Method for improving barrier layer adhesion to HDP-FSG thin films

The present invention relates to the manufacture of integrated circuits, and more specifically, to a method of forming fluorinated silicate glass ("FSG") films with good adhesion to silicon nitride in a high-density-plasma chemical-vapor-deposition ("HDP-CVD") system. A method of formation of a damascene FSG film with good adhesion to silicon nitride in an HDP-CVD system. Silane (SiH), silicon tetrafluoride (SiF), oxygen (O) and argon (Ar) are used as the reactant gases. SiH, SiF, and Oreact to form the FSG. Ar is introduced to promote gas dissociation. All four gases are used for depositing most of the FSG film. SiHis not used during deposition of the interfacial part of the FSG film. The interfacial part of the FSG film refers either to the topmost portion, if silicon nitride is to be deposited on top of the FSG or the bottom portion if the FSG is to be deposited on top of silicon nitride. Using SiHwith the SiFtends to mitigate the destructive effects of SiFthroughout most of the deposition. By removing the SiHfrom the deposition of the interfacial part of the FSG film less hydrogen is incorporated into the film in the interfacial region and adhesion to overlying or underlying silicon nitride is improved.