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

Paper AS-MoM4
Fundamentals and Applications of a New Bi-cluster Liquid Metal Ion Source

Monday, November 15, 2004, 9:20 am, Room 210A

Session: SIMS I - Cluster Probe Beams and General Topics
Presenter: F. Kollmer, ION-TOF GmbH, Germany
Authors: F. Kollmer, ION-TOF GmbH, Germany
P. Hoerster, ION-TOF GmbH, Germany
R. Moellers, ION-TOF GmbH, Germany
D. Rading, ION-TOF GmbH, Germany
T. Grehl, ION-TOF GmbH, Germany
E. Niehuis, ION-TOF GmbH, Germany
Correspondent: Click to Email
In recent years Au cluster primary ions emitted from a LMIS (liquid metal ion source) have been successfully applied for the analysis of organic surfaces by TOF-SIMS. Compared to monoatomic primary ion bombardment the use of Au clusters leads to a considerable enhancement of the secondary ion yield up to several orders of magnitude. As the corresponding increase in the damage cross section is much smaller, the ion formation efficiency as a cumulative measure of the sensitivity of the analysis process, also increases significantly. In particular the Au cluster source combines the fundamental benefits of cluster ion bombardment with a high brightness source allowing to push the lateral resolution in organic imaging down to the 100-nm range. In this contribution fundamental as well as practical aspects of a newly developed Bi-cluster liquid metal ion source are addressed and compared with the capabilities of a Au cluster source. The Bi-cluster source offers excellent prospects for organic surface analysis since a large fraction of the primary ion current is emitted as singly and doubly charged clusters (up to Bi@sub 7@@super 2+@). Even at low emission currents stable operation is achieved which is advantageous with respect to the lifetime of the source and the spot size of the primary ion beam.