Influence of stress on the electron core level energies of noble gases implanted in hard amorphous carbon films

In this work, we report the influence of the structural properties of the a morphous carbon matrix on the core-level electrons of implanted noble gases (Ar, Ne and Kr) used in the sputtering deposition process. The films were prepared in an ion beam-assisted deposition chamber (IBAD) including two Ka uffman ion sources. Some fractional noble gas is trapped in the film during the assisted deposition and is subjected to the highly strained environmen t of the carbon matrix. X-Ray photoelectron spectroscopy shows that the nob le-gas core-level energies shift linearly to lower binding energies with in creasing compressive stress. It is suggested that these shifts are caused b y compression of the outer valence wave-function of the implanted gas and b y an extra-screening effect from valence electrons of the host atoms. The u se of noble-gas core-level energy is proposed as a probe to determine the f ilm stress. (C) 2001 Elsevier Science B.V. All rights reserved.