Study of thermal desorption of UV/ozone oxide on InP

1992 ◽  
Vol 70 (10-11) ◽  
pp. 1043-1049 ◽  
Author(s):  
D. Comedi ◽  
G. Balcaitis ◽  
B.J. Robinson ◽  
D. A. Thompson
Keyword(s):  
Thermal Desorption ◽  
High Energy ◽  
Ion Scattering ◽  
Fixed Temperature ◽  
Thermally Induced ◽  
P Loss ◽  
Structural Deterioration ◽  
Short Annealing ◽  
Oxide Removal ◽  
Uv Ozone

Commercially available (001) InP substrates have been treated by exposure to UV/ozone to produce surface oxide layers suitable for thermal desorption prior to epitaxial growth. Thermally induced changes in composition and structure of the oxidized surfaces in vacuum have been studied using Auger electron spectroscopy (AES), reflection high-energy electron diffraction (RHEED), and Rutherford backscattering/channeling (RBSC). It is found that for temperatures above 440–450 °C the oxide becomes unstable. Thermal oxide desorption in vacuum above 460 °C always results in a P-depleted surface. At 460 °C the oxide can be thermally removed without noticeable P loss; however, the time requried for this process is approximately 2 h. Time-dependent AES results for oxide desorbing at a fixed temperature can be described by assuming a thinning process with a constant thinning rate for short annealing times; however, for longer times the desorption rate increases considerably. After complete oxide removal, the resulting clean (001) InP surface shows a 2 × 1 RHEED pattern, while the corresponding measured In surface peak intensity as measured by RBSC is close to that obtained for a clean MBE grown surface. Significant structural deterioration of the surface is detected at high temperatures (≈ 495 °C) by RHEED nad RBSC. The average O/In composition ratio of the oxide layer has been determined by ion scattering methods.

Epitaxy of Au on Ag(111) Studied by High-Energy Ion Scattering

1981 ◽  
Vol 47 (9) ◽  
pp. 657-660 ◽  
Author(s):  
R. J. Culbertson ◽  
L. C. Feldman ◽  
P. J. Silverman ◽  
H. Boehm
Keyword(s):  
High Energy ◽  
Ion Scattering

scholarly journals Beating in the RHEED Intensity Oscillations during Surfactant Mediated GaAs Molecular Beam Epitaxy: Process Physics and Modeling

VLSI Design ◽  
1998 ◽  
Vol 6 (1-4) ◽  
pp. 405-408
Author(s):  
Vamsee K. Pamula ◽  
R. Venkat
Keyword(s):  
Molecular Beam ◽  
Flux Ratio ◽  
High Energy ◽  
Equation Model ◽  
High Energy Electron ◽  
Fixed Temperature ◽  
Mbe Growth ◽  
Molecular Beam Epitaxial ◽  
Monolayer Coverage ◽  
Period Of Oscillation

In a recent work, beating in the reflection high energy electron diffraction (RHEED) intensity oscillations were observed during molecular beam epitaxial (MBE) growth of GaAs with Sn as a surfactant. The strength of beating is found to be dependent on the Sn submonolayer coverage with strong beating observed for 0.4 monolayer coverage. For a fixed temperature and flux ratio (Ga to As), the period of oscillation decreases with increasing Sn coverage. In this work, we have developed a rate equation model of growth to investigate this phenomenon. In our model, the GaAs covered by the Sn is assumed to grow at a faster rate compared to the GaAs not covered by Sn. Assuming that the electron beams reflected from the Sn covered surface and the rest of the surface are incoherent, the results of the dependence of the RHEED oscillations on Sn submonolayer coverages for various Sn coverages were obtained and compared with experimental data and the agreement is good.

Growth of Transition Metal Films on AL(110) Surfaces

1995 ◽  
Vol 399 ◽  
Author(s):  
R.J. Smith ◽  
Adli A. Saleh ◽  
V. Shutthanandan ◽  
N.R. Shivaparan ◽  
V. Krasemann
Keyword(s):  
High Energy ◽  
Metal Films ◽  
Surface Strain ◽  
The Other ◽  
Photoemission Spectroscopy ◽  
Alloy Formation ◽  
Ion Scattering ◽  
X Ray ◽  
Photoelectron Diffraction ◽  
Ti Films

ABSTRACTThe growth of thin Pd, Ni, Fe and Ti films on Al(110) surfaces has been studied using high-energy ion scattering (HEIS), x-ray photoemission spectroscopy and photoelectron diffraction techniques. Of these four metals, only Ti grows as an epitaxial overlayer, while the other metals mix with the substrate to form surface alloys. In the HEIS experiments the backscattered ion yield from Al surface atoms is measured as a function of metal coverage on the Al surface. A decrease in the Al scattering is observed for Ti deposition while the other metals result in increased Al scattering, attributed to alloy formation. An explanation for the exceptional growth behavior of Ti on Al is provided using a model of surface strain associated with aluminide formation.

Preparation of Ge (100) Substrates for High-Quality Epitaxial Growth of Group IV Materials

2003 ◽  
Vol 794 ◽  
Author(s):  
Mark Nowakowski ◽  
Jordana Bandaru ◽  
L.D. Bell ◽  
Shouleh Nikzad
Keyword(s):  
Epitaxial Growth ◽  
Chemical Treatment ◽  
Photoelectron Spectroscopy ◽  
High Energy ◽  
Ozone Treatment ◽  
High Quality ◽  
Surface Evolution ◽  
Chemical Treatments ◽  
Before And After ◽  
Uv Ozone

ABSTRACTWe compare various wet chemical treatments, in preparing high-quality Ge (100) surfaces suitable for molecular beam epitaxy (MBE). Various surface treatments are explored such as UV-ozone treatment followed by exposure to chemical solutions such as de-ionized (DI) water, hydrofluoric acid (HF), or hydrochloric acid (HCl). Chemical treatments to remove the oxide are performed in a nitrogen environment to prevent further formation of surface oxide prior to surface analysis. Following chemical treatments, in situ reflection high-energy electron diffraction (RHEED) analysis is performed to observe the surface evolution as a function of temperature. In a separate chamber, we analyze each sample, before and after chemical treatment by x-ray photoelectron spectroscopy (XPS) to directly determine the oxide desorption following each chemical treatment. Our results of this comparative study, the effectiveness of each chemical treatment, and the stability of the passivated surface suggest that UV ozone cleaning, followed by 10% HCl is the best choice for removing most of the oxide. Furthermore, we present evidence of high quality epitaxial growth of SnxGe1−x on wafers prepared by our method.

Structural and Magnetocaloric Properties of Ball Milled LaFe13−xSix(H,C)y

MRS Advances ◽  
2017 ◽  
Vol 2 (56) ◽  
pp. 3447-3452
Author(s):  
L. Bessais ◽  
M. Phejar ◽  
V. Paul-Boncour
Keyword(s):  
Curie Temperature ◽  
Magnetic Moments ◽  
Synthesis Method ◽  
Annealing Treatment ◽  
Interstitial Site ◽  
High Energy ◽  
Magnetocaloric Properties ◽  
Magnetovolume Effect ◽  
Short Annealing ◽  
Giant Magnetocaloric Effect

ABSTRACTLaFe13−xSix compounds display a giant magnetocaloric effect near 200 K. The insertion of light elements (H, C) is used to improve the Curie temperature near ambient temperature for magnetic refrigeration applications. We have developed a synthesis method with a short annealing treatment compared to classical melting techniques. The parent intermetallic alloys were synthesized by high energy ball milling. The insertion of H atoms was carried out using a Sievert apparatus and the carbon atom was inserted by solid/solid reaction. Moreover, structural and magnetic results were carried out by neutron diffraction and Mössbauer spectrometry for H content (y = 0.7,1.5) and C content (y = 0.7). The cell parameter and the Fe magnetic moments versus temperature are determined. The misunderstanding on interstitial site is clarified. The magnetovolume effect on the Curie temperature is explained by combination of the structural and magnetic properties. The advantages and drawbacks of each type of element insertion are discussed.

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