Preface

Auger electron spectroscopy (AES) sputter depth profiling of an ISO reference material of the GaAs/AlAs superlattice was investigated using low-energy Ar + ions. Although a high depth resolution of ∼1.0 nm was obtained at the GaAs/AlAs interface under 100 eV Ar + ion irradiation, deterioration of the depth resolution was observed at the AlAs/GaAs interface. The Auger peak profile revealed that the enrichment of Al due to preferential sputtering occurred during sputter etching of the AlAs layer only under 100 eV Ar + ion irradiation. In addition, a significant difference in the etching rates between the AlAs and GaAs layers was observed for low-energy ion irradiation. Deterioration of the depth resolution under 100 eV Ar + ion irradiation is attributed to the preferential sputtering and the difference in the etching rate. The present results suggest that the effects induced by the preferential sputtering and the significant difference in the etching rate should be taken into account to optimize ion etching conditions using the GaAs/AlAs reference material under low-energy ion irradiation.

Section: Depth Resolutionmentioning

confidence: 50%

Section: Depth Resolutionmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Preferential sputtering observed in Auger electron spectroscopy sputter depth profiling of AlAs/GaAs superlattice using low‐energy ions

Mizuhara

Bungo

Nagatomi

et al. 2005

“…Details of the FLIG are described elsewhere. 3,4 The FLIG was attached to a scanning Auger electron microprobe (JAMP-10, Jeol) through an ICF-114 conflat flange. The incident angle of the ion beam was 60°from the surface normal.…”

Section: Floating-type Low-energy Ion Gun (Flig)mentioning

confidence: 99%

High‐resolution Auger depth profiling by sub‐keV ion sputtering

Inoue

Shimizu

Lee

et al. 2005

Auger electron spectroscopy depth profiling of a GaAs/AlAs superlattice sample was performed with Ar + ions of 100-500 eV using a compact floating-type low-energy ion gun. The practical etching rate of >1.5 nm min At the sputtering energy of 100 eV, remarkable improvement of the depth resolution at the leading edge (1z l = 1.3 nm) has been observed but this is followed by considerable deterioration at the trailing edge (1z t = 2.7 nm). Dynamic Monte-Carlo simulation for sputtering energies of 150-300 eV was performed for comparison. Although the Monte-Carlo simulation overestimates the depth resolutions by ∼0.6 nm larger than the relevant experimental values, it describes the energy dependence of the depth resolution with considerable success.

“…4,5 A depth resolution of ¾1.8 nm was also reported by Shimizu and Inoue for sputter depth profiling of the GaAs/AlAs superlattice using 150-eV Ar C ions. 6 In addition to these studies, which mainly focused on the depth resolution itself, several studies dealing with the measurement of the thickness of the mixing layer by means of medium-energy ion scattering 7,8 and transmission electron microscopy (TEM) 9 -13 have also been reported. Those studies also revealed that the application of low-energy ions is effective in high-depth-resolution sputter depth profiling.…”

Section: Introductionmentioning

confidence: 99%

Dependence of depth resolution on primary energy of low‐energy Ar⁺ Ions (100–1000 eV) in AES sputter depth profiling of GaAs/AlAs superlattice

Bungo

Nagatomi

Takai

2006

The dependence of the depth resolution on the primary energy of low-energy Ar + ions in Auger electron spectroscopy (AES) sputter depth profiling of an ISO reference material GaAs/AlAs superlattice was investigated for the ion incidence angle of 50°from the sample surface normal. The depth resolution was found to improve as the square root of the primary energy of the ions as the primary energy decreased from 1000 to 200 eV. In contrast, a deterioration of the depth resolution was observed at 100 eV, which was induced by the difference in the etching rates between GaAs and AlAs and preferential sputtering. Further investigation of AES sputter depth profiling under irradiation of 100-eV Ar + ions at the incident angle of 70°revealed that the difference in the etching rate and preferential sputtering could be suppressed by changing the incident angle from 50°to 70°, leading to a depth resolution of ∼1.3 nm with 100 eV. The present results confirmed that glancing incidence is effective in achieving higher depth resolution from the point of view of the reduction of not only atomic mixing but also the difference in the etching rates and preferential sputtering. Careful attention is required for optimizing conditions of low-energy ion irradiation in sputter depth profiling using the GaAs/AlAs reference material.