METALORGANIC CHEMICAL-VAPOR-DEPOSITION OF TANTALUM NITRIDE BY TERTBUTYLIMIDOTRIS(DIETHYLAMIDO)TANTALUM FOR ADVANCED METALLIZATION

Abstract

We deposited tantalum nitride (TaN) frlrns by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) using a new precursor tertbutylimidotris(diethylamido)tantalum (TBTDET). Strong Ta-N double bond in the precursor preserved the ''TaN'' portion during the pyrolysis process. This method has yielded low-resistivity films. It changed from 10 m Omega cm (deposited at 500 degrees C) to 920 mu Omega cm (obtained at 650 degrees C). The carbon and oxygen concentrations were low in the films deposited at 600 degrees C, as determined by x-ray photoelectron spectroscopy. Transmission electron microscopy and x-ray diffraction analysis indicated that the as-deposited films exhibited polycrystalline structures with the lattice constants close to the bulk TaN value. The TaN barrier layer was successfully applied as a glue layer for CVD tungsten (W) metallization schemes. (C) 1995 American Institute of Physics.