H-passivation of Si(100) By Wet Chemical Cleaning: Discovery of Ordering

1998 ◽  
Vol 513 ◽  
Author(s):  
V. Atluri ◽  
N. Herbots
Keyword(s):  
Ion Beam ◽  
Elastic Recoil ◽  
Signal To Noise ◽  
Chemical Cleaning ◽  
Elastic Recoil Detection ◽  
Ion Channeling ◽  
Atomic Force ◽  
Beam Analysis ◽  
Wet Chemical ◽  
First Time

ABSTRACTSi(100) is H-passivated via a modified pre-RCA cleaning followed by etching in HF:alcohol, to produce ordered (1 × 1) templates which desorb at low temperature (T ≥ 600°C). Four sets of 12 wafers, each set processed identically, are used to test reproducibility, and are characterized by Ion Beam Analysis (IBA), Tapping Mode Atomic Force Microscope (TMAFM), and Fourier Transform Infrared Spectroscopy (FTIR). The absolute coverage of oxygen and carbon is measured by ion channeling combined with nuclear resonance at 3.05 MeV for oxygen and 4.265 MeV for carbon, improving the signal to noise by a factor 10 for oxygen and by 120 for carbon. It is then possible for the first time to measure ordering of oxygen atoms with respect to the surface by comparing the amount of oxygen from rotating random spectra to the disordered oxygen measured by channeling. Hydrogen is measured via the elastic recoil detection (ERD) of 4He2+ at 2.8 MeV.Si(100) etched in HF:methanol after a modified preliminary RCA cleaning yields the cleanest surface. The data suggest that Si(100) passivated by HF in alcohol is terminated by an ordered hydroxide layer, which desorbs at lower temperatures than the more refractory Si02.

Comparison and Reproducibility of H-Passivation of Si(100) with HF in Methanol, Ethanol, Isopropanol and Water by IBA, TMAFM, and FTIR'

1997 ◽  
Vol 477 ◽  
Author(s):  
V. Atluri ◽  
N. Herbots ◽  
D. Dagel ◽  
H. Jacobsson ◽  
M. Johnson ◽  
...  
Keyword(s):  
Ion Beam ◽  
Complex Surface ◽  
Nuclear Reaction Analysis ◽  
Elastic Recoil ◽  
Elastic Recoil Detection ◽  
Ion Channeling ◽  
Selective Area ◽  
Atomic Force ◽  
Average Factor ◽  
Lower Temperature

ABSTRACTThree different HF:alcohol solutions are investigated to etch native SiO2 and passivate Si(100) surfaces with H which can the be desorbed at low temperature (T < 600°C). The resulting passivated Si(100) surfaces are compared using as a reference Si(100) passivated by a standard aqueous HF: solution (1:98 parts of HF: H2O). After a modified RCA cleaning, Si(100) etched by HF:Methanol, HF:IPA, or HF:Ethanol, is characterized by Ion Beam Analysis (IBA), Tapping Mode Atomic Force Microscope (TMAFM), and Fourier Transform Infrared Spectroscopy (FTIR). The absolute coverage of O and C is measured by nuclear reaction analysis (NRA) combined with ion channeling at 3.05 MeV for O and 4.265 MeV for C. Hydrogen is measured via the elastic recoil detection (ERD) of 4He2+ at 2.8 MeV.Compared to aqueous HF, HF:alcohol passivates Si(100) leaving a lower O residue by an average factor of 0.62 and a similar C residue. H coverage is higher by an average factor of 1.43. Surface coverages are found to be reproducible in average by 1.4 × 1014 atoms/cm2 for C, and by 1.25 × 1014 atoms/cm2 for O when measured by IBA on samples identically processed. H coverage is reproducible within 5.5% when measured by ERD.Selective area analysis by TMAFM shows that an increasing number of particulates is responsible for the apparent increase in root-mean -square (rms) surface roughness when the rms is measured over a whole image. Taking this effect into account, all passivated surfaces exhibit similar roughness when compared to the original Si(100) surface with little difference between alcohols and with the reference aqueous HF solution.FTIR in the attenuation total reflection (ATR) mode detected SiHx species mostly as a dihydride. Both IBA and FTIR detected significant levels of oxygen on surfaces passivated HF in alcohol and aqueous HF. This indicates that while Si(100) exhibits more H when passivated with HF in alcohol and can be desorbed at lower temperature than when treated with aqueous HF, H is not bonded to Si only but likely bonds into a more complex surface termination, such as SiOH.

Discovery of Long Range Order in Thin (2-20 NM) SiO2 Films by Ion Beam Analysis

1998 ◽  
Vol 510 ◽  
Author(s):  
N. Herbots ◽  
V. Atluri ◽  
Q. B. Hurst ◽  
J. M. Shaw ◽  
S. Banerjee ◽  
...  
Keyword(s):  
Room Temperature ◽  
Ion Beam ◽  
Ambient Air ◽  
Chemical Cleaning ◽  
Ion Beam Analysis ◽  
Ion Channeling ◽  
Oxidation Rates ◽  
Beam Analysis ◽  
Wet Chemical ◽  
20 Nm

AbstractSiO2 films, 2-20 nm thick, were grown on passivated, ordered Si(100) to correlate electrical properties and oxidation rates with processing for ultra-thin gate oxides. Ordered Si(l 00) (1 × 1) stable in ambient air was obtained at room temperature by wet chemical cleaning. The thickest oxides were grown by Rapid Thermal Oxidation at 850°C, the thinnest at room temperature. O was detected by Ion Beam Analysis (IBA) using a combination of ion channeling with the 3.05 MeV 16O(α,α)16O nuclear resonance. It then becomes possible to measure order in thin SiO2 by comparing the total amount of O from rotating random spectra to disordered O detected by ion channeling, and detect the alignment of O with the atoms in Si(100)

Long Range Order in Ultra-Thin SiO2 Grown on Ordered Si(100)

1999 ◽  
Vol 567 ◽  
Author(s):  
Q.B. Hurst ◽  
N. Herbots ◽  
J.M. Shaw ◽  
M.M. Floyd ◽  
D.J. Smith ◽  
...  
Keyword(s):  
Room Temperature ◽  
Ion Beam ◽  
Ambient Air ◽  
High Energy ◽  
Thermally Grown Oxide ◽  
Chemical Cleaning ◽  
Ion Channeling ◽  
Beam Analysis ◽  
Charge Analysis ◽  
Wet Chemical

ABSTRACTIn this paper, we investigate the correlation of electrical properties and structure of 1-4 nm thick SiO2 grown on H-passivated Si(100) for ultra-thin gate applications. Ordered (1×1) Si(100) stable in ambient air is obtained at room temperature by wet chemical cleaning. Ion Beam Analysis using a combination of ion channeling and 16O(α,α)16O nuclear resonance yields Si areal densities lower than that of a bulk-terminated Si crystal as calculated by Monte-Carlo simulations. This result indicates shadowing of Si substrate atoms by Si atoms in the thermally grown oxide. Detection of order by ion channeling is supported by Reflection High Energy Electron Diffraction (RHEED). C-V and I-V measurements are generally inconclusive for ultra-thin (1-2 nm) oxides because of leakage and breakdown. Surface charge analysis enables a comparison between ordered oxides and conventional oxides. The results are promising.

Characterization of SiC Thin Film Obtained by Magnetron Reactive Sputtering: IBA, IR and Raman Studies

2005 ◽  
Vol 483-485 ◽  
pp. 287-290
Author(s):  
H. Colder ◽  
M. Morales ◽  
Richard Rizk ◽  
I. Vickridge
Keyword(s):  
Nuclear Reaction ◽  
Hydrogen Content ◽  
Rutherford Backscattering Spectrometry ◽  
Ion Beam ◽  
Nuclear Reaction Analysis ◽  
Elastic Recoil ◽  
Crystalline Fraction ◽  
Elastic Recoil Detection ◽  
Beam Analysis

Co-sputtering of silicon and carbon in a hydrogenated plasma (20%Ar-80%H2) at temperatures, Ts, varying from 200°C to 600°C has been used to grow SiC thin films. We report on the influence of Ts on the crystallization, the ratio Si/C and the hydrogen content of the grown films. Film composition is determined by ion beam analysis via Rutherford backscattering spectrometry, nuclear reaction analysis via the 12C(d,p0)13C nuclear reaction and elastic recoil detection analysi(ERDA) for hydrogen content. Infrared absorption (IR) has been used to determine the crystalline fraction of the films and the concentration of the hydrogen bonded to Si or to C. Complementary to IR, bonding configuration has been also characterized by Raman spectroscopy. As Ts is increased, the crystalline fraction increases and the hydrogen content decreases, as observed by both ERDA and IR. It also appears that some films contain a few Si excess, probably located at the nanograin boundaries.

Characterization of Plasma Immersion Deposited Multilayer Coatings by Ion Beam Techniques Combined with Energy Filtered Transmission Electron Microscopy

2005 ◽  
Vol 908 ◽  
Author(s):  
Florian Schwarz ◽  
Joerg K. N. Lindner ◽  
Maik Häeberlen ◽  
Goetz Thorwarth ◽  
Claus Hammerl ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ion Beam ◽  
Hard Coatings ◽  
Elemental Distribution ◽  
Elastic Recoil ◽  
Elastic Recoil Detection ◽  
Detection Analysis ◽  
Transmission Electron ◽  
Beam Analysis

AbstractMultilayered and nanostructured coatings of amorphous carbon (DLC), silicon composite multilayers and nanocluster containing films today have great potential for applications as hard coatings, wear reduction layers and as diffusion barriers in biomaterials. Plasma immersion ion implantation and deposition (PIII&D) is a powerful technique to synthesize such films. The quantitative nanoscale analysis of the elemental distribution in such multielemental films and thin film stacks however is demanding.In this paper it is shown how the high spatial resolution capabilities of energy filtered trans-mission electron microscopy (EFTEM) chemical analysis can be combined with accurate and standard-less concentration determination of ion beam analysis (IBA) techniques like Rutherford Backscattering Spectroscopy (RBS) and Elastic Recoil Detection Analysis (ERDA) to achieve absolute and accurate multielement concentration profiles in complicated nanomaterials.

Extended Damage Depth Determinations in AR- and H-Implanted Silica Glass

1993 ◽  
Vol 316 ◽  
Author(s):  
G.W. Arnold ◽  
G. Battaglin ◽  
P. Mazzoldi
Keyword(s):  
Silica Glass ◽  
Ion Beam ◽  
Fused Silica ◽  
Rutherford Backscattering ◽  
High Fluence ◽  
Elastic Recoil ◽  
Ion Beam Analysis ◽  
Elastic Recoil Detection ◽  
Beam Analysis ◽  
Damage Depth

ABSTRACTDamage depths for Ar-implanted fused silica have been examined by Rutherford backscattering (RBS) and elastic recoil detection (ERD) ion-beam analysis. H incursion (6 at. %) from ambient atmospheres to twice TRIM values was found for damage depths which intersected the surface. H implants were used to decorate Ar damage for deeper Ar implants. The incursion of H for high-fluence implants is important for optoelectronic applications.

Ion Implantation and Ion Beam Analysis of Lithium Niobate

1988 ◽  
Vol 128 ◽  
Author(s):  
G. W. Arnold
Keyword(s):  
Refractive Index ◽  
Ion Beam ◽  
Beam Line ◽  
Ambient Atmosphere ◽  
Elastic Recoil ◽  
Elastic Recoil Detection ◽  
Enhanced Diffusion ◽  
Surface Contaminants ◽  
Radiation Enhanced Diffusion ◽  
Beam Analysis

ABSTRACTImplantations of He and Ti were made into LiNbO3 and the H and Li profiles determined by elastic recoil detection (ERD) techniques. The loss of Li and gain of H depends upon the supply of surface H (surface contaminants or ambient atmosphere). For 50 keV He implants into LiNbO3 through a 200 Å Al film, the small Li loss is governed by the interface H. This is also the case for He implants into uncoated LiNbO3 in a beam line with low hydrocarbon surface contamination; similar implants under conditions of greater hydrocarbon deposition result in proportionally larger Li loss and H gain in the implant damage region. The exchange is possible only for those He energies, i.e., 50 keV, where the damage profile intersects the surface. For Ti implants Li is lost with little H gain. For this case the Li loss is believed to result from radiation-enhanced diffusion. Where He implantation is used to establish waveguiding in LiNbO3, the presence or absence of H in the implanted region is crucial with regard to refractive index stability, due to the replacement of H by Li from the bulk.

Ion-Beam Analysis of Polymer Surfaces and Interfaces

MRS Bulletin ◽  
1996 ◽  
Vol 21 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Edward J. Kramer
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ion Beam ◽  
Inorganic Materials ◽  
Elastic Recoil ◽  
Short Article ◽  
Ion Beam Analysis ◽  
Elastic Recoil Detection ◽  
Neutron Reflection ◽  
Discouraged Workers ◽  
Beam Analysis

Ion-beam analysis of chemical composition as a function of depth is by now well-established for inorganic materials and is an important method of investigating growth of thin films. It has been applied to polymers much more recently, perhaps because fairly obvious problems with radiation damage discouraged workers in this field initially. Ion-beam analysis has developed, however, into a analytical tool that complements other methods, such as x-ray photoelectron spectroscopy and neutron reflection, very well. The purpose of this short article is to give the reader an introduction to its current uses in polymers.The ion beams of ion-beam analysis are typically highly energetic (1–5 MeV) beams of 4He++. While other beams are used, for example, 3He and 15N, alpha particle beams are used in the vast majority of experiments reported in the literature. Two major categories of experiments are carried out with such beams. Rutherford backscattering (RBS) spectrometry to detect heavy elements in the polymer and forward recoil spectrometry (FRES) (also known as elastic recoil detection) to detect the isotopes hydrogen and deuterium. The basic principles for each method are similar.

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.

Sign in / Sign up

Export Citation Format

Share Document