Effect of Low-Energy Ion Bombardment on the Texture and Microstructure of Platinum Films

We study the effect of low-energy ion bombardment on the texture and structure of an 80-nm-thick platinum film deposited at room temperature. The film is treated in an inductively coupled Ar plasma with a negative voltage of 45-125 V applied to the samples and an ion-current density of 3.3 mA/cm(2). A series of treatments at each voltage results in thinning of the film; after each treatment, its structural parameters are determined by X-ray diffraction analysis and compared with the parameters of Pt films 20-60 nm thick deposited under the same conditions. The treatment at 75-125 V decreases the average size of the coherently diffracting domains by 10-25%; at 45 V, such a decrease is not observed. The results are explained by the formation and accumulation of radiation defects; the rate of their formation is lower at 45 V. Film sputtering in all modes does not worsen the sharpness of the film texture.