AIR GAP INTERCONNECTS USING CARBON-BASED FILMS
First Claim
1. A method of forming an interconnect structure comprising:
- forming a sacrificial inter-metal dielectric (IMD) layer over a substrate, wherein the sacrificial IMD layer comprising a carbon-based film;
forming a plurality of metal interconnect lines within the sacrificial IMD layer;
removing the sacrificial IMD layer; and
depositing a non-conformal dielectric layer to form air gaps between the plurality of metal interconnect lines.
1 Assignment
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Accused Products
Abstract
A method of forming an interconnect structure comprising: forming a sacrificial inter-metal dielectric (IMD) layer over a substrate, wherein the sacrificial IMD layer comprising a carbon-based film, such as amorphous carbon, advanced patterning films, porous carbon, or any combination thereof; forming a plurality of metal interconnect lines within the sacrificial IMD layer; removing the sacrificial IMD layer, with an oxygen based reactive process; and depositing a non-conformal dielectric layer to form air gaps between the plurality of metal interconnect lines. The metal interconnect lines may comprise copper, aluminum, tantalum, tungsten, titanium, tantalum nitride, titanium nitride, tungsten nitride, or any combination thereof. Carbon-based films and patterned photoresist layers may be simultaneously removed with the same reactive process. Highly reactive hydrogen radicals processes may be used to remove the carbon-based film and simultaneously pre-clean the metal interconnect lines prior to the deposition of a conformal metal barrier liner.
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Citations
50 Claims
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1. A method of forming an interconnect structure comprising:
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forming a sacrificial inter-metal dielectric (IMD) layer over a substrate, wherein the sacrificial IMD layer comprising a carbon-based film; forming a plurality of metal interconnect lines within the sacrificial IMD layer; removing the sacrificial IMD layer; and depositing a non-conformal dielectric layer to form air gaps between the plurality of metal interconnect lines. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 47, 48, 49, 50)
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10. A method of forming an interconnect structure comprising:
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providing a substrate on which to form the interconnect structure; blanket depositing a carbon-based film over the substrate; blanket depositing a non-carbon-based film over the carbon-based film; blanket depositing a layer of photoresist over the non-carbon-based film; patterning the photoresist layer; transferring the patterned photoresist layer onto the non-carbon-based film; transferring the patterned non-carbon-based film to the carbon-based film; removing the patterned photoresist layer; blanket depositing a metal conductor layer; planarizing the metal conductor layer; removing the patterned carbon-based film; and blanket depositing a non-conformal dielectric layer, wherein the non-conformal dielectric layer forms air gaps in regions between the planarized metal conductors. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A method of forming an interconnect structure comprising:
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providing a substrate having an air gap area and an exclusion area; blanket depositing a first carbon-based film over the substrate; blanket depositing a non-carbon-based film over the first carbon-based film; blanket depositing and patterning an interconnect photoresist layer with an interconnect pattern; transferring the interconnect pattern to the non-carbon-based film; transferring the interconnect pattern to the first carbon-based film; removing the patterned interconnect photoresist layer; blanket depositing and planarizing a metal layer to form a plurality of planarized metal interconnect lines; blanket depositing a first barrier layer; blanket depositing and patterning an exclusion photoresist layer to protect the exclusion area; removing the first barrier layer from the air gap area; removing the patterned exclusion photoresist layer from the exclusion area and removing the patterned first carbon-based film from the air gap area; and blanket depositing a non-conformal dielectric layer to form air gaps in the air gap area, wherein the air gaps are positioned between the planarized metal interconnect lines. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36)
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37. A method of forming an interconnect structure comprising:
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providing a substrate having a first level metal interconnect structure; blanket depositing a second level ILD layer, a second level carbon-based film, a second level etch stop layer, and a second level hard mask layer; blanket depositing and patterning a second level trench patterned photoresist layer; transferring the second level trench pattern to the second level hard mask layer; removing the second level trench patterned photoresist layer; blanket depositing and patterning a second level via photoresist layer; transferring the second level via pattern to the second level etch stop layer; transferring the second level via pattern to the second level carbon-based film and removing the second level via patterned photoresist layer; transferring the second level via pattern to the second level ILD layer; transferring the second level via pattern to the surface the first level metal interconnect structure; transferring the second level trench pattern to the second level via patterned etch stop to form a second level trench patterned etch stop; transferring the second level trench pattern to the second level via patterned carbon-based layer to form a second level trench patterned carbon-based layer; removing the second level trench patterned hard mask; blanket depositing and planarizing a conductive metal to form a plurality of second level metal interconnect lines and a plurality of metal vias in contact with the first level metal interconnect structure; removing the second level trench patterned etch stop layer to expose the second level trench patterned carbon-based film; removing the second level trench patterned carbon-based film; and blanket depositing and planarizing a second level non-conformal dielectric layer to forming a second level air gap in the planarized non-conformal dielectric layer in the regions between the second level metal interconnect lines. - View Dependent Claims (38, 39)
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40. A method of forming an interconnect structure comprising:
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providing a substrate having a first level metal interconnect structure and a first level barrier layer cap; blanket depositing a second level ILD layer, a second level carbon-based film, a second level etch stop film, and a second level hard mask layer; blanket depositing and patterning a second level via patterned photoresist layer; transferring the second level via pattern to the second level hard mask layer and the second level etch stop film; transferring the second level via pattern to the second level carbon-based film and removing the second level via patterned photoresist layer; transferring the second level via pattern to the second level ILD layer; blanket depositing and patterning a second level trench patterned photoreist layer; transferring the second level trench pattern to the second level hard mask layer and the second level etch stop film; transferring the second level trench pattern to the second level via patterned carbon-based film and removing the second level trench patterned photoresist layer; transferring the via pattern from the second level via patterned ILD layer to the first level barrier layer cap; blanket depositing and planarizing a plurality of second level metal interconnect lines with a plurality of metal vias in contact with the first level metal interconnect structure; removing any remaining portion of the second level trench patterned hard mask layer and the second level trench patterned etch stop film; removing the second level trench patterned carbon-based film; and blanket depositing and planarizing a second level non-conformal dielectric layer, whereby forming second level air gaps in the dielectric regions between the second level metal interconnect lines. - View Dependent Claims (41, 42, 43)
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44. A method of forming an interconnect structure comprising:
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providing a substrate having a first level metal interconnect structure and a second level ILD layer; blanket depositing and patterning a second level via patterned photoresist layer; transferring the second level via pattern to the second level ILD layer and to the surface of the first level metal interconnect structure; removing the second level via patterned photoresist layer; performing a blanket metallization deposition and planarization to form a plurality of metal vias in electrical contact with the first metal interconnect structure; selectively depositing a selective via metal cap over the metal vias; blanket depositing a second level carbon-based film and a second level hard mask layer; blanket depositing and patterning a second level trench patterned photoresist layer; transferring the second level trench pattern to the second level second hard mask layer; transferring the trench pattern onto the second level carbon-based film to form a second level trench patterned carbon-based film; removing the second level trench patterned photoresist layer; removing the second level trench patterned hard mask layer; blanket depositing and planarizing a metal layer to form a plurality of second level metal interconnect lines in electrical contact with the metal vias; removing the second level trench patterned carbon-based film; and blanket depositing and planarizing a second level non-conformal dielectric layer forming second level air gaps in the dielectric regions between the second level metal interconnect lines. - View Dependent Claims (45, 46)
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Specification