The crystallographic texture and the grain size have been measured by X-ray diffraction techniques for about 200 nm-thick Cu films sputter-deposited on amorphous Ta 3 5 Si 1 8 N 4 7 and Ti 3 3 Si 2 3 N 4 4 underlayers, and for comparison also on TiN underlayers and oxidized silicon, all on Si (100) substrates. The (111) texture of the as-deposited Cu films increases in the sequence TiN<SiO 2 <Ti 3 3 Si 2 3 N 4 4 <Ta 3 5 Si 1 8 N 4 7 . Amorphous Ta 3 5 Si 1 8 N 4 7 and Ti 3 3 Si 2 3 N 4 4 layers evidently promote quite effectively the growth of highly (111) textured Cu films. After vacuum annealing at 450 o C for 30 min the texture of Cu rises on Ti 3 3 Si 2 3 N 4 4 , falls on Ta 3 5 Si 1 8 N 4 7 , while that on TiN and on SiO 2 changes little and the sequence becomes TiN<SiO 2 <Ta 3 5 Si 1 8 N 4 7 <Ti 3 3 Si 2 3 N 4 4 . The grain size of the as-deposited Cu films increases in the sequence Ti 3 3 Si 2 3 N 4 4 <SiO 2 <Ta 3 5 Si 1 8 N 4 7 <Ti 4 7 N 5 3 and rises moderately upon annealing, least for TiN and most for SiO 2 and Ti 3 3 Si 2 3 N 4 4 .