Chemical/mechanical polishing for ULSI planarization
First Claim
1. A method of forming a planar surface on a semiconductor wafer, on which there is a rugged surface with broad indentations, comprising the steps of:
- forming a first layer over said rugged surface;
forming a hard film layer over said first layer;
patterning said first layer and said hard film layer to form polishing stop islands in the broad indentations;
forming a second layer over said rugged surface and said polishing stop islands, to create a top surface for polishing, said top surface and said rugged surface being less hard than said hard film layer;
polishing said top surface in a vertical direction to remove portions of said top surface, until said top surface is co-planar with top of said polishing stop islands; and
removing the remainder of said hard film layer to complete said planar surface.
2 Assignments
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Accused Products
Abstract
A method of planarizing a wafer surface by using a polishing stop with chemical/mechanical polishing is described. A semiconductor wafer, on which there is a rugged surface with broad indentations, is provided. A first layer is formed over the rugged surface. A hard film layer is formed over the first layer. The first layer and the hard film layer are patterned to form polishing stop islands in the broad indentations. A second layer is formed over the rugged surface and the polishing stop islands, to create a top surface for polishing, the top surface and the rugged surface being less hard than the hard film layer. The top surface is polished in a vertical direction to remove portions of the top surface, until the top surface is co-planar with the top of the polishing stop islands. The remainder of the hard film layer is removed to complete the planar surface.
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Citations
20 Claims
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1. A method of forming a planar surface on a semiconductor wafer, on which there is a rugged surface with broad indentations, comprising the steps of:
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forming a first layer over said rugged surface; forming a hard film layer over said first layer; patterning said first layer and said hard film layer to form polishing stop islands in the broad indentations; forming a second layer over said rugged surface and said polishing stop islands, to create a top surface for polishing, said top surface and said rugged surface being less hard than said hard film layer; polishing said top surface in a vertical direction to remove portions of said top surface, until said top surface is co-planar with top of said polishing stop islands; and removing the remainder of said hard film layer to complete said planar surface. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of forming a planar surface on a semiconductor wafer on which there is a first dielectric layer and a patterned first metal layer, comprising the steps of:
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forming a second dielectric layer with broad indentations over said first dielectric layer and said patterned first metal layer; forming a third dielectric layer over said second dielectric layer; forming a hard film layer over said third dielectric layer; patterning said third dielectric layer and said hard film layer to form polishing stop islands in said broad indentations; forming a fourth dielectric layer over said second dielectric layer and said polishing stop islands, to create a top surface for polishing, said fourth and second dielectric layers being less hard than said hard film layer; polishing said top surface in a vertical direction to remove portions of said top surface, until said top surface is co-planar with top of said polishing stop islands; and removing the remainder of said hard film layer to complete said planar surface. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A method of forming a semiconductor wafer having multiple levels of metallization with planar interlevel dielectric layers between each level of metallization, on which there is a first dielectric layer with broad indentations and a patterned first metal layer, comprising the steps of:
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forming a second dielectric layer over said first dielectric layer and said patterned first metal layer; forming a third dielectric layer over said second dielectric layer; forming a hard film layer over said third dielectric layer; patterning said third dielectric layer and said hard film layer to form polishing stop islands in the broad indentations; forming a fourth dielectric layer over said second dielectric layer and said polishing stop islands, to create a top surface for polishing, said fourth and second dielectric layers being less hard than said hard film layer; polishing said top surface in a vertical direction to remove portions of said top surface, until said top surface is co-planar with top of said polishing stop islands; and removing the remainder of said hard film layer to complete said planar surface and form an interlevel dielectric. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification