Decomposition Of Arsine Research Articles

Raman investigations on AsH3 decomposition in MOVPE

The decomposition of arsine was studied by Raman spectroscopy in an atmospheric pressure MOVPE system. The temperature distribution in a vertical reactor with a 2-inch susceptor was established from the rotation modes of H2 and N2. The decomposition of AsH3 in H2 took place in the temperature range 420–820 K, close to the substrate. The broadening of the observed AsH stretching vibration band of AsH3 versus temperature suggests the presence of AsHn (n<3) compounds. The simulation of AsH3 and AsH spectra at various temperatures was compared to the experimental data.

Palladium-gate mos devices for arsine detection

Pd-MOS structures with holes in the gate metal have been prepared for detecting arsine, and investigated in a flow system. The samples show a reversible decrease of threshold voltage on admixtures of arsine to an air stream (temperature range 350 K to 470 K). A change of threshold voltage of 34 mV is found for 0.1 ppm arsine in air ( T = 433 K). For arsine concentrations of 2.5 ppm, a response time of 40 s and a recovery time of 300 s are observed at 450 K. The response of the same structures to small concentrations of H 2 has also been investigated. Sensitivity and response are comparable to the results found for arsine. This similarity points to a decomposition of arsine at the Pd surface, with subsequent diffusion of hydrogen to the metal-oxide interface.

Numerical Analysis of Group-V Element Transport and Incorporation at a Growing Surface in MOCVD Reactor

The growth rate of epitaxial film by MOCVD is determined by the transport of group-III elements. However, group-V elements influence the electronic properties. It is often said about undoped GaAs that an increase of supplied arsine causes a p/n conductivity type conversion. A numerical model which considers the diffusion and decomposition of arsine is proposed. Using this model, the concentration of arsenic at a growing surface can be obtained as a function of the substrate temperature and the laminar fluid film thickness. Considering the properties of phosphine, the surface concentration of phosphorus can also be obtained. The phosphorus distribution coefficient of GaAsxP1-x can be well described by using the estimated concentrations of arsenic and phosphorus with a simplified equilibrium of the surface reaction.

A study of arsenic(III) and arsenic(V) reduction and of arsine decomposition in hydride-generation atomic absorption spectrometry

The difference in behaviour of arsenic(III) and arsenic(V) in their conversion to arsine by reduction with sodium tetrahydroborate, and the role of the addition of oxygen and hydrogen to the carrier gas in the production of arsenic atoms are described.

Homogeneous and heterogeneous thermal decomposition rates of trimethylgallium and arsine and their relevance to the growth of GaAs by MOCVD

The rate of decomposition of trimethylgallium (TMGa) and arsine is measured by sampled gas infrared absorption spectroscopy. The decomposition of TMGa is observed to go to completion at temperatures above 475°C as measured by the concentration of CH 4 that is formed in the decomposition process. An activation energy of 58–62 kcal/mol is measured for the loss of the first methyl group. The decomposition of arsine is characterized by strong surface interactions. The activation energy for the decomposition of arsine in a quartz vessel is 34 kcal/mol. The activation energy for decomposition of AsH 3 in the presence of GaAs wafers was found to be 18 kcal/mol. The implications of these results for the growth of GaAs by metalorganic chemical vapor deposition (MOCVD) are discussed.

In situ, real-time diagnostics of OMVPE using IR-diode laser spectroscopy

Absorption IR-diode laser spectroscopy was used to monitor the vibrational frequencies of gaseous species within an OMVPE reactor. The IR-diode laser system, when tuned to a metalalkyl line, served as an on-line monitor of flow dynamics in the OMVPE reactor. The effects of gas velocity, diffusion into or out of dead spaces, pressure variations, etc. were readily identified and measured. Absorption lines associated with the metastable methyl radical were observed during the decomposition of trimethylindium and trimethylgallium. Results indicate that the decomposition of the metal alkyls proceeds via the removal of methyl radicals, and that there is a maximum methyl production at a temperature which increases with group III metal-carbon bond strength, i.e. In-C, Ga-C, Al-C. It is also observed that the CH 3 radicals play a significant role in the decomposition of arsine and the formation of GaAs in OMVPE.

Effect of Arsenic Partial Pressure on Capless Anneal of Ion‐Implanted GaAs

A capless anneal of ion‐implanted was performed under different partial pressure of arsenic controlled by decomposition of arsine. Sheet carrier concentration of implanted with Mg or Si increased with increasing arsenic partial pressure, while that of S+ implanted showed an opposite trend which corresponded to the different lattice sites occupied in the crystal. The site‐occupation rate and ionization rate of implanted impurity atoms were thermodynamically determined by analyzing the variation of the sheet carrier concentration with the partial pressure of arsine. The site‐occupation rate was found to be larger than 90% for the case of Mg or S implantation. The ionization rate of the substitutional atoms limited the doping efficiency of implanted impurities in these cases, while both the site‐occupation rate and the ionization rate were responsible for the doping efficiency of Si implantation.

Optical and electrical properties of amorphous arsenic

Amorphous arsenic prepared by plasma decomposition of arsine has been characterized using field-effect conductance, thermopower, optical absorption, and photoconductivity measurements. It is found that the Fermi level is located in a density of states ∼ 10 17 cm −3 eV −1 approximately in the center of the forbidden gap, that conduction occurs via electrons in extended states in the conduction band, and that the optical and photoelectrical properties are very similar to those of bulk a-As. It is concluded that a model involving a negative correlation energy for localized states is inappropriate for this material.

A new GaAs, GaP, and GaAsxP1−x vacuum deposition technique using arsine and phosphine gas

A new vacuum deposition process for depositing thin films of GaAs, GaP, and GaAsxP1−x is described. This process is similar to the standard molecular beam technique except that the arsenic and phosphorus are supplied from the decomposition of arsine and phosphine gas. The advantages of this process over the more conventional one-source and two-source molecular beam techniques are that the new gas-source process is more easily controlled and more reproducible and the deposition source materials are essentially inexhaustible, permitting a large number of samples to be coated during a single run. The process has been optimized for depositing polycrystalline films 800–1000-Å thick with sheet resistivities exceeding 1013 Ω/square for use as a resistive sea for silicon-diode-array camera tube targets. Variations in the deposition parameters, such as gallium temperature, the ratio of gallium to arsenic or phosphorus flux incident on the substrates, deposition time, and substrate temperature, were made to determine their effects on the film properties. A standard process was developed which permitted reproducible deposition of films which satisfactorily met the requirements of the camera tube application.

Techniques for the preparation of thick and thin arsenic targets suitable for cyclotron irradiation

An apparatus is described for the preparation of arsenic metal targets 130 mg cm −2 thick by the sublimation of arsenic metal. The targets are used for the cyclotron production of 77Br. An apparatus for the production of arsenic metal targets 400 μg cm −2 thick by the decomposition of arsine is also described. The targets are being used for excitation function measurements.

A Theoretical Consideration of Simple Catalytic Reactions. Decomposition of Gaseous Hydrides

Abstract The decomposition of arsine, stibine, tin hydride, methane, germane, hydrogen selenide and nickel carbonyl on the surface of the corresponding elements have been discussed from the statistical mechanical view-point. As these decompositions are catalytic reactions of the simplest type, several reasonable assumptions enable us to calculate the rates of each elementary step of each reaction and hence to decide the rate-determining step in a semi a priori fashion. It is shown that the calculations impose definite limitations to the possible mode of decompositions of this kind.

The Decomposition of Arsine

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Decomposition of ArsineKenzi TamaruCite this: J. Phys. Chem. 1955, 59, 8, 777–780Publication Date (Print):August 1, 1955Publication History Published online1 May 2002Published inissue 1 August 1955https://doi.org/10.1021/j150530a020RIGHTS & PERMISSIONSArticle Views374Altmetric-Citations63LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (456 KB) Get e-Alerts

CATALYSIS ON FILMS OF ARSENIC, ANTIMONY, AND GERMANIUM

Arsenic, antimony, and germanium films laid down on glass surfaces by decomposition of the hydrides have been studied from the standpoint of reaction kinetics in three sets of reactions: the decomposition of hydrides and deuterides, the interaction of hydrides and molecular deuterium, and the exchange reaction of hydrogen and deuterium. Only in the first of these have the surfaces marked catalytic activity. The orders of reaction and the activation energies have been determined. The accelerated catalytic influence of foreign elements, notably antimony in arsine decomposition, has been established. The results obtained contrast strikingly with the properties of clean filaments and evaporated films among the transition elements. The results emphasize the basic importance of chemical factors and de-emphasize the importance of surface cleanliness as a controlling factor in problems of chemisorption and surface catalysis.

282. Studies on some metal electrodes. Part VII. The behaviour of arsenic electrodes prepared by sublimation and decomposition of arsine out of contact with air

282. Studies on some metal electrodes. Part VII. The behaviour of arsenic electrodes prepared by sublimation and decomposition of arsine out of contact with air

The Mercury-Photosensitized Decomposition of Arsine

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Mercury-Photosensitized Decomposition of ArsineNorwood L. Simmons and Arnold O. BeckmanCite this: J. Am. Chem. Soc. 1936, 58, 3, 454–459Publication Date (Print):March 1, 1936Publication History Published online1 May 2002Published inissue 1 March 1936https://doi.org/10.1021/ja01294a020RIGHTS & PERMISSIONSArticle Views26Altmetric-Citations3LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (586 KB) Get e-Alerts Get e-Alerts

I. The combination of hydrogen and oxygen in contact with hot surfaces

A large number of observations on the rates of chemical reactions in homogeneous systems, e. g. , in solutions, has proved that the velocity of a given reaction is determined by its order in accordance with the principle of mass action. It has been frequently assumed that the velocities of gaseous reactions are governed by the same law, although the few measurements which have been so far made hardly justify the assumption. Take, for example, the decomposition of arsine, the velocity of which was determined by enclosing the gas, at atmospheric pressure, in a glass bulb maintained at 310° and recording the pressure at the end of successive time intervals. The results showed that the velocity of decomposition is directly proportional to the concentration of the arsine. On the assumption that the rate of change was governed by the law of mass action, it was concluded that the decomposition was a monomolecular one. But it is known that at temperatures below about 1000° the vapour of arsenic consists of tetratomic molecules, and, therefore, the equation for the decomposition of arsine at 310° must be written 4AsH 3 = As 4 + 6H 2 . If so, then assuming that the decomposition takes place in a homogeneous system, its velocity should, according to theory, be proportional to the fourth power of the arsine concentration, and not to the first power as the experiment proves it to be. The discrepancy here indicated has been explained by the further assumption that the reaction really proceeds in stages, as follows:— ( a ) The monomolecular decomposition of arsine at finite velocity AsH 3 = As + 3H; ( b ) The subsequent combinations of (1) four arsenic atoms forming the complex As 4 , and (2) two hydrogen atoms forming H 2 , both combinations taking place with relatively infinite velocities.