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Inert gas entrapment in films produced by ion-assisted physical vapour deposition processes
Classified abstracts 6903-691 2 23 6903. Electric-field-assisted deposition of optical coatings it is possible to improve the stability of optical coatings if an electric field is applied during deposition. A.c. and d.c. electric fields have been used in the preparation of narrow-band filters consisting of ZnS and cryolite layers and edge filters of ZnS and MgF2. As a result, the shift in the wavelength of prominent features in the spectral transmittance is reduced ,:onsiderably even for coatings subjected to 100% relative humidity. P F Gu, Thin Solid Films, 156, 1988, 153-160. 23 .6904. Inert gas entrapment in films produced by ion-assisted physical vapour deposition processes l~he quantity of inert gas entrapped in films grown by ion-assisted physical vapour deposition (PVD) processes may influence considerably the physical properties of films. Therefore, the characteristics of inert gas entrapment are of particular importance. These characteristics have been studied for the case of argon ions trapped in titanium films. We express the atomic concentration ratio in the film (sorption ratio) ? = [Ar]/[Ti] as a function of the dimensionless quantity Cto,, which is the relative density of the ion flux (ratio of ion flux density to condensing material atom flux density). The results show that to some extent an increase in C~o,results in a gradual increase in 7, followed by saturation. This saturation starts for C~o.values of about 0.4 for ion energies ranging from 0.1 to 1.2 keV. For an ion energy of 0.6 keV and Cio, ~ 1, we find a maximum quantity of argon entrapped in the films (about 20 at%). The quantity of argon entrapped in films produced by currently used ion-assisted PVD technologies was estimated to be within 0.1 5 at%. G I Grigorov and I N Martev, Thin Solid Films, 156, 1988, 265-269. 23 6905. Morphology and structure of gold silver and copper layers obtained by sputtering during ion bombardment of targets from these metals The mechanism by which gold, silver and copper layers are formed by sputtering during the ion bombardment of targets of these metals has been investigated experimentally. Empirical evidence is given to show that, during the bombardment of metal foils with an appropriate thickness under certain conditions with argon ions, sputtering on both sides of the target occurs, namely forward and transmission sputtering. Transmission electron microscopy, scanning electron microscopy and transmission high energy electron diffraction were used to study the morphologies and structures of the layers obtained by both types of sputtering. Some possible applications of such layers are suggested. Miko Marlnov, Thin Solid Films, 157, 1988, 315-323. 23 6906. Low temperature growth of AIN and AlzO3 films by the simultaneous use of a microwave ion source and an ionized cluster beam system We have prepared aluminium nitride (AIN) and oxide (A1203) films at a substrate temperature of 100°C by the simultaneous use of a microwave ion source and an ionized cluster beam system. For A1N, transparent and amorphous films with high packing density were obtained. Both A1N and A|203 films were chemically and thermally stable. Furthermore, the A1203 films could be made polycrystalline by increasing the incident energy of the oxygen ion beam and the acceleration voltage of ionized aluminium clusters. The electrical resistivity of the A1N and AI203 films was higher than 5 x 1013[~ cm and the breakdown voltage was larger than 3 x l06 V cm 1. The chemical reaction between aluminium and reactive gas (i.e. nitrogen and oxygen) could be promoted by ionizing the reactive gas. Also, the ionization of aluminium clusters could improve the quality of the films as a result of combination with the reactive gas ions even at a low substrate temperature. Hiroshi Takaoka et al, Thin Solid Films, 157, 1988, 143-158. 23 6907. High temperatures stability of plasma-enhanced chemically vapour deposited titanium silicide due to two-step rapid thermal annealing The high temperature stability of plasma-enhanced chemically vapour deposited titanium silicide (TiSix) annealed at 1000°C is studied. A multilayer structure consisting of Si(1000 ,~)/TiSix(1200 ,~)/Si(700/~) is deposited successively over thermal oxide on a silicon substrate. When one-step rapid thermal annealing is performed at 1000°C, a rough TiSix Si interface forms and an increase in sheet resistance occurs. However, a stable interface and sheet resistance can be attain using a two-step rapid thermal sequence consisting of a 700°C pre-anneal and 1000°C postanneal owing to the fact that stoichiometric TiSix possessing an even
TiSix-Si interface is formed with this pre-anneal. Pre-anneals at 600 and 800°C result in an inhomogeneous interface when followed by the postanneal at 1000°C. Two-step annealing with a 700°C pre-anneal is a promising process technology for very large scale integrated circuit fabrication. Tohru Hara et al, Thin Solid Films, 157, 1988, 135-142. 23 6908. Plasma deposition of amorphous hydrogenated carbon films on III-V semiconductors Amorphous hydrogenated carbon films were grown on GaAs, InP and fused silica substrates using plasmas generated from hydrocarbon gases. Methane and n-butane sources were utilized. The effects of flow rate and power density on film growth were investigated. Carbon was the major constituent in the films. The degree of asymmetry at the carbon-semiconductor interface was approximately independent of the power density. Different H~C bonding configurations were detected by the technique of secondary ion mass spectrometry. Band gaps up to 3 eV were obtained from optical absorption studies. Breakdown strengths as high as 6 x l0 s V m-~ were measured. John J Pouch et al, Thin Solid Films, 157, 1988, 97 104. 23 6909. Thin palladium films prepared by metal--organic plasma-enhanced chemical vapour deposition A method for the deposition of palladium films using the allylcyclopentadienyl palladium complex is reported. In a plasma-enhanced chemical vapour deposition process bright metallic films can be produced at low temperatures. The resistivity of these films approaches that of bulk palladium. If oxygen is used as the carried gas the films consist of PdO. E Fenrer and H Snhr, Thin Solid Films, 157, 1988, 81 86. 23 6910. Deposition of device quality silicon dioxide thin films by remote plasma enhanced chemical vapor deposition A multichamber system specifically designed for growing Si-based dielectric films on processed and characterized semiconductor surfaces is described. The system consists of a semiconductor surface preparation chamber, an in situ surface analysis chamber, a dielectric deposition chamber, and two load-lock sample introduction chambers. Device quality silicon dioxide thin films have been grown on Si substrates. The electrical and structural properties of these films are discussed. Sang SKim et al, J Vac Sci Technol, A6, 1988, 1740-1744. 23 6911. Variations in the reflectance of TiN, ZrN and HfN The gold-like color and high hardness of the group IVB nitrides have allowed their use as scratch-resistant decorative coatings. The color can be varied with composition and mode of preparation. In the present work, TiN, ZrN and HfN films with different nitrogen-to-metal ratios were prepared on stainless steel by reactive sputtering. Half of each sample was vacuum annealed at 900°C for 1 h. The lattice parameters, reflectance and color were determined. The lattice parameters remained above equilibrium even after tempering. The experimental reflectance curves were analyzed in terms of the reflectance minima (between the screened Drude plasma edge and the onset of interband transitions) and the value of the reflectance at a photon energy of 1 eV (which is representative of the relaxation behavior). For all three nitrides the reflectance minimum is reduced to lower values of photon energy and reflectance as the nitrogen content is increased through the stoichiometric point. The reflectance at 1 eV increases concurrently. The degree of yellowness increases with nitrogen content, but no consistent effect of tempering could be defined. The behavior is described as the combined result of charge transfer from the metal to the metalloid atom (thus changing the effective density of conduction electrons) and of varying concentrations of vacancies and interstitials. A J Perry et al, Thin Solid Films, 157, 1988, 255 265. 23 6912. Characterization of PECVD deposited silicon oxynitride thin films The characterization of PECVD grown silicon oxynitride thin films is described. Rutherford backscattering spectrometry (RBS) elastic recoil detection analysis (ERDA) and nuclear reaction analysis (NRA), were used to quantify the film composition. Bonding within the film was investigated using infrared spectroscopy (IR). It was observed that the deposition of the silicon oxynitride layer grown using a fixed ratio of 981
TiSix-Si interface is formed with this pre-anneal. Pre-anneals at 600 and 800°C result in an inhomogeneous interface when followed by the postanneal at 1000°C. Two-step annealing with a 700°C pre-anneal is a promising process technology for very large scale integrated circuit fabrication. Tohru Hara et al, Thin Solid Films, 157, 1988, 135-142. 23 6908. Plasma deposition of amorphous hydrogenated carbon films on III-V semiconductors Amorphous hydrogenated carbon films were grown on GaAs, InP and fused silica substrates using plasmas generated from hydrocarbon gases. Methane and n-butane sources were utilized. The effects of flow rate and power density on film growth were investigated. Carbon was the major constituent in the films. The degree of asymmetry at the carbon-semiconductor interface was approximately independent of the power density. Different H~C bonding configurations were detected by the technique of secondary ion mass spectrometry. Band gaps up to 3 eV were obtained from optical absorption studies. Breakdown strengths as high as 6 x l0 s V m-~ were measured. John J Pouch et al, Thin Solid Films, 157, 1988, 97 104. 23 6909. Thin palladium films prepared by metal--organic plasma-enhanced chemical vapour deposition A method for the deposition of palladium films using the allylcyclopentadienyl palladium complex is reported. In a plasma-enhanced chemical vapour deposition process bright metallic films can be produced at low temperatures. The resistivity of these films approaches that of bulk palladium. If oxygen is used as the carried gas the films consist of PdO. E Fenrer and H Snhr, Thin Solid Films, 157, 1988, 81 86. 23 6910. Deposition of device quality silicon dioxide thin films by remote plasma enhanced chemical vapor deposition A multichamber system specifically designed for growing Si-based dielectric films on processed and characterized semiconductor surfaces is described. The system consists of a semiconductor surface preparation chamber, an in situ surface analysis chamber, a dielectric deposition chamber, and two load-lock sample introduction chambers. Device quality silicon dioxide thin films have been grown on Si substrates. The electrical and structural properties of these films are discussed. Sang SKim et al, J Vac Sci Technol, A6, 1988, 1740-1744. 23 6911. Variations in the reflectance of TiN, ZrN and HfN The gold-like color and high hardness of the group IVB nitrides have allowed their use as scratch-resistant decorative coatings. The color can be varied with composition and mode of preparation. In the present work, TiN, ZrN and HfN films with different nitrogen-to-metal ratios were prepared on stainless steel by reactive sputtering. Half of each sample was vacuum annealed at 900°C for 1 h. The lattice parameters, reflectance and color were determined. The lattice parameters remained above equilibrium even after tempering. The experimental reflectance curves were analyzed in terms of the reflectance minima (between the screened Drude plasma edge and the onset of interband transitions) and the value of the reflectance at a photon energy of 1 eV (which is representative of the relaxation behavior). For all three nitrides the reflectance minimum is reduced to lower values of photon energy and reflectance as the nitrogen content is increased through the stoichiometric point. The reflectance at 1 eV increases concurrently. The degree of yellowness increases with nitrogen content, but no consistent effect of tempering could be defined. The behavior is described as the combined result of charge transfer from the metal to the metalloid atom (thus changing the effective density of conduction electrons) and of varying concentrations of vacancies and interstitials. A J Perry et al, Thin Solid Films, 157, 1988, 255 265. 23 6912. Characterization of PECVD deposited silicon oxynitride thin films The characterization of PECVD grown silicon oxynitride thin films is described. Rutherford backscattering spectrometry (RBS) elastic recoil detection analysis (ERDA) and nuclear reaction analysis (NRA), were used to quantify the film composition. Bonding within the film was investigated using infrared spectroscopy (IR). It was observed that the deposition of the silicon oxynitride layer grown using a fixed ratio of 981