Structures and methods for integration of ultralow-k dielectrics with improved reliability
AssigneeInternational Business Machines Corporation
InventorsStephen M. Gates, Son Nguyen
Life of this patent
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Abstract
An improved back end of the line (BEOL) interconnect structure comprising an ultralow k (ULK) dielectric is provided. The structure may be of the single or dual damascene type and comprises a dense thin dielectric layer (TDL) between a metal barrier layer and the ULK dielectric. Disclosed are also methods of fabrication of BEOL interconnect structures, including (i) methods in which a dense TDL is provided on etched opening of a ULK dielectric and (ii) methods in which a ULK dielectric is placed in a process chamber on a cold chuck, a sealing agent is added to the process chamber, and an activation step is performed.
Claims10
A back end of the line (BEOL) interconnect structure comprising:
- (a) an ultralow k (ULK) dielectric, having a dielectric constant of up to about 3, and conductive metal features provided on a substrate;
- (b) a liner barrier layer between said ULK dielectric and said conductive metal features;
- and
- (c) a thin dielectric layer (TDL), having a thickness of up to about 5 nanometers, between the liner barrier layer and the ULK dielectric, wherein the TDL comprises a dense dielectric film having hermetic barrier capability, said film comprising a different material than the material of the ULK dielectric, wherein said material comprises at least one material selected from the group consisting of:
- (i) materials of formula:
- SixOwNyHz,
- wherein x ranges from about 0.35 to about 0.45, w ranges from 0 to about 0.1, y ranges from about 0.45 to about 0.55, and z ranges from 0 to about 0.2;
- (ii) materials of formula:
- SixOxCwNyHz,
- wherein x ranges from about 0.2 to about 0.3, v ranges from 0 to about 0.1, w ranges from about 0.25 to about 0.35, y ranges from about 0.1 to about 0.2, and z ranges from 0 to about 0.35;
- and
- (iii) materials of formula:
- SixCwOyHz,
- wherein x ranges from about 0.22 to about 0.32, w ranges from about 0.15 to about 0.3, y ranges from about 0.3 to about 0.5, and z ranges from 0 to about 0.3.
Dependencies are inferred from the claim text.