Surface analysis at low to ultrahigh vacuum by ion scattering and direct recoil spectroscopy

Abstract
The surface analytical methods designated as mass spectroscopy of recoiled ions (MSRI) and direct recoil spectroscopy (DRS) are characterized by the incidence of energetic ions on the sample and the detection of scattered primary beam particles or recoil‐sputtered surface atoms that are energy and/or mass analyzed. The use of time‐of‐flight for energy analysis of scattered primary particles and recoiled surface atoms creates a powerful technique for structural and elemental analysis of surfaces. Time‐of‐flight ion scattering and recoil spectroscopy are emerging as viable surface analysis tools with particular strength for in situ monitoring during low pressure (<few mTorr) thin film processing. DRS has the distinct advantage over most other surface spectroscopies of being able to measure surface hydrogen. MSRI is particularly useful for elemental and isotopic surface analysis and, in several important cases (e.g., N), is considerably more sensitive than secondary ion mass spectroscopy. This review covers the latest applications of MSRI and DRS in a variety of thin film growth and nucleation studies, highlighting the many advantages presented by these unique spectroscopies.