. It had the drawback of becoming thicker.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide only a passage for vacuuming on the rotary shaft of the polishing head and omit the passage for pressing. An object of the present invention is to provide a polishing apparatus that can simplify the structure of the polishing head. Another object of the present invention is to provide a polishing apparatus capable of uniformly pressing the wafer onto the polishing cloth over the entire surface thereof.

[0011]

In order to achieve the above-mentioned object, the present invention provides a platen having an upper surface on which a polishing cloth is adhered and rotating, and a wafer which is attracted and rotated while the wafer is fixed on the plate. A polishing head that can be pressed against the polishing cloth on the board,
In a polishing apparatus provided with a loader device for temporarily mounting a wafer and attaching and detaching the wafer to and from the polishing head, the polishing head includes a rotating shaft and a top plate connected to a tip of the rotating shaft. A top plate having a main body, a top plate having a lower surface on which a wafer suction surface is attached so as to rotate integrally with the main body, and a pressing portion abutting against the center of the back surface of the top plate; A top plate pressing air cylinder concentrically incorporated in the plate main body, forming an air passage for supplying air to the top plate pressing air cylinder in the top plate main body, and an outer surface of the top plate main body When a joint with a check valve is attached to the inlet opening to the, and the polishing head moves on the loader device, To, and is characterized in that it has disposed detachably air supply device connectable to said check valve attached fittings.

Further, in the polishing apparatus according to the present invention, the air supply device is connected to an actuator so as to be movable back and forth, and supplies air in association with the wafer suction operation of the polishing head on the loader device. It is characterized by having done.

Further, according to the present invention, the tip portion of the pressing portion of the top plate pressing air cylinder is formed in a hemispherical shape, and a concave curved surface is formed on the back surface of the top plate with which the tip of the pressing portion abuts. It is characterized by

According to the present invention, when the polishing head is stopped on the loader device for adsorbing the wafer on the loader device, the air supply device is actuated to move forward toward the polishing head to move the top plate. It is connected to a joint with a check valve provided in.

When the air supplied from the air supply device is filled in the air cylinder for pressing the top plate from the passage in the top plate, the air supply device is separated from the joint with the check valve of the polishing head, and the polishing head is removed. , Move to just above the surface plate. During this time, the pressure of the filled air is maintained by the check valve of the joint with the check valve.

The polishing head on the surface plate presses the adsorbed wafer against the polishing cloth on the upper surface of the surface plate, and the top plate pressing air cylinder in the top ring body is urged by the above-mentioned filled air. The piston presses the center of the top plate to ensure a high degree of flatness of the wafer by polishing.

[0017]

DETAILED DESCRIPTION OF THE INVENTION A polishing apparatus embodying the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a side view showing the overall configuration of the polishing apparatus, and FIG. 2 is a plan view of the polishing apparatus. In FIGS. 1 and 2, 10 is a base of the polishing apparatus, and 11 is a surface plate for polishing the wafer 50. A loader device 12 attaches and detaches the wafer 50 to and from the polishing head 13. The wafer 50 is placed on the loader device 12 manually or by a robot. The polishing head 13 on which the wafer 50 is vacuum-adsorbed includes an arm 14
The arm 14 is driven by a turning motor 15 and can be turned between the surface plate 11 and the loader device 12 while holding the wafer 50 by suction.

The polishing head 13 is connected to a rotary shaft 16 as will be described later, and the rotary shaft 16 is rotatably supported by the arm 14 via a bearing (not shown) and is rotated by a motor 17. Further, the polishing head 13 and the rotary shaft 16 as a whole are connected to an air cylinder 18 for raising and lowering the polishing head via a rotary joint 19, and the polishing head 13 is raised and lowered while rotating the polishing head 13 under the driving action of a motor 17. The wafer 50 adsorbed by the operation of the air cylinder 18 for press can be pressed against the polishing cloth 20 attached to the upper surface of the surface plate 11. The polishing liquid is supplied to the polishing cloth 20 from a polishing liquid supply device (not shown).

Next, FIG. 3 is a sectional view showing the structure of the polishing head 13 in detail. The polishing head 13 includes a top plate main body 22 and a top plate 23. Of these, the top plate main body 22 is concentric with the tip of the rotary shaft 16 and is an automatic centering device. It is attached via a core bearing 24, and the top plate 23 is fixed to the top plate body 22 using fastening elements such as bolts.

The lower surface of the top plate 23 has the wafer 5
.., which are formed so as to penetrate through the top plate 23. The plurality of vacuum holes 27, 27 ... The vacuum holes 27, 27 ... Are in communication with the vacuum passages 28, 29 via the vacuum chamber 26 formed by the recessed portion of the lower surface of the top plate body 22 and the upper surface of the top plate 23. . One end of a vacuum hose 31 is connected to the vacuum passage 29 via a joint 30, and the other end of the vacuum hose 31 is formed on the rotary shaft 16 in the longitudinal direction via a joint 32. 33
Is to be connected to.

In this embodiment, the rotation transmission rods 34A, 34 are provided between the rotary shaft 16 and the top plate body 22.
B is provided so as to be able to abut, and thereby the rotation of the rotary shaft 16 is transmitted to the top plate body 22.

However, the polishing head 13 is provided with an air cylinder 35 for pressing the top plate in addition to the above vacuum suction means. The air cylinder 35 for pressing the top plate is concentrically incorporated in the top plate body 22, and the top of the top plate body 22 is attached to the tip of the pressing piston 36 of the air cylinder 35.
A hemispherical pressing portion 39 is formed at the tip protruding downward from the lower surface of the. The pressing portion 39 is the top plate 23.
It comes into contact with the center of the back surface of the.

Compressed air is supplied from a passage 38 to the cylinder chamber 37 of the air cylinder 35 containing the pressing piston 36. The passage 38 is formed so as to extend to the outer surface of the top plate body 22, and a joint 40 in which a check valve is previously installed is attached to the passage inlet opening to the outer surface of the top plate body 22. Has been.

FIG. 1 shows an air supply device 42 provided with connecting means (not shown) such as a quick joint so that it can be detachably connected to the check valve-equipped joint 40. The air supply device 42 is arranged near the loader device 12, and is configured to be movable forward and backward by being connected to an actuator such as an air cylinder (not shown) so as to be brought into contact with and separated from the loader device 12. The air supply device 42
Is supplied with air pressurized to a predetermined pressure from an air supply pipe via a stop valve 43.

The present polishing apparatus is constructed as described above, and its operation will be described below.

First, when the polishing head 13 moves to directly above the loader device 12 as the arm 14 rotates, the polishing head lifting air cylinder 18 in the polishing head 13 is moved.
Is activated, and the suction surface on the lower surface of the top plate 23 comes into contact with the wafer 50 set on the loader device 12. At this time, a vacuum pump (not shown) is started, and the wafer 50 is attracted to the top plate 23 of the polishing head 13.

At the same time as such suction operation, the air supply device 42 advances to the polishing head 13 stopped on the loader device 12. When the air supply device 42 is connected to the joint 40 with a check valve attached to the outer peripheral surface of the top plate body 22 of the polishing head 13, the compressed air controlled to a predetermined pressure is passed through the passage 38 to the cylinder chamber 37. To fill. After that, the air supply device 42 retreats, but the pressure of the compressed air filled in the cylinder chamber 37 is maintained even after the air supply device 42 is separated from the check valve-equipped joint 40 by the check valve controlled internally. Has become.

Next, when the polishing head 13 is swiveled to just above the surface plate 11, the polishing head elevating air cylinder 18 is actuated and the wafer 50 sucked and held on the top plate 22 of the polishing head 13 is fixed. Polishing cloth 2 on board 11
Press to zero. At this time, the wafer 50 is pressed against the polishing cloth 20 by the centering action of the self-centering bearing 24. Further, the surface plate 11 and the polishing head 13 start rotating. From an abrasive supply device (not shown), an abrasive of alkaline colloidal silica aqueous solution is supplied for polishing.

While the wafer 50 is being polished on the surface plate 11, the central portion of the top plate 22 is constantly pressed by the pressing portion 39 of the pressing piston 36.
The negative pressure of 6 prevents the center portion from being deformed and the self-aligning bearing 24 from pressing the outer periphery of the top plate 22 to deform the center portion in the same manner as described above. Is evenly pressed against the polishing cloth 20. Also, preferably, the pressing portion 3
A concave curved surface 44 may be formed at the center of the back surface of the top plate 23 so as to correspond to the hemispherical shape of No. 6, in which case the pressing portion 39, the concave curved surface 44, and the wafer 50.
It is preferable that the centers of the two are coaxial.

[0030]

As is apparent from the above description, according to the first and second aspects of the present invention, an air supply device for supplying air to the top plate pressing air cylinder that pressurizes the top plate is provided on the top plate. Since it is configured so that it can be connected to the loader device while it is stopped by using the mounted check valve-equipped joint, the rotary shaft of the polishing head is equipped with a vacuum suction passage and a pressurization passage. The passage for pressure can be omitted and it can be made into one system only for the vacuum passage,
Moreover, the structure of the top plate of the polishing head can be greatly simplified.

[Brief description of drawings]

FIG. 1 is a side view showing the overall configuration of a polishing apparatus embodying the present invention.

FIG. 2 is a plan view of the polishing apparatus shown in FIG.

FIG. 3 is a cross-sectional view showing a configuration of a polishing head of a polishing apparatus.

[Explanation of symbols]

 10 base 11 surface plate 12 loader device 13 polishing head 14 arm 15 swing motor 16 rotary shaft 18 air cylinder for lifting polishing head 20 polishing cloth 22 top plate body 23 top plate 24 self-aligning bearing 26 vacuum chamber 27 vacuum holes 34A, 34B Rotation transmission rod 36 Pushing piston 35 Air cylinder for pushing top plate 37 Cylinder chamber 39 Pushing part 40 Joint with check valve 42 Air supply device

Claims (3)

[Claims] 1. A surface plate having an upper surface on which a polishing cloth is attached and rotating, a polishing head capable of pressing the wafer on the polishing cloth on the surface plate while rotating the adsorbed wafer, and a temporary wafer. In a polishing apparatus including a loader device for mounting and demounting a wafer on and from a polishing head, the polishing head includes a rotating shaft, a top plate body connected to a tip of the rotating shaft, and a top plate body. A top plate, which is mounted so as to rotate integrally with the plate body and has a wafer suction surface formed on the lower surface, and a piston having a pressing portion that abuts the center of the back surface of the top plate, and is concentric with the top plate body. An air cylinder for pressing the top plate, and an air passage for supplying air to the air cylinder for pressing the top plate is provided with the top plate pressing air cylinder. And a check valve joint at the inlet opening to the outer surface of the top plate body, and when the polishing head moves on the loader device, the check valve joint. An air supply device that is detachably connectable to the polishing device. 2. The air supply device is configured to be connected to an actuator so as to be movable back and forth, and to supply air in conjunction with a wafer suction operation of a polishing head on a loader device. The polishing apparatus according to claim 1. 3. The top end of the pressing portion of the top plate pressing air cylinder is formed in a hemispherical shape, and a concave curved surface is formed on the back surface of the top plate with which the top end of the pressing portion abuts. The polishing apparatus according to claim 1, wherein the polishing apparatus is a polishing apparatus.