JPH05343375A - Polisher - Google Patents

Abstract

PURPOSE:To improve polishing speed to perform precise polishing by providing a plurality of abrasive supply ports opening on a surface of a disk. CONSTITUTION:A substrate 22 to be polished is held by a holding jig 21 and placed oppositely to a disk 23 having a polishing surface. Abrasive 24 is diffused through an abrasive supply path 26 into an abrasive diffusion chamber 27 and passes through abrasive supply ports 25 opening on the surface of the disk 23 to be directly supplied between the substrate 22 and the disk 23. While load is applied to the substrate 22 through the holding jig 21, either or both the substrate 22 and the disk 23 are rotated to slide, whereby the substrate 22 is polished. Thus an increase in polishing speed can be observed with respect to an increase in the number of rotations in a high rotation region where the polishing speed has been conventionally at a certain value or lower while no drop in flatness of the polished surface is observed.

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 of a type which supplies an abrasive between a work piece and a surface plate having a polishing surface.

[0002]

2. Description of the Related Art Generally, when polishing a substrate-shaped object such as a semiconductor wafer, as shown in FIG. 5, the substrate 42 is placed in opposition to a surface plate (hereinafter simply referred to as a surface plate) 43 having a polishing surface. While supplying the polishing agent 44 between the surface plate 43 and the surface plate 43, a load is applied to the substrate 42 opposed to the surface plate 43, and one or both of the substrate 42 and the surface plate 43 are rotated so as to slide to perform polishing. The way is done. In this case, the polishing agent 44 is often supplied onto the surface plate 43 near the substrate 42 using a nozzle 45.

In order to polish the substrate 42, it is necessary to supply the polishing agent 44 between the substrate 42 and the surface plate 43 at least, and in order to increase the polishing rate and perform the polishing accurately. It is necessary that the polishing agent 44 be sufficiently and uniformly supplied between the substrate 42 and the surface plate 43. However, in this conventional method, the abrasive 44 is less likely to enter between the substrate 42 and the surface plate 43 as the load during polishing increases,
When the number of rotations of the surface plate 43 is further increased, the abrasive 44 is less likely to be held on the surface plate 43 due to centrifugal force.
Sufficient and uniform supply of the abrasive 44 will not be performed. The situation during this period will be described below with reference to FIGS. 6 and 7.

FIG. 6 shows an example of the relationship between the rotation speed, the polishing speed and the flatness of the surface to be polished. On the contrary, it decreases. Substrate 4 after polishing
Regarding the flatness of the surface to be polished of No. 2, the rotation speed is 300 rpm.
With the above, it becomes significantly worse. Regarding the flatness, here, as shown in FIG. 8, using the maximum polishing amount 53 (Pmax) and the minimum polishing amount 54 (Pmin) within the surface of the substrate 51 to be polished, (Pmax-Pmin) / (Pmax + Pmi)
n) × 100%. In FIG. 8, reference numeral 52 represents a reference surface of the substrate 51 to be polished before polishing.

FIG. 7 shows an example of the relationship between the load, the polishing rate, and the flatness of the surface to be polished. Although the appropriate load region varies depending on the characteristics of the polishing apparatus, generally, the polishing rate increases as the load increases, but In this example, the load is 500g / cm ²
As described above, the supply and discharge of the polishing agent 44 between the surface plate 43 and the substrate 42 are not smoothly performed, and the polishing rate is reduced. The flatness of the surface to be polished is also 300 g / cm ^{2 in} this example. The best in the vicinity, but 400g / cm ² When it exceeds, it gets worse.

[0006]

As described above, in the conventional polishing apparatus, the polishing agent cannot be sufficiently and uniformly supplied between the substrate to be polished and the surface plate. Therefore, the polishing rate is increased and the polishing is performed accurately. Could not be done. Therefore, the present invention is intended to provide a polishing apparatus capable of sufficiently and uniformly supplying an abrasive between a substrate to be polished and a surface plate.

[0007]

In order to achieve the above object, in the present invention, an object to be polished held by a holder is placed on a surface plate having a polishing surface on its surface, and the surface plate and the object to be polished are opposed to each other. Supplying an abrasive between the objects, applying a load to the object to be polished,
In the polishing apparatus for polishing the surface of the object to be polished by repeatedly moving or rotating one or both of the object to be polished and the surface plate, the surface is introduced from a non-polished surface of the surface plate, and An abrasive introduction path provided inside the surface plate, an abrasive diffusion chamber connected to the abrasive introduction path and provided inside the surface plate for diffusing the abrasive, the abrasive diffusion chamber and the Provided is a polishing device having a polishing agent supply port for communicating a polishing surface.

[0008]

In the present invention, since a plurality of abrasive supply ports are provided on the surface of the surface plate, it is possible to always supply the abrasive uniformly.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a first embodiment of the present invention, in which a substrate 22 to be polished is held by a holder 21 and placed on a surface plate 23 having a polishing surface. The abrasive 24 passes through the abrasive supply path 26 and is diffused in the abrasive diffusion chamber 27.
It is directly supplied between the substrate 22 and the surface plate 23 through an abrasive supply port 25 having a hole formed on the surface of 3. Then, the substrate 22 is polished by rotating one or both of the substrate 22 and the surface plate 23 while sliding a load on the substrate 22 through the holder 21. Next, a second embodiment of the present invention will be described with reference to FIG. The substrate 33 to be polished in FIG. 2 is held on a holder 31 and has a surface plate 33 smaller than the substrate.
Are opposite to each other. The abrasive 34 is an abrasive supply path 36.
It is diffused through the polishing agent in the polishing agent diffusion chamber 37, and is supplied between the substrate 32 and the polishing table 33 from the polishing agent supply port 35 formed in the surface of the polishing table 33. The substrate 33 is polished by rotating one or both of the substrate 32 and the surface plate 33 while sliding a load on the substrate 32 through the surface plate 33.

With the structure shown in FIGS. 1 and 2, the abrasive 24 or 34 is continuously and directly supplied between the substrate 22 or 32 and the surface plate 23 or 33. Therefore, uneven supply of the polishing agent due to an increase in the load and the number of rotations during polishing is eliminated. The effect of this on the polishing rate and the flatness of the surface to be polished will be described with reference to FIGS. 3 and 4.

FIG. 3 is an example showing the relationship between the number of revolutions, the polishing rate, and the flatness of the surface to be polished in this embodiment. The polishing rate was decreased in the conventional method at 300 rpm.
Even with the above, the polishing rate is increased. Further, the flatness of the surface to be polished after polishing is not significantly decreased due to the increase of the rotation speed, and a good result of 10 several percent, which is equivalent to the rotation speed region below 300 rpm, can be obtained. Further, as shown in FIG. 4, even when the load is increased, the polishing rate corresponding to the increase in the load is increased and the flatness in the high load region is prevented from being lowered.

It should be noted that the abrasive supply ports 25 and 35 in FIGS. 1 and 2 are holes or grooves, and their material, size, position and shape are not specified, and the number thereof may be any number. .. The material, size, position and shape of the abrasive supply paths 26 and 36 are not specified, and the number thereof may be any number.

In this embodiment, one or both of the substrate to be polished and the surface plate are rotated. However, one or both of the substrate to be polished and the surface plate are repeatedly moved so as to slide laterally. Good.

[0014]

As described in detail above, according to the method of the present invention, the polishing agent can be directly supplied between the substrate to be polished and the surface plate having the polishing surface through the polishing agent supply port. Therefore, as the rotation speed increases, the polishing speed increases in the high rotation region where the conventional polishing speed is less than a certain value, and the flatness of the surface to be polished after polishing also depends on the rotation speed. No significant decrease is seen, and good results equivalent to those in the low rotational speed region can be obtained. Further, even when the load is increased, the polishing rate is increased in a region where the polishing rate and the flatness are reduced by the conventional method, and the reduction in the flatness can be suppressed.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of a polishing apparatus of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the polishing apparatus of the present invention.

FIG. 3 is a diagram showing the relationship between the number of revolutions, the polishing speed, and the flatness of the surface to be polished in the polishing apparatus of the present invention.

FIG. 4 is a diagram showing a relationship between a load, a polishing rate, and flatness of a surface to be polished in the polishing apparatus of the present invention.

FIG. 5 is a cross-sectional view of a polishing apparatus according to the related art.

FIG. 6 is a diagram showing the relationship between the number of revolutions, the polishing speed, and the flatness of the surface to be polished in the conventional polishing apparatus.

FIG. 7 is a diagram showing a relationship between a load, a polishing rate, and flatness of a surface to be polished in a conventional polishing apparatus.

FIG. 8 is an explanatory diagram of definitions of a maximum polishing amount and a minimum polishing amount.

[Explanation of symbols]

 21 ... Holding tool 22 ... Substrate to be polished 23 ... Surface plate 24 ... Abrasive 25 ... Abrasive supply port 26 ... Abrasive supply path 27 ... Abrasive diffusion chamber

Claims (1)

[Claims] 1. An object to be polished held by a holder is placed on a surface plate having a polishing surface on its surface, and an abrasive is supplied between the surface plate and the object to be polished, to the object to be polished. Load,
In a polishing apparatus for polishing the surface of the workpiece by repeatedly moving or rotating one or both of the object to be polished and the surface plate, the surface is introduced from a non-polishing surface of the surface plate, and An abrasive introduction path provided inside the surface plate, an abrasive diffusion chamber connected to the abrasive introduction path and provided inside the surface plate for diffusing the abrasive, the abrasive diffusion chamber and the A polishing apparatus comprising: a polishing agent supply port for communicating a polishing surface.