Ion-induced topography, depth resolution, and ion yield during secondary ion mass spectrometry depth profiling of a GaAs/AlGaAs superlattice: Effects of sample rotation

Abstract

Quantitative depth profiling resonance ionization mass spectrometry of GaAs/AlGaAs heterojunction bipolar transistors J. Vac. Sci. Technol. B 10, 385 (1992); 10.1116/1.586363High resolution secondary ion mass spectrometry depth profiling using continuous sample rotation and its application to superlattice and deltadoped sample analysis Effects of sample rotation and sputtering conditions on the depth resolution and ion yield during secondary ion mass spectrometry (SIMS) sputter depth profiles have been studied on bulk GaAs and a GaAs( 5 nm)/ Alo 3 GIlo. 7 As(5 nm) superiattice. Profiles without sample rotation with 1.0-7.0 keY O 2 + show a rapid degradation of the depth resolution with increasing sputter depth. Profiles with Ar + show only slight degradation. Scanning electron microscope (SEM) studies indicate that degradation is associated with development of periodic surface ripples. The wavelength of the ripples is energy dependent and increases with increasing ion impact energy. With sample rotation, no degradation of the depth resolution is observed and SEM micrographs indicate that surfaces sputtered with rotation are smooth. In addition, with 3.0 keY at significant changes in the secondary ion yield of AsO + from bulk GaAs are observed at a depth of -200 nm. No changes are observed with sample rotation. Our results demonstrate that sample rotation during SIMS depth profiling prevents and can reverse the development of surface topography that both degrades depth resolution and changes secondary ion yield. Thus, interpretation and quantitation of SIMS analysis is facilitated.

Dual beam depth profiling of organic materials: Variations of analysis and sputter beam conditions

“…1a) resembles this effect. [16] One possibility to minimize sputter-induced surface roughening is sample rotation, as suggested by Zalar. [17] For the conditions in this study, only sputtering in combination with sample rotation reveals satisfying results.…”

Sputtering Behavior and Evolution of Depth Resolution upon Low Energy Ion Irradiation of GaAs

“…As mentioned above, intermediate to high energy keV O 2 + ion bombardment of GaAs has been reported to lead to transient ion yield changes and topography formation (15)(16)(17).…”

“…This progressive degradation of depth resolution is most pronounced for the lower O 2 + impact energies. We argue that relatively poor depth resolution in GaAs at low O 2 + impact energy is caused by formation of surface topography (15)(16)(17), induced by high surface O-concentrations. We will present a more detailed investigation of energy-and angular effects on depth resolution in GaAs and discuss the impact on sputter yield and surface O-concentration in a forthcoming publication (24).…”

Dry Etching of Copper Phthalocyanine Thin Films: Effects on Morphology and Surface Stoichiometry

“…Ion sputtering is often employed by surface analysis techniques, such as auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), and sary ion mass spectrometry (SIMS), to generate depth profiles of multilayer films. The limits imposed on depth profiling by the effects of ion sputtering on surface topography have been studied thoroughly for many metal and semiconductor thin films [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ]. Ripples and cones are among the most common surface features produced by ion bombardment.…”

“…Ripples and cones are among the most common surface features produced by ion bombardment. The severity of surface topography changes during ion sputtering depends on the characteristics of the sample and the ion beam, and can often be reduced by means of sample rotation [ 5 , 12 , 13 ]. Accurate depth profiling of polymer and organic layers is considerably more challenging than inorganic materials, but has been improved as of late [ 14 , 15 , 16 , 17 , 18 , 19 , 20 ].…”