Methods and apparatuses for uniform reduction of the in-feature wet etch rate of a silicon nitride film formed by ald

Abstract

Disclosed herein are methods of depositing a SiN film having a reduced wet etch rate. The methods may include adsorbing a film precursor comprising Si onto a semiconductor substrate in a processing chamber to form an adsorption-limited layer of precursor, and then removing unadsorbed precursor from the volume surrounding the adsorbed precursor. The adsorbed precursor may then be reacted by exposing it to a plasma comprising N-containing ions and/or radicals to form a SiN film layer on the substrate, and the SiN film layer may then be densified by exposing it to a He plasma. The foregoing steps may then be repeated to form another densified SiN film layer on the substrate. Also disclosed herein are apparatuses for depositing SiN films having reduced wet etch rates on semiconductor substrates which employ the foregoing techniques.