KR20100119398A

KR20100119398A - Apparatus of chemical mechanical polishing

Info

Publication number: KR20100119398A
Application number: KR1020090038495A
Authority: KR
Inventors: 이상현
Original assignee: 주식회사 하이닉스반도체
Priority date: 2009-04-30
Filing date: 2009-04-30
Publication date: 2010-11-09

Abstract

A platen to which the polishing pad to be used for polishing the wafer is attached and rotated, a wafer head portion to mount the wafer and to be introduced onto the polishing pad; A conditioner which is positioned at the rear side of the wafer head portion with respect to the rotational direction of the platen and removes by-products accompanying polishing of the wafer from the polishing pad, and is positioned at the front of the wafer head portion with respect to the rotational direction of the platen. A slurry nozzle part for dispersing slurry to the polishing pad portion in front of the wafer head part, a slurry supply part connected to the slurry nozzle part to supply slurry, and a slurry nozzle part connected to the slurry nozzle part A chemical mechanical polishing equipment including a pressurized gas supply for supplying pressurized gas to a slurry nozzle portion to provide a spray pressure for injecting a pressurized spray into the slurry nozzle unit.

Description

Apparatus of chemical mechanical polishing

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor device manufacturing equipment, and more particularly, to chemical mechanical polishing (CMP) equipment for suppressing scratches on a wafer.

As semiconductor devices such as memory devices are rapidly integrated and pattern sizes are reduced, planarization processes using chemical mechanical polishing (CMP) have been introduced to alleviate the step difference caused largely on a wafer. This chemical mechanical polishing process is introduced not only in the planarization of the interlayer insulating layer but also in the patterning of the conductive layer. Moreover, in order to increase the productivity of semiconductor devices, the use of 300 mm large diameter wafers with a larger aperture diameter than 200 mm is frequently used, and more CMP processes are also introduced.

When performing the CMP process, scratches may be caused on the surface of the polishing target layer on the wafer, and such scratches may act as a cause of device defects. In order to prevent scratches, a disk-type conditioner is introduced. The conditioner is introduced in front of the head for holding and introducing the wafer based on the rotation direction of the platen on which the polishing pad is mounted. At the front of the conditioner, a slurry supply unit for supplying a slurry is introduced to supply the slurry by dropping the slurry onto the polishing pad.

The supplied slurry is moved to the position where the conditioner is introduced by the rotation of the platen, and the disk of the conditioner is rotated with a sweep operation to disperse the supplied slurry onto the polishing pad. This sweep and rotation of the disk causes the slurry on the polishing pad to be dispersed in the polishing pad, and the portion of the polishing pad in which the slurry is dispersed is moved to the head mounted wafer by rotation of the platen. As the conditioner is positioned at the front end of the wafer head, it is difficult to effectively remove the by-products generated by the polishing of the wafer. In addition, there is a limit to evenly spraying the slurry into the pad by the action of the conditioner alone.

Since the slurry feeding method simply drops the slurry onto the pad from above, the polishing pad area that the slurry initially reaches is very limited. Slurry away from one place on such limited polishing pads is limited in being effectively and evenly dispersed within the pads by conditioning through diamond disks. In addition, the wear on the pad due to the diamond disk may be increased, leading to an increase in the scratch causing source.

As the slurry is conditioned before reaching the wafer, foreign matter present in the pores or grooves of the polishing pad, such as excessively sized slurry particles or abrasive by-products, pad contaminants, pad debris, etc. Scratch sources can be mixed with the slurry to polish the wafer. In this case, scratching of the wafer may be caused more severely.

The present invention is to provide a chemical mechanical polishing (CMP) equipment that can increase the conditioning effect on the polishing pad to effectively suppress the occurrence of scratches on the wafer.

One aspect of the present invention is a platen attached to the rotating polishing pad to be used for polishing the wafer (platen); A wafer head portion which mounts the wafer and is introduced onto the polishing pad; A conditioner introduced at a rear side of the wafer head portion with respect to the rotational direction of the platen to remove by-products accompanying polishing of the wafer from the polishing pad; A slurry nozzle part which is positioned in front of the wafer head part with respect to the rotational direction of the platen and sprays a slurry to be dispersed in the polishing pad part in front of the wafer head part; A slurry supply part connected to the slurry nozzle part to supply the slurry; And a pressurized gas supply unit connected to the slurry nozzle unit to supply a pressurized gas to the slurry nozzle unit to provide a pressurized gas for injecting the slurry onto the polishing pad.

The slurry nozzle unit may include a rectangular or elliptical nozzle hole extending in a direction transverse to the platen.

The rectangular nozzle port may be provided in plural numbers so as to be connected in a direction transverse to the platen.

The pressurized gas supply unit may provide nitrogen gas (N ₂ ) at a pressure of 15 lbf as the pressurized gas.

Embodiment of the present invention can provide a chemical mechanical polishing (CMP) equipment that can effectively suppress the occurrence of scratches on the wafer to increase the conditioning effect on the polishing pad.

1 to 3 are views showing the chemical mechanical polishing equipment according to an embodiment of the present invention.

Referring to FIG. 1, a chemical mechanical polishing (CMP) device according to an exemplary embodiment of the present invention includes a platen 100 that is attached and rotated with a polishing pad 101 to be used to polish a wafer. When CMP polishing, the platen 100 is rotated in the platen rotation direction. At this time, the platen 100 is rotated at a speed of approximately 87rpm. A wafer head 200 for introducing a wafer to be polished on the platen 100 is introduced, and the wafer head 200 has an edge at the center of the polishing pad 101 for uniform polishing of the wafer. Fine movement is performed in the negative direction or the opposite direction.

A conditioner 300 is introduced, including a diamond disk 301, positioned behind the wafer head 200 with respect to the rotational direction of the platen. The conditioner 300 is located at the rear side of the wafer head portion 200 where the polishing action is performed so that the diamond disk 301 conditions the portion of the polishing pad 101 participating in the polishing. Accordingly, the portion of the polishing pad 101 that participates in the polishing action in the wafer head portion 200 moves to the conditioner 300 position by the rotation of the platen 100, and the diamond disk 301 of the conditioner 300 is moved. It is recovered by sweep and rotational motion. The diamond disk 301 rotates at approximately 93 rmp higher than the rotation speed of the platen 100 and is controlled to reciprocate on the polishing pad 101 about 19 times per minute. The conditioner 300 serves to remove by-products and foreign matters accompanying polishing of the wafer from the polishing pad 101 and to discharge them, and to restore the grooves and the surface state of the polishing pad 101 to the normal state. Do it.

Since the conditioner 300 is located at the rear side of the wafer head part 200, the conditioning operation may be more effectively performed than when the conditioner 300 is located at the front side of the wafer head part 200. Since the conditioner 300 directly and immediately removes by-products and foreign matters caused by the CMP action in the wafer head 200, these by-products and foreign matters are introduced into the new slurry supplied to the polishing pad 101 and the slurry is removed. Can be effectively inhibited from being contaminated or reintroduced into the wafer head portion 200 being polished, thereby acting as a source that causes defects such as scratches on the wafer.

A slurry nozzle 400 for supplying a slurry for polishing the wafer is introduced to be positioned in front of the wafer head 200 with respect to the rotational direction of the platen 100. The slurry nozzle unit 400 is introduced such that a nozzle hole 403 is provided in the nozzle bar 401, and the nozzle hole 403 is provided to face the surface of the polishing pad 101. The slurry nozzle portion 400 is introduced at a position opposite the conditioner 300 with the wafer head portion 200 interposed therebetween, and in front of the wafer head portion 200 and the conditioner 300 in consideration of the rotation of the platen. It is introduced to be located on the back side.

As the slurry nozzle part 400 is introduced to the rear side of the conditioner 300, the slurry 405 supplied through the slurry nozzle part 400 is part of the polishing pad 101 in which impurities and foreign substances have been removed and recovered by conditioning. To be provided. Since the portion of the polishing pad 101 where the slurry 405 is provided is already conditioned by the conditioner 300, scratch sources such as by-products caused by the CMP polishing process or debris or slurry particles used for polishing oversized sizes may be removed. Incorporation into the newly supplied slurry 405 can be effectively suppressed. Accordingly, the slurry 405 transferred to the wafer head 200 by the rotation of the platen 100 may maintain a clean state in which a scratch source such as a byproduct or a foreign material is prevented from being mixed, and thus the slurry 405 may be maintained. The induction of scratches can be effectively suppressed on the wafer to be CMP by the action of.

On the other hand, in the embodiment of the present invention, since it is difficult to expect the dispersing action of the slurry 405 by the conditioner 300, the slurry 405 provided at the time of supply of the slurry 405 is evenly distributed on the polishing pad 101. The slurry 405 supplied through the nozzle hole 403 of the slurry nozzle part 400 may be supplied by a pressure injection method. To this end, as shown in FIG. 2, the nozzle bar 401 is connected to a slurry supply part 407 for supplying the slurry 405, and also pressurized to supply a pressurized gas that provides an injection pressure for pressurized injection. The gas supply part 409 is connected. The pressurized gas supply part 409 provides nitrogen gas N ₂ to the nozzle port 403 through the nozzle bar 401 at a pressure of approximately 15 blf.

The slurry 405 is injected and supplied to the area on the polishing pad 101 which is wider than the opening area of the nozzle port 403 by such a pressure injection method. At this time, the nozzle port 403 is provided to have a rectangular or oval shape as shown in FIG. 2 in a circular form so that the slurry 405 is provided in a wider polishing pad 101 area. At this time, the long axis direction of the rectangular or oval nozzle port 403 is set in the longitudinal direction of the polishing pad 101, that is, the direction crossing the platen 100 to cross, the rectangular nozzle port 403 extending long. By rotating the platen 100, the slurry 405 is evenly sprayed on the surface of the polishing pad 101 having a larger area. Further, in consideration of the large area of the polishing pad 101, two or more nozzle nozzles 403 are arranged so that the ends of the longitudinal direction are connected in the direction crossing the platen 100 as shown in FIG. Be sure to By introducing a plurality of nozzle holes 403 in this manner, the slurry 405 is evenly sprayed onto the area on the wide polishing pad 101.

Since the slurry 405 of FIG. 1 is sprayed onto the polishing pad 101 by a pressure spray method, it is possible to directly supply and disperse the slurry onto the surface of the polishing pad 101, unlike the method of dropping the slurry by free fall. Do. Thus, it is not necessary to have the conditioner 300 disposed behind the slurry nozzle portion 400 subsequent to the slurry nozzle portion 400 for the dispersion of the slurry 405. In addition, since the slurry 405 is provided on the polishing pad 101 in a pressurized spraying manner, the spraying pressure can induce the effect of evenly dispersing the particles in the slurry 405, thereby causing scratches due to the aggregation of the slurry particles. Induction can be suppressed.

In the embodiment of the present invention, since the polishing pad 101 is conditioned before the slurry 405 is provided, the slurry 405 provided on the polishing pad 101 is mixed with by-products, foreign matters or debris generated during CMP polishing. This can effectively suppress the flow into the wafer under CMP. Further, before the slurry 405 is provided, the slurry may be conditioned on the surface of the polishing pad 101 in which the polishing pad 101 is conditioned so that pores present in the polishing pad 101 are not blocked and kept in an open state. 405 may be provided. Accordingly, the polishing pad 101 can polish the wafer in a cleaner state, thereby inducing the effect of increasing the life of the pad 101.

The condition of the polishing pad 101 can be improved more effectively, and the forced pressure injection of the slurry 405 can lead to the slurry 405 being more evenly dispersed on the polishing pad 101, A constant polishing removal profile can be realized by inducing an improvement in polishing rate of CMP polishing and also by reducing fluctuations in the polishing removal profile.

1 is a view showing a chemical mechanical polishing equipment according to an embodiment of the present invention.

2 and 3 are views showing a slurry nozzle unit according to an embodiment of the present invention.

Claims

A platen to which a polishing pad to be used for polishing the wafer is attached and rotated;

A wafer head portion which mounts the wafer and is introduced onto the polishing pad;

A conditioner introduced at a rear side of the wafer head portion with respect to the rotational direction of the platen to remove by-products accompanying polishing of the wafer from the polishing pad;

A slurry nozzle part which is positioned in front of the wafer head part with respect to the rotational direction of the platen and sprays a slurry to be dispersed in the polishing pad part in front of the wafer head part;

A slurry supply part connected to the slurry nozzle part to supply the slurry; And

And a pressurized gas supply unit connected to the slurry nozzle unit to supply pressurized gas to the slurry nozzle unit to provide a pressurized pressure for inducing the slurry to be pressurized onto the polishing pad.

The method of claim 1,

The slurry nozzle unit comprises a rectangular or elliptical nozzle hole extending in the direction transverse to the platen and chemical mechanical polishing equipment.

The method of claim 2,

Wherein the rectangular nozzle sphere is a plurality of chemical mechanical polishing equipment is arranged in a row in the direction transverse to the end of the platen.

The method of claim 1,

The pressurized gas supply unit provides nitrogen gas (N ₂ ) to the pressurized gas at a pressure of 15 lbf.