JPH07251372A - Polishing device - Google Patents

Abstract

PURPOSE:To provide a polishing device which is compact as a whole, easily to isolated and easily seals each of instruments in it. CONSTITUTION:A device for polishing the surface of a polishing objective article by interposing the polishing objective article between a turn table l and a top ring main body 5 and pressing it with specified pressure is furnished with a pressing mechanism to press the top ring main body 5 against the turn table 1 by vertically moving a support shaft 6 holding the top ring main body 5 and an oscillating mechanism having an oscillating shaft 16 to oscillate a region of the top ring main body 5 on the turn table 1 and deviated from the turn table 1. An oscillating region of the top ring main body 5 consists of a small oscillating region to oscillate by pressing the polishing objective article on the turn table l, an intermediate oscillating region to receive the polishing objective article and to be detached from it in a region deviated from the turn table 1 and a large oscillating region to carry out cleaning or shunting the top ring main body 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing apparatus, and more particularly to a polishing apparatus for polishing a polishing object such as a semiconductor wafer into a flat and mirror surface.

[0002]

2. Description of the Related Art In recent years, as the degree of integration of semiconductor devices has increased, circuit wiring has become finer and the distance between wirings has become smaller. In particular, in the case of optical lithography of 0.5 μm or less, the depth of focus becomes shallow, so that the flatness of the image plane of the stepper is required. Therefore, it is necessary to flatten the surface of the semiconductor wafer. As one means of this flattening method, polishing is performed by a polishing device.

Conventionally, this type of polishing apparatus has a turntable and a top ring that rotate independently of each other, and the top ring applies a constant pressure to the turntable so that the space between the turntable and the top ring is increased. The surface of the object to be polished is flattened and mirror-finished with the object to be polished interposed therebetween.

5 and 6 are views showing a conventional polishing apparatus. FIG. 5 is a vertical sectional view and FIG. 6 is a plan view.
In FIGS. 5 and 6, reference numeral 31 is a turntable, and above the turntable 31, a top ring main body 3 for holding a polishing object such as a semiconductor wafer on its lower surface is provided.
2 are arranged. The top ring body 32 is supported by the top ring head 33.

The top ring head 33 is a sliding mount 3
The top ring head 33 is supported by a ball screw 37 connected to a motor 36 via a gear box 35 so that the top ring head 33 can reciprocate linearly on a slide base 34. The reference numeral 38 indicates the turntable 3
The reference numeral 39 is a top ring cover.

[0006]

In the above polishing apparatus, the top ring body 32 moves linearly on the turntable and in a range other than the turntable, and therefore has the drawbacks listed below.

(1) As shown in FIG. 6, a receiving position A11 of a polishing object and a polishing position A1.
2. A top ring main body cleaning position, a top ring main body retracting position A13 when the polishing cloth of the turntable is replaced, and a polishing target detachment position A14 are linearly arranged. Therefore, the movable slide base 34, the gear box 3
5 and the motor 36 are arranged in a straight line, and the entire polishing apparatus becomes large.

(2) Since the polishing abrasive liquid used for polishing by the object to be polished ranges from strongly acidic (PH1) to strongly alkaline (PH12), it is caused by scattering of the abrasive liquid or an atmosphere containing the abrasive liquid. Therefore, it is necessary to take measures to prevent the corrosion of equipment. Therefore, the top ring head 33 is provided with a cover 39. And polishing room R
1 is separated from the top ring head and the drive chamber R2 of the turntable by providing a cover 38 on the table, but since the top ring head 33 moves linearly, as shown in FIG. Large cutout 3
8a (length 1, width w) is provided. Therefore, the atmosphere containing the polishing liquid enters the drive chamber R2 through the cutout 38a. Although it is conceivable to seal the cutout 38a, the structure of the seal itself becomes complicated and the seal is not perfect. For the above reasons, there has been a problem that the equipments are corroded, the lifespan of the equipments is shortened, and the maintenance cost is high.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polishing apparatus in which the entire apparatus is compact and each device in the apparatus can be easily isolated and sealed.

[0010]

In order to achieve the above-mentioned object, a polishing apparatus of the present invention has a turntable and a top ring body, each of which has an abrasive cloth on its upper surface which rotates at an independent number of revolutions. Holding the top ring body in a polishing device that polishes the surface of the polishing target object by pressing it with a predetermined pressure by interposing the polishing target object between the turntable and the top ring main body and making the surface flat and mirror-finished. A rocking mechanism having a pressing mechanism for vertically moving the supporting shaft to press the top ring body against the turntable, and a rocking shaft for rocking the top ring body on the turntable and in a range deviating from the turntable. The top ring body has a swinging range that pushes an object to be polished onto the turntable. A small swing range in which the polishing target swings, a middle swing range in which a polishing object is received and released in a range deviating from the turntable, and a large swing range in which the top ring body is washed or retracted. It is characterized by that.

[0011]

With the above construction, the polishing object can be pressed by the vertical force on the turntable surface on which the top ring body has adhered the polishing cloth. The top ring body receives the polishing object, performs polishing while swinging on the turntable, and removes the polishing object after the polishing is completed. Then, after the removal of the object to be polished, the cleaning of the top ring body can be performed within the swinging range (drawing an arc) of the top ring body.

A swing mechanism for swinging the top ring body is installed adjacent to the turntable and the swing mechanism is arranged in the drive chamber. With the above mechanism and arrangement, the device can be made compact. Separating and sealing the polishing chamber and the drive chamber, the rocking shaft has a sealing material (circular rotary seal)
Can be easily and completely provided.

With the polishing apparatus thus constructed, the apparatus becomes compact and the area occupied by the polishing apparatus in the clean room can be reduced. In addition, since the equipment in the apparatus can be separated and sealed from the scattering of the polishing abrasive liquid and the atmosphere containing the abrasive liquid, the life of the equipment can be extended and the maintenance cost can be reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the polishing apparatus according to the present invention will be described below with reference to FIGS. FIG. 1 is a cross-sectional view showing the overall structure of the polishing apparatus, which is taken along line I-
It is an I line sectional view. FIG. 2 is a plan view of FIG.

In FIGS. 1 and 2, reference numeral 1 is a turntable, and a rotary shaft 1a of the turntable 1 is connected to a turntable motor 3 via a timing belt 2 and is rotationally driven. Also, the rotating shaft 1a
Is supported by a bearing stand 4 having a bearing therein.

A top ring body 5 for holding a polishing object such as a semiconductor wafer is arranged above the turntable 1. The top ring body 5 is fixed to and supported by a support shaft 6, and the support shaft 6 is supported by a vertical motion bearing bearing 7 and is vertically movable. The upper end of the support shaft 6 is connected to a pneumatic cylinder 8 via a rotary connecting tool 25. The pneumatic cylinder 8 moves the support shaft 6 up and down to press the top ring body 3 against the turntable 1. Has become.

The support shaft 6 is connected to a rotary cylinder 10 via a key 9 as shown in FIG.
0 is supported by a rotary bearing 11, and has a timing pulley 12 on its outer peripheral portion. Then, the timing pulley 12 has a rotary shaft 14 a of the top ring main body rotary motor 14 via a timing belt 13.
It is connected to a timing pulley 15 fixed to (see FIG. 1). Therefore, by rotating the top ring body rotation motor 14, the timing pulley 1
The rotary cylinder 10 and the support shaft 6 rotate integrally via the timing belts 13 and 12, and the top ring body 5 rotates.

On the other hand, a swing shaft 16 is arranged outside the turntable 1, and a top ring head 17 holding the top ring body 5, the support shaft 6 and the like is provided on the upper end of the swing shaft 16. ing. The lower part of the swing shaft 16 is supported by a pair of upper and lower swing bearings 18 so as to be perpendicular to the turntable surface, and the gear 1
It is connected to a swing drive motor 21 via 9, 20. Therefore, by swinging the swing drive motor 21 forward and backward, the swing shaft 16 rotates and the top ring head 17 rotates.
The top ring body 5 swings around the swing shaft 16 via the. The swing drive motor 21 is composed of a servo motor, and the number of rotations and the rotation speed of the motor can be arbitrarily controlled by the servo motor control device.

The polishing chamber R1 and the driving chamber R2 are separated by a cover 23 on the table.
A portion where the swing shaft 16 penetrates the cover 23 is sealed by a circular rotary seal 24.

According to the polishing apparatus constructed as described above, the swing shaft 16 is rotated by rotationally driving the swing drive motor 21 as shown in FIG. 4, and the top ring body 5 is subjected to polishing. Turntable 1
A small swing range A that is pressed against and swings at a predetermined angle around the polishing position A2, and a receiving position A that receives a polishing object in a range that deviates from the turntable 1.
1 and a detachment position A3 for detaching the polishing object, a middle swing range B, a top ring body retreat position A4 when cleaning the top ring body 5 and replacing the turntable polishing cloth, and a polishing object. The large swing range C that swings between the receiving position A1 for receiving the object and the receiving position A1 is swung.

According to this embodiment, however, after the polishing object is received at the polishing object receiving position A1, the swing shaft 16 is rotated to move the top ring body 5 onto the turntable 1. After that, the pneumatic cylinder 8 is operated to push the top ring body 5 against the turntable 1, and the top ring body 5 is swung within a small swing range A around the polishing position A2 to perform polishing. Next, the top ring body 5 is swung in the middle swing range B to remove the polishing object at the removal position A3 of the polishing object.

Next, the top ring body 5 is moved in the large swing range C.
The top ring main body 5 is cleaned at the top ring main body cleaning position A4 by rocking. Then, the top ring body 5
Is swung in the large swing range C to return the top ring body 5 to the polishing object receiving position A1 and receive the next polishing object. After cleaning the top ring body 5, the top ring body 5 can be moved in the arrow E direction to return the top ring body 5 to the polishing object receiving position A1.

[0023]

As described above, according to the present invention, the effects listed below can be obtained. (1) Since the polishing apparatus can be made compact, the area occupied by the polishing apparatus in the clean room can be reduced. (2) Since each device inside the device can be isolated and sealed,
The life of the equipment can be extended and the maintenance cost can be reduced. (3) The polishing device can be made compact and the manufacturing cost of the device can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the overall configuration of an embodiment of a polishing apparatus of the present invention, which is a cross-sectional view taken along line I-I of FIG.

FIG. 2 is a plan view of FIG.

FIG. 3 is a vertical cross-sectional view showing the main configuration of the polishing apparatus of the present invention.

FIG. 4 is an operation explanatory view of the polishing apparatus of the present invention.

FIG. 5 is a vertical cross-sectional view showing the overall configuration of a conventional polishing apparatus.

FIG. 6 is a plan view of FIG.

[Explanation of symbols]

 1 turntable 3 turntable motor 5 top ring main body 6 support shaft 7 vertical bearing bearing 8 pneumatic cylinder 10 rotary cylinder 11 rotary bearing 14 top ring main body rotary motor 16 swing shaft 17 top ring head 18 swing bearing 21 swing Drive motor 23 Cover 24 Circular rotary seal R1 Polishing chamber R2 Drive chamber A Small swing range B Medium swing range C Large swing range

Claims (3)

[Claims] 1. A turntable having a polishing cloth adhered to an upper surface thereof rotating at an independent number of revolutions, and a top ring body, wherein a polishing object is interposed between the turntable and the top ring body. In a polishing device for polishing the surface of the polishing object by pressing with a pressure of 10 to flatten and mirror-finish the support ring holding the top ring body, the top ring body is pressed against the turntable. A pressing mechanism,
A swing mechanism having a swing shaft for swinging the top ring body on the turntable and a range deviating from the turntable, wherein the swing range of the top ring body is such that the polishing target is the turntable. A small swinging range in which the top ring body is washed or retracted, a small swinging range in which the polishing target is pressed and swung, a medium swinging range in which a polishing object is received and released in a range deviating from the turntable, and a large swinging range in which the top ring body is washed or retracted. A polishing device comprising: 2. The polishing apparatus according to claim 1, wherein the support shaft and the swing shaft are connected via a top ring head. 3. A cover for covering the drive unit of the turntable and the swing mechanism is provided, and a sealant is provided at a portion where the swing shaft penetrates the cover. Polishing equipment.