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.

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)

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.

Defects and AlSb Precipitate Nucleation in Laser Irradiated Aluminum

1981 ◽  
Vol 4 ◽  
Author(s):  
P. S. Peercy ◽  
D. M. Follstaedt ◽  
S. T. Picraux ◽  
W. R. Wampler
Keyword(s):  
Room Temperature ◽  
Laser Energy ◽  
Ion Beam ◽  
Threshold Energy ◽  
Single Pulse ◽  
Temperature Profiles ◽  
Beam Analysis ◽  
Slip Deformation ◽  
Precipitate Nucleation ◽  
Substrate Temperatures

ABSTRACTLattice defects and precipitates induced in unimplanted and Sb-implanted <110> single crystal Al by single pulse irradiation with a Q-switched ruby laser were studied using ion beam analysis and electron microscopy. The absorbed laser energy during irradiation is directly measured in these studies to allow precise numerical modeling of the melt times and temperature profiles. For unimplanted Al, slip deformation gives rise to increased channeled yields throughout the analyzed depth and occurs for energies well below the melt threshold energy of 3.5 J/cm2. Slip deformation is also observed for irradiation energies above the melt threshold energy, and melting is accompanied by a discontinuous increase in the minimum channeling yield, X min- Implanted Sb (to ∼2 at.% peak concentrations) is found to impede epitaxial regrowth and result in polycrystalline Al formation for laser energies such that the melt front is believed not to penetrate through the Sb-containing region. For deeper melt depths, a metastable alloy is formed with up to 35% of the Sb located in substitutional sites. AlSb precipitate formation in the melt was not observed for room temperature irradiations; however, randomly oriented AlSb precipitates are observed for irradiation at substrate temperatures of 100 and 200 °C These measurements yield an estimated time for nucleation of AlSb precipitates in molten Al of 5 nsec < tnuc < 25 nsec.

Growth of Thin Nickel Silicide Layers on Clean B-Doped Si(111) Surfaces at Room Temperature

1989 ◽  
Vol 160 ◽  
Author(s):  
L. Luo ◽  
G. A. Smith ◽  
W. M. Gibson
Keyword(s):  
Monte Carlo ◽  
Computer Simulations ◽  
Room Temperature ◽  
High Energy ◽  
Nickel Silicide ◽  
Growth Stages ◽  
Initial Growth ◽  
Fourth Layer ◽  
Ion Channeling ◽  
Thin Nickel

AbstractThe initial growth stages of Ni on clean B-doped Si(111) were studied at room temperature using high energy Ion channeling and Monte Carlo computer simulations of the Ni/Si interface. The results suggest that the first monolayer of Ni atoms diffuse to reaction sites in the fourth layer of the Si(111) substrate where nickel suicide growth begins. Further Ni deposition (up to ~ 3 ML) leads to the growth of NiSi2 which is thought to be a diffusion barrier that terminates further formation of NiSi2 at room temperature.

Near Infrared Photoluminescence of NCVSi- Centers in High-Purity Semi-Insulating 4H-SiC Irradiated with Energetic Charged Particles

2020 ◽  
Vol 1004 ◽  
pp. 355-360
Author(s):  
Shin Ichiro Sato ◽  
Takuma Narahara ◽  
Shinobu Onoda ◽  
Yuichi Yamazaki ◽  
Yasuto Hijikata ◽  
...  
Keyword(s):  
High Purity ◽  
Room Temperature ◽  
Near Infrared ◽  
Ion Beam ◽  
High Energy ◽  
Implantation Dose ◽  
Implantation Technique ◽  
Photoluminescence Intensity ◽  
Wide Range ◽  
Excitation Laser

This paper reports optical propertites of negatively charged NCVSi- centers in silicon carbide (a nitrogen substituting for a carbon atom adjacent to a silicon vacancy) whose emission wavlength is 1100-1500 nm at room temperature. High-purity semi-insulating (HPSI) 4H-SiCs are implanted with high energy N ion beams and subsequently thermally annealed to form NCVSi centers. We investigated a wide range of N ion implantation dose using a micro ion beam implantation technique and observed the photoluminescence intensity from the SiC-NV centers. We show that under conditions of heavy implantation, the excitation laser power excites residual defects and their fluorescences intereferes with the emission from the NCVSi- centers. These results allow us to clarify the requirements to optically detect isolated single NCVSi- centers at lightly implanted conditions.

Solvent and Curing Effects on Diffusion at Polyimide Interfaces

1989 ◽  
Vol 154 ◽  
Author(s):  
S. F. Tead ◽  
E. J. Kramer ◽  
T. P. Russell ◽  
W. Volksen
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Spin Coating ◽  
Room Temperature ◽  
Ion Beam ◽  
Complete Conversion ◽  
Thermally Activated ◽  
Post Annealing ◽  
Analysis Technique ◽  
Beam Analysis

AbstractInterdiffusion at interfaces between deuterated polyamic acid (d-PAA) and polyimide (PI) films was investigated with forward recoil spectrometry, an ion beam analysis technique. The PI films were prepared by spin – coating a solution of PAA on a silicon substrate, followed by an anneal at a temperature Ti, which produced partial or complete conversion of the PAA to PI. An overlayer of d-PAA was added in one set of samples by spin – coating from solution and in another set by transferring (in the absence of solvents) a dry d- PAA film onto the PI surface. The bilayer samples were then either annealed at a temperature Td or allowed to stand at room temperature. Bilayers prepared by spin – coating d-PAA from solution directly on partially cured PI films had interdiffusion distances w that decreased with increasing values of Ti to immeasurable levels by Ti = 200 °C. The decrease in w with increasing Ti is thought to be caused by a positive Flory parameter between PAA and PI which increases with the imide fraction in the PI film; the result is an increasing immiscibility between the swollen polymer layers. No interdiffusion occurred in the solventless – transfer samples for any combination of temperatures Ti or Td from room temperature up to 400 °C. Post – annealing of spin – coated bilayers at a temperature Td up to 400 °C was ineffective in producing any additional interdiffusion. Both of these results indicate that thermally activated interdiffusion (even for initially unimidized samples) does not exist in the absence of solvents, an effect attributed to the rapid increase of the glass transition temperature of the polymer with imidization.

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