AVS 51st International Symposium
    Applied Surface Science Monday Sessions
       Session AS-MoM

Invited Paper AS-MoM2
Cluster Primary Ion Beam Secondary Ion Mass Spectrometry for 2 and 3 Dimensional SIMS Analysis

Monday, November 15, 2004, 8:40 am, Room 210A

Session: SIMS I - Cluster Probe Beams and General Topics
Presenter: G. Gillen, National Institute of Standards and Technology
Authors: G. Gillen, National Institute of Standards and Technology
P. Chi, National Institute of Standards and Technology
A.J. Fahey, National Institute of Standards and Technology
C.M. Mahoney, National Institute of Standards and Technology
M.S. Wagner, National Institute of Standards and Technology
Correspondent: Click to Email
The use of novel monoatomic and cluster primary ion beams for Secondary Ion Mass Spectrometry (SIMS) has several potential advantages for surface analysis. Cluster ion sputtering results in a reduced penetration depth for the constituent atoms of the cluster, which should improve SIMS depth resolution and minimizes the sputter depth over which the build up of the primary beam gives non-linear sputter and ion yield enhancements (the so-called transient region). Cluster bombardment may also reduce sputter-induced topography created during ion beam analysis of metal films. For organic surface characterization, cluster primary ion beam offers large improvements in sensitivity and, in selected cases, immunity to primary-beam-induced degradation of the sample. At NIST we are working on the application of novel primary ion beam SIMS for practical surface analysis. Several types of prototype ion sources are currently being evaluated for this application including; SF5+ , C8- and C60+. A variety of materials have been analyzed using these new ion sources including low energy ion implants of arsenic and phosphorous in silicon, boron delta-doped layers, surface metals, metal films, organic films and polymers. Recent key findings include the observation of improved depth resolution for semiconductor analysis and a reduction in beam-induced topography for metal films. Our most recent efforts have been focused on extending the cluster SIMS technique for the molecular depth profiling of organic thin films. Combined with secondary ion imaging we will demonstrate the unique capability of cluster SIMS to provide true 3 dimensional molecular surface analysis.