Showing papers on "Sputtering published in 1976"
IBM1
TL;DR: In this paper, a kinetic model has been formulated to describe the time variation of the surface composition during sputtering, and the individual sputter yields for Cu and Ni atoms in the alloy and the depth of the altered layer where the composition is altered by sputtering were determined.
187 citations
TL;DR: In this paper, a zero order approximation of ion collection during sputtering is presented, and the accumulation of implantation profiles and the build-up of surface concentrations and collected quantities are described in detail for Gaussian range distributions.
Abstract: This paper presents a zero order approximation of ion collection during sputtering. Neglecting diffusion, range shortening and knock-on effects and assuming a constant sputtering yield general analytical results are developed which allow a comparison with experimental data. The accumulation of implantation profiles and the build-up of surface concentrations and collected quantities are described in detail for Gaussian range distributions. A thorough discussion of available experimental results indicates that the model is suitable for a variety of projectile-target combinations, in particular for medium mass noble gas atoms collected in high melting point targets. Application to sputtering experiments presents further evidence of a strong fluence dependence of the silicon sputtering yield. Some comments are devoted to recently reported analytical and numerical treatments of ion collection during sputtering.
164 citations
TL;DR: In this article, the characteristics of the sputter-etching process which are responsible for these difficulties are discussed and an attempt is made to assess their significance in the analysis of solid samples.
Abstract: Ion‐bombardment sputtering is used in combination with various analytical approaches in the surface analysis of solid samples. Although the advantages of sputter etching in this application far outweigh the disadvantages, there are several ways in which the sputter‐etching process can cause interpretational difficulties. The characteristics of the sputter‐etching process which are responsible for these difficulties include: (a) the fact that the elemental composition of a sputter‐etched surface will in general be different from that of the bulk solid, (b) the tendency of certain materials to develop extensive microtopographical structure when they are subjected to ion bombardment, and (c) the fact that ion bombardment can cause motion of atoms in the sample by direct momentum transfer, cascade mixing, enhanced diffusion, or, in the case ofionized species, enhanced drift motion. A discussion of these effects wil be presented and an attempt will be made to assess their significance in the analysis of solid samples.
127 citations
TL;DR: In this paper, the properties of d.c. sputtered molybdenum-silicon Schottky diodes are described and a model is proposed which is capable of explaining most features of the observed C-V and I-V characteristics.
Abstract: The properties of d.c. sputtered molybdenum-silicon Schottky diodes are described. Although it is possible to produce near ideal characteristics when a low sputtering voltage is used for a short time, increased voltage and time lead to significant deviation from the ideal. A model is proposed which is capable of explaining most features of the observed C-V and I-V characteristics. This model assumes that sputtering damage causes donor-like traps to be created close to the semiconductor surface. It is found that an exponential distribution of traps with characteristic length in the range 10–100 A and an energy level of 0·43 eV below the conduction band is sufficient to account for the observed characteristics. The modification to the I–V characteristics is due to tunnelling through the top of the Schottky barrier where it is narrowed by the presence of the excess trapped charge.
124 citations
TL;DR: In this article, the authors used tantalum diaphragms on the surface of yttrium iron garnet (YIG) to measure the charge build-up caused by bombardment of insulating samples with energetic particles.
Abstract: The generation of charge build‐up, caused by bombardment of insulating samples with energetic particles, and its role in altering the relative secondary‐ion currents and reducing their absolute values, sometimes even to zero, are discussed. Proposed methods for charge reduction by bombardment with negative ions or with neutral particles, or by use of an auxiliary electron beam or spray gun, are shown to be not useful in every experimental situation. A further method involving introduction of an auxiliary conducting electrode when using negative primary ions is considered mechanistically, and tested by placing tantalum diaphragms onto the surface of yttrium iron garnet (YIG). The final charging values and mass spectra thus obtained are compared to those measured when using bare and metallic grid‐covered surfaces of the same YIG sample. The satisfactory results achieved with the diaphragm show that SIMS analyses of insulators can be performed in a simple, quick, and inexpensive manner.
120 citations
TL;DR: In this article, the chemical and physical effects of 10−15 keV H1+, D1+ and He+ ion bombardments to graphite and SiC have been conducted using the techniques of Raman scattering and scanning electron microscopy (SEM).
117 citations
TL;DR: In this article, the authors describe the arrival at the substrate of a thin film and its formation and growth, including simple interfacial adhesion, interdiffusion between two materials, formation of intermediate layers and mechanical adhesion.
111 citations
TL;DR: In this paper, the authors investigated the erosion of pyrolytic graphite and silicon carbide due to the bombardment with monoenergetic hydrogen ions with energies of 600 to 7500 eV in the temperature range of near room temperature to 750°C.
106 citations
01 May 1976
TL;DR: In this paper, the authors summarized a body of knowledge which has been developed on the characteristics of transducer quality ZnO film layers, and focused attention on those sputtering parameters and microstructural properties which characterize a superior surface-wave transducers.
Abstract: The piezoelectric film layer transducer represents the most efficient method for generating and detecting surface acoustic waves on nonpiezoelectric substrates. ZnO, which has a strong piezoelectric effect and can readily be sputtered as an oriented crystalline composite on a wide variety of substrates, is a natural choice as the piezoelectric film layer. This paper summarizes a body of knowledge which has been developed on the characteristics of transducer quality ZnO film layers, and focuses attention on those sputtering parameters and microstructural properties which characterize a superior surface-wave transducer film. Requisite sputtering conditions are high substrate temperatures (150-300°C), modest deposition rates (0.5-1.0 µm/h), low background vapor pressures (<5 µm Hg) and an ultraclean vacuum system. Transducer quality surface-wave films are characterized by their optical clarity, high density, smooth surface, small crystallite size, and well-oriented crystallite axes. Such ZnO films will play an important role in future surface acoustic wave device technology.
104 citations
TL;DR: Saturation magnetizations and magnetic anisotropy constants for a series of amorphous GdCo films prepared by thermal evaporation were determined by means of ferromagnetic resonance and a force balance magnetometer.
Abstract: Saturation magnetizations and magnetic anisotropy constants were determined for a series of amorphous GdCo films prepared by thermal evaporation. The films covered the composition range from Gd0.05Co0.95 to Gd0.40Co0.60 and were studied by means of ferromagnetic resonance and a force balance magnetometer. The films, in contrast to those prepared by sputtering, had a hard perpendicular direction of magnetization when Co was less than 91 at.%, and easy and moderate directions within the plane of the film. The anisotropy constant can be expressed in terms of sublattice magnetizations by Ku=0.660MCo2 +2.218MCoMGd+0.097MGd2. The results are explained based on a pair‐ordering mechanism. The composition and temperature dependence of saturation magnetization is essentially the same in evaporated and sputtered films.
TL;DR: The model of track production in dielectric materials was investigated as a possible source of sputtered particles at high bombarding energies in this article, where it was shown that it is possible to produce sputtered particle at high explosive energies.
Abstract: The ’’ion explosion’’ model of track production in dielectric materials in investigated as a possible source of sputtered particles at high bombarding energies.
TL;DR: In this paper, a review of the application of ion etching (both ion beam milling and rf sputter etching) to pattern delineation in integrated circuit fabrication is presented.
Abstract: This paper is a review of the application of ion etching (both ion beam milling and rf sputter etching) to pattern delineation in integrated circuit fabrication. Typical equipment and use conditions are described along with the advantages and disadvantages of each process. Two case histories are described where ion etching has been successfully used to pattern delineate the metallization levels of silicon integrated circuits by sputter etching and magnetic bubble devices by ion milling.
IBM1
TL;DR: In this article, a deconvolution method has been developed to facilitate the retrieval of the actual profile from the observed profile by reducing the sputter broadening effect, which can be separated into contributions from original surface roughness and sputtering effects.
TL;DR: In this article, the sputtering patterns of NaCl irradiated with low energy electrons were separated into component features from the directional ejection of halogen atoms and a random evaporation of the metal atoms.
Abstract: We have separated the sputtering patterns of NaCl irradiated with low energy electrons into component features from the directional ejection of halogen atoms and a random evaporation of the metal atoms. The sputtering yields anti-correlate with exciton luminescence. Lifetime studies reveal the presence of several exciton states with different diffusion energies. The sputtering yield shows a resonance with the production of surface excitons. The experiments confirm the view that defect formation in the halogen sub-lattice proceeds by a non-radiative exciton decay which initiates a replacement collision sequence along a chain of halogen ions.
TL;DR: In this article, a wide range of vapour-quenched Al-Ni, Al-Cu and Al-Fe alloys have been prepared by co-sputtering in an r.c.f.
TL;DR: Cermet MgO/Au films prepared by rf sputtering have been found to be highly absorbing in the solar spectrum and highly transparent in the infrared as discussed by the authors, with solar absorptivity of over 0.9 and infrared emissivity of less than 0.1.
Abstract: Cermet MgO/Au films prepared by rf sputtering are found to be highly absorbing in the solar spectrum and highly transparent in the infrared. Excellent selective absorbers, with solar absorptivity of over 0.9 and infrared emissivity of less than 0.1, have been produced by depositing such films on metal substrates. Films deposited on Mo‐coated stainless steel are stable in air up to 400 °C.
TL;DR: In this article, the total erosion yields by sputtering and blistering for 1 to 15 keV H2+ bombardment at normal incidence have been measured by weight loss of 304 stainless steel, pyrolytic graphite, carbon fibres, glassy carbon and SiC.
TL;DR: In this article, an introduction to dry processing techniques such as ion beam etching, rf sputter etching and plasma etching is presented. And a short description of the systems is followed by a comparison of their properties relevant to the fabrication of electronic and optical devices.
Abstract: This paper is an introduction to dry processing techniques such as ion beam etching, rf sputter etching, and plasma etching. A short description of the systems is followed by a comparison of their properties relevant to the fabrication of electronic and optical devices. The comparison includes etch rates and their dependence on various parameters, masking materials and dimensional accuracy in pattern delineation, obtainable aspect ratios, and edge profiles. The paper concludes with some examples of plasma‐ and ion‐etched patterns.
Patent•
11 Aug 1976
TL;DR: In this article, a thin film absorber stack consisting of an absorptive film of titanium, zirconium or hafnium suboxide, subcarbide or subnitride superposed on a reflective film of silver, aluminum or copper display spectrally selective characteristics.
Abstract: Thin film absorber stacks consisting of an absorptive film of titanium, zirconium or hafnium suboxide, subcarbide or subnitride superposed on a reflective film of silver, aluminum or copper display spectrally selective characteristics. The absorptive film may be prepared by reactively sputtering the metal or the metal carbide in argon or other inert gas with small amounts of gas containing carbon, oxygen or nitrogen or their combinations, or by reaction of the metal film in air or other gas.
TL;DR: In this paper, a formalism is presented for extracting diffusion coefficients from concentration profiles measured by analytical techniques such as Auger electron spectroscopy, secondary ion mass spectrometry, low energy and high energy ion scattering.
TL;DR: In this article, the transition temperature of Niobium films with thickness greater than 2000 A was near 9.2 K, the bulk value, while Tc decreased linearly with inverse thickness for films thinner than 1000 A.
Abstract: Superconducting niobium films, both cylindrical and planar, have been prepared by rf sputtering in an uhv chamber which is routinely pumped to a residual pressure of 3×10−9 Torr (7.6×10−7 Pa). The superconducting transition temperature Tc of films with thicknesses greater than 2000 A was near 9.2 K, the bulk value, while Tc decreased linearly with inverse thickness for films thinner than 1000 A. Superconductivity was observed for the first time in Nb films thinner than 50 A; the Tc of a 40 A film was 4.4 K while for a 27 A film the onset of the transition was about 2 K. Electrical continuity was maintained down to a nominal film thickness of less than 10 A, but this film was not superconducting above 1.5 K. These results will be compared with a model which predicts the dependence of Tc on thickness.
TL;DR: In this paper, the sputtering yield of ionic crystals has been investigated at room temperature and with low ion energies, and the results indicate that sputtering yields are considerable higher than could be accounted for by regular collision cascade theories (e.g. Sigmund).
TL;DR: In this paper, low energy ion-scattering spectrometry has been used to obtain the composition depth profiles of air-formed oxide films on a series of iron-chromium alloys.
Abstract: Low energy ion‐scattering spectrometry has been used to obtain the composition‐depth profiles of air‐formed oxide films on a series of iron‐chromium alloys. By using iron, chromium, , , and as standards, the atom composition ratios Cr/Fe and have been obtained quantitatively as a function of sputtering time. The air/oxide interface appears to be oxygen‐rich or metal‐deficient. The Cr/Fe ratio is low at this interface but increases and peaks a few angstroms inside it. This ratio then diminishes continuously to its value in the alloy at the oxide/metal interface. The ratio diminishes continuously from the air/oxide to the oxide/metal interface and appears to be independent of alloy composition. There is no region of constant concentration of any of the components. The average Cr content of the oxide varies linearly with alloy composition but exceeds the Cr content of the alloy. This may be associated with the method of surface preparation. Based on differences in the shape of the composition profiles, it is speculated that the distribution and bonding of cations in the oxide phase, not their concentration, differentiate the stainless from the nonstainless alloys.
TL;DR: The backputtering yield of gold bombarded with gold ions has been measured in the energy range from 60 keV to 20 MeV as discussed by the authors, where the targets were polycrystalline, self-supporting gold foils, 3000-6000 A thick, and the sputtering yield was determined by measuring the thickness decrease of the target by means of forward scattering of protons.
TL;DR: In this paper, the photon and ion emissions which result from the sputtering of metals by ion bombardment depend strongly on the surface composition of the metal and the primary current density, and the results reveal some similarities in the behaviour of the two emissions.
TL;DR: In this paper, the influence of film thickness, electron and ion beam energies, ion beam current density and initial surface roughness on depth resolution was investigated, showing that the width of the transition region increases with the square root of the product of ion beam energy and film thickness.
TL;DR: In this article, absolute sputtering yields for the consttuents of the thin film compounds PtSi and NiSi on bombardment with 900 eV and 20 keV Ar were obtained.
TL;DR: In this article, preferential sputtering has been studied for the binary systems AgAu, Au, and Cu, and it was shown that the enrichment is larger in the topmost surface layer and decreases with increasing depth.