KR20080061992A - Chemical mechanical polishing device - Google Patents

Abstract

From the polishing pad, a supply for supplying a polishing slurry on a CMP pad, a polishing head for introducing a wafer to be polished, and a polishing residue caused by polishing of the wafer are filtered from the polishing pad. A chemical mechanical polishing apparatus including a residue retaining plate to be removed is provided.

Description

Chemical mechanical polishing apparatus

1 is a view schematically illustrating a chemical mechanical polishing (CMP) apparatus according to an embodiment of the present invention.

2 and 3 are schematic views for explaining a polishing residue removing unit according to an embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of semiconductor devices, and more particularly to a chemical mechanical polishing (CMP) device.

As the degree of integration of semiconductor devices is increased and design rules are reduced, a process of planarizing a layer by introducing a chemical mechanical polishing process is used. For example, chemical mechanical polishing is used to planarize an insulating layer which insulates a semiconductor element from an element, and to remove a target layer. The performance of the CMP process may involve the occurrence of polishing defects, such as scratches, on the surface of the polished layer. Abrasive scratches may be caused by polishing residues, such as residues of polished film or slurry residues, resulting from polishing on the polishing pad.

Abrasive scratches are defects that cause defects in the operation of semiconductor devices, thereby limiting the application of chemical mechanical polishing to semiconductor device manufacturing processes. Thus, in order to suppress or reduce chemical mechanical polishing (CMP) scratch defects, it is possible to pre-filter the aggregated particles of the polishing slurry provided for polishing, or to condition the polishing pad surface by a conditioner. Methods are suggested. Nevertheless, there is still a need for the development of a method that can effectively suppress the occurrence of abrasive scratches by substantially abrasive residues.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a chemical mechanical polishing (CMP) device capable of suppressing the occurrence of scratch defects on a surface of a polishing target layer on a wafer on which semiconductor devices are integrated.

One aspect of the present invention for the above technical problem, a chemical mechanical polishing pad (pad), a supply for supplying a polishing slurry (slurry) on the pad, a polishing head (head) for introducing a wafer to be polished on the pad And a residue retaining plate for filtering out the polishing residue caused by polishing of the wafer and removing it from the polishing pad.

A chemical mechanical polishing apparatus further includes a support body for supporting an edge portion of the locking plate to contact the surface of the polishing pad, and a cleaning liquid spraying unit for spraying a cleaning liquid on the polishing residue filtered by the locking plate.

The edge portion of the locking plate may be formed of a soft material to make contact with the surface of the polishing pad. The locking plate is positioned in front of the slurry supply portion and introduced to prevent the polishing residue from reaching the slurry supplied with.

According to the present invention, a chemical mechanical polishing (CMP) device capable of suppressing polishing scratch defects on the surface of a polishing target layer on a wafer on which semiconductor elements are integrated can be provided.

An embodiment of the present invention provides a chemical mechanical polishing (CMP) apparatus incorporating a polishing residue removal unit for filtering out by-product film residue and slurry residues generated by polishing remaining on a polishing pad. The abrasive residue removal portion serves to pre-filter the abrasive residue so that it does not reach the portion where the abrasive slurry is newly supplied. The abrasive residue removal portion is provided with a cleaning liquid such as deionized water which is bonded on the polishing pad to filter the polishing residue, and deionized water which removes the polishing residue filtered by the residue locking plate from the polishing pad. It may be configured to include a cleaning liquid injection unit for spraying.

By introducing the polishing residue removing unit including the locking plate and the cleaning liquid spraying unit, it is possible to remove polishing residues such as by-products or slurry residues generated after polishing from the polishing pad surface. The polishing slurry is supplied onto the polishing pad from which the polishing residue is removed to perform polishing of the polishing target layer. Therefore, it is possible to suppress or prevent the occurrence of abrasive scratches by scratch-inducing particle sources such as abrasive residues.

1 is a view schematically illustrating a chemical mechanical polishing (CMP) apparatus according to an embodiment of the present invention. 2 and 3 are schematic views for explaining a polishing residue removing unit according to an embodiment of the present invention.

Referring to FIG. 1, in the chemical mechanical polishing apparatus according to an embodiment of the present invention, a polishing pad 100 for chemical mechanical polishing is attached onto a polishing table, and a wafer is held on the polishing pad 100. A grinding head portion 200 to be introduced is introduced. A slurry supply unit 300 or a slurry inlet for supplying a polishing slurry on the polishing pad 100 is introduced. In addition, conditioner 400 is introduced to restore or activate the surface of polishing pad 100.

The slurry supplied by the slurry supply unit 300 is supplied onto the polishing pad 200 which is rotated by the rotation of the polishing table, and the wafer and the polishing pad under the polishing head unit 200 are rotated by the polishing pad 200. It is supplied to the interface region between the 200 surfaces. The polishing process is performed on the surface of the wafer by the polishing action of the polishing slurry and the polishing pad 200. Polishing residues may be left on the polishing pad 100, including polishing by-products such as film material particles falling off from the polishing target layer by the polishing process, or slurry residues used for polishing. A residue retaining plate 500 for filtering out the polishing residue from the polishing pad 100 is introduced into contact with the polishing pad 100.

2 and 3 together with FIG. 1, the residue retaining plate 500 may be introduced in the form of a blade that contacts the surface across the polishing pad 100. The residue retaining plate 500 is composed of a soft material having an edge portion 501 in contact with the polishing pad 100, and remains in contact with the surface of the polishing pad 100 and remains on the surface of the polishing pad 100. It serves to filter water (101 in FIG. 2). Since the polishing pad 100 is rotating, when the residue stopping plate 500 is fixed in contact with the surface of the polishing pad 100, the polishing residues 101 are caught by the residue stopping plate 500.

Accordingly, the polishing residue 101 no longer remains in the polishing pad portion 103 at the back passing through the residue retaining plate 500. Thus, the polishing pad portion 103 at the rear has a substantially clean surface state, and the polishing pad 100 portion 103 in this clean surface state is provided below the slurry supply portion (300 in FIG. 1). Thus, the slurry to be supplied is provided to the polishing pad 100 portion 103 in a clean surface state, and this slurry is provided to the polishing target surface of the wafer under the polishing head portion 200. Therefore, it is possible to substantially suppress that the polishing residue is provided at the interface between the wafer and the polishing pad 100, that is, the polishing surface. It is possible to prevent the polishing residue from being undesirably provided on the polishing surface, thereby substantially suppressing or preventing the occurrence of scratch defects caused by the polishing residue.

Depending on the angle across the polishing pad 100 of the residue retaining plate 500, the stuck polishing residue 101 may be pushed out of the polishing pad 100 to be removed. Nevertheless, in order to more effectively remove the abrasive residue 101 caught in the residue retaining plate 500, injection of a cleaning liquid such as deionized water may be introduced. For example, the residue retaining plate 500 may be supported by a support body 510 in the form of a bar as shown in FIGS. 2 and 3.

The support body 510 may be formed of a hard material and may be formed of a material that does not cause a pollution source. The body 510 may be provided with a cleaning solution spraying unit 530 for spraying a cleaning solution to the polishing residues filtered by the locking plate 500. The cleaning liquid spraying unit 530 sprays the cleaning liquid, for example, deionized water or pure water, to the polishing residue 101 caught on the locking plate 500 through an injection nozzle or the like. Accordingly, the caught abrasive residue 101 is pushed out of the polishing pad 100 by the spraying pressure of the cleaning liquid.

In this way, when the cleaning liquid injection is introduced, it is possible to more effectively suppress the polishing residue 101 from affecting the newly supplied polishing slurry. In addition, since the abrasive residue 101 is removed by the injection of the cleaning liquid, foreign matter that can flow around the polishing table from inside and outside the chemical mechanical polishing apparatus can also be removed.

According to the present invention described above, it is possible to suppress the occurrence of scratch defects on the polishing surface of the wafer or the polishing target film due to the polishing residue. In addition, it is possible to suppress the foreign matter which may enter the chemical mechanical polishing apparatus from affecting the polishing surface. Particle sources that can cause scratch defects can be effectively removed, resulting in a more stable chemical mechanical polishing process and improving the efficiency of the polishing process.

As mentioned above, although this invention was demonstrated in detail through the specific Example, it is not preferable that this invention is interpreted as limited to this. Embodiments of the invention are preferably to be interpreted as being provided to those skilled in the art to more fully describe the invention. In addition, it can be understood that the present invention can be modified or improved by those skilled in the art within the technical idea of the present invention.

Claims (4)

Chemical mechanical polishing pads; A supply unit for supplying a polishing slurry on the pad; A polishing head portion for introducing a wafer to be polished on the pad; And And a residue retaining plate that filters the polishing residue caused by polishing of the wafer and removes it from the polishing pad. The method of claim 1, A support body supporting the edge portion of the locking plate against the polishing pad surface; And And a cleaning liquid spraying unit for spraying a cleaning liquid to the polishing residues filtered by the locking plate. The method of claim 2, An edge portion of the locking plate is formed of a soft material to contact the surface of the polishing pad. The method of claim 1, And the locking plate is located in front of the slurry supply unit to prevent the polishing residue from reaching the slurry to which the polishing residue is supplied.

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