US Patent 7270709 Method and apparatus of generating PDMAT precursor

A precursor and method for filling a feature in a substrate. The method generally includes depositing a barrier layer, the barrier layer being formed from pentakis(dimethylamido)tantalum having less than about 5 ppm of impurities. The method additionally may include depositing a seed layer over the barrier layer and depositing a conductive layer over the seed layer. The precursor generally includes pentakis(dimethylamido)tantalum having less than about 5 ppm of impurities. The precursor is generated in a canister coupled to a heating element configured to reduce formation of impurities.