scholarly journals Characteristics of oxide layer grown on gallium arsenide using 2. 8 eV translational energy atomic oxygen

1990 ◽  
Author(s):  
J.B. Cross ◽  
M.A. Hoffbauer ◽  
J.D. Farr ◽  
V.M. Bermudez ◽  
O.J. Glembocki
Keyword(s):  
Gallium Arsenide ◽  
Oxide Layer ◽  
Atomic Oxygen ◽  
Translational Energy

Characteristics of Oxide Layer Grown on Gallium Arsenide Using 2.8-eV Translational Energy Atomic Oxygen

1990 ◽  
Vol 204 ◽  
Author(s):  
J.B. Cross ◽  
M.A. Hoffbauer ◽  
J.D. Farr ◽  
O.J. Glembocki ◽  
V.M. Bermudez
Keyword(s):  
Raman Spectroscopy ◽  
Gallium Arsenide ◽  
High Temperature ◽  
Thermal Oxidation ◽  
Oxide Layer ◽  
Atomic Oxygen ◽  
Oxidation States ◽  
Translational Energy ◽  
Oxidation Processes ◽  
As Species

ABSTRACTOxide layers that are thick (>200 Å and uniform have been produced on GaAs (110) and (100) by reacting the substrate (Ts<160°C) with high translational energy (1-3 eV) neutral atomic oxygen at flux levels of∼50 monolayers/second. The Ga and As species are formed in their highest oxidation states, which implies formation of either Ga2O3 and As2O5 or GaAsO4. Raman spectroscopy indicates that there is no metallic (amorphous or crystalline) As in the oxide or at the interface between the oxide and substrate and that there is no appreciable oxidation induced disorder of the substrate as is seen in high temperature thermal oxidation processes.

Kinetics of heterogeneous processes

2005 ◽  
Author(s):  
Boris S. Bokstein ◽  
Mikhail I. Mendelev ◽  
David J. Srolovitz
Keyword(s):  
Oxide Layer ◽  
Atomic Oxygen ◽  
Reaction Rate ◽  
Heterogeneous Reaction ◽  
Effective Rate Constant ◽  
Internal Oxide ◽  
Reactant Concentration ◽  
Rate Determining Step ◽  
Oxidation Reduction ◽  
Heterogeneous Processes

Most practical reactions that occur in synthesizing or processing materials are heterogeneous. These include oxidation, reduction reactions, dissolution of solids in liquids, and most solid-state phase transformations. Consider the oxidation of a metal by exposure of a solid metal to an atmosphere with a finite partial pressure of oxygen. In order for oxidation to occur, molecular oxygen must dissociate into atomic oxygen on the metal surface. In some cases, atomic oxygen diffuses into the metal and reacts to form an internal oxide, while in others, the reaction occurs at the surface. In the latter case, thickening of the oxide layer requires either metal or oxygen diffusion through the growing oxide layer. This example demonstrates that heterogeneous processes commonly involve several steps. The first step is usually the transport of a reactant through one of the phases to the interface. The second is the adsorption (segregation) or chemical reaction on the interface. Finally, the last third step is the diffusion of the products into the growing phase or the desorption of the product. Since the entire heterogeneous process is a type of complex reaction, there is usually one step that controls the rate of the process, that is, is the rate-determining step. Recall that the rate-determining step is the slowest (fastest) step for a consecutive (parallel) reaction (see Sections 8.2.1 and 8.2.2). Consider the case of a consecutive heterogeneous reaction in which one of the reactants is transported through the fluid phase to the solid–fluid interface, where a first-order reaction takes place. The reaction rate ωr in such a case is ωr=kcx, where cx is the concentration of the reactant on the interface. Since the reactant is consumed at the interface, cx is smaller than the reactant concentration far from the interface, c0. It is usually easier to measure the reactant concentration in the bulk fluid. Therefore, it is convenient, to rewrite the reaction rate in terms of the bulk concentration in the fluid and an effective rate constant . . . ωr = kcx = keffc0. (11.1) . . . It is easiest to see the relation between keff and k by considering the steady-state case.

Laser Ablation Of Solid Ozone

2000 ◽  
Vol 617 ◽  
Author(s):  
Hidehiko Nonaka ◽  
Tetsuya Nishiguchi ◽  
Yoshiki Morikawa ◽  
Masaharu Miyamoto ◽  
Shingo Ichimura
Keyword(s):  
Laser Ablation ◽  
Laser Fluence ◽  
Atomic Oxygen ◽  
Room Temperature ◽  
Laser Light ◽  
Time Of Flight ◽  
Translational Energy ◽  
Uv Laser ◽  
Quadrupole Mass ◽  
Time Of Flight Method

AbstractSpecies ablated from solid ozone by a UV laser were investigated using a time-of-flight method through a quadrupole mass filter. The results show that UV-laser ablation of solid ozone can produce a pulsed ozone beam with a translational energy far above that of room temperature. Highconcentration ozone from an ozone jet generator is solidified on a sapphire substrate attached to a copper block which is cooled to 30 to 60 K on a cryocooler head and the solid ozone is irradiated by pulsed laser light from a KrF laser (248 nm). The ablated species were a mixture of ozone and molecular oxygen as well as atomic oxygen due to photodissociation of ozone. At a substrate temperature of 30 K, the total amount of ablated ozone increases as the laser fluence increases to 13 mJcm−2. Beyond this fluence, enhanced decomposition of ozone occurs. Gaussian fitting of the time-of-flight signals of the ablated ozone reveals an average thermal energy exceeding 1,500 K. The velocity also increases when the laser fluence enters saturation at 2,300 K at 13 mJcm−2.

MoS2 Interactions with 1.5 eV Atomic Oxygen

1988 ◽  
Vol 140 ◽  
Author(s):  
J.A. Martin ◽  
J.B. Cross ◽  
L.E. Pope
Keyword(s):  
Oxide Layer ◽  
Atomic Oxygen ◽  
Diffusion Rate ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Reaction Products ◽  
Crystallite Orientation ◽  
Protective Oxide ◽  
Protective Oxide Layer ◽  
Degree Of Oxidation

AbstractExposures of MoS2 to 1.5 eV atomic oxygen in an anhydrous environment reveal that the degree of oxidation is essentially independent of crystallite orientation and thesurface adsorbed reaction products are MoO3 and MoO2. A mixture ofoxides and sulfide exist over a depth of about 90 Å and this layer has a low diffusion rate for oxygen. It is concluded that a protective oxide layer will form on MoS2 upon exposure to the atomic-oxygen-rich environment of low earth orbit.

Growth of oxide layers on gallium arsenide with a high kinetic energy atomic oxygen beam

1990 ◽  
Vol 57 (21) ◽  
pp. 2193-2195 ◽  
Author(s):  
M. A. Hoffbauer ◽  
J. B. Cross ◽  
V. M. Bermudez
Keyword(s):  
Gallium Arsenide ◽  
Kinetic Energy ◽  
Atomic Oxygen ◽  
Oxide Layers ◽  
High Kinetic Energy

Translational energy dependence of the reaction of atomic oxygen with polyimide films

1987 ◽  
Vol 24 (5) ◽  
pp. 454-458 ◽  
Author(s):  
Graham S. Arnold ◽  
Daniel R. Peplinski ◽  
Franklin M. Cascarano
Keyword(s):  
Energy Dependence ◽  
Atomic Oxygen ◽  
Translational Energy ◽  
Polyimide Films

Structural changes in silicon-on-insulator material during post-implantation annealing

1986 ◽  
Vol 44 ◽  
pp. 736-737
Author(s):  
C. O. Jung ◽  
S. J. Krause ◽  
S.R. Wilson
Keyword(s):  
Integrated Circuits ◽  
Oxide Layer ◽  
High Speed ◽  
Structural Changes ◽  
Device Fabrication ◽  
Silicon On Insulator ◽  
High Quality ◽  
Radiation Hardened ◽  
Post Implantation ◽  
Very High

Silicon-on-insulator (SOI) structures have excellent potential for future use in radiation hardened and high speed integrated circuits. For device fabrication in SOI material a high quality superficial Si layer above a buried oxide layer is required. Recently, Celler et al. reported that post-implantation annealing of oxygen implanted SOI at very high temperatures would eliminate virtually all defects and precipiates in the superficial Si layer. In this work we are reporting on the effect of three different post implantation annealing cycles on the structure of oxygen implanted SOI samples which were implanted under the same conditions.

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