SIMS quantification of SiGe composition with low-energy ion beams

Abstract

Systematic SIMS analyses with low-energy (250 eV ∼1 keV) oxygen, cesium and krypton primary beams have been carried out on a set of fully strained uniform epitaxial Si1-xGex films (x = 5 ∼ 60%), as well as a germanium ion-implanted silicon standard to investigate the matrix effect under various conditions. It is shown that preferential ion yield enhancement of one matrix component over the other can occur as the result of primary ion incorporation. Through defining a matrix yield factor, this work demonstrated that constant secondary ion yield ratios between Si ion and Ge ion over a large concentration range are only valid under some very specific analysis conditions. Emphases were placed on oxygen beam analyses with regard to steady-state ion yields and surface transients. Both show some unique features only accessible under low-energy conditions. Copyright © 2010 John Wiley & Sons, Ltd.