KR101079468B1 - Carrier for double side polishing apparatus and double side polishing method using the same - Google Patents

Abstract

The present invention relates to a carrier for a double-side polishing apparatus and a double-side polishing method using the same. The carrier for a double-side polishing apparatus of the present invention is installed between the upper and lower plates of the double-side polishing apparatus, rotated by a sun gear and an internal gear, a mounting hole for mounting a wafer, and a plurality of discharge holes for discharging the polishing liquid. Formed carrier plate; And a dressing block inserted into the discharge hole, the dressing block polishing the pad of the upper plate and the pad of the lower plate as the carrier plate is rotated.

Carrier, Double Side Grinding Machine, Sun Gear, Internal Gear, Dressing Block

Description

Carrier for double side polishing apparatus and double side polishing method using same {Carrier for double side polishing apparatus and double side polishing method using the same}

The present invention relates to a carrier for a double-side polishing apparatus and a double-side polishing method using the same, and more particularly, to a carrier for a double-side polishing apparatus and a double-side polishing method using the same to improve the flatness of the pad friction with the wafer during double-side polishing of the wafer. It is about.

Wafers, such as single crystal silicon wafers, which are raw materials for manufacturing semiconductor devices, etc., are largely manufactured through a shaping process, a polishing process, and a cleaning process, and further selectively grow the epitaxial layer. Can be done. The shaping process is again a slicing process in which single crystals of ingot form are cut into wafer forms, a lapping process in which a wafer is mechanically polished to remove defects caused by the slicing process and to control thickness. It can be subdivided into the etching process which chemically removes the defect resulting from a process, and the grinding process which removes the defect resulting from an etching process. In addition, the polishing process is a double side polishing (DSP) process that removes surface defects caused by the shaping process and improves the flatness of the wafer by polishing a thickness of about 10 to 20 µm, and about 1 µm. It can be divided into a final polishing process in which the internal and external thickness is finely polished to improve roughness, thereby mirroring.

Here, the polishing process typically uses a double side polishing apparatus to polish both sides of the wafer. The double-sided polishing apparatus includes a lower plate having a pad attached to the upper surface, an upper plate attached to the upper surface of the pad, and a carrier installed between the upper plate and the lower plate and mounted with a wafer.

More specifically, an internal gear is provided on the outer circumference of the lower plate, and a sun gear is installed at the center of the upper plate. The internal gear and the sun gear rotate in opposite directions as the upper and lower plates rotate in opposite directions.

The carrier has a substantially disc shape and is placed in engagement with the sun gear and the internal gear. In the carrier, a mounting hole for mounting the wafer is formed. Therefore, the surface of the wafer is in close contact with the pad of the upper plate and the pad of the lower plate in the state of being mounted on the carrier. At this time, the wafer in close contact with the pad is mechanically and chemically polished by a slurry (hereinafter, referred to as a “polishing liquid”) in which frictional force due to relative motion and a mixture of abrasive particles and various additives are mixed.

That is, when the double-sided polishing device is operated, the lower platen and the upper platen are rotated in opposite directions to each other, and the internal gear and the sun gear are also rotated in the opposite directions in association with each other. By rotating the internal gear and the sun gear, the carrier rotates and rotates to polish the wafer by the polishing liquid and the high pressure processing pressure.

On the other hand, in the pad for polishing the wafer, as pressure is applied for polishing the polishing liquid and the wafer, as the polishing time of the wafer increases, the surface of the pad becomes uneven and causes flatness of the wafer.

Thus, in the double-side polishing apparatus, after replacing the pads installed on the upper and lower plates, the operation for flattening the pads is performed. That is, after a pad is replaced, a dummy run or a test run (hereinafter referred to as 'pad conditioning') for a predetermined number of times, for example, about 40 to 60 runs is performed. After that, the flatness of the polished wafer is measured, and if the measured flatness satisfies the reference value, a prime wafer operation is performed. If the measured flatness does not meet the reference value, the pad conditioning operation is performed until the flatness reaches the reference value.

This pad conditioning operation, that is, planarization of the pad takes up more than 30% of the time according to the polishing process. That is, the use period of the pad is about six days, and since the half and half of the time is required for the pad flattening operation, the pad flattening operation greatly affects the productivity of the wafer.

In addition, the pad conditioning operation generally requires a quality verification operation using a dummy wafer immediately after conditioning, and as a result of frequent modifications by the operator, deterioration of the wafer quality and productivity are caused.

The present invention has been made to solve the above problems, and the carrier for a double-side polishing apparatus to reduce the preparation time for producing a wafer by improving the flatness of the pad for polishing the wafer while polishing both sides of the wafer and The purpose is to provide a double-sided polishing method using the same.

In order to achieve the above object, the carrier for a double-side polishing apparatus of the present invention is installed between the upper and lower plates of the double-side polishing apparatus, rotated by the sun gear and the internal gear, and the mounting hole and the polishing liquid for mounting the wafer. A carrier plate having a plurality of discharge holes for discharging; And a dressing block inserted into the discharge hole, the dressing block polishing the pad of the upper plate and the pad of the lower plate as the carrier plate is rotated.

Dressing block is preferably made of a shape through the center.

In this case, the dressing block is preferably made to have a thickness corresponding to the thickness of the carrier plate so as to smoothly discharge the polishing liquid or made to have a thickness smaller by a predetermined interval than the thickness of the carrier plate.

In addition, the dressing block is preferably diamond.

On the other hand, the dressing block is preferably installed in all discharge holes or at least one discharge hole.

Preferably, when the dressing block is installed in all the discharge holes, it is bonded and integrally attached to the carrier plate.

Preferably, the dressing block and the discharge hole is geared to engage the dressing block is selectively removable.

A polishing method using a carrier for a double-side polishing apparatus, which is another aspect of the present invention, includes: (a) installing any one of the carriers for the double-side polishing apparatus between the upper and lower plates of the double-side polishing apparatus; And (b) operating the double-side polishing apparatus to polish both sides of the wafer and to simultaneously polish the pads of the upper and lower plates by the carrier.

The carrier for a double-side polishing apparatus according to the present invention and the double-side polishing method using the same have the following effects.

First, as the wafer is double-sided polished and the flatness of the pad for polishing the wafer is improved, not only the quality of the wafer but also the preparation time for producing the wafer is greatly shortened.

Secondly, production is increased by not having to condition the pads separately.

Third, the use time of the pad increases according to maintaining the flatness of the stable pad, thereby reducing the cost of the pad.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

1 is a plan view showing a carrier for a double-side polishing apparatus according to a preferred embodiment of the present invention, Figure 2 is a partial cutaway perspective view showing a double-side polishing apparatus according to a preferred embodiment of the present invention, Figure 3 is a It is a cross section.

Referring to the drawings, the carrier for the double-sided extension device 100 is used to be mounted to the double-side polishing device 200. The double-sided polishing apparatus 200 is installed to face the upper surface plate 210, the upper surface plate 210 attached to the lower surface of the pad 212, the lower surface plate 230, the lower surface plate, the pad 232 is attached to the upper surface Internal gear 240 is installed on the outer periphery of the 230, the sun gear 220 is installed in the center of the upper plate (210) and rotates in the opposite direction to the internal gear 240, and the upper plate 210 And a carrier 100 for a double-side polishing apparatus installed between the lower plate 230 and rotated by the sun gear 220 and the internal gear 240.

A nozzle (not shown) for supplying a polishing liquid is installed at an upper portion of the upper plate 210, and an inlet (not shown) penetrated so that the polishing liquid supplied through the nozzle flows into the lower plate 230. ) Is formed. That is, the polishing liquid is supplied through the inlet when the wafer W is polished.

The wafer W is installed in the carrier 100 for the double-side polishing apparatus installed between the upper plate 210 and the lower plate 230, and the wafer W is the upper plate 210 and the lower plate 230. Friction with pads 212 and 232 attached thereto. As a result, both surfaces of the wafer W are polished. That is, the wafer is rubbed and polished, as the pad 212 of the upper plate 210 and the pad 232 of the lower plate 230 rotate in opposite directions.

The gear portion formed on the outer circumferential surface of the sun gear 220 and the gear portion formed on the inner surface of the internal gear 240 are meshed with the gear 121 formed on the outer circumferential surface of the carrier 100 for a double-side polishing apparatus. Accordingly, as the upper plate 210 and the lower plate 230 are rotated by a driving source (not shown), the carrier 100 for the double-side polishing apparatus rotates and revolves.

The carrier 100 for the double-side polishing apparatus supports the wafer W polished by the upper plate 210 and the lower plate 230, and the upper plate 210 and the lower plate 230 for polishing the wafer W. It serves to maintain the planarization of the pad (212) (232).

More specifically, the carrier 100 for a double-side polishing apparatus includes a carrier plate 120 installed between the upper plate 210 and the lower plate 230, and a dressing block 140 installed on the carrier plate 120. .

The carrier plate 120 has a gear 121 formed on the outer circumferential surface thereof so as to be engaged with the sun gear 220 and the internal gear 240. In addition, the carrier plate 120 is provided with a mounting hole 122 for mounting the wafer W and a plurality of discharge holes 124 for discharging the polishing liquid.

A wafer W is installed in the mounting hole 122, and a holding part 123 is installed at an inner circumference of the mounting hole 122 to prevent damage to an edge portion of the wafer W. Can be. For example, the holding part 123 is made of aramid resin to protect the chamfer of the wafer W from being damaged.

The plurality of discharge holes 124 are formed through the carrier plate 120 to discharge the polishing liquid. Therefore, the polishing liquid is supplied to the pad 232 of the lower surface plate 230, that is, the lower surface of the wafer W through the upper surface of the wafer W and the discharge hole 124.

The dressing block 140 is installed in the discharge hole 124. More specifically, the dressing block 140 is formed so as to penetrate the center portion is formed through the polishing liquid is inserted into the discharge hole 124 is installed. For example, the dressing block 140 may be installed by being bonded to the carrier 100 for manufacturing the double-side polishing apparatus, or may be selectively fitted into the discharge hole 124 of the carrier plate 120 that is already manufactured.

When the dressing block 140 is integrally formed in the manufacture of the carrier plate 120, the dressing block 140 is preferably installed in the plurality of outlet holes 124.

In addition, when the dressing block 140 is selectively fitted to the discharge hole 124, that is, when it is selectively detachably installed, the dressing block 140 may include at least one discharge hole among the plurality of discharge holes 124. 124 is preferably installed. Although not shown, the inner circumferential surface of the discharge hole 124 of the carrier plate 120 and the outer circumferential surface of the dressing block 140 are gear-shaped to fit each other when the dressing block 140 is attached to the discharge hole 124. Is formed. Accordingly, the dressing block 140 is easily detached from the discharge hole 124 and the dressing block 140 is engaged with the gear of the discharge hole 124 when the carrier plate 120 rotates.

 In addition, the dressing block 140 is preferably made of diamond. The dressing block 140 is made of a diamond material to facilitate polishing of the pads 212 and 232, which are commonly used, and thus, detailed description thereof will be omitted.

On the other hand, although the dressing block 140 is shown in each of the plurality of discharge holes 124 is installed, the number of installation of the dressing block 140 can be appropriately increased or decreased in consideration of the required degree of polishing, given polishing time, and the like. have.

The dressing block 140 is installed to have a thickness equal to the carrier plate 120 or a thickness smaller than the thickness of the carrier plate 120 when installed in the discharge hole 124. Thus, the polishing liquid supplied when the wafer W is polished is smoothly supplied to the lower plate 230 pad 232 through the discharge hole 124. In addition, the dressing block 140 of the carrier plate 120 in consideration of the compression range of the pads 212 and 232 due to the processing pressure of the upper plate 210 and the lower plate 230 of the double-side polishing apparatus 200. It is made of a thickness equal to or smaller than the thickness. Here, the thickness as small as a predetermined interval is a state in which the pads 212, 232 can be processed to maintain the flatness while polishing the wafer (W) according to the compression range of the pads (212, 232) and the degree of polishing of the pads It should be understood that the range of.

Therefore, the wafer W and the dressing block 140 installed on the carrier 100 for the double-side polishing apparatus are brought into contact with the pads 212 and 232 of the upper plate 210 and the lower plate 230 so as to contact the wafer W. Along with polishing, the conditioning work, which is the planarization process of the pads 212 and 232, is simultaneously performed.

Meanwhile, reference numeral '110', which is not described, is a carrier holder for installing the carrier 100 for the double-side polishing apparatus.

Next, a method of polishing using the carrier 100 for a double-side polishing apparatus having the above structure will be described.

First, a carrier 100 for a double-side polishing apparatus is installed between the top plate 210 and the bottom plate 230 of the double-side polishing apparatus 200. In this case, the gear 121 formed on the outer circumferential surface of the carrier 100 is installed to mesh with the sun gear 220 and the internal gear 240.

After installing the carrier 100 for the double-side polishing apparatus, the upper and lower plates 210 and 230 are rotated by angles. Since the upper plate 210 and the lower plate 230 rotate in opposite directions, the sun gear 220 and the internal gear 240 also rotate in opposite directions, so that the carrier 100 for the double-side polishing device rotates. The pads 212 and 232 are polished at the same time as the revolving process, and the wafers W are polished by the pads 212 and 232.

As a result, by grinding the wafer W and simultaneously conditioning the pads 212 and 232, the service life of the pads 212 and 232 is improved, as well as the productivity and quality of the wafer W. This is improved.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto, and the technical spirit of the present invention and the following will be understood by those skilled in the art to which the present invention pertains. Various modifications and variations are possible, of course, within the scope of equivalents of the claims to be described.

1 is a plan view showing a carrier for a double-side polishing apparatus according to a preferred embodiment of the present invention.

Figure 2 is a partially cut perspective view showing a double-side polishing apparatus according to a preferred embodiment of the present invention.

3 is a cross-sectional view showing a double-side polishing apparatus according to a preferred embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100 carrier 120 carrier plate

140: dressing block 200: double-sided polishing apparatus

210: upper plate 230: lower plate

220: sun gear 240: internal gear

212, 232: Pad W: Wafer

Claims (8)

A carrier plate installed between the upper and lower plates of the double-side polishing apparatus and rotated by the sun gear and the internal gear, and having a mounting hole for mounting the wafer and a plurality of discharge holes for discharging the polishing liquid; And And a dressing block inserted into the discharge hole and grinding the pad of the upper plate and the pad of the lower plate as the carrier plate is rotated. The dressing block is installed in all discharge holes or at least one discharge hole, When the dressing block is installed in the discharge hole is bonded to a carrier for a double-side polishing apparatus, characterized in that attached to the carrier plate integrally. The method of claim 1, Dressing block is a carrier for a double-side polishing apparatus, characterized in that the center portion is formed through. 3. The method of claim 2, The dressing block is configured to have a thickness corresponding to the thickness of the carrier plate so as to smoothly discharge the polishing liquid, or a carrier for a double-side polishing apparatus, characterized in that the thickness is smaller than the thickness of the carrier plate by a predetermined interval. The method of claim 1, A carrier for a double-side polishing apparatus, characterized in that the dressing block is diamond. delete delete A carrier plate installed between the upper and lower plates of the double-side polishing apparatus and rotated by the sun gear and the internal gear, and having a mounting hole for mounting the wafer and a plurality of discharge holes for discharging the polishing liquid; And And a dressing block inserted into the discharge hole and grinding the pad of the upper plate and the pad of the lower plate as the carrier plate is rotated. A carrier for a double-side polishing apparatus, characterized in that the dressing block and the discharge hole are formed in a gear shape so that the dressing block is selectively detachable. (a) installing a carrier according to any one of claims 1 to 4 and 7 between an upper plate and a lower plate of the double-side polishing apparatus; And (b) operating both sides of the wafer to polish both sides of the wafer and simultaneously polishing the pads of the upper plate and the lower plate by the carrier; both sides using the carrier for the double-side polishing device, comprising: Polishing method.

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