Presentation on theme: "SIMS-EDX system for a standard-free analysis Yu. Kudriavtsev, R.Asomoza Sección Electrónica del Estado Solido, Departamento Ingeniería Eléctrica, CINVESTAV-IPN,"— Presentation transcript:
SIMS-EDX system for a standard-free analysis Yu. Kudriavtsev, R.Asomoza Sección Electrónica del Estado Solido, Departamento Ingeniería Eléctrica, CINVESTAV-IPN, Av. IPN #2508, México, DF 07360, México email@example.com
Introduction SIMS as any other technique has advantage as well as weak points. The most important disadvantage is poor quantification of SIMS data: by using implanted standards quantification can be done with an experimental error of around ±20%. SIMS analysis of main elements (the concentration range of 1%-100%) cannot be quantified by SIMS using implanted standards; a special calibration procedure should be performed, because of non-linear dependence between concentration of the element of interest and experimental secondary ion current, monitored for it. Energy dispersive X-ray spectroscopy ideally complements SIMS, because of standard free quantitative analysis of most of the elements with the concentration from 0.01 atomic % to 100 atomic %.
General idea: Utilize an Electron Gun of any SIMS instrument, used typically for charge compensation, to excite characteristic X-Ray emission from analyzed sample to realize Energy Dispersive X-ray spectroscopy method with the SIMS instrument.
Installation of EDD at ims-6f instrument Si crystal of EDD Primary ion trap EDX detector: Exterior view
A modified Strip: the closed window protect EDD in the SIMS mode
Application of EDX-SIMS instrument: I. Semiconductors 1.Quantitative analysis of solid solutions: bulk, thick films, thin films. See Poster Section: Tue-pos-43 2. Calibration of SIMS (RSFs) for main element analysis in complex materials. 3. Shallow junction analysis (LEXES “inside“). II. Metals and alloys: Quantitative analysis of bulk, thick films and thin films. III. Glass (including natural), ceramics, minerals, etc. Quantitative analysis of bulk, thick films and thin films. X-ray spectrum of obsidian
Two different strategies: I.Perform a quantification of main elements by EDX, then analyze dopants and contamination by SIMS MBE grown 1 micron epi-layer of Al 0.2 Ga 0.8 N: EDX spectrum and SIMS depth profile
II. “Internal calibration” of SIMS
ElementoTi*Al*VMoZrFeSi Concentración, % atómicos 126.96.36.199.00.1 Fig. RSFs as a function of Ionization potential of element. Points show experimental RSFs, found by SIMS with using of EDX data. EDX spectrum and found composition of Ti allow
Fragments of mass- spectrum, acquired by SIMS for Ti allow
ElementoCertificateEDXSIMSFalla, % H0.072%n/d0.091%<26% Bn/d 3E-4%n/d C0.044%n/d0.050%<15% N0.028%n/d0.062%x2 Nan/d 4E-4%n/d Al2.72%9.2%*2.72%*n/d Si0.12%0.1% <15% Kn/d 3E-6%n/d Can/d 6E-5%n/d Ti87.4%83.2%*87.4%n/d V4.2%4.54.5%<7% CrSuma: 0.03%n/d0.027%n/d Mnn/d0.011%n/d Fe0.0950.10.1%<5% NiSuma: 0.03%n/d0.002%n/d Cun/d Zr0.058n/d0.06%<4% Mo2.7%3.0% <10% Inn/d 1.4E-4%n/d Table 1 Composition of Ti allow, defined by EDX/SIMS in comparison with Certificate of the provider. * Rose rows corresponds to elements used for SIMS calibration.
Conclusions: 1.EDX technique ideally complements SIMS for a quantitative analysis of complex materials. 2.Any SIMS instrument, equipped by an Electron Gun, can be “modified” to perform EDX analysis. 3.Energy of primary electron beam can be varied from 0 to 10keV, this means we can vary thickness of the analyzed layer from several microns down to a hundred nanometers. 4.Standard-free analysis in the “full” range of concentration: from 100 atomic % down to 10 -7 atomic %, can be realized with a reasonable accuracy. THANK YOU FOR YOUR ATTENTION!