Glow Discharge Reactor Research Articles

Concentration Measurements and Depth Profiling of Phosphorus and Boron by Means of (p,γ) Resonant Reactions

ABSTRACTSmall concentrations of phosphorus and boron in thin films have been measured by detection of proton induced prompt γ-rays. This technique is almost free of interference from other elements in the film or the substrate. Furthermore it is possible to obtain depth information without sputtering. The detection limit of both elements is around 100 ppm; depth resolution at shallow depths in silicon is about 50 nm in the case of boron, whereas it is better than 10 nm in the case of phosphorus.As an application of this method, the incorporation of phosphorus and boron in thin films of hydrogenated amorphous silicon is measured. The films were prepared in a glow discharge reactor by mixing PH3 or B2H6 with the SiH4/H2 gas mixture.

Preparation of tris(η 5-cyclopentadienylcobaltmonocarbonyl) cluster complex by a plasma technique

The glow discharge reaction of cyclopentadienyldicarbonylcobalt(I) CpCo(CO) 2 was carried out in an inductively coupled cylindrical reactor at various flow rates and rf power levels. The deposition rate at low ratios of power to flow rate (W/F) is highest near the monomer inlet; a relatively uniform deposition rate distribution is observed at higher values of W/F. This suggests a plasma reaction of relatively rapid kinetics occurring at low W/F but not at higher W/F. The product of this reaction deposited at the monomer inlet was analyzed by infrared and 1Hnmr spectroscopy and was found to include the cluster complex tris(η 5-cyclopentadienylcobaltmonocarbonyl), [CpCo(CO)] 3. The maximum yield of [CpCo(CO)] 3 was obtained at the lowest W/F attainable with our reactor.

Integrated type multi-bandgap a-Si solar cells

A new type of solar cell, called the “integrated type multi-bandgap a-Si solar cell”, in which stacked type solar cells having different bandgaps are integrated on one substrate, was proposed. Materials, design theory and a processing method were investigated. As a narrow bandgap material, a-SiSn:H was first deposited from a glow discharge reaction, and the photovoltaic effect of a-SiSn:H was observed. As a wide bandgap material, a-SiN:B:H deposited from a glow discharge was found to have good properties for use in solar cells. An optimum design theory for this type of a-Si solar cell was established, and it was found to be useful for the fabrication of the integrated structure.

The 0·9 eV defect luminescence band in sputtered and other forms of plasma-deposited a-Si: H

Abstract The photoluminescence properties of a low-energy (0·9 eV) emission band are examined for a wide variety of samples of a-Si: H prepared in both glow-discharge and sputtering reactors, and are compared with those of similar bands seen in microcrystalline and crystalline silicon. We also report the first photoluminescence measurements on magnetron-sputtered films, which suggest that this material has defect densities as low as those found in good quality glow-discharge a-Si: H.

Effects of Surface Conditions of Substrates upon Performance of a-Si Photovoltaic Cells

The growth process of a-Si film deposited onto an ITO substrate by a glow discharge reaction in SiH4 was investigated by transmission electron microscopy. The a-Si film grows to form an island structure at the first step (0–200Å-thick) of the growth process. The p-layer of conventional ITO/p-i-n photovoltaic cells has an island structure with a thickness in the range of 50 to 200Å. A multi-junction model in which a-Si photovoltaic cells consist of an ITO/p-i-n junction (hetero-face junction) and an ITO/i-n junction (hetero junction) is proposed. The radius of the island structure in the p-type a-Si is calculated with this model. The result of the calculation is in approximate agreement with that of the observation by transmission electron microscopy. The dependence of the open-circuit voltage of Glass/ITO/p-i-n photovoltaic cells upon the p-layer thickness can be explained by the multi-junction model.

Deposition and characterization of thin SiO x films

Thin (less than 500 Å) homogeneous SiO x (1.5 < x < 2.0) films prepared from the glow discharge reaction of silane or a silane derivative with an oxidant such as nitrous oxide or oxygen have shown considerable promise as dielectric layers. The chemical composition and properties of these films are relatively insensitive to the glow discharge geometry, the gas composition and the power. Oxidant-rich plasma mixtures provide denser films and thus greater protection against atmospheric attack on the underlying material. The films were characterized using infrared spectroscopy, Auger depth profile analysis, transmission electron microscopy, scanning electron microscopy, multiple-drop liquid contact angle measurements and ellipsometry.

The composition of organo-tin polymer films on metallic substrate materials

Glow discharge films with various ratios of carbon to tin were deposited on various metals and on glass. The ratio of carbon to tin was determined quantitatively by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The AES data correlated well with the XPS data. The X-ray beam and electron impact effects on organo-tin films influence the composition and are discussed in detail. The ratio of carbon to tin was not constant throughout the glow discharge reactor and this inhomogeneity is accounted for by the prevalence of “atomic” polymerization rather than “molecular” polymerization. We demonstrated that the substrate material had a definite influence on the composition of the films.

The Glow-discharge Reactions of Amines

Abstract The glow-discharge reactions of propylamine, dipropylamine, and N,N-dimethyl-2-methyl-1-propenylamine were studied. The results show that the primary amines yield RN=CHR′ and RNHCH2CN, and that the secondary amines produce R(R′)NCH(R″)CN. N,N-Dimethyl-2-methyl-1-propenylamine produces a series of imine and nitrile.

The Glow-discharge Reactions of Pyrrole, Pyrrolidine, and Butylamine

Abstract The glow-discharge reactions of pyrrole, pyrrolidine, and butylamine were carried out. Pyrrolidine produces a complex mixture of products, the most prevalent of which is (Remark: Graphics omitted.) (R: H, CH3, and C2H5), and butylamine yielded primarily CH3(CH2)3N=CHR (R: CH3, C2H5, and C3H7) along with CH3(CH2)3NHCH2CN, whereas pyrrole afforded a mixture of acrylonitrile, crotononitrile, benzene, α-methylpyrrole and β-methylpyrrole, together with large amounts of HCN. The formation of characteristic products, α-(1-pyrrolidinyl) nitrile derivatives with pyrrolidine, and the yield of butylaminoacetonitrile with butylamine can be explained by considering the formation of a resonance-stabilized α-cyanoalkyl radical as the most probable intermediate which attacks a nitrogen atom of pyrrolidine and that of butylamine or which recombines with pyrrolidine-N-radical and butylamine-N-radical.

Morpholine and Thiophene in Glow Discharge Reactions.

Morpholine and Thiophene in Glow Discharge Reactions.

TRAPPING EXPERIMENT OF RADICAL SPECIES PRODUCED BY GLOW DISCHARGE REACTION OF SOME AROMATIC COMPOUNDS

Abstract The authors have described the successful application of spin trapping as a diagnosis of short-lived free radicals formed from the glow discharge reaction of aromatic compounds. For example, in the decomposition of toluene, benzyl radical was trapped by nitrosobenzene or pheny1-N-t-butylnitrone.

Studies on the Materials Obtained in the Reactor from the Glow Discharge Reaction of Benzene and Glow Discharge Reactions of Benzene-Water and Benzene-Methanol

In the reactions of benzene in glow discharge, the polymeric materials were dbtained in glow column chromatography, napthalene and biphenyl were isolated and the presence of fluorene, phenanthrene and or anthracene, and biacenaphthylene was also estimated by the studies of the mass spectra of another spots. A yellowish polymer, obtained by means of the reprecipitation in methanol of the latter portion, was estimated to be a polymer having a skeleton of some condensed-ring compun ds, On the basis of its IR spectru. and its eleme ntary analysis.The glow discharge experiments of both benzene water and benzene-Tmethanel were also undertaken. ln the former case, the presence of phenol and o, m p-cteole was confirmed along with that of products, obtained by glow discharge reaction of benzene, in terms of GLC analysis of liquid product and, in addition, benzyl alcchol was isolated in the latter case.

MOS Diode with SiO2 Film Prepared by Glow Discharge Reaction

MOS Diode with SiO₂ Film Prepared by Glow Discharge Reaction

The Reaction of Aromatic Hydrocarbons with Acetonitrile and Acrylonitrile in the Glow Discharge

The glow discharge reactions of acetonitrile and acrylonitrile with benzene and toluene were studied. Liquid products which have been determined quantitatively in this study include benzonitrile, benzylcyanide, o-, m-, p-tolunitriles, and propionitrile in addition to the products due to the glow discharge reaction of benzene and toluene.Comparative results of the% yield (normalized to exclude polymeric products and gaseous products) of cyano substituted hydrocarbons are shown in Table 1 and 2.The high % yield of cyano products in the reactions of acetonitrile and acrylonitrile with benzene suggests the production of active cyano species by one step fission.Since the reaction of acrylonitrile with benzene gave a considerably higher proportion of polymeric products than that of acetonitrile with benzene, the % yield of the liquid products of the former was relatively lower than the latter.The effect of flow rate ratio of reactants and the distance of electrode separation upon % yield of each product was also discussed.

Characterization of Silicon Nitride Films

Various “silicon nitride” films have been prepared from , N2, , and in an rf‐promoted glow discharge reaction. These films are described primarily through the use of infrared absorption. Aided by ultraviolet absorption, the inclusion of excess silicon or of oxygen in the films is readily followed. Changes in index of refraction, etch rates in HF acid, and electrical conductivity of the films are correlated with the optical absorption study. Comparisons of these films with those formed by pyrolysis or by reactive sputtering are made. Some reproducible physical properties of an amorphous film are stated.

Electrical Properties of Silicon Oxide Films Prepared by Glow Discharge Reaction

Electrical Properties of Silicon Oxide Films Prepared by Glow Discharge Reaction

Some Properties of Silicon Nitride Films Produced by Radio Frequency Glow Discharge Reaction of Silane and Nitrogen

Silicon nitride films are deposited on silicon wafer at low temperature by radio frequency glow discharge reaction of silane and nitrogen. The main peak position of infrared transmission spectra, the growth rate and the etch rate of the nitride films change respectively from 870 to 820 cm-1, from 0.8 to 6.5Å/sec and from 150 to 5Å/sec in 15% HF etchant with changing silane concentration from 0.1 to 2.5 mol %. The etch rate is larger than that of the thermally grown silicon nitride. The dielectric constant of nitride films changes from 8 to 5 with changing substrate temperature from 500 to 25°C. The nitride film deposited at as high temperature as 500°C shows a large hysteresis of C–V curve. The silicon nitride film deposited at the substrate temperature of 300°C and at the silane concentration of 0.5 mol % is stable against B–T treatment as well as thermally grown silicon nitride films. The value of flat-band surface charge ranges from 7 to 14×10''/cm2, the value is relatively small in comparison with that of thermally grown nitride.

The Preparation and Properties of Silicon Nitride Produced by a Radio Frequency Glow Discharge Reaction of Silane and Nitrogen: Preparation and Properties of Silicon Nitride

The Preparation and Properties of Silicon Nitride Produced by a Radio Frequency Glow Discharge Reaction of Silane and Nitrogen: Preparation and Properties of Silicon Nitride

1851. Preparation and properties of thin films silicon-nitrogen compounds produced by a radio frequency glow discharge reaction: R C G Swan et al, J Electron Soc, 114 (7), July 1967, 714–717

In the present study we explore the structural, electronic and thermoelectric properties of IV-VI semiconductors using first principle calculations based on the density functional theory. Generalized gradient approximation (GGA-PBEsol) is used as an exchange-correlation functional for the structural properties of the different crystal phases of these semiconductors. The compounds SnS, SnSe, GeS and GeSe favor orthorhombic structure, lead chalcogenides (PbS, PbSe and PbTe) are stable in the cubic rocksalt structure, while SnS2 and SnSe2 exist in hexagonal structure. For band structures additional to GGA, modified Becke and Johnson (mBJ) exchange potential is used. These compounds are narrow band gap semiconductors in the energy range 0.2–2.8 eV. These binary IV-VI chalcogenides have direct band gap nature in cubic crystals while indirect in the orthorhombic phases. The post-DFT (BoltzTraP) calculations are performed to estimate Seebeck coefficient, electric and thermal conductivities, power factor and figure of merit of these compounds to check their applicability in thermoelectric devices. Spin orbit coupling effect influences the electronic and thermoelectric properties of these compounds due to the large size of the constituent elements. Further, the total thermal conductivity is computed using ad-hoc calculation with the experimental results. The calculated values of figure of merit for PbS, PbSe, PbTe and SnTe are in the range 0.68–0.77 at room temperature.

The Preparation and Properties of Thin Film Silicon‐Nitrogen Compounds Produced by a Radio Frequency Glow Discharge Reaction

Silicon nitride was deposited by a radio frequency glow discharge reaction of silane and ammonia. Films were deposited at a fixed substrate temperature of 300°C but the silane/ammonia concentration was varied between 3 and 50%. The effect of changing gas concentrations has been correlated with the change in physical and electrical properties of the deposited material. In particular, measurements of dielectric constant, loss factor, and voltage breakdown strength have been made as well as surface studies by the MOS technique. Material properties have also been qualitatively studied by monitoring IR absorption, chemical etch rate, and film growth rate.