Some characteristics in the interaction of slow highly charged Iq+ ions with a Si(1 1 1) 1 × 1-H surface

We have observed secondary particles and photons emitted from hydrogen terminated Si(1 1 1) 1 × 1 surfaces in the interactions with highly charged ions (HCIs) of iodine having a wide range of charge state, q, from I17+ up to I53+, fully stripped iodine ion. A TOF-SIMS (time-of-flight secondary ion mass spectrometry) apparatus has been used to investigate secondary emissions where protons are dominant signals in the TOF spectra. Measured yields of H+ and H2+ show strong q-dependences, proportional to q3.4 and q5, respectively. For Si+, while the yield remains constant for q < ∼ 25, it begins increasing with q1.4 at higher q (∼25). The mechanism of secondary emissions is briefly discussed.