Abstract
Using scanning tunneling microscopy (STM) and time of flight secondary ion mass spectrometry (TOF/SIMS), we observed radiation effects on a Si(111)-(7 X 7) surface in the collision of a single highly charged ion (HCI) with a charge state q up to q = 50. The STM observation with atomic resolution revealed that a nanometer sized crater-like structure was created by a single HCI impact, where the size increased rapidly with q. The secondary ion yields also increased with q in which multiply charged Si ions (Sin+) were clearly observed in higher q HCI-collisions. The sputtering mechanism is briefly discussed, based on the so-called Coulomb explosion model.
2006 Elsevier B.V. All rights reserved.
Keywords: Highly charged ion (HCI); Si(111)-(7 X 7) surface; Scanning tunneling microscope (STM); Time of flight secondary ion mass spectrometry
(TOF/SIMS)

doi:10.1016/j.susc.2006.11.002