Surface morphology of the Ar+ ion-irradiated Ag/Si(111) system

In the present study, a 500 Angstrom thin ng film was deposited by thermal evaporation on 5% HF etched Si(1 1 1) substrate at a chamber pressure of 8 x 10(-6) mbar. The films were irradiated with 100 KeV Ar+ ions at room temperature (RT) and at elevated temperatures to a fluence of 1 x 10(16) cm(-2) at a fur of 5.55 x 10(12) ions/cm(2)/s. Surface morphology of the Ar ion-irradiated Ag/Si(1 1 1) system was investigated using scanning electron microscopy (SEM). A percolation network pattern was observed when the him was irradiated at 200 degrees C and 400 degrees C. The fractal dimension of the percolated pattern was higher in the sample irradiated at 400 degrees C compared to the one irradiated at 200 degrees C. The percolation network is still observed in the film thermally annealed at 600 degrees C with and without prior ion irradiation. The fractal dimension of the percolated pattern in the sample annealed at 600 degrees C was lower than in the sample post-annealed (irradiated and then annealed) at 600 degrees C. All these observations are explained in terms of self-diffusion of Ag atoms on the Si(1 1 1) substrate, inter-diffusion of Ag and Si and phase formations in Ag and Si due to Ar ion irradiation. (C) 2000 Elsevier Science B.V. All rights reserved.