Si precursors for deposition of SiN at low temperatures

摘要

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%).

主权项

1. A plasma enhanced atomic layer deposition (PEALD) 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 nitrogen is flowed continuously to the reaction space throughout steps (a)-(d) and steps (a) through (d) are repeated until a silicon nitride film of a desired thickness is formed; wherein the silicon reactant is H2SiI2, wherein the silicon nitride thin film is deposited on at least one three-dimensional feature, and wherein a ratio of an etch rate of the silicon nitride thin film in 0.5% aqueous HF in a sidewall of the at least one three-dimensional feature to an etch rate of the silicon nitride thin film in 0.5% aqueous HF on a top surface of the at least one three-dimensional feature is less than 2.