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Indexed by:会议论文

Date of Publication:2012-01-01

Included Journals:CPCI-S、Scopus

Volume:32

Page Number:635-639

Key Words:computer simulation; surface relaxation; surface energy; alumina

Abstract:R-plane sapphire is the preferred substrate material for silicon-based radiation-hard devices and RF integrated circuits. Ab initio periodic Hartree-Fock simulations of r-plane sapphire slabs are presented with a particular focus on the surface relaxation and the surface energy. The calculations show that there is a considerable relaxation of the four outermost atomic layers of r-plane sapphire. A comparison with c-, a- and m-plane sapphire shows that the surface energy of fully relaxed r-plane sapphire is considerably larger than the surface energy of c-plane sapphire, but similar to the surface energies of a- and m-plane sapphire. The implications of these findings for chemical mechanical polishing (CMP) and electrolytic in-process dressing (ELID) grinding of sapphire are discussed briefly. (C) 2012 Published by Elsevier B.V. Selection and/or peer review under responsibility of Chinese Vacuum Society (CVS).