Sealing porous structures
First Claim
1. A method of fabricating an integrated circuit including a porous insulating layer having a plurality of trenches extending from an upper surface of the insulating layer, the method comprising:
- blocking the pores on an exposed surface of the insulating layer, wherein blocking is performed preferentially upon upper surfaces of the insulating layer;
after blocking the pores, forming no more than about one monolayer of a first reactant species in a self-limited and self-saturating reaction; and
reacting a second reactant species with the 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. An alternating process can also be arranged by selection of pulse separation and/or pulse duration to achieve reduced conformality relative to a self-saturating, self-limiting atomic layer deposition (ALD) process. In still another arrangement, layers with anisotropic pore structures can be sealed by selectively melting upper surfaces. Blocking is followed by a self-limiting, self-saturating atomic layer deposition (ALD) reactions without significantly filling the pores.
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Citations
29 Claims
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1. A method of fabricating an integrated circuit including a porous insulating layer having a plurality of trenches extending from an upper surface of the insulating layer, the method comprising:
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blocking the pores on an exposed surface of the insulating layer, wherein blocking is performed preferentially upon upper surfaces of the insulating layer;
after blocking the pores, forming no more than about one monolayer of a first reactant species in a self-limited and self-saturating reaction; and
reacting a second reactant species with the monolayer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of depositing a film over a structure having openings therein, comprising an alternating deposition process, wherein a plurality of sequential reactant pulses are separated from one another, the alternating process optimized to achieve a level of conformality between that of an atomic layer deposition (ALD) process and a chemical vapor deposition (CVD) process.
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11. A method for controlling conformality of a deposited film on a semiconductor substrate, the method comprising:
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providing the substrate with a plurality of openings at a surface thereof;
providing a sequence of at least two different, mutually reactive reactants in temporally separated and alternating reactant pulses;
selecting separations of the reactant pulses and durations of the reactant pulses to control the conformality of the film deposited in the openings in the surface of the semiconductor substrate, wherein the separations and durations are selected to achieve reduced conformality compared to a corresponding atomic layer deposition (ALD) process that is optimized to achieve maximum conformality with minimum cycle length for the substrate topography; and
exposing the semiconductor substrate to the sequence of the reactant pulses with the selected separations and durations to deposit the film. - View Dependent Claims (12, 13)
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14. A semiconductor fabrication process, comprising:
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providing a low k dielectric having an anisotropic pore structure and larger openings therein;
preferentially sealing an upper surface of the low k dielectric layer; and
conducting an atomic layer deposition process (ALD) to deposit directly over the sealed upper surface wherein preferentially sealing comprises melting a portion of the k dielectric. - View Dependent Claims (15, 16, 17, 18, 19)
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20. A semiconductor fabrication process, comprising:
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providing a low k dielectric having an anisotropic pore structure and larger openings therein;
preferentially sealing an upper surface of the low k dielectric layer; and
conducting an atomic layer deposition process (ALD) to deposit directly over the sealed upper surface wherein preferentially sealing comprises depositing a sealing layer with reduced conformality compared to an atomic layer deposition (ALD) process in which self-saturating and self-limiting surface reactions take place within the openings and over the upper surface. - View Dependent Claims (21, 22)
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23. A method for deposition of a film on a semiconductor substrate, the method comprising:
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providing the substrate, the substrate having at a surface thereof different regions with different levels of accessibility;
providing a sequence of at least two different, mutually reactive reactants in temporally separated and alternating reactant pulses;
selecting separations of the reactant pulses and/or durations of the reactant pulses to achieve self-saturation and self-limiting atomic layer deposition (ALD) mode deposition on the most accessible regions on the substrate surface and depletion effects in less accessible regions on the substrate surface; and
exposing the semiconductor substrate to the sequence of the reactant pulses with the selected temporal separations and durations to deposit the film. - View Dependent Claims (24, 25, 26, 27, 28, 29)
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Specification