Showing papers on "Layer by layer published in 1983"

Direct observation of layer-by-layer wetting of graphite by ethylene

Abstract: It has been demonstrated directly by use of x-ray diffraction that at temperatures below the triple point of bulk ethylene (103.8 K) adsorption of ethylene onto the basal planes of graphite only occurs up to a finite number of molecular layers. Further addition of molecules results in the formation of bulk crystallites. Reversible transitions between the total number of layers adsorbed and the coexisting bulk are observed.

High performance optical storage medium with separate mechanical servo tracks embedded within the medium

Abstract: An optical storage medium incorporates stacked servo and data layers with the pattern of the servo layer being prepared prior to preparation of the data layer. The servo pattern comprises an undulation in a very thin film of high optical index material on the surface of the substrate of the medium. The undulating layer containing the servo pattern is separated from the active layer of the medium by a thin dielectric spacer film. The data layer is employed for formation of vesicular, or ablative or other marks forming surface discontinuities formed by any of the usual pit forming techniques. The preformatted servo information formed in the servo layer as buried undulations in the thin film is read out in amplitude or phase contrast. The thin undulating layer is of a significantly different index of refraction from the substrate and the next intervening layer. This layer can be transparent or semi-transparent. A smoothing layer is then applied over the phase-contrast layer to reduce any undulations at the top surface on which the active layer is formed. The amount of energy absorbed by the active layer of the structure is optimized for the data recording wavelength by choice of thickness of the smoothing layer.

Method of growing an alloy film by a layer-by-layer process on a substrate, and a method of making a semiconductor device

Abstract: A method of growing an alloy film by a layer-by-layer process on a substrate is described, together with a method of making an semiconductor device in which an alloy film is grown on a substrate by a layer-by-layer process. The atomic ratio of constituents present in the alloy film is determined during growth of the film from the growth rates of the alloy film and of at least one intermediate film consisting of at least one constituent of the alloy. The intermediate film or films are grown between the alloy film and the substrate. During growth of each film, the growth surface is irradiated with a beam of electrons and measurement is carried out of the period of oscillations in the intensity of the stream of electrons diffracted at the growth surface, or specularly reflected by the growth surface, or emitted from the growth surface, or of the current flowing to ground through the substrate. These periods are equal to the respective times taken to grow on a monolayer of the respective film.

Piezoelectric thin film composite oscillator

Abstract: PURPOSE:To obtain a composite oscillator which is free of spurious response and has excellent characteristics by specifying the thickness ratio between a piezoelectric thin film and a silicon diaphragm and the ratio between the overall thickness and electrode size. CONSTITUTION:The thickness of the ZnO piezoelectric thin film 25 is denoted as T1, and the thickness of the thin layer part of the silicon diaphragm consisting of a silicon thin film 23 and an SiO2 thin film 24 by doping boron to high concentration is denoted as T2; and the overall thickness of an oscillation part of multilayer structure is T and the diameter of an upper electrode 27 on the oscillation position is L. Then when their ratios are substituted by X=T2/T1 and Y=L/T so that Y -20X+8.2 (where 0

Thin-Film Electrode Fabrication Techniques

Abstract: After a long developmental effort, we can now fabricate, using thin-film techniques, both rigid modiolar multielectrodes and flexible scala tympani multielectrodes which we believe appropriate for long-term implantation in human subjects. In vitro and in vivo life tests are in progress to confirm this expectation.

The determination of electron inelastic mean free path using evaporated films

Abstract: Monte Carlo simulations of the growth of evaporated films have been carried out under various assumptions affecting the type of growth. The corresponding curves of Auger signal from the film as a function of deposition time have been analyzed to extract values for the electron inelastic mean free path λ. A smoothness parameter C defined as the fraction of the substrate covered after the deposition of 1 monolayer equivalent of atoms, is used to characterize the degree to which growth is layer by layer, i.e., one layer is complete before the next one begins. It has been found that values of λ correct to within 10% can be obtained for values of C as low as 0.85; below C values of 0.85 the results for λ become unreliable. It is shown that film formation may be made essentially layer by layer by a reasonable choice of the deposition flux density and the substrate temperature, provided that the system is one in which atoms can walk off terraces. It is also shown that elastic electron backscattering should not affect these calculations significantly.

Method of manufacturing semiconductor device, including a step of patterning a conductor layer

Abstract: A conductor layer is formed on an insulating film which is formed on a semiconductor substrate and which consists of a thick portion and a thin portion with a step therebetween. A film made of material having an etch rate substantially equal to that of the material of the conductor layer is formed on the layer. The film, which has a substantially flat upper surface, and the conductor layer form a laminated structure. Those portions of the laminated structure which are on the thin portion of the insulating film and said step have substantially the same thickness. A mask layer of a predetermined pattern is formed on the laminated structure. Using the mask layer, the laminated structure is selectively etched, the selected portions of the conductor layer and film being etched at the same etching rate. Thereafter, the mask layer and the remaining film are removed.

Photomagnetic recording carrier

Abstract: PURPOSE:To obtain an inexpensive recording carrier with a high S/N ratio and an increment of performance exponent by forming successively a thin film of a garnet compound containing Bi, a vertically magnetized metallic magnetic film and a metallic reflective film as well as a transparent nonmagnetic dielectric film when necessary on a transparent substrate. CONSTITUTION:A garnet thin film 2 containing Bi is formed on the upper surface of a transparent substrate 1 by a sputtering or vapor deposition process, etc. A magnetic thin film 3 whose magnetization facilitating axis is vertical to the film surface is formed on the film 2 by the same process. In addition, a metallic reflective film 4 and a nonmagnetic dielectric film 5 of SiO2 or SiO are formed on the film 3 by the same process. The film 3 uses an Mn or Co crystalline magnetic thin film. For the film 2, an amorphous film of about 0.4mum thickness is formed by a sputtering process with a sintered matter (100mm.phi) of a compound (Bi0.7Y2.3Fe5O12) used as a target. Then an amorphous film 3 of Fe58CO22Tb20 is formed with about 0.04mum thickness as the film 3 by a vacuum vapor deposition process. Then an Al film and SiO2 film are formed with about 0.1mum thickness on the film 3 as films 4 and 5 respectively.

Composite polyester film for magnetic recording medium

Abstract: PURPOSE: To obtain a film for a vapor-deposited video tape which has a surface free from deposition of oligomer on one surface and of which the other surface has good runnability by specifying respectively the roughness on both surfaces of a composite film provided with a coating layer. CONSTITUTION: A full-surface coating layer C consisting essentially of a water- soluble high polymer and a silane coupling agent is formed on the outside surface of the layer A of a composite polyester film laminated with the layer A consisting of polyester and a layer B consisting of polyester in which fine particles exist. The polyester film for vapor deposition of a thin magnetic metallic film is constituted of the layer C of which the roughness on the outside surface is ≤0.006μ Ra value and the layer B of which the roughness on the outside surface is 0.005W0.040μ Ra value. The layer A of the film is heated by the layer C and even if the temp. increases, the deposition of oligomer on the outside surface of the layer C is obviated. When the Ra value on the outside surface of the layer C exceeds 0.006μ, the magnetic surface of the thin film is roughened and the S/N decreases. When the Ra value on the outside surface of the layer B deviates from the lower limit, the runnability with a metallic roll and guide bar is poor. COPYRIGHT: (C)1985,JPO&Japio

Fine processing method of thin film

Abstract: PURPOSE: To attain the patterning of a thin film requiring no remover liquid whose acidity and basicity affect other objects and capable of lifting said film although the film thickness of a metallic layer is increased, by forming a pattern thin film on said metallic layer containing a metal having a low melting point and a low boiling point. CONSTITUTION: A metallic layer 6 of a low melting point and a low boiling point is previously formed on a substrate or a base film 5 by a mask vapor deposition process, a mask thermal spray process or a plating process, etc. In this case, an etching process is also applied when necessary. Then a thick film 7 for patterning is formed on the layer 6 by various types of film producing processes. The substrate is heated up to a level higher than the melting and boiling points of the layer 6 after the film 7 is formed. Otherwise only the layer 6 is heated up to a level higher than its melting and boiling points by a high-frequency induction heating process. Thus the film 7 is processed minutely with the pressure of the layer 6 which is gasified. Thus a desired film undergoes patterning. In this case, it is possible to increase previously the film thickness of the layer 6 up to a sufficient level. Therefore the patterning is easy for the desired film. COPYRIGHT: (C)1984,JPO&Japio

High speed erasing and rebiasing of thermoptic thin films in the medium and long-wave infrared

Abstract: Apparatus for rapidly erasing and rebiasing a thermoptic thin film in the near and medium infrared. A thermal insulating material (56) is disposed adjacent a thermoptic vanadium oxide thin film (50). The insulating layer has high transmittance in the 3-5 or 8-12 micrometer spectral bands. A layer of resistive semiconductor material (54) having high transmittance in the 3-5 or 8-12 micrometer band is disposed between the layer of insulating material and the vanadium oxide thin film. A multilayer dielectric thin film stack is superposed adjacent the vanadium oxide thin film, or is disposed in two parts adjacent the upper and lower surfaces of the thermoptic thin film. The multilayer dielectric stack, in combination with the thermoptic film, the resistive layer and the insulating layer provides a low reflectance, high transmittance condition over the 3-5 or 8-12 micrometer band when the thermoptic film is in its semiconducting state and a high reflectance condition over the same band when the thermoptic film is in its metallic state. The resistive layer is connected to a current generator (18) which supplies a current to the resistive layer dissipating heat into the vanadium oxide thin film and into the insulating layer. A thermal body (24), having high thermal conductivity and interfacing with the insulating layer at the opposite boundary from the thermoptic thin film, contains a conduit (34) through which a refrigerated liquid (26) is flowed to establish a thermal gradient from the thermoptic thin film to the fluid.

Use of a length scale for characterization of adsorption kinetics in a layer-by-layer method

Abstract: In the layer-by-layer method, it is proposed to express the constants which characterize the rate of adsorption and longitudinal transfer by a length scale. A layer of equilibrium adsorption L e is determined for which the elution concentration at any moment of time is numerically equal to c(~), equivalent to the mean value of adsorption ~ of this layer. The material balance equation for the equilibrium adsorption layer is written in the form

Thin Film Deposition Techniques

Abstract: As already pointed out in Chapter 1, a deposition technique and its associated process parameters have a characteristic effect on the nucleation- and growth-dominated microstructure of a thin film and thereby on its physical properties. Two-dimensional materials of thicknesses ranging from angstroms to hundreds of micrometers can be prepared by a host of so-called thin film as well as thick film techniques. The latter methods involve the preparation of thin materials from a paste or liquid form of the bulk material. The two sets of techniques yield thin film materials of widely different microstructures and properties.

Production of extremely thin bondable film

Abstract: PURPOSE: To obtain an extremely thin bondable film which is free from crease and does not have unevenness in coating, by forming an adhesive layer on a thick carrier film before transferring it onto a thin film. CONSTITUTION: An adhesive layer is formed on a thick carrier film and then transferred onto a thin film substrate. The term "thin film substrage" used herein refers to an extremely thin film of 20μ or below in thickness. Example of the carrier films are films of 20μ or above in thickness, such as oriented polypropylene film, polyethylene film and mold release films for use in release paper. The thin film substrate is chosen from among those which have higher adhesion to the adhesive than the carrier film. Examples of such film substrates are polyimide and polyester films. Plastic films such as polyethylene or polypropylene film whose surface has been subjected to a discharge treatment or a primer treatment to improve adhesion can be also used as the film substrate. COPYRIGHT: (C)1985,JPO&Japio

Thickness Measurement, Rate Control And Automation In Thin Film Coating Technology

Abstract: There are many processes known for fabricating thin films/1, 2.Among them the group of physical vapor deposition processes comprising evaporation, sputtering and ion plating has received special attention.Especially evaporation but also the other PVD techniques are widely used to deposit various single and multilayer coatings for optical and electrical thin film applications/3,4/.A large number of parameters is important in obtaining the required film properties in a reproducible manner when depositing thin films by such processes.Amongst the many are the film thickness, the condensation rate,the substrate temperature,as well as the qualitative and the quantitative composition of the residual gas of primary importance.First of all the film thickness is a dimension which enters in practically all equations used to characterize a thin film. However,when discussing film thickness,definitions are required since there one has to distinguish between various types of thicknesses e.g.geometrical thickness,mass thickness and optical thickness.The geometrical thickness,often also called physical thickness,is defined as the step height between the substrate surface and the film surface.This step height multiplied by the refractive index of the film is termed the optical thickness and is expressed generally in integer multiples of fractional parts of a desired wavelength.The mass thickness finally is defined as the film mass per unit area obtained by weighing.Knowing the density and the optical data of a thin film its mass thickness can be converted into the corresponding geometrical as well as optical thickness.However,with ultrathin films ranging between a few and several atomic or molecular "layers"the concept of a film thickness may become senseless since often no closed film exists of such minor deposits.Although film thickness is a length,the measurement of it can,obviously,not be accomplished with conventional methods for length determinations but requires special methods.The great efforts made to overcome this problem led to a remarkable number of different,often highly sophisticated film thickness measuring methods reviewed in various articles such ase.g./5,6/.With some of the methods,it is possible to carry out measurement under vacuum during and after the film formation other determinations have to be undertaken outside the deposition chamber only after the film has been produced.Many of the methods cannot be employed for all film substances,and there are varying limits as regards the range of thickness and measuring accuracy.Furthermore, with these methods the film to be measured is often specially prepared or dissolved during measurement and therefore becomes useless for additional investigations or applications.If only those methods which can be employed during the film deposition are considered,then the very large number of methods is considerably reduced.Insitu measurements,however,are highly desired since many basic investigations and practically all industrial applications require a precise knowledge of thefilm thickness at any instant to enable termination of the deposition process at the predetermined right moment.Apartfrom few exceptions in practical film deposition only optical measuring units andmass determination monitors are used.

Method for pattern formation

Abstract: PURPOSE:To obtain the high-accuracy thin film pattern by a method wherein when a substrate is coated with a metallic thin film and further with an organic high molecule layer, on which an opening is formed and the metallic thin film is etched by using this opening to be made into the predetermined pattern, the oxide substance of the thin film exposed in the opening is removed in advance. CONSTITUTION:A metallic this film 2 of Mo and etc. is deposited on a substrate 1 by the electron beam vapor deposition method and further an organic high molecule layer 3, an SiO2 intermediate layer 4 and a negative resist layer 5 are laminated. Next, an opening is formed on the layer 5 and the layer 4 is subjected to an reactive ion etching by CF4 + 33% H2 mix gas to form an opening. Then, the similar opening is formed on the layer 3 by electron-beam drawing and the development to follow. After that, the exposed part of the thin film 2 is removed by reactive ion etching with using said opening. At this time, an oxide film 6 produced in the exposed part of the thin film 2 is removed by being immersed in water, ethyl alcohol or acetone before etching.

Substrate material for thin film magnetic head with insulating film

Abstract: PURPOSE:To perform the crystal systematic matching of insulating film and substrate made of Al2O3 remarkably improving the coating strength by a method wherein an Al2O3 base thin film comprising the same components as those of substrate and more Al2O3 content than that of substrate is laid between the insulating thin film and the substrate as an intermediate layer. CONSTITUTION:An Al2O3 base thin film to be laid between an Al2O3 base thin film for electric insulation as an intermediate layer shall be e.g. in case the substrate is composed of 65% Al2O3-35% TiC base substrate, Al2O3-TiC base thin film comprising 65% or more Al2O3 and 35% or less TiC. The total thickness of Al2O3 base thin film as an intermediate layer and another insulating Al2O3 thin film shall be 1-50mum. While the thickness of the Al2O3 base thin film as the intermediate layer shall exceed 0.1mum to augment the adhesion between the substrate and the insulating Al2O3 thin film. Besides, the surface roughness of the Al2O3 base substrate shall not exceed 1,000Angstrom to augment the adhesion to the insulating Al2O3 thin film through the intermediate of the Al2O3 base thin film as the intermediary layer.

Studies of thin films in binary fluid mixtures using ellipsometry

Abstract: In certain binary solutions, the lower of the two liquid phases forms a layer that intrudes between the upper liquid phase and the vapor. We used ellipsometry to measure the intruding layer's thickness-it was between 7 nm and 40 nm in a system consisting of C7F,, (perfluoromethylcyclohexane) and C7HI4 (methycyclohexane). The thickness varies approximately as L-' / ' , where L is the height spanned by the upper liquid phase. This behavior was predicted by de Gennes, who used the idea that the long-ranged part of the intermolecular potential governs the layer's thickness. Deviations from L-'/' behavior occur near consolute points. In similar systems, which consisted of various alcohols and C,F,,, we have located transitions from complete wetting (of the liquid-vapor interface) to incomplete wetting far from consolute points. The system we have studied in greatest detail is isopropanolC7FI4. In this system, the transition occurs near 38\" C. In one sample, the transition was reproducibly bracketed within 0.03\" C. Just above the transition temperature, the wetting layer's thickness was 35 2 nm. The thickness changed, a t most, by 3 nm as the temperature was raised to 50\" C. The thickness dependence on L (the height above the two phase equilibrium) is not consistent with a -yj power law and indicates that the long-range forces affecting film thickness are much weaker than in the system (C7FI4-C7H,,) mentioned previously. This thickness is a factor of four greater than that we measured in the C7H,,-C7F,, system under comparable conditions. We can speculate that the factor of four reflects a much larger interfacial tension between the film and the substrate in the isopropanol-C7F,, system. The larger interfacial tension is reasonable, because the isopropanol-C7F,, system is not near a critical point. As a function of T. the surface wetting transition appears to be first order. In de Genne's model, a first-order transition can occur if the long-range forces give rise to an attractive term that tends to reduce the film thickness. Ethanol, isopropanol, and n-butanol, when mixed separately with C7F,,, provide a series of systems with thermally driven wetting transitions. T , (C,H,0H-C7F14) > 50\" C. while T, (C,H90H-C7F,,) < 2 3 O C. Thus, we now have an easily studied system undergoing a wetting transition far from a critical point to complement the system we studied near a critical point.

Ceramic tile and process for its production

Abstract: The invention relates to a tile with a ceramic body, it having at least two layers (1, 2) of different apparent density and the structure of the layer (2) corresponding to a conventional body structure layer and the layer (1) being interspersed with macropores. The invention relates, furthermore, to a process for producing the tile, a ceramic mass, mixed with pore-forming agent, being introduced layer by layer into a mould, slightly pressed if appropriate, and the layer of the dense ceramic mass subsequently being applied and subsequently ceramically fired in the usual way.

Film Growth of GaN on a c-Axis Oriented ZnO Film Using Reactive Ionized-Cluster Beam Technique and Its Application to Thin Film Devices : C-4: THIN FILM DEVICES

Abstract: An attempt to grow a GaN film on a c-axis oriented ZnO film has been performed using reactive ionized-cluster beam deposition technique developed by one of the authors. ZnO film as a substrate is shown to serve as an adequate nucleation seed for growing GaN films, because the lattice misfit between the both materials is about 0.46%. Film growth of GaN has been achived at relatively low substrate temperatures up to 450°C. Measurements of structural and optical properties of grown GaN films are made, and the crystallinity is evaluated for the purpose of developing opto-electronic thin film devices.