Ta and Ta-N films sputtered with pure Ar, 10%, 20%, 30%, 40%, 50%, and 60% N-2/Ar gas ratios were found to be a mixture of beta-Ta and bcc-Ta, bcc-Ta, bcc-TaNx, expanded bcc-TaNx, hcp-Ta2N, fcc-TaN, and fcc-TaN (nearly amorphous) phases, respectively. The resistivity was found to be lowest in samples sputtered with 10% N-2/Ar and increase with nitrogen content in samples deposited with 10% to 60% N-2/Ar. For Cu layers deposited on these films, the growth orientations were found to depend strongly on the microstructures of underlying Ta and Ta-N films. The Cu (111)/(200) ratio was decreased with the nitrogen content of Ta-N films.