Reliable BEOL integration process with direct CMP of porous SiCOH dielectric
First Claim
1. A method of fabricating an interconnect structure comprising:
- providing a structure comprising a porous ultra low k (ULK) dielectric having a dielectric constant of less than 3.0 on a substrate, said porous ULK dielectric having at least one opening located therein;
filling said at least one opening with at least a conductive material;
planarizing at least said conductive material utilizing a CMP slurry to provide a planarized structure having an upper surface of said conductive material that is substantially coplanar with an upper surface of said ULK dielectric, said ULK dielectric is exposed to said CMP slurry and said planarizing provides a planarized ULK dielectric with patterned conductors having a leakage current density that is lower than that measured without an UV radiation exposure step, and a breakdown field that is higher than that measured without an UV radiation exposure step;
exposing said planarized structure to UV radiation at a temperature from about 200°
to about 450°
C.;
subjecting said planarized structure to a plasma preclean process; and
forming a capping layer on at least said conductive material.
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Accused Products
Abstract
The present invention relates to methods of improving the fabrication of interconnect structures of the single or dual damascene type, in which there is no problem of hard mask retention or of conductivity between the metal lines after fabrication. The methods of the present invention include at least steps of chemical mechanical polishing and UV exposure or chemical repair treatment which steps improve the reliability of the interconnect structure formed. The present invention also relates to an interconnect structure which include a porous ultra low k dielectric of the SiCOH type in which the surface layer thereof has been modified so as to form a gradient layer that has both a density gradient and a C content gradient.
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Citations
20 Claims
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1. A method of fabricating an interconnect structure comprising:
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providing a structure comprising a porous ultra low k (ULK) dielectric having a dielectric constant of less than 3.0 on a substrate, said porous ULK dielectric having at least one opening located therein; filling said at least one opening with at least a conductive material; planarizing at least said conductive material utilizing a CMP slurry to provide a planarized structure having an upper surface of said conductive material that is substantially coplanar with an upper surface of said ULK dielectric, said ULK dielectric is exposed to said CMP slurry and said planarizing provides a planarized ULK dielectric with patterned conductors having a leakage current density that is lower than that measured without an UV radiation exposure step, and a breakdown field that is higher than that measured without an UV radiation exposure step; exposing said planarized structure to UV radiation at a temperature from about 200°
to about 450°
C.;subjecting said planarized structure to a plasma preclean process; and forming a capping layer on at least said conductive material. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A method of fabricating an interconnect structure comprising:
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providing a structure comprising a porous ultra low k (ULK) dielectric having a dielectric constant of less than 3.0 on a substrate and at least one opening located therein, said porous ULK dielectric is formed by deposition and curing and having about 50% or less of porogen after said curing; filling said at least one opening with at least a conductive material; planarizing at least said conductive material utilizing a CMP slurry to provide a planarized structure having an upper surface of said conductive material that is substantially coplanar with an upper surface of said ULK dielectric, said ULK dielectric is exposed to said CMP; exposing said planarized structure to UV radiation at a temperature from about 200°
to about 450°
C.;subjecting said planarized structure to a plasma preclean process; and forming a capping layer on at least said conductive material.
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20. A method of fabricating an interconnect structure comprising:
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providing a structure comprising a porous ultra low k (ULK) dielectric having a dielectric constant of less than 3.0 on a substrate, said porous ULK dielectric having at least one opening located therein, and said porous ULK dielectric is formed by providing at least a first precursor comprising atoms of Si, C, O and H and an inert gas into a reactor, depositing said ULK dielectric using said first precursor and thereafter curing; filling said at least one opening with at least a conductive material; planarizing at least said conductive material utilizing a CMP slurry to provide a planarized structure having an upper surface of said conductive material that is substantially coplanar with an upper surface of said ULK dielectric, said ULK dielectric is exposed to said CMP slurry; exposing said planarized structure to UV radiation at a temperature from about 200°
to about 450°
C.;subjecting said planarized structure to a plasma preclean process; and forming a capping layer on at least said conductive material.
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Specification