Ta films formed on Si(100) and quartz substrates by sputtering technique usually lead to a textured beta-Ta with tetragonal crystal lattice. The beta-Ta film has a high resistivity. As a comparison, low resistivity alpha-Ta with cubic crystal lattice can be formed by sputtering on TaN. Crystal study shows that the sputtered TaN film has a preferred (111) growth plane and the alpha-Ta has a preferred (110) growth plane. Both are textured films. The growth mechanism of the alpha-Ta on TaN is ascribed to epitaxy.