METHOD FOR REDUCING ROUGHNESS AND IMPROVING STEP COVERAGE OF TUNGSTEN THIN FILM TO FORM TUNGSTEN NUCLEUS FORMING THIN FILM

摘要

PURPOSE: A method for reducing roughness and improving step coverage of a tungsten thin film is provided to form a tungsten nucleation thin film by supplying reducing gas and tungsten-containing gas to a substrate. CONSTITUTION: A semiconductor substrate is disposed in a reaction chamber(301). The semiconductor substrate is heated(303). A PNL(pulse nucleation layer) process is performed on the semiconductor substrate by using tungsten-containing gas and reducing gas to form a tungsten nucleation layer on the semiconductor substrate(305). A tungsten bulk layer(307) is deposited on the nucleation layer by a CVD(chemical vapor deposition) process. A tungsten cap layer is deposited on the tungsten bulk layer by a PNL deposition technique.