DEPTH PROFILE OF CHEMICAL-SPECIES IN MULTIPLE DOPED TRIMETHYLSILANE FILM ON SI(100) SURFACES BY LOW-ENERGY AR IONS

A thin film on a Si (1 0 0) substrate fabricated by a series of proces ses of trimethylsilane (TMSiH) doping, electron irradiation. heating a nd cooling was used to investigate the composition and the chemical sp ecies of the film as functions of depth. A 3.1 keV Ar+ ion beam was ap plied to sputter away the sample surface. After each sputtering, the s urface composition and its chemical bonding environment were analyzed by X-ray Photoelectron Spectroscopy O(PS). A silicon carbide and oxide contaminating surface gradually changed to a pure silicon surface and correspondingly, the dominant C-C and Si-C bonds disappeared during s puttering. Because of the evolution of the chemical environment during sputtering, these experimental results allow us to assign chemical bo nds to XPS peaks of the TMSiH covered Si (1 O O) system even though th e coverage is only few tenths of a Langmuir (L). (C) 1998 Published by Elsevier Science B.V. All rights reserved.