Deposition of SiN

Abstract

Methods and precursors for forming silicon nitride films are provided. In some embodiments, silicon nitride can be deposited by atomic layer deposition (ALD), such as plasma enhanced ALD. In some embodiments, deposited silicon nitride can be treated with a plasma treatment. The plasma treatment can be a nitrogen plasma treatment. In some embodiments the silicon precursors for depositing the silicon nitride 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%). In some embodiments, a method for depositing silicon nitride films comprises a multi-step plasma treatment.

What is claimed is: 
     
         1 . A method of forming a SiN thin film on a substrate in a reaction space comprising:
 contacting the substrate with a silicon precursor comprising iodine to provide a first silicon species adsorbed on a surface of the substrate;   contacting the substrate comprising the first silicon species adsorbed on the surface with a first plasma comprising activated hydrogen species thereby forming SiN on the substrate; and   conducting a nitrogen plasma treatment, wherein the nitrogen plasma treatment comprises contacting the substrate comprising SiN with a second plasma formed from a nitrogen containing gas substantially free of hydrogen-containing species to form the SiN thin film.