Optimizing the Depth Resolution of Rutherford Backscattering Through Modeling of Noise Sources

1986 ◽  
Vol 69 ◽  
Author(s):  
John R. Abelson ◽  
T. W. Sigmon
Keyword(s):  
Rutherford Backscattering Spectrometry ◽  
Grazing Angle ◽  
Depth Resolution ◽  
Normal Incidence ◽  
Low Noise ◽  
Forward Scattering ◽  
Rutherford Backscattering ◽  
Acceptance Angle ◽  
Noise Sources ◽  
Near Surface

AbstractGrazing angle configurations improve the depth resolution of Rutherford Backscattering Spectrometry (RBS) because the path length of scattered particles is geometrically increased. But in the limit of very grazing angles the resolution degrades due to the finite detector acceptance angle and low angle forward scattering of the beam, considerations which are not present in near-normal incidence geometries. The forward scattering, for example, worsens the depth resolution approximately as the square of the depth, rather than the familiar square root dependence of energy straggling. We present a simple computational scheme which predicts the depth resolution in any target as a function of scattering depth, beam energy, and the grazing angle. The calculations are simpler than previous studies because we use analytic expressions in place of numerical inputs without loss of accuracy. The results lead directly to an optimum depth resolution. We find good agreement between the predicted resolution and measurements on thin silicon dioxide and amorphous silicon films. Finally, we calculate the resolution expected with the use of ion beams heavier than He+, and find improved near surface depth resolution if a low noise detector is used.

Hgl−xCdxTe Near Surface Characterization using Computer Aided Rutherford Backscattering Spectrometry

1986 ◽  
Vol 90 ◽  
Author(s):  
T.-M. Kao ◽  
T. W. Sigmon
Keyword(s):  
Surface Characterization ◽  
Rutherford Backscattering Spectrometry ◽  
Grazing Angle ◽  
Surface Region ◽  
Rutherford Backscattering ◽  
Structural Defects ◽  
Near Surface ◽  
Lattice Disorder ◽  
Defect Densities ◽  
Distributed Dislocations

ABSTRACTIn this work, we report the use of Rutherford backscattering(RBS) measurements and computer simulations to provide accurate stoichiometry information and semi-quantitative defect densities for the near surface region of Hg1−xCdxTe (MCT). The accuracy of the Hg1−xCdx Te x-values determined by our method is found to be comparable to other commonly used methods, such as FTIR or the electron microprobe. The data obtained as structural defects from RBS channeling measurements are in basic agreement with other techniques, such as chemical etching. The sensitivity of the channeling measurement to uniformly distributed dislocations is found to be about 107−108 cm−2, however, for dislocations forming subgrains, the detectable level of dislocation comes to 105 – 106 cm−2. The depth profiles of lattice disorder resulting from ion implantation into MCT are also extracted from RBS channeling measurements using these simulation programs. These profiles are found to closely match the calculated profiles for the displaced atoms calculated using an implantation modeling program (TRIM). We also report on the use of channeling-in-grazing-angle-out technique for evaluating the stoichiometry of the first few monolayers of the MCT surface.

scholarly journals Analytical Possibilities of Rutherford Backscattering Spectrometry and Elastic Recoil Detection Analysis Methods

2016 ◽  
Vol 26 (1) ◽  
pp. 83 ◽  
Author(s):  
Vu Duc Phu ◽  
Le Hong Khiem ◽  
A. P. Kobzev ◽  
M. Kulik
Keyword(s):  
Rutherford Backscattering Spectrometry ◽  
Depth Resolution ◽  
Rutherford Backscattering ◽  
Elastic Recoil ◽  
Elastic Recoil Detection Analysis ◽  
Near Surface ◽  
Elastic Recoil Detection ◽  
Depth Profiles ◽  
Detection Analysis ◽  
Three Samples

This paper presents the results of an experimental study of three samples containing various elements in the near-surface layers. The depth profiles of all the elements of different atomic masses from hydrogen to silver were investigated by Rutherford Backscattering Spectrometry (RBS) and Elastic Recoil Detection Analysis (ERDA). The experiments were performed by using the low-energy (about 2 MeV) 4He+ ion beams. The obtained results demonstrate the possibility of the RBS and ERDA methods in the investigation of depth profiles of any mass element with an atomic concentration of about 0.01 at.% and a depth resolution close to 10 nm.

Reaction of Amorphous Minb Films with Crystalline Metal Overlayers

1984 ◽  
Vol 37 ◽  
Author(s):  
E. A. Dobisz ◽  
B. L. Doyle ◽  
J. H. Perepezko ◽  
J. D. Wiley ◽  
P. S. Peercy
Keyword(s):  
Metal Film ◽  
Rutherford Backscattering Spectrometry ◽  
Amorphous Film ◽  
Depth Resolution ◽  
Rutherford Backscattering ◽  
Amorphous Films ◽  
The Stability ◽  
Metal Overlayers ◽  
Crystalline Metal ◽  
High Depth

AbstractIn many cases the stability of amorphous films is influenced by interaction with metallic crystalline overlayers. Such interactions between Au, Ni, Nb and Ta overlayers and a-(Ni-Nb) films are reported. During interdiffusion Au overlayers reacted with a-(Ni-Nb) to form two different adjacent crystalline layers. In order to study the influence of relaxation of the amorphous film on overlayer reaction several a-(Ni-Nb) samples were pre-annealed prior to Au deposition. High depth resolution Rutherford Backscattering Spectrometry (RBS) demonstrates that preannealing lowers the diffusion poefficient of Au in a-(Ni-Nb) at 4500C from 7.5×10−22 m2/s to 8.7×10−23 m22/s. During interdiffusion Ta was discovered to be substantially more inert than Au. For example, negligible interdiffusion between Ta and a-(Ni-Nb) at 505°C after 25 hours implies a diffusivity of less than 5×10−24 m2/s. These observations allow assessment of some of the requirements for increasing the stability of crystalline-amorphous metal film layered structures.

Materials Analysis with High Energy Ion Beams Part I: Rutherford Backscattering

MRS Bulletin ◽  
1987 ◽  
Vol 12 (6) ◽  
pp. 26-29 ◽  
Author(s):  
H-J. Gossmann ◽  
L.C. Feldman
Keyword(s):  
Elemental Analysis ◽  
Surface Composition ◽  
Rutherford Backscattering Spectrometry ◽  
High Energy ◽  
Ion Beams ◽  
Rutherford Backscattering ◽  
Near Surface ◽  
Materials Analysis ◽  
Quantitative Elemental Analysis ◽  
High Energy Ions

AbstractThis article discusses the underlying principles of Rutherford backscattering spectrometry (RBS). Consideration of the theory of the interaction of high energy ions with solids leads to the conclusion that quantitative elemental analysis of the near-surface composition of solids can be performed by RBS. Examples are given.

Strain and Compositional Analysis of InGaN/GaN Layers

2000 ◽  
Vol 639 ◽  
Author(s):  
Sérgio Pereira ◽  
Maria. R. Correia ◽  
Estela Pereira ◽  
C. Trager-Cowan ◽  
F. Sweeney ◽  
...  
Keyword(s):  
Driving Force ◽  
Rutherford Backscattering Spectrometry ◽  
Compositional Analysis ◽  
Depth Resolution ◽  
Indium Content ◽  
Rutherford Backscattering ◽  
X Ray Diffraction ◽  
Strained Layers ◽  
X Ray ◽  
Strain Components

ABSTRACTWe investigate strain and composition of epitaxial single layers of wurtzite InxGa1−xN (0<x<0.25) grown by MOCVD on top of GaN/Al203 substrates. It is shown that significant inaccuracies may arise in composition assessments if strain in InxGa1−xN/GaN heterostructures is not properly taken into account. Rutherford backscattering spectrometry (RBS) measures composition, free from the effects of strain and with depth resolution. Using X-ray diffraction (XRD) we measure both a- and c- parameters of the strained wurtzite films. By measuring both lattice parameters and solving Hooke's equation, a good estimation for composition can be obtained from XRD data. The agreement between RBS and XRD data for composition allows reliable values for perpendicular (εzz) and parallel strain components ( (εxx) to be determined. RBS and depth resolved cathodoluminescence (CL) measurements further indicate that the indium content is not uniform over depth in some samples. This effect occurs for the most strained layers, suggesting that strain is the driving force for compositional pulling.

A Study of the Decomposition of GaN during Annealing over a Wide Range of Temperatures

2002 ◽  
Vol 743 ◽  
Author(s):  
M. A. Rana ◽  
H. W. Choi ◽  
M. B. H. Breese ◽  
T. Osipowicz ◽  
S. J. Chua ◽  
...  
Keyword(s):  
Rutherford Backscattering Spectrometry ◽  
Chemical Vapor ◽  
Depth Resolution ◽  
Surface Region ◽  
Organic Chemical ◽  
Near Surface ◽  
Wide Range ◽  
Metal Organic ◽  
Amorphous Surface ◽  
Nitride Layers

ABSTRACTAnnealing experiments were carried out on gallium nitride layers, which were grown on sapphire through Metal Organic Chemical Vapor Deposition (MOCVD). Rutherford Backscattering Spectrometry (RBS) was performed on as-grown and annealed GaN samples using a 2 MeV proton beam to study the stoichiometric changes in the near-surface region (750 nm) with depth resolution better than 50 nm. No decomposition was measured for temperatures o up to 800 °C. Decomposition in the near-surface region increased rapidly with a further increase o of temperature, resulting in a near-amorphous surface-region for annealing at 1100 °C. The depth profiles of nitrogen and incorporated oxygen in the decomposed GaN are extracted from the nanoscale RBS data for different annealing temperatures. The surface roughness of the GaN layers observed by atomic force microscopy (AFM) is consistent with RBS decomposition measurements. We describe the range of annealing conditions under which negligible decomposition of GaN is observed, which is important in assessing optimal thermal processing conditions of GaN for both conventional and nanoscale optoelectronic devices.

Sign in / Sign up

Export Citation Format

Share Document