Method of eliminating etch ridges in a dual damascene process
First Claim
1. A method for forming a semiconductor structure, comprising:
- forming a first opening in a dielectric layer;
filling the first opening with a fill material;
etching the dielectric layer to form a second opening overlying the filled first opening with a given dielectric etch chemistry, wherein the fill material etches at an etch rate that is within 60% of an etch rate that the dielectric layer etches for the given dielectric etch chemistry.
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Accused Products
Abstract
A dual damascene process employs a via fill material (38) with an etch rate that is within 60% of an etch rate that an underlying dielectric layer (34) etches for a given dielectric etch chemistry in which a trench (48) and via (50) are being formed. In one embodiment, an organic via fill material plug (40) is employed in conjunction with a bottom anti-reflective coating (BARC) material layer (42). Both the organic via fill material plug (40) and the BARC material layer (42) are selected to have a material with an etch rate that within 60% of an etch rate that an underlying dielectric layer (34) etches for a given dielectric etch chemistry in which the trench (48) and via (50) are formed.
245 Citations
20 Claims
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1. A method for forming a semiconductor structure, comprising:
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forming a first opening in a dielectric layer;
filling the first opening with a fill material;
etching the dielectric layer to form a second opening overlying the filled first opening with a given dielectric etch chemistry, wherein the fill material etches at an etch rate that is within 60% of an etch rate that the dielectric layer etches for the given dielectric etch chemistry. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for forming a dual damascene structure, comprising:
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forming a via in a dielectric layer;
filling the via with an organic fill material layer;
etching back the organic via fill material to form an organic via fill material plug that resides in the via below a top surface of the dielectric layer;
depositing a bottom anti-reflective coating (BARC) layer over the dielectric layer that fills the via above the organic via fill material plug; and
anisotropically etching the dielectric layer to form a trench overlying the via with a given dielectric etch chemistry, wherein the fill material etches at an etch rate that is within 60% of an etch rate that the dielectric layer etches for the given dielectric etch chemistry. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A method for forming a via-first dual damascene structure, comprising:
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forming a via in a dielectric layer comprised of at least one of silicon oxide (SiO), silicon dioxide (SiO2), silicon nitride (Si3N4), (SiN), oxygen silicon glass (OSG), black diamond (BD-2), silicon carbon (SiC) and silicon carbon monoxide (SiCO);
filling the via with an organic fill material layer;
etching back the organic via fill material to form an organic via fill material plug that resides in the via below a top surface of the dielectric layer;
depositing a bottom anti-reflective coating (BARC) layer over the dielectric layer that fills the via above the organic via fill material plug; and
etching a trench in the dielectric layer overlying the via with an etch chemistry comprising an anisotropic etch with a plasma gas mixture of carbon tetrafluoride (CF4), carbon trifluoride (CF3), octafluorocyclobutane (C4F8) and oxygen (O2), wherein the organic fill material and the BARC layer have an etch rate that is within 60% of an etch rate that the dielectric layer etches for the given dielectric etch chemistry to provide a via-first dual damascene structure substantially free of etch ridges. - View Dependent Claims (18, 19, 20)
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Specification