کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1680937 | 1518745 | 2012 | 4 صفحه PDF | دانلود رایگان |
This work presents in-situ near and below sputter-threshold studies for GaSb(1 0 0) at energies 50, 100 and 200 eV and current densities near 50 μAcm−2. Variation of incident particle energy probes the energy deposition distribution and its relation to surface composition. In-situ analysis is conducted over irradiation modification using Ar singly-charged ions at normal incidence of the surface using complementary techniques including: X-ray photoelectron spectroscopy (XPS) and ion-scattering spectroscopy (LEISS). The former probes 1–3 nm and the latter technique probes the first 1–2 ML or 0.3–0.6 nm. Ex-situ analysis includes HR–SEM to correlated surface morphology with surface composition studied in-situ during irradiation. Results indicate ordering of nanodot formation at fluence threshold of about 1017 cm−2. Both XPS and LEISS identify Ga2O3 islands formation due to GaSb chemical affinity for oxygen followed by an initial enhancement of Ga/Sb = 1.20 ratio and then a sharp drop in Ga relative concentration with LEISS reaching a Sb-dominated terminating 1–2 nm region corresponding to the implantation depth between 50 and 200 eV. XPS shows a slight enrichment of Ga in sub-surface layers that levels to a 1:1 stoichiometry of the crystalline GaSb(1 0 0) surface.
Journal: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms - Volume 272, 1 February 2012, Pages 210–213