Si PRECURSORS FOR DEPOSITION OF SiN AT LOW TEMPERATURES
AssigneeASM IP Holding B.V.
InventorsAntti J. Niskanen, Shang Chen, Viljami Pore
Life of this patent
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Abstract
Methods and precursors for depositing silicon nitride films by atomic layer deposition (ALD) are provided. In some embodiments the silicon precursors comprise an iodine ligand. The silicon nitride films may have a relatively uniform etch rate for both vertical and the horizontal portions when deposited onto three-dimensional structures such as FinFETS or other types of multiple gate FETs. In some embodiments, various silicon nitride films of the present disclosure have an etch rate of less than half the thermal oxide removal rate with diluted HF (0.5%).
Claims31
A method of depositing a silicon nitride thin film on a substrate in a reaction space comprising:
- (a) introducing a vapor-phase silicon reactant into the reaction space so that the silicon precursor is adsorbed to a surface of the substrate;
- (b) removing excess silicon reactant and reaction byproducts;
- (c) contacting the adsorbed silicon reactant with a reactive species generated by a plasma from a nitrogen precursor;
- (d) removing excess reactive species and reaction byproducts;
- wherein steps (a) through (d) are repeated until a silicon nitride film of a desired thickness is formed and wherein the silicon reactant comprises iodine.
A method of depositing a silicon nitride thin film comprising:
- (a) loading a substrate having at least one three-dimensional feature into a reaction space;
- (b) introducing a silicon-containing precursor into the reaction space so that the silicon precursor is adsorbed to a surface of the substrate;
- (c) purging the reaction space of excess silicon-containing precursor and reaction byproducts;
- (d) introducing a nitrogen precursor into the reaction space;
- (e) purging the reaction space of excess nitrogen precursor and reaction byproducts;
- and
- repeating steps (b) through (e) until a silicon nitride thin film of a desired thickness is formed;
- wherein the silicon-containing precursor comprises iodine,
- wherein the silicon nitride thin film has a step coverage of more than about 50% on the at least one three-dimensional feature;
- wherein an etch rate of the silicon nitride thin film is less than about 5 nm/min in 0.5% aqueous HF;
- and
- wherein a ratio of an etch rate of the silicon nitride thin film in a sidewall of the at least one three-dimensional feature to an etch rate of the silicon nitride thin film on a top surface of the at least one three-dimensional feature is less than about 4.
(canceled)
A method of depositing a silicon nitride thin film on a substrate comprising:
- (a) exposing the substrate to a vapor-phase silicon precursor so that the silicon precursor is adsorbed to a surface of the substrate;
- (b) exposing the substrate to a purge gas and/or a vacuum to remove excess silicon precursor and reaction byproducts from the substrate surface;
- (c) contacting the adsorbed silicon precursor with species generated by a nitrogen containing plasma;
- and
- (d) exposing the substrate to a purge gas and/or a vacuum to remove the species of a nitrogen containing plasma and reaction byproducts from the substrate surface and from the proximity of the substrate surface;
- wherein steps (a) through (d) are repeated until a silicon nitride film of a desired thickness is formed;
- and
- wherein the silicon precursor comprises iodine.
A method of depositing a silicon nitride thin film on a substrate comprising at least one three-dimensional feature comprising:
- exposing the substrate to a vapor-phase silicon reactant so that the silicon reactant is adsorbed to a surface of the substrate;
- exposing the substrate to a purge gas and/or a vacuum to remove excess silicon reactant and reaction byproducts from the substrate surface;
- contacting the adsorbed silicon reactant with a nitrogen precursor;
- exposing the substrate to a purge gas and/or a vacuum to remove the excess nitrogen precursor from the substrate surface and from the proximity of the substrate surface;
- repeating steps (a) through (d) until a silicon nitride thin film of a desired thickness is formed;
- wherein the silicon-containing precursor contains iodine
- wherein the silicon nitride thin film has a step coverage of more than about 50%;
- wherein an etch rate of the silicon nitride thin film is less than about 5 nm/min in 0.5% aqueous HF;
- and
- wherein a ratio of an etch rate of the silicon nitride thin film in a sidewall of the at least one three-dimensional feature to an etch rate of the silicon nitride thin film on a top surface of the at least one three-dimensional feature is less than about 4.
Dependencies are inferred from the claim text.