Chemical mechanical polishing apparatus and method having a soft backed polishing head
First Claim
1. A polishing head for positioning a substrate having a surface on a polishing surface of a polishing apparatus having a drive mechanism to rotate the polishing head during the polishing operation, the polishing head comprising:
- a carrier adapted to hold the substrate during a polishing operation, the carrier having a lower surface;
a flexible member secured to the carrier and extending across the lower surface thereof, the flexible member having a receiving surface adapted to engage the substrate, and a plurality of openings extending through a thickness of the flexible member to the receiving surface;
a spacer disposed between the flexible member and the lower surface to form a cavity defined by the lower surface of the carrier, the spacer, the flexible member and the substrate;
a passageway in communication with the lower surface for introducing a pressurized fluid into the cavity so as to press the substrate against the polishing surface during the polishing operation;
wherein the number and size of the plurality of openings are selected to enable the pressurized fluid to be applied directly to the substrate; and
wherein at least one of the plurality of openings has an edge angled in relation to a direction of rotation of the polishing head to stiffen the flexible member to increase coupling of rotational energy to substrate.
1 Assignment
0 Petitions
Accused Products
Abstract
A polishing apparatus (100) and method for polishing and planarizing a substrate (105) is provided that achieves a high-planarization uniformity across the substrate, while providing a more efficient use of slurry. In one embodiment, the apparatus (100) includes a subcarrier (160) with a flexible member (185) attached to a lower surface (165) of it on which the substrate is held. The flexible member (185) has at least one hole (195) therein so that a pressurized fluid introduced between the flexible member and the subcarrier (160) directly presses the substrate (105) against a polishing surface (125) during operation. The number and size of the holes (195) are selected to provide sufficient friction between the flexible member (185) and the substrate (105) to cause it to rotate when a drive mechanism rotates the subcarrier (160). In another embodiment, the subcarrier (160) further includes a port adapted to draw a vacuum on a cavity (215) between the lower surface (165) and the flexible member (185), and the flexible member and the substrate (105) serve as a valve (225) to isolate the port from the cavity when a predetermined vacuum has been achieved.
40 Citations
34 Claims
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1. A polishing head for positioning a substrate having a surface on a polishing surface of a polishing apparatus having a drive mechanism to rotate the polishing head during the polishing operation, the polishing head comprising:
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a carrier adapted to hold the substrate during a polishing operation, the carrier having a lower surface;
a flexible member secured to the carrier and extending across the lower surface thereof, the flexible member having a receiving surface adapted to engage the substrate, and a plurality of openings extending through a thickness of the flexible member to the receiving surface;
a spacer disposed between the flexible member and the lower surface to form a cavity defined by the lower surface of the carrier, the spacer, the flexible member and the substrate;
a passageway in communication with the lower surface for introducing a pressurized fluid into the cavity so as to press the substrate against the polishing surface during the polishing operation;
wherein the number and size of the plurality of openings are selected to enable the pressurized fluid to be applied directly to the substrate; and
wherein at least one of the plurality of openings has an edge angled in relation to a direction of rotation of the polishing head to stiffen the flexible member to increase coupling of rotational energy to substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of polishing a substrate having a surface using a polishing apparatus having a polishing head, a polishing surface and a drive mechanism to rotate the polishing head during the polishing operation, the polishing head having a carrier provided with a lower surface and a flexible member extending across the lower surface, the flexible member having a receiving surface adapted to engage the substrate, and a plurality of openings extending through a thickness to the receiving surface, the method comprising steps of:
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positioning the substrate on the receiving surface to form a cavity defined by the lower surface of the carrier, the flexible member and the substrate;
positioning the polishing head on the polishing surface so that the surface of the substrate rests on the polishing surface;
introducing a pressurized fluid into the cavity through a passageway in communication with the lower surface so as to press the substrate against the polishing surface during the polishing operation, the pressurized fluid extending through the openings so as to be exerted directly against the substrate; and
rotating the polishing head to impart rotational energy to substrate, wherein at least one of the plurality of openings has an edge angled in relation to a direction of rotation of the polishing head to stiffen the flexible member to increase coupling of rotational energy to substrate. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21)
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22. A polishing head for positioning a substrate having a surface on a polishing surface of a polishing apparatus, the polishing head comprising:
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a carrier adapted to hold the substrate during a polishing operation, the carrier having a lower surface, and a port extending through the lower surface for supplying suction;
a flexible member secured to the carrier and extending across the lower surface, the flexible member having a receiving surface for engaging the substrate, and at least one hole extending through the thickness to the receiving surface;
a spacer disposed between the flexible member and the lower surface to form a cavity defined by the lower surface of the carrier, the spacer, the flexible member and the substrate; and
wherein the flexible member is movable from first position in which the flexible member is spaced apart from the lower surface in the vicinity of the port and a second position in which a portion of the flexible member engages the lower surface around the port to cover and seal the port when a predetermined vacuum has been achieved, thus minimizing undesirable stresses on the substrate. - View Dependent Claims (23, 24, 25, 26, 27, 28)
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29. A method of polishing a substrate having a surface using a polishing apparatus comprising a polishing surface and a polishing head adapted to hold the substrate during a polishing operation, the polishing head having a carrier with a lower surface, a flexible member secured to the carrier and extending across the lower surface, the flexible member having a receiving surface adapted to receive the substrate, the flexible member having a thickness and at least one hole extending through the thickness to the receiving surface, and a spacer disposed between the flexible member and the lower surface, the method comprising steps of:
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receiving the substrate on the receiving surface, to form a cavity defined by the lower surface of the carrier, the spacer, the flexible member and the substrate;
drawing a vacuum on the cavity through a port in the lower surface, to hold the substrate to the carrier;
isolating the port from the cavity when a predetermined vacuum has been achieved by covering and sealing the port with a portion of the flexible member, thereby minimizing an amount of stress to which the substrate is exposed; and
positioning the surface of the substrate on the polishing surface. - View Dependent Claims (30)
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31. A polishing head for positioning a substrate having a surface on a polishing surface of a polishing apparatus having a drive mechanism to rotate the polishing head during the polishing operation, the polishing head comprising:
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a carrier adapted to hold the substrate during a polishing operation, the carrier having a lower surface, and a port extending through the lower surface for supplying suction;
a flexible member secured to the carrier and extending across the lower surface thereof, the flexible member having a receiving surface for engaging the substrate, and a plurality of openings extending through a thickness of the flexible member to the receiving surface;
a spacer disposed between the flexible member and the lower surface to form a cavity defined by the lower surface of the carrier, the spacer, the flexible member and the substrate;
a passageway in communication with the lower surface for;
drawing a vacuum on the cavity to hold the substrate against the receiving surface during a loading operation; and
introducing a pressurized fluid into the cavity so as to press the substrate against the polishing surface during the polishing operation;
wherein the number and size of the plurality of openings are selected to enable the pressurized fluid to be applied directly to the substrate;
wherein at least one of the plurality of openings has an edge angled in relation to a direction of rotation of the polishing head to stiffen the flexible member to increase coupling of rotational energy to substrate; and
wherein the flexible member is movable from first position in which the flexible member is spaced apart from the lower surface in the vicinity of the port and a second position in which a portion of the flexible member engages the lower surface around the port to cover and seal the port when a predetermined vacuum has been achieved, thus minimizing undesirable stresses on the substrate. - View Dependent Claims (32, 33, 34)
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Specification