Formation of titanium nitride on semiconductor wafer by reaction of titanium with nitrogen-bearing gas in an integrated processing system

A process for forming a layer of substantially all titanium nitride on a semiconductor wafer having titanium silicide portions previously formed thereon which comprises:

• a) forming a titanium layer on said wafer and over said previously formed titanium silicide portions thereon in a vacuum deposition chamber in the substantial absence of oxygen-bearing gases;
• b) transferring the titanium coated wafer to a sealed annealing chamber without substantially exposing the newly formed titanium layer to oxygen-bearing gases;
• c) annealing the titanium-coated semiconductor wafer in a nitrogen-bearing atmosphere in said sealed annealing chamber, and in the substantial absence of oxygen-bearing gases, at an annealing temperature of from 400.degree. C. up to below about 600.degree. C. for a period of from about 20 to about 60 seconds whereby substantially all of said titanium will react with said nitrogen to form said layer of substantially all titanium nitride on said wafer;
• d) further annealing said wafer at a temperature of from about 800.degree. C. to about 900.degree. C. for a period of from about 20 to about 60 seconds to form a stable phase of stoichiometric titanium nitride (TiN) on said wafer;
• e) masking said titanium nitride layer after said annealing steps;
• and
• f) then selectively removing unmasked portions of said titanium nitride layer to thereby form a conductive titanium nitride pattern on said wafer.

A process for forming a layer of substantially all titanium nitride on a semiconductor wafer which comprises:

• a) cleaning said wafer in a cleaning chamber for a period of time ranging from about 1 to about 500 seconds by flowing into the chamber a gaseous mixture containing at least one reactive gas at a rate of from about 2 to about 500 sccm reactive gas and from about 10 to about 1000 sccm carrier gas while maintaining a plasma at a power ranging from about 20 to about 500 watts;
• b) transferring said cleaned wafer from said cleaning chamber to a vacuum deposition chamber without substantially exposing said cleaned wafer to oxygen-bearing gases using a sealed central chamber maintained at a pressure which ranges from about 10.sup.-9 to about 10.sup.-5 Torr which is interconnected to both said cleaning chamber and said vacuum deposition chamber;
• c) forming a titanium layer on said wafer in said vacuum deposition chamber in the substantial absence of oxygen-bearing gases;
• d) transferring the titanium coated wafer to a sealed annealing chamber without substantially exposing the newly formed titanium layer to oxygen-bearing gases;
• e) annealing the titanium-coated semiconductor wafer in a nitrogen-bearing atmosphere in said sealed annealing chamber, and in the substantial absence of oxygen-bearing gases, at an annealing temperature of from 400.degree. C. up to below about 600.degree. C. for a period of from about 20 to about 60 seconds whereby substantially all of said titanium will react with said nitrogen to form said layer of substantially all titanium nitride on said wafer;
• f) further annealing said wafer at a temperature of from about 800.degree. C. to about 900.degree. C. for a period of from about 20 to about 60 seconds to form a stable phase of stoichiometric titanium nitride (TiN) on said wafer;
• g) masking said titanium nitride layer after said annealing steps;
• and
• h) then selectively removing unmasked portions of said titanium nitride layer to thereby form a conductive titanium nitride pattern on said wafer.