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The surface transient in Si for SIMS with oblique low‐energy O 2 + beams
Author(s) -
Jiang Z. X.,
Alkemade P. F. A.
Publication year - 1999
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/(sici)1096-9918(199903)27:3<125::aid-sia490>3.0.co;2-8
Subject(s) - ion , secondary ion mass spectrometry , wafer , analytical chemistry (journal) , atomic physics , chemistry , penetration depth , silicon , penetration (warfare) , oxide , materials science , optics , physics , nanotechnology , organic chemistry , engineering , chromatography , operations research
The surface transient in Si and SiGe for secondary ion massspectrometry (SIMS) analysis with low‐energy andobliquely incident O 2 + beams was studied.In particular, the transition width ( z tr , thedepth at which equilibrium secondary Si + intensitywas reached) was measured for various impact energies (0.56keV≤ E p ≤2 keV) and incidence angle(45°<θ<77° to the surface normal). For E p <700 eV and θ>60°, thetransition widths for relatively fresh surfaces were 3–4 nm,offering good conditions for ultra‐shallow SIMS analysis. At E p =1 keV and θ=60°, thedifferences in z tr between various secondary ions(Si + , SiO + , Ge + and GeO + ) were marginal and only O + and Si 2 + ions reached equilibriumsignificantly earlier. We found that z tr is abouttwice the mean penetration depth of the primary ions. In addition, the thickness of the native oxide of Si wafers wasmeasured as a function of the storage time in air. It varied from 0.6nm after 1 day to 1.5 nm after 2 years. Copyright © 1999 JohnWiley & Sons, Ltd.