Characterization of Microcrystalline Si Films by MeV Ion Scattering Techniques

2000 ◽  
Vol 638 ◽  
Author(s):  
W. Bohne ◽  
J. Röhrich ◽  
B. Selle ◽  
M. Birkholz ◽  
F. Fenske ◽  
...  
Keyword(s):  
Electron Cyclotron Resonance ◽  
Ion Beam ◽  
Impurity Content ◽  
Heavy Ion ◽  
Ion Scattering ◽  
Elastic Recoil ◽  
Interference Structure ◽  
Detection Analysis ◽  
Apparent Similarity ◽  
Si Films

AbstractRutherford Backscattering Spectroscopy (RBS) and channeling studies with 1.4 MeV−4He ions as well as Heavy-Ion Elastic Recoil Detection Analysis (HI-ERDA) with 230 MeV 129Xe ions have been applied to characterize structural properties and the impurity content of thin Si films. The analytical potential of these ion-beam techniques is demonstrated for two types of samples: (1) μc-Si films prepared by dc magnetron sputtering in a pure Ar plasma and (2) homoepitaxial Si films deposited by low-temperature electron-cyclotron resonance PECVD at the transition from oriented to disordered growth. For μc-Si the atomic area density N.d obtained by RBS was compared with the optical thickness n.d (n=refractive index) derived from the interference structure of IR reflection spectra. It is shown that the ratio R=n.d/N.d of these quantities can serve as a figure of merit for the degree of crystalline order. An apparent similarity was found in the case of the epitaxially grown films between the Si disorder profiles evaluated from the RBS channeling spectra and the hydrogen and oxygen profiles determined by HI-ERDA. This suggests that hydrogen and oxygen are preferentially incorporated in the disordered parts of the films.

Experimental Study on the Role of Hydrogen in the Breakdown of Low-Temperature Si Epitaxy

2001 ◽  
Vol 686 ◽  
Author(s):  
J. Platen-Schwarzkopf ◽  
W. Bohne ◽  
W. Fuhs ◽  
K. Lips ◽  
J. Röhrich ◽  
...  
Keyword(s):  
Hydrogen Diffusion ◽  
Electron Cyclotron Resonance ◽  
Defect Density ◽  
Chemical Vapor ◽  
High Growth ◽  
Heavy Ion ◽  
Growth Surface ◽  
Elastic Recoil ◽  
Detection Analysis ◽  
Si Epitaxy

AbstractHomoepitaxial Si layers were grown on Si(100) at temperatures of 325 - 500 °C by Electron-Cyclotron Resonance Plasma-Enhanced Chemical Vapor Deposition (ECR PECVD) from a gas mixture of SiH4,H2 and Ar. Ar was added in order to realize high growth rates where the breakdown of epitaxy was well observed. Si disorder depth profiles derived from RBS channeling spectra were compared with hydrogen depth distributions measured by Heavy-Ion Elastic Recoil Detection Analysis (HI-ERDA) and Secondary Ion Mass Spectroscopy (SIMS). The results suggest that the transition from epitaxial to amorphous growth proceeds through two stages: (1) a highly defective but still ordered growth with the defect density increasing as the growth proceeds and (2) the formation of conically shaped precipitates of amorphous Si. Both regions act as an increasingly effective sink for excessive hydrogen which diffuses from the growth surface into the bulk of the sample. In perfectly grown epitaxial films, where the overall concentration of excessive hydrogen was low, the hydrogen diffusion tail was found to extend far beyond the interface into the Si substrate.

Amorphous Silicon Precipitates in (100) c-SI Films Grown by ECRCVD

1999 ◽  
Vol 557 ◽  
Author(s):  
M. Birkholz ◽  
J. Platen ◽  
I. Sieber ◽  
W. Bohne ◽  
J. Röhrich ◽  
...  
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Electron Cyclotron Resonance ◽  
Depth Profiling ◽  
Film Surface ◽  
Chemical Vapor ◽  
Elastic Recoil ◽  
Pronounced Increase ◽  
Detection Analysis ◽  
Si Films

AbstractSilicon films were grown on (100) n-Si with an electron-cyclotron resonance chemical vapor deposition (ECRCVD) system by decomposition of SiH4 at 325°C. Structure and composition of thin films were investigated by SEM, Raman spectroscopy, elastic recoil detection analysis (ERDA) and TEM. Excellent epitaxial growth was achieved for some hundred nm thickness. For more than 1 μm thick films, however, SEM revealed the occurrence of conical structures orientated upside-down with their basal plane in the film surface. Depth-profiling of the elemental composition of thin films by means of ERDA showed the hydrogen content CH to exhibit a pronounced increase with increasing film thickness. Raman spectroscopy evidenced the coexistence of c-Si and a-Si:H by the occurrence of two bands at 520 and 480 cm-1, the ratio of which was found to depend sensitively upon the position of the laser spot on the sample. All experimental results could be consistently explained by assuming the conical precipitates to consist of a-Si:H which was finally proven by coherent electron beam diffraction (CEBD).

Composition and Structure of Epitaxial CaF2 Layers at the First Stages of Their Growth on Si(111)

2001 ◽  
Vol 696 ◽  
Author(s):  
R. Würz ◽  
W. Bohne ◽  
W. Fuhs ◽  
J. Röhrich ◽  
M. Schmidt ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Film Growth ◽  
Stoichiometric Composition ◽  
Interface Reaction ◽  
Heavy Ion ◽  
Interface Layer ◽  
Buffer Layers ◽  
Ex Situ ◽  
Elastic Recoil ◽  
Detection Analysis

AbstractCaF2 films with thicknesses in the monolayer range (<20 Å) were grown on Si(111) by evaporation from a CaF2 source at UHV conditions. They were characterized ex-situ by Heavy-Ion Elastic Recoil Detection Analysis (HI-ERDA), RBS/Channeling, X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM). The F/Ca ratio of the films was found to depend on the growth temperature Ts and to deviate appreciably from the stoichiometric composition (F/Ca=2). Due to an interface reaction which leads to a CaF-interface layer a change from polycrystalline to epitaxial growth occurs at Ts=450°C. At higher temperature film growth started with a closed layer of CaF on top of which CaF2 layers with an increasing fraction of pinholes were formed. By means of a two-step process at different temperatures, the amount of pinholes could be strongly reduced. It was found, that buffer layers of CaF2 with a CaF interface layer introduced in Au/p-Si contacts enhance the barrier height by as much as 0.36eV to values of 0.64eV.

Iodine Induced Damage in Semiconductor Materials During Heavy Ion Recoil Elastic Recoil Detection Analysis

1996 ◽  
pp. 849-852
Author(s):  
Scott R. WALKER ◽  
Peter N. JOHNSTON ◽  
Ian F. BUBB ◽  
Warren B. STANNARD ◽  
David N. JAMIESON ◽  
...  
Keyword(s):  
Heavy Ion ◽  
Semiconductor Materials ◽  
Elastic Recoil ◽  
Elastic Recoil Detection Analysis ◽  
Elastic Recoil Detection ◽  
Detection Analysis

scholarly journals Time-Of-Flight ERDA for Depth Profiling of Light Elements

2020 ◽  
Vol 4 (4) ◽  
pp. 40
Author(s):  
Keisuke Yasuda
Keyword(s):  
Ion Beam ◽  
Time Of Flight ◽  
Depth Profiling ◽  
Depth Resolution ◽  
Semiconductor Detectors ◽  
Light Elements ◽  
Elastic Recoil ◽  
Measurement Sensitivity ◽  
Elastic Recoil Detection ◽  
Detection Analysis

The time-of-flight elastic recoil detection analysis (TOF-ERDA) method is one of the ion beam analysis methods that is capable of analyzing light elements in a sample with excellent depth resolution. In this method, simultaneous measurements of recoil ion energy and time of flight are performed, and ion mass is evaluated. The energy of recoil ions is calculated from TOF, which gives better energy resolution than conventional Silicon semiconductor detectors (SSDs). TOF-ERDA is expected to be particularly applicable for the analysis of light elements in thin films. In this review, the principle of TOF-ERDA measurement and details of the measurement equipment along with the performance of the instrumentation, including depth resolution and measurement sensitivity, are described. Examples of TOF-ERDA analysis are presented with a focus on the results obtained from the measurement system developed by the author.

Comparative study of the oxide scale thermally grown on titanium alloys by ion beam analysis techniques and scanning electron microscopy

2008 ◽  
Vol 23 (8) ◽  
pp. 2245-2253 ◽  
Author(s):  
A. Gutiérrez ◽  
F. Pászti ◽  
A. Climent-Font ◽  
J.A. Jiménez ◽  
M.F. López
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Composition ◽  
Titanium Alloys ◽  
Oxide Scale ◽  
Ion Beam ◽  
Elastic Recoil ◽  
Detection Analysis ◽  
Nb Content ◽  
Scanning Electron

In the present work, the oxide layers developed at elevated temperature on three vanadium-free titanium alloys, of interest as implant biomaterials, were studied by Rutherford backscattering spectroscopy, elastic recoil detection analysis, and scanning electron microscopy. The chemical composition of the alloys investigated, in wt%, was Ti–7Nb–6Al, Ti–13Nb–13Zr, and Ti–15Zr–4Nb. Upon oxidation in air at 750 °C, an oxide scale forms, with a chemical composition, morphology, and thickness that depend on the alloy composition and the oxidation time. After equal exposure time, the Ti–7Nb–6Al alloy exhibited the thinnest oxide layer due to the formation of an Al2O3-rich layer. The oxide scale of the two TiNbZr alloys is mainly composed of Ti oxides, with small amounts of Nb and Zr dissolved. For both TiNbZr alloys, the role of the Nb-content on the mechanism of the oxide formation is discussed.

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