- Details
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Category: Tungsten Patents
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Published on Wednesday, 23 January 2013 09:03
A method of forming a composite tungsten film on a substrate is described. The composite tungsten film comprises sequentially deposited tungsten nucleation layers and tungsten bulk layers. Each of the tungsten nucleation layers and the tungsten bulk layers have a thickness less than about 300 Å. The tungsten nucleation layers and the tungsten bulk layers are formed one over the other until a desired thickness for the composite tungsten film is achieved. The resulting composite tungsten film exhibits good film morphology. The tungsten nucleation layers may be formed using a cyclical deposition process by alternately adsorbing a tungsten-containing precursor and a reducing gas on the substrate. The tungsten bulk layers may be formed using a chemical vapor deposition (CVD) process by thermally decomposing a tungsten-containing precursor.
The tungsten nucleation layers may be formed using a cyclical deposition process by alternately adsorbing a tungsten-containing precursor and a reducing gas on the substrate. The tungsten bulk layers may be formed using a chemical vapor deposition (CVD) process by thermally decomposing a tungsten-containing precursor.
The composite tungsten film is compatible with integrated circuit fabrication processes. In one integrated circuit fabrication process, the composite tungsten film may be used as word and/or bit line metallization to read and write data to memory cell devices. For a word and/or bit line fabrication process, a preferred process sequence includes providing a substrate having a word and/or bit line pattern defined in a dielectric material layer. The word and/or bit line pattern defined in the dielectric material includes a barrier layer thereon. Thereafter, a composite tungsten film comprising sequentially deposited tungsten nucleation layers and tungsten bulk layers, each having a thickness less than about 300 Å, are formed one over the other on the barrier layer until a desired thickness for the composite tungsten film is achieved.