The effect of low-energy ion bombardment on the density and crystal structure of thin films

The effect of low-energy ion bombardment on the growth and properties of th in films deposited by rf plasma sputtering at low substrate temperatures is studied. The dependences of the film thickness, density, crystal structure , and conductivity on the bias voltage applied to the substrate are obtaine d. At biases ranging from 0 to -30 V, nickel films are polycrystalline; at higher biases, they exhibit axial (111) texture. At the bias -60 V, the den sity of the Ni films is close to that of the bulk metal and the crystal str ucture of the films is the most ordered. With a further increase in the bia s, the density of the films drops because of gas (argon and residual gases) atoms incorporated into the films. The same bias dependence of the density is observed for amorphous films of binary alloys of d and f metals. In thi s case, the films deposited at the substrate bias -40 V have the highest de nsity. (C) 2001 MAIK "Nauka/Interperiodica".