Reactive Gas Partial Pressure Research Articles

The influence of N 2 partial pressure and substrate bias on electron density and temperature in a dc sputtering diode

Single probes and grid probes were used to study the density and the energy of the slow and secondary electron groups in the negative glow plasma of a dc diode sputtering system. The influence of a negatively biased electrode and of a reactive gas partial pressure were specially examined. When the bias voltage is varied from 0 to −200 V the densities of the slow and secondary electron groups clearly increased but their energies suffer little change. The electron density value can increase threefold. Introduction of a reactive gas (N 2) into the gas discharge (Ar) leads to a rapid decrease in the density and the energy of the slow electron group when a critical pressure p c is reached. The secondary group density decreases regularly when the nitrogen pressure increases but the energy remains constant.

Reactive sputter deposition: A quantitative analysis

An analysis of the reactive d.c. sputter deposition of compound films (metal oxides and nitrides) is presented. It leads to a model describing the process in terms of three easily accessible parameters: the reactive gas flow rate G, the sputtering power W and the sputtering yield of the target. It is shown that, for typical sputtering conditions, the reactive gas partial pressure, a variable in previous models, is of secondary importance. The model establishes the ration W/G as a fundamental parameter of reactive sputtering and predicts accurately the magnitudes of W/G for the deposition of such diverse films as TiN and Cd 2SnO 4. Detailed measurements of the reactive sputtering of titanium and aluminium targets in the presence of nitrogen and oxygen are presented and it is shown that the usual hysteresis effects depend mainly on intrinsic material properties that are only weakly modified by varying process conditions.

Device applications of reactive ion beam sputter deposited superconducting thin films

The technique of Reactive Ion Beam Sputter Deposition has been used in the preparation of metal oxide thin-film composites which have a promising potential for superconducting device applications. We have investigated the correlation between film deposition parameters such as reactive gas (oxygen) partial pressure, substrate temperature, target composition etc., with the film microstructure and superconducting properties. The resulting granular and amorphous films are extremely stable with respect to repeated temperature cycling. We have demonstrated the use of these materials as base electrodes in Josephson tunnel junctions and as weak-link Josephson switches. The extremely smooth surface topography of the films also implies low flux-pinning thresholds which should be useful in fluxoid memory and logic devices.

Mechanisms of reactive sputtering of indium III: A general phenomenological model for reactive sputtering

A phenomenological model of reactive sputtering is presented which accounts for changes in the target sputtering rate R and the impinging ion current i T with the reactive gas partial pressure p i. The model was applied to the following two divergent cases: the sputtering of indium in a weakly reactive Ar-N 2 discharge and the sputtering of indium in a strongly reactive N 2-O 2 discharge. In experiments R and i T were both found to decrease monotonically with p N 2 in Ar-N 2 discharges, whereas R exhibited an abrupt decrease and i T an abrupt increase in N 2-O 2 discharges at a critical value of p O 2 . Fitting of the model to the experimentally measured values of R versus p i allowed a determination of the target nitride and oxide surface coverages Θ i as well as of the sticking coefficients ϕ i of N 2 and O 2 on the indium target. Values of Θ N and ϕ N for indium sputtered in Ar-N 2 were much lower than the corresponding values of Θ O and ϕ O for indium sputtered in O 2-N 2, in agreement with experimental observations.

反応性スパッタリングによる鉄の酸化物および窒化物薄膜の作成

Thin films of iron oxides and nitrides containing various amount of oxygen and nitrogen were prepared by an R.F. reactive sputtering. Changing the partial pressure of reactive gases (oxygen and nitrogen) from 5×10-6 to 5×10-3 Torr in argon gas (total pressure : PO2 (or PN2) + PAr = 5×10-3 Torr), thin films were deposited onto the glass substrates.The deposition rate and the properties of the films such as electrical resistivity, crystal structure and chemical composition were examined with the partial pressure of reactive gases. A critical pressure at which the deposition rate of the films decreased drastically was observed by the reactive sputtering in argon plasma at the partial pressure of oxygen (2×10-4 Torr) and nitrogen (4×10-4 Torr). In both cases of the Fe-O2 and Fe-N2 reactive sputtering, the structures of the deposited films were observed to begin changing in the region of the critical pressures, namely, FeO, Fe2O3 and Fe3O4 in the Fe-O2 system and Fe2N, Fe3N and Fe4N in the Fe-N2 system were observed over the critical pressures.Reactive sputtering experiments under helium gas instead of argon gas were also carried out in order to reveal the interaction between the plasma gases with different mass and the target surfaces in the sputtering process.

Sputtering of metals in the presence of reactive gases

The sputtering yields of Ti, Ta, Mo and W bombarded by Ar ions were measured in situ by a weight loss measurement as a function of the partial pressure of reactive gas (O 2 or N 2). The sputtering yields decreased to about 0.4–0.1 of the initial value in the presence of a reactive gas for every gas-target combination studied. All the curves were of sigmoidal shape with an inflection point that depended on the primary ion current density. The results were interpreted in terms of a monolayer chemisorption of the reactive gas on the target surface using the assumption that the actual sputtering yield can be expressed as a linear combination of the sputtering yield of the clean target and the sputtering yield of the target covered with the adsorbed layer.

The influence of the target material on sputter etching processes

The presence of reactive gases as contaminants of the gas atmosphere in a sputter etching machine can cause a strong increase in the etch rate of commonly used photoresist masks. When an appropriate part of the target material has a high getter efficiency, the partial pressure of reactive gases can be markedly reduced. The influence of a copper and of a titanium target on the partial pressure of oxygen in a sputter etching equipment has been investigated. The use of a titanium target results in a drastic decrease in the etch rate of photoresist masks at oxygen pressures in the range 10 -6–10 -4 Torr.

Structure and properties of arc-sprayed titanium, niobium, and molybdenum coatings

Since density, ductility, and homogeneity of titanium coatings have a special significance by reason of the use of such coatings in the fabrication of chemical apparatus and equipment, metallurgical tests were conducted with a view to determining the effect of the gas atmosphere on these properties. The various tests yielded the following findings. Photographs of the structure of the coatings taken through a light-optical and electron-optical microscope reveal that arc-sprayed titanium coatings are completely dense, crack-free, and homogeneous if they have been applied in a shielding gas atmosphere of highest-purity argon. Adding reactive gases such as nitrogen to the shielding gas atmosphere causes inhomogeneous, brittle, and cracked coatings to be produced which are characterized by segregations in the direction of the temperature gradient. Examination under a scanning electron microscope and a photoemission electron microscope reveals the presence of dentritic nitrides in nitrated arc-sprayed titanium coatings. Structural examinations conducted with an x-ray diffractometer reveal that arc-sprayed titanium applied in an inert gas atmosphere does not contain foreign phases, which means that it is free from oxides and nitrides and may hence be regarded as homogeneous. By reason of the high cooling rate obtaining in thermal spraying, the transformation of the lattice structure of the titanium from the β-phase into the a-phase which, in equilibrium, occurs at 882 °C, is partially suppressed so that the spray coatings contain unstable β-titanium in addition to the stable a-titanium. As the partial pressure of the nitrogen increases the super-cooled β-phase of the titanium decreases in proportion to the increase in a-Ti stabitization. The angle shift of the diffraction reflections already noted in spraying in an atmosphere of highest-purity argon, increases with rising nitrogen content since, for one thing, the internal tensile stresses increase with increasing embrittlement of the structure and, for another, the interstitial solution of the nitrogen expands the mixed crystal. Microhardness measurements prove that the hardness of the coatings is low if gas/metal reactions are avoided, whereas the rising partial pressure of reactive gases causes the hardness to increase markedly, which is an indication of decreased ductility of the coatings. Electrochemical measurements prove that arc-sprayed coatings applied in an inert gas atmosphere exhibit the same behavior as the starting materials. The usability of such coatings as a protection against aggresive media has therefore been demonstrated.

General purpose metallurgical vacuum system: (USA)Anon, Res & Develop, 15 (12), Dec 1964, 50–51

<dm:abstracts xmlns:dm="http://www.elsevier.com/xml/dm/dtd"><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" view="all" class="author" id="aep-abstract-id5"><ce:section-title>Publisher Summary</ce:section-title><ce:abstract-sec view="all" id="aep-abstract-sec-id6"><ce:simple-para id="fsabs003" view="all">Various aspects of early vacuum science and technology are discussed in the chapter. The use of vacuum equipment for deposition (and etching) processes introduces problems associated with pumping and disposing of possibly toxic, flammable, and corrosive processing gases, as well as reactive gases used for <ce:italic>in situ</ce:italic> cleaning of vacuum systems. Specialized vacuum equipment and <ce:italic>in situ</ce:italic> chamber plasma-etch-cleaning techniques are developed to address these concerns. With the advent of reactive deposition and hybrid processing, the control of gas composition and mass flow has become an important aspect of vacuum engineering and technology. This includes partial pressure control and gas manifolding in processing chambers. Differentially pumped mass spectrometers can be used to monitor and control partial pressures of gases. Optical emission spectroscopy is also used to control the partial pressures of reactive gases in reactive sputter deposition. Optical emission has been used for many years to detect the end-point in plasma etching for semiconductor processing.</ce:simple-para></ce:abstract-sec></ce:abstract></dm:abstracts>

High vacuum getter ion pump : ( Great Britain) Anon., ngineer, 216 (5609), July 26, 1963, 162

<dm:abstracts xmlns:dm="http://www.elsevier.com/xml/dm/dtd"><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" view="all" class="author" id="aep-abstract-id5"><ce:section-title>Publisher Summary</ce:section-title><ce:abstract-sec view="all" id="aep-abstract-sec-id6"><ce:simple-para id="fsabs003" view="all">Various aspects of early vacuum science and technology are discussed in the chapter. The use of vacuum equipment for deposition (and etching) processes introduces problems associated with pumping and disposing of possibly toxic, flammable, and corrosive processing gases, as well as reactive gases used for <ce:italic>in situ</ce:italic> cleaning of vacuum systems. Specialized vacuum equipment and <ce:italic>in situ</ce:italic> chamber plasma-etch-cleaning techniques are developed to address these concerns. With the advent of reactive deposition and hybrid processing, the control of gas composition and mass flow has become an important aspect of vacuum engineering and technology. This includes partial pressure control and gas manifolding in processing chambers. Differentially pumped mass spectrometers can be used to monitor and control partial pressures of gases. Optical emission spectroscopy is also used to control the partial pressures of reactive gases in reactive sputter deposition. Optical emission has been used for many years to detect the end-point in plasma etching for semiconductor processing.</ce:simple-para></ce:abstract-sec></ce:abstract></dm:abstracts>

418. Metal joining service for industry: Anon., Nucl. Power, 7, June 1962, 48

<dm:abstracts xmlns:dm="http://www.elsevier.com/xml/dm/dtd"><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" view="all" class="author" id="aep-abstract-id5"><ce:section-title>Publisher Summary</ce:section-title><ce:abstract-sec view="all" id="aep-abstract-sec-id6"><ce:simple-para id="fsabs003" view="all">Various aspects of early vacuum science and technology are discussed in the chapter. The use of vacuum equipment for deposition (and etching) processes introduces problems associated with pumping and disposing of possibly toxic, flammable, and corrosive processing gases, as well as reactive gases used for <ce:italic>in situ</ce:italic> cleaning of vacuum systems. Specialized vacuum equipment and <ce:italic>in situ</ce:italic> chamber plasma-etch-cleaning techniques are developed to address these concerns. With the advent of reactive deposition and hybrid processing, the control of gas composition and mass flow has become an important aspect of vacuum engineering and technology. This includes partial pressure control and gas manifolding in processing chambers. Differentially pumped mass spectrometers can be used to monitor and control partial pressures of gases. Optical emission spectroscopy is also used to control the partial pressures of reactive gases in reactive sputter deposition. Optical emission has been used for many years to detect the end-point in plasma etching for semiconductor processing.</ce:simple-para></ce:abstract-sec></ce:abstract></dm:abstracts>

A thermoelectric vacuum gauge

<dm:abstracts xmlns:dm="http://www.elsevier.com/xml/dm/dtd"><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" view="all" class="author" id="aep-abstract-id5"><ce:section-title>Publisher Summary</ce:section-title><ce:abstract-sec view="all" id="aep-abstract-sec-id6"><ce:simple-para id="fsabs003" view="all">Various aspects of early vacuum science and technology are discussed in the chapter. The use of vacuum equipment for deposition (and etching) processes introduces problems associated with pumping and disposing of possibly toxic, flammable, and corrosive processing gases, as well as reactive gases used for <ce:italic>in situ</ce:italic> cleaning of vacuum systems. Specialized vacuum equipment and <ce:italic>in situ</ce:italic> chamber plasma-etch-cleaning techniques are developed to address these concerns. With the advent of reactive deposition and hybrid processing, the control of gas composition and mass flow has become an important aspect of vacuum engineering and technology. This includes partial pressure control and gas manifolding in processing chambers. Differentially pumped mass spectrometers can be used to monitor and control partial pressures of gases. Optical emission spectroscopy is also used to control the partial pressures of reactive gases in reactive sputter deposition. Optical emission has been used for many years to detect the end-point in plasma etching for semiconductor processing.</ce:simple-para></ce:abstract-sec></ce:abstract></dm:abstracts>

Properties of electrical insulating materials of the laminated, phenol-methylene type

<dm:abstracts xmlns:dm="http://www.elsevier.com/xml/dm/dtd"><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" view="all" class="author" id="aep-abstract-id5"><ce:section-title>Publisher Summary</ce:section-title><ce:abstract-sec view="all" id="aep-abstract-sec-id6"><ce:simple-para id="fsabs003" view="all">Various aspects of early vacuum science and technology are discussed in the chapter. The use of vacuum equipment for deposition (and etching) processes introduces problems associated with pumping and disposing of possibly toxic, flammable, and corrosive processing gases, as well as reactive gases used for <ce:italic>in situ</ce:italic> cleaning of vacuum systems. Specialized vacuum equipment and <ce:italic>in situ</ce:italic> chamber plasma-etch-cleaning techniques are developed to address these concerns. With the advent of reactive deposition and hybrid processing, the control of gas composition and mass flow has become an important aspect of vacuum engineering and technology. This includes partial pressure control and gas manifolding in processing chambers. Differentially pumped mass spectrometers can be used to monitor and control partial pressures of gases. Optical emission spectroscopy is also used to control the partial pressures of reactive gases in reactive sputter deposition. Optical emission has been used for many years to detect the end-point in plasma etching for semiconductor processing.</ce:simple-para></ce:abstract-sec></ce:abstract></dm:abstracts>

The production of liquid air on a laboratory scale

<dm:abstracts xmlns:dm="http://www.elsevier.com/xml/dm/dtd"><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" view="all" class="author" id="aep-abstract-id5"><ce:section-title>Publisher Summary</ce:section-title><ce:abstract-sec view="all" id="aep-abstract-sec-id6"><ce:simple-para id="fsabs003" view="all">Various aspects of early vacuum science and technology are discussed in the chapter. The use of vacuum equipment for deposition (and etching) processes introduces problems associated with pumping and disposing of possibly toxic, flammable, and corrosive processing gases, as well as reactive gases used for <ce:italic>in situ</ce:italic> cleaning of vacuum systems. Specialized vacuum equipment and <ce:italic>in situ</ce:italic> chamber plasma-etch-cleaning techniques are developed to address these concerns. With the advent of reactive deposition and hybrid processing, the control of gas composition and mass flow has become an important aspect of vacuum engineering and technology. This includes partial pressure control and gas manifolding in processing chambers. Differentially pumped mass spectrometers can be used to monitor and control partial pressures of gases. Optical emission spectroscopy is also used to control the partial pressures of reactive gases in reactive sputter deposition. Optical emission has been used for many years to detect the end-point in plasma etching for semiconductor processing.</ce:simple-para></ce:abstract-sec></ce:abstract></dm:abstracts>

Researchers on the vacuum

<dm:abstracts xmlns:dm="http://www.elsevier.com/xml/dm/dtd"><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" view="all" class="author" id="aep-abstract-id5"><ce:section-title>Publisher Summary</ce:section-title><ce:abstract-sec view="all" id="aep-abstract-sec-id6"><ce:simple-para id="fsabs003" view="all">Various aspects of early vacuum science and technology are discussed in the chapter. The use of vacuum equipment for deposition (and etching) processes introduces problems associated with pumping and disposing of possibly toxic, flammable, and corrosive processing gases, as well as reactive gases used for <ce:italic>in situ</ce:italic> cleaning of vacuum systems. Specialized vacuum equipment and <ce:italic>in situ</ce:italic> chamber plasma-etch-cleaning techniques are developed to address these concerns. With the advent of reactive deposition and hybrid processing, the control of gas composition and mass flow has become an important aspect of vacuum engineering and technology. This includes partial pressure control and gas manifolding in processing chambers. Differentially pumped mass spectrometers can be used to monitor and control partial pressures of gases. Optical emission spectroscopy is also used to control the partial pressures of reactive gases in reactive sputter deposition. Optical emission has been used for many years to detect the end-point in plasma etching for semiconductor processing.</ce:simple-para></ce:abstract-sec></ce:abstract></dm:abstracts>