MOCVD of tungsten nitride thin films using W(CO)6 and NH3 for copper barrier applications

A method of forming a tungsten nitride thin film in an integrated circuit, comprising:

• preparing a silicon substrate on a silicon wafer and placing the silicon wafer in a heatable chuck in a CVD vacuum chamber and heating the silicon wafer to a temperature of between about 350° C. to 430° C.;
• placing a known quantity of W(CO)6 in a variable-temperature bubbler to provide gaseous W(CO)6;
• setting the variable-temperature bubbler to a predetermined temperature;
• passing a hydrogen carrier gas through the variable-temperature bubbler and carrying the gaseous W(CO)6 with the hydrogen carrier gas into the CVD vacuum chamber;
• introducing NH3 reactant gas into the CVD vacuum chamber;
• reacting the gaseous W(CO)6 and the NH3 reactant gas above the surface of the silicon wafer in a deposition process to deposit a polycrystalline cubic phase W2N thin film barrier layer on the surface of the silicon wafer;
• and
• completing the integrated circuit containing the W2N thin film.

A method of forming a tungsten nitride thin film in an integrated circuit, comprising:

• preparing a silicon substrate on a silicon wafer and placing the silicon wafer in a heatable chuck in a CVD vacuum chamber, heating the silicon wafer to a temperature of between about 350° C. to 430° C., and maintaining the pressure in the CVD vacuum chamber at between about 30 mtorr. and 1000 mtorr;
• placing a known quantity of W(CO)6 in a variable-temperature bubbler to provide gaseous W(CO)6;
• setting the variable-temperature bubbler to a predetermined temperature;
• passing a hydrogen carrier gas through the variable-temperature bubbler and carrying the gaseous W(CO)6 with the hydrogen earlier gas into the CVD vacuum chamber;
• introducing NH3 reactant gas into the CVD vacuum chamber;
• reacting the gaseous W(CO)6 and the NH3 reactant gas above the surface of the silicon wafer in a deposition process to deposit a polycrystalline cubic phase W2N thin film on the surface of the silicon wafer for between about one minute and 60 minutes;
• and
• completing the integrated circuit containing the W2N thin film.