Studies of Surfaces of Materials Using Low Energy Ion Beams

Characterization of solid surfaces using low energy, i.e. ¿ 10keV, ion beams has gained increasing popularity during the past decade. The three most commonly used low energy ion beam techniques are: secondary ion mass spectrometry (SIMS), sputter-induced photon spectrometry (SIPS) and ion scattering spectrometry (ISS). As far as detection sensitivity is concerned, SIMS is probably superior to almost all surface analytical techniques. Impurity levels in the parts per million range can be easily determined. SIMS is widely applied to semiconductor problems in which concentration-versus-depth information is usually sought. SIPS is especially suited to compositional analysis of non-conducting materials since, unlike techniques based on detection of charged particles, charging of the sample surface by the primary beam does not affect the collection of optical radiation from sputtered excited atoms. ISS is probably the best available technique for studying the composition of the topmost surface layer of any material. Its monolayer sensitivity due to the properties of low energy scattering is unique among surface analytical techniques. This paper discussed the use of each of these three techniques to solve problems in materials science.