Formation of titanium nitride on semiconductor wafer by reaction of titanium with nitrogen-bearing gas in an integrated processing system
Patent 5236868 Issued on August 17, 1993. Estimated Expiration Date: 
August 17, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
August 17, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesMethod for making low barrier Schottky devices of the electron beam evaporation of reactive metals Method and apparatus for making ohmic and/or Schottky barrier contacts to semiconductor substrates Reactive sputter cleaning of semiconductor wafer Process to increase tin thickness Vacuum chamber slit valve Semiconductor and process of fabrication thereof Patent #: 4855798 InventorApplicationNo. 511652 filed on 04/20/1990US Classes:438/653, At least one layer forms a diffusion barrier257/E21.16, From a gas or vapor, e.g., condensation (EPO)257/E21.302, Nitriding of silicon-containing layer (EPO)438/655, Silicide438/669, And patterning of conductive layer438/685, Refractory group metal (i.e., titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), or alloy thereof)438/906, CLEANING OF WAFER AS INTERIM STEP438/976TEMPORARY PROTECTIVE LAYERExaminersPrimary: Quach, T. N.Attorney, Agent or FirmForeign Patent References
International ClassH01L 021/283AbstractA process is disclosed for forming a layer of titanium nitride on a semiconductor wafer which comprises forming a titanium layer on the wafer in a vacuum deposition chamber in the substantial absence of oxygen-bearing gases; transferring the titanium coated wafer to a sealed annealing chamber without substantially exposing the newly formed titanium layer to oxygen-bearing gases; annealing the titanium-coated semiconductor wafer in a nitrogen-bearing atmosphere in the sealed annealing chamber, and in the substantial absence of oxygen-bearing gases, at an annealing temperature of from 400° C. up to below about 650° C. to form a titanium nitride compound on the wafer; and further annealing the wafer at a temperature of from about 800° C. to about 900° C. to form a stable phase of stoichiometric titanium nitride (TiN) on the wafer. The resulting layer of titanium nitride may be patterned to form local interconnects on the wafer, as well as to provide barrier portions between underlying titanium silicide and metal contacts such as aluminum. In a preferred embodiment, the initial annealing temperature ranges from about 400° C. up to below about 600° C. whereby substantially all of the titanium will react with the nitrogen to form titanium nitride on the wafer.Other References
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