JPH0929591A - Substrate polishing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high polishing rate while ensuring a flatness in a substrate surface. SOLUTION: In a substrate polishing device in which a substrate holding bed 3 for holding a substrate 4 is arranged being opposed to a polishing plate 1, the substrate holding bed 3 incorporates a medium supply system 5 for supplying a temperature control medium such as gas of liquid. The substrate holding bed 3 also incorporates a medium circulating part 9 for circulating the temperature control medium fed from the medium supply system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate polishing apparatus, and is particularly suitable for use in flattening the surface of a semiconductor substrate.

[0002]

2. Description of the Related Art FIG. 5 is a schematic block diagram showing an example of a conventional substrate polishing apparatus, which is a CMP (Chemical Mechanical Polishing) apparatus for flattening irregularities on a semiconductor substrate by a chemical mechanical polishing action. Shows the configuration of. In the substrate polishing apparatus shown in FIG. 5, the polishing plate 51
A polishing pad 52 is stretched on the upper surface of the. On the other hand, a substrate holder 53 is arranged above the polishing plate 51, and a substrate suction film 54 is provided on the lower surface of the substrate holder 53.
The substrate 55 is held via. Also the substrate holder 5
A nozzle 56 for supplying an abrasive is installed near 3 so that the abrasive (slurry) sucked up by a pump 58 from an abrasive supply tank 57 is supplied onto the polishing pad 52 through the nozzle 56 during polishing. It has become.

In the substrate polishing process, the polishing plate 51 and the substrate holding table 53 are each rotated in a predetermined direction to supply an appropriate amount of polishing agent from the nozzle 56, and the substrate 55 held by the substrate holding table 53 is polished. Press on the pad 52. As a result, the surface to be polished of the substrate 55 (lower surface in the figure)
Are polished by the chemical polishing action of alkali in the polishing agent and the mechanical polishing action of silica.

By the way, in this type of substrate polishing apparatus, as is clear from FIGS. 6A and 6B, as a factor that determines the polishing rate, a known polishing processing pressure (pressing force of the substrate against the polishing pad). In addition, the substrate temperature during polishing is considered to be a major factor. Therefore, conventionally, in order to realize a high polishing rate while ensuring the flatness in the substrate surface, measures such as increasing the polishing processing pressure and controlling the temperature of the polishing agent and the polishing plate 51 to a constant level are taken. It is being appreciated.

[0005]

However, if the polishing pressure is increased, the substrate 55 may be damaged by that amount, which may adversely affect the device characteristics. On the other hand, in the method of controlling the temperature of the polishing agent or the polishing plate 51 to a constant level, all of them are methods of indirectly controlling the temperature of the substrate 55 during polishing, so that the temperature distribution in the substrate surface is not uniform. Could not be eliminated, and this appeared as variations in the polishing rate within the surface of the substrate.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a substrate polishing apparatus in which a substrate holding table for holding a substrate is arranged so as to face a polishing plate. And a medium supply system for supplying a temperature control medium consisting of Further, the substrate holding table has a medium circulating portion inside for circulating the temperature control medium supplied from the medium supply system.

Therefore, in the substrate polishing apparatus of the present invention, the temperature control medium supplied from the medium supply system is circulated in the medium circulating section of the substrate holding table so that the substrate holding table and the substrate held by the substrate holding table are circulated. The heat exchange is uniformly performed within the substrate surface. This eliminates the temperature non-uniformity in the surface of the substrate and suppresses the variation in the polishing rate, and the high polishing rate is realized by increasing the temperature of the temperature control medium.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic configuration diagram illustrating an embodiment of a substrate polishing apparatus according to the present invention. In the substrate polishing apparatus shown in FIG. 1, a polishing pad 2 is stretched on the upper surface of a polishing plate (polishing platen) 1. A substrate holder 3 is arranged above the polishing plate 1 so as to face the polishing plate 1. The substrate holder 3 holds the substrate 4, which is a material to be polished, on the lower surface side facing the polishing pad 2.

A medium supply system 5 for supplying a temperature control medium composed of gas or liquid is connected to the substrate holder 3. The medium supply system 5 generates a temperature control medium controlled to a predetermined temperature level and supplies it to the substrate holding table 3 with a driving force of a pump or the like.

The substrate holder 3 has a double cylindrical structure in which a shaft portion connected to the substrate holder 3 is composed of an outer cylinder 6 and an inner cylinder 7. A partition plate 8 that divides the internal space of the substrate holding table 3 into upper and lower parts is attached to the lower end of the inner cylinder 7, whereby a medium circulating portion 9 is formed inside the substrate holding table 3. Here, the pipe of the medium supply system 5 is connected to the inner cylinder 7, and the temperature control medium supplied through the inner cylinder 7 circulates in the medium circulation part 9 of the substrate holding table 3 as shown by the arrow in the figure. It is composed.

Further, in the substrate polishing apparatus of the present invention, as shown in FIG. 2, the disk-shaped substrate holding plate 1 is provided on the lower end side (substrate holding side) of the substrate holding table 3 on which the substrate 4 is actually held.
0 is provided. The substrate holding plate 10 is made of a high thermal conductive material such as aluminum or copper, and is detachably attached to the lower end side of the substrate holding table 3. Further, an O-ring 11 is incorporated in a fitting portion between the plate mounting portion of the substrate holding base 3 and the substrate holding plate 10 in order to maintain airtightness and watertightness.

Next, a procedure for polishing a substrate using the substrate polishing apparatus having the above structure will be described. First, in the substrate polishing process, as shown in FIG. 3, the substrate holding plate 10 is removed from the lower end portion of the substrate holding table 3. Next, as shown in FIG. 4A, a brazing agent 11 such as, for example, heat-melted paraffin is applied to the substrate holding surface side of the previously removed substrate holding plate 10, and then the brazing agent 11 is applied.
The substrate 4 is attached to the substrate holding plate 10 by using as an adhesive. By the way, as a method of applying the brazing agent 11, if the so-called spin coating method is adopted in which the brazing agent 11 is dropped from above while rotating the substrate holding plate 10 at a high speed, the brazing agent 11 is thinly and uniformly applied on the substrate holding plate 10. It is suitable because it can be applied.

Subsequently, as shown in FIG. 4B, the substrate 4
The substrate holding plate 10 attached with is attached to the lower end of the substrate holding base 3 again, and polishing of the substrate 4 is started in this state.
At this time, the temperature control medium composed of gas or liquid is supplied from the medium supply system 5 to the substrate holding table 3. The temperature control medium supplied to the substrate holder 3 is, as shown in FIG.
And is sent to the medium circulation unit 9 through which it flows radially from the inner peripheral side to the outer peripheral side in the space secured between the partition plate 8 and the substrate holding plate 10.

Further, the temperature control medium flowing on the substrate holding plate 10 flows around the peripheral edge of the partition plate 8 from the outer peripheral side to the inner peripheral side of the substrate holding base 3, and then the outer cylinder 6 and the inner cylinder. It is pushed up through the space secured between 7 and
It is discharged from the substrate holder 3 as it is. After that, for the substrate holding table 3, during the polishing of the substrate 4, the medium supply system 5
From this, the temperature control medium is continuously supplied, and the supplied temperature control medium circulates in the medium circulation unit 9 of the substrate holding table 3.

As described above, in the substrate polishing apparatus having the above structure, the temperature control medium supplied from the medium supply system 5 is circulated in the medium circulating section 9 of the substrate holding table 3 while the substrate 4 is being circulated.
Since the temperature of is controlled directly by the substrate holder 3,
At the time of polishing the substrate, heat exchange between the substrate holding plate 10 mounted on the lower end of the substrate holding table 3 and the substrate 4 held by the substrate holding plate 10 is uniformly performed over the entire area of the substrate 4. As a result, the temperature of the substrate 4 can be kept constant during polishing, and it is possible to suppress variations in the polishing rate within the surface of the substrate.

Further, the temperature of the temperature control medium supplied from the medium supply system 5 is increased to control the temperature of the substrate 4 during polishing to a constant high temperature level, thereby increasing the polishing processing pressure as in the conventional case. Therefore, a high polishing rate can be realized very suitably.

Further, since the substrate holding plate 10 made of a high thermal conductive material is provided on the substrate holding side of the substrate holding table 3 and the substrate 4 is directly held by the substrate holding plate 10, the substrate is being polished. The heat exchange between the holding table 3 (substrate holding plate 10) and the substrate 4 is smoothly performed. As a result, the temperature distribution on the surface of the substrate becomes more uniform, and it becomes possible to effectively suppress variations in the polishing rate.

In the above-described embodiment, the substrate 4 is adhered to the substrate holding plate 10 of the substrate holding table 3 via the brazing agent 11, but this is direct to the substrate holding plate 10. The purpose is to smoothly perform heat exchange between the two while avoiding damage to the substrate 4 due to surface contact, and for the same reason, for example, the substrate holding plate 10
The substrate 4 may be adhered to the substrate via a heat conductive adhesive.

[0019]

As described above, according to the substrate polishing apparatus of the present invention, the temperature control medium supplied from the medium supply system is circulated in the medium circulating section of the substrate holding table, so that the substrate holding table and the substrate are Since the heat exchange between the substrate and the substrate is performed uniformly over the entire substrate, the temperature of the substrate can be kept constant during polishing. As a result, variations in the polishing rate within the surface of the substrate are suppressed, so that the in-plane uniformity in the flattening polishing can be improved. Also, without increasing the polishing processing pressure as in the past,
By simply raising the temperature of the temperature control medium circulated in the medium circulation unit, it is possible to realize a high polishing rate while ensuring good in-plane uniformity.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram illustrating an embodiment of a substrate polishing apparatus according to the present invention.

FIG. 2 is a partial detailed view of FIG.

FIG. 3 is a diagram (part 1) explaining an example of a substrate polishing procedure.

FIG. 4 is a diagram (part 2) explaining an example of a substrate polishing procedure.

FIG. 5 is a schematic configuration diagram showing an example of a conventional substrate polishing apparatus.

FIG. 6 is a diagram illustrating a determinant of a polishing rate.

[Explanation of symbols]

 1 Polishing Plate 3 Substrate Holding Table 4 Substrate 5 Medium Supply System 9 Medium Circulation Section 10 Substrate Holding Plate

Claims (2)

[Claims] 1. A substrate polishing apparatus in which a substrate holding table for holding a substrate is arranged so as to face a polishing plate, and a medium supply for supplying a temperature control medium made of gas or liquid to the substrate holding table. A substrate polishing apparatus comprising a system, wherein the substrate holding table has a medium circulating unit for circulating the temperature control medium supplied from the medium supply system therein. 2. The substrate polishing apparatus according to claim 1, wherein the substrate holding table has a substrate holding plate made of a high thermal conductive material on the substrate holding side thereof.