Copper interconnect patterning
AssigneeChartered Semiconductor Manufacturing Ltd.
InventorSudipto Ranendra Roy
Life of this patent
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Abstract
A improved and new method for forming dual damascene etch back of copper lines and interconnects (studs) using a combination of oxidation of Cu and chemical/mass transport of the Cu oxide by the action of acid. The etch back solves the dishing problem in that it planarized the Cu. Etch back rates can be high at high temperatures. The surface of the substrate is kept clean and free of polishing scratches from CMP. The process produces better uniformity across the substrate and better electrical performance due the increased copper line cross-sectional area.
Claims21
A method of forming conducting metal lines and interconnects (studs) in vias and trenches in the fabrication of integrated circuit devices, that forms planarized structures comprising:
- providing a substrate upon which insulating material is deposited;
- said insulating material is patterned and etched to form via holes and trenches in a dual damascene process;
- depositing a conducting barrier layer that conforms to the insulating material and to the via holes and trenches;
- said barrier layer lines said via holes and trenches;
- depositing a conducting metal over the entire substrate filling said via holes and trenches;
- oxidizing the surface of said conducting metal layer over the entire substrate, using oxidizing agents to form a metal oxide layer;
- and etching back said metal oxide layer by purely chemical means, stopping on the barrier layer.
A method of forming conducting copper metal lines and interconnects (studs) in vias and trenches in the fabrication of integrated circuit devices, that forms planarized structures comprising:
- providing a substrate upon which insulating material is deposited;
- said insulating material is patterned and etched to form via holes and trenches in a dual damascene process;
- depositing a conducting barrier layer of Ta/TaN that conforms to the insulating material and to the via holes and trenches;
- said barrier layer lines said via holes and trenches;
- depositing a conducting copper metal over the entire substrate filling said via holes and trenches;
- providing a reactor;
- introducing O.sub.2 and HCl gas into said reactor to form copper oxide and removing copper oxide by HCl acidic gas and continuing until the conducting copper metal is planarized back to said conducting barrier layer.
A method of forming conducting copper metal lines and interconnects (studs) in vias and trenches in the fabrication of integrated circuit devices, that forms planarized structures comprising:
- providing a substrate upon which insulating material is deposited;
- said insulating material is patterned and etched to form via holes and trenches in a dual damascene process;
- depositing a conducting barrier layer of Ta/TaN that conforms to the insulating material and to the via holes and trenches;
- said barrier layer lines said via holes and trenches;
- depositing a conducting copper metal over the entire substrate filling said via holes and trenches;
- providing a reactor;
- introducing pyrogenic H.sub.2 O and HCl gas into said reactor to form copper oxide and removing copper oxide by HCl acidic gas and continuing until the conducting copper metal is planarized back to said conducting barrier layer.
A method of forming conducting copper metal lines and interconnects (studs) in vias and trenches in the fabrication of integrated circuit devices, that forms planarized structures comprising:
- providing a substrate upon which insulating material is deposited;
- said insulating material is patterned and etched to form via holes and trenches in a dual damascene process;
- depositing a conducting barrier layer of Ta/TaN that conforms to the insulating material and to the via holes and trenches;
- said barrier layer lines said via holes and trenches;
- depositing a conducting copper metal over the entire substrate filling said via holes and trenches;
- providing a bath or spray/spin station;
- providing steam and/or de-ionized water to oxidize conducting copper metal forming copper oxide;
- providing dilute HCl (approximately 0.1 Molar) for copper oxide removal and continuing removal of copper oxide until the conducting copper metal is planarized back to said conducting barrier layer;
- providing a DI water rinse in N.sub.2 blow dry followed by a thin coating of BTA, Benzo-Triazol or TTA, Tetra-Triazol corrosion protection material.
Dependencies are inferred from the claim text.