Protective layers prior to alternating layer deposition
First Claim
1. A damascene metallization process, comprising:
- forming a trench in a desired wiring pattern in a porous insulating layer above a semiconductor substrate;
forming a contact via extending downwardly from a floor of the trench to expose at least part of an underlying conductive element;
blocking pores in an insulating layer sidewall partially defining the trench;
after blocking the pores, lining surfaces of the trench and contact via with no more than about one monolayer by exposure to a first reactant species; and
reacting a second reactant species with the lining monolayer.
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Accused Products
Abstract
Method and structures are provided for conformal lining of dual damascene structures in integrated circuits, and particularly of openings formed in porous materials. Trenches and contact vias are formed in insulating layers. The pores on the sidewalls of the trenches and vias are blocked, and then the structure is exposed to alternating chemistries to form monolayers of a desired lining material. In exemplary process flows chemical or physical vapor deposition (CVD or PVD) of a sealing layer blocks the pores due to imperfect conformality, and is followed by an atomic layer deposition (ALD), particularly alternately pulsed metal halide and ammonia gases injected into a constant carrier flow. An alternating process can also be arranged to function in CVD-mode within pores of the insulator, since the reactants do not easily purge from the pores between pulses. Self-terminated metal layers are thus reacted with nitrogen. Near perfect step coverage allows minimal thickness for a diffusion barrier function, thereby maximizing the volume of a subsequent filling metal for any given trench and via dimensions.
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Citations
28 Claims
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1. A damascene metallization process, comprising:
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forming a trench in a desired wiring pattern in a porous insulating layer above a semiconductor substrate;
forming a contact via extending downwardly from a floor of the trench to expose at least part of an underlying conductive element;
blocking pores in an insulating layer sidewall partially defining the trench;
after blocking the pores, lining surfaces of the trench and contact via with no more than about one monolayer by exposure to a first reactant species; and
reacting a second reactant species with the lining monolayer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification