Exact compositional analysis of SiGe alloys by matrix effect compensated MCs+-SIMS

SiGe alloy, owing to its high electron and hole mobility, has potential applications in high-speed microelec- tronic device technology. The optimization of such tech- nology requires the precise determination of Ge concentra- tion in the full range of composition and the understanding and control of the Ge-Si interdiffusion phenomenon. The most appropriate analytical technique with highest detection sensitivity (∼subparts per billion) for measuring elemental concentration is secondary ion mass spectrometry (SIMS). However, strong compositional dependence of secondary ion yield, i.e. "matrix effect," has always made SIMS quan- tification extremely difficult. A procedure for the accurate quantification of Ge concentration in molecular beam epi- taxy (MBE)-grown Si1−xGex (0 <x< 0.72) alloys based on MCs + -SIMS approach has been proposed. The "matrix effect" is shown to be completely suppressed for all Ge concentrations irrespective of impact Cs + ion energies. The novel methodology has successfully been applied for direct quantitative composition analysis of Si/Ge multilayer struc- ture.