Vacuum Evaporation System Research Articles

Experimental Study on Fabrication Technique of a Ni/Ti Supermirror using the Electron Beam Evaporation System

Basic study on the fabrication technique of a Ni/Ti supermirror using the vacuum evaporation system with an electron gun has been carried out to improve the neutron reflectivity.The substrate roughness dependency to the reflectivity was investigated using polished glass floats with different surface roughnesses using neutron reflectometry. It was concluded that the substrate roughness in the order of several sub-nanometers was very sensitive to the neutron reflectivity of the Ni/Ti supermirror. The reflectivity was improved to 80% for the Ni/Ti supermirror with an effective critical angle of 2 times that of natural nickel using fine polished glass substrate with a surface roughness of 0.51 nm rms.The effect of oxidizing Ni and Ti layers to the neutron reflectivity, which were deposited by changing the oxygen gas conditions in the chamber, was investigated. The oxidation effect prevents the deformation of the Ni/Ti supermirror structure, and the reflectivity shows an increase of almost 20% for the Ni/Ti supermirror with an effective critical angle of 2.6 times that of natural nickel by depositing in an atmosphere of oxygen gas with a partial pressure of 1 × 10−5 Torr.From the depth profile by X-ray photoelectron measurement (XPM) and neutron reflectometry results, it was concluded that the reflectivity increase by oxidation mentioned is caused by decreasing the interface roughness and the interfacial diffusion between Ni and Ti layer, and it is not caused by forming a NiO compound which increases the scattering potential of the Ni layer.

Preparation of optical quality ZnCdTe thin films by vacuum evaporation

A procedure to make optical quality thin films of Zn(x)Cd(1-x)Te by use ofvacuum evaporation of the ternary compound has been developed. Thestarting point was the preparation of the compound that was then usedas the source in a simple vacuum evaporation system. Thecharacteristics of a film containing 85% ZnTe (x =0.85) are presented. Electron microscope, atomic forcemicroscope, x-ray and optical spectral measurements were made. Theindex of refraction was determined at room temperature fromtransmittance measurements in the range of from 580 to 800 nm and wasfound to agree within 1% with values found by others for singlecrystals. We did this by assuming a Sellmeier equation and a knownindex of refraction at infinite wavelength. The calculation alsoyielded the roughness of the film.

Experimental Study on Fabrication Technique of a Ni/Ti Supermirror using the Electron Beam Evaporation System.

Basic study on the fabrication technique of a Ni/Ti supermirror using the vacuum evaporation system with an electron gun has been carried out to improve the neutron reflectivity. The substrate roughness dependency to the reflectivity was investigated using polished glass floats with different surface roughnesses using neutron reflectometry. It was concluded that the substrate roughness in the order of several sub-nanometers was very sensitive to the neutron reflectivity of the Ni/Ti supermirror. The reflectivity was improved to 80% for the Ni/Ti supermirror with an effective critical angle of 2 times that of natural nickel using fine polished glass substrate with a surface roughness of 0.51 nm rms. The effect of oxidizing Ni and Ti layers to the neutron reflectivity, which were deposited by changing the oxygen gas conditions in the chamber, was investigated. The oxidation effect prevents the deformation of the Ni/Ti supermirror structure, and the reflectivity shows an increase of almost 20% for the Ni/Ti ...

Hysteresis characteristics of vacuum-evaporated ferroelectric PbZr 0.4Ti 0.6O 3 films on Si(111) substrates using CeO 2 buffer layers

We demonstrate the ferroelectric behavior of PZT films grown on Si(111) substrates by using CeO 2 buffer layer. PZT (90 nm) films were prepared by electron beam assisted vacuum evaporation system and CeO 2 (27 nm) films were prepared by MBE (molecular beam epitaxy). It is found that a hysteresis is not shown in the capacitance-voltage ( c–v) characteristics of CeO 2/Si structures, whereas a hysteresis is obtained in the c–v plot of PZT/CeO 2/Si structures, which is due to the ferroelectric nature of the PZT film. In addition, it is shown that the leakage current of PZT/CeO 2/Si is as low as 10 −7 A/cm 2 at 8 V.

Facility for the development of the multilayer neutron mirror at KUR

The facility for the development of the multilayer mirror as a device for handling slow neutrons is described. The facility consists of a vacuum evaporation system, a neutron reflectometer and a reflectivity calculation program. The properties of the evaporation are discussed. The neutron reflectometer makes use of the time-of-flight method and can measure the reflectivity down to 10 −4. In the reflectivity calculation program, we adopt a neutron optical method with a modified optical potential, in which the contrast between layers is reduced, and the potential around the layer boundary is smoothed. It is shown that with a suitable choice of calculation parameters, experimental reflectivity of a supermirror is well reproduced by the calculation.

Atomic Layer-by-Layer Deposition of La-Sr-Cu-O Films

Abstract La-Sr-Cu-O films have been prepared as-deposited condition by an atomic layer-by-layer deposition technique in a high vacuum evaporation system with multi-electron-beam-gun sources. The film quality is crucially dependent on the substrate temperature, oxidation gas, and source material. It is found that the layer-by-layer successive deposition of the three elements is superior to the simultaneous deposition.

Apparatus with permanent magnet flipper for magnetic circular dichroism absorption measurements

An apparatus with permanent magnet flipper was designed and constructed to study magnetic circular dichroism (MCD) of various magnetic materials. The permanent magnet flipper is similar to a single period of undulator magnets but has two holes to allow the incident light to go through. The maximum magnetic field at the sample position is 1.2 T and its direction is switched by a linear motion of the magnet flipper. It was mounted in an ultrahigh vacuum chamber equipped with a vacuum evaporation system and a sample holder cooled to liquid nitrogen temperature. The MCD signal of Ni in the 3p-3d absorption region was successfully measured within an accuracy of 0.01%.

Measurements of vapour stream density with the electron emission method

A method of measuring vapour stream density in vacuum evaporation systems, based on the change in electron emission properties of a metallic thermocathode, is presented. The measuring gauge and supply-control system are described in detail. The experimental calibration characteristic and response times for Ti, Ni and Cr are presented for gauges fitted with W, Re and Ir cathodes. Simple construction, high sensitivity, small dimensions of the vapour detector and its self-cleaning ability make the method useful for control of vacuum evaporation processes of many substances.

A decision framework for evaluating vacuum pumping technology

An analytic model for the selection of vacuum pumping technology is presented. The model identifies selection issues, which may be classified into two groups according to whether they directly contribute or are detrimental to the pumping system performance. These two groups of issues, entitled benefit and cost, respectively, are analyzed through a decision-making methodology called the analytic hierarchy process (AHP). Application of this methodology to the benefit and cost issues results in a priority structure leading to selection of the best choice from a given set of candidate systems. Results of this evaluation are given for a specific case of a vacuum evaporation system.

Thickness Dependence of Magnetic Properties in CoCr Film by High-Rate Evaporation

The relation between film thickness and magnetic properties of CoCr films prepared by the high-rate evaporation techinique which is well suited to mass production, as well as the film growth process itself, were investigated. CoCr films were deposited with a web-coater type vacuum evaporation system. The crystallographic orientation of the films becomes stable during initial layer formation process (? 0.02 ?m), but H c? continues to decrease with the increase of film thickness above 0,05 ?m. This corresponds to changes of the film microstructure.

Co-Ni-Fe Underlayer for Double-Layer Perpendicular Media

Co, whose vapour pressure is close to that of Ni and Fe, has been added to Ni-Fe system to get a lower coercive force H c and a higher initial permeability ?i for the fabrication process by web coating vacuum evaporation. A Co-Ni-Fe film 0.8 ?m thick shows in-plane magnetic isotropy for all Co concentrations we investigated, and ?i is three times as large as that of the binary Ni-Fe film when 15 to 30 wt% Co is added. These results show that the Co-Ni-Fe film in 0.8 ?m thick prepared by the web coater vacuum evaporation system is appropriate for the underlayer of a double-layer perpendicular recording disk.

An evaporation system for the preparation of ternary compounds

A computer-controlled high vacuum evaporation system has been constructed for the fabrication of ternary compounds such as the Chevrel phase materials. The latter are formed on a substrate held at high temperatures with the constituent elements being deposited from some combination of electron beam sources, resistively heated Langmuir sources, and Knudsen sources. Unique features of the system include the techniques employed to handle sulfur in a high vacuum environment, and the monitoring and control system used to ensure the formation of stoichiometric compounds with a high degree of compositional uniformity.

Vacuum evaporation system for depositing thick polycrystalline silicon

Thick polysilicon (>1 mm) deposition on heated SiO2-coated silicon substrates at high deposition rate (≥4 μm/min) at temperatures to 1100 °C was achieved by vacuum evaporation of silicon using two high power e guns. The deposition system was able to accommodate ten 75 mm diam substrates or eight 100 mm diam substrates. The system was designed as an alternative to the CVD process for depositing polysilicon material for dielectrically isolated integrated circuit substrates. This paper describes the system design and its capabilities.

Simple high vacuum evaporation system with low-temperature substrate

An ultrahigh vacuum system has been constructed which permits deposition of thin films onto 4.2-K substrates. The evaporation mechanism is contained within a small cylindrical vessel which is totally immersed in liquid (4)He. This device has been used to study superconductivity in PbBi and Ga, PdH and PdD, and most recently, transport properties of ultrathin films.

Unification of rotary motion feedthroughs for ultrahigh vacuum evaporation systems: G A Shaumyan et al, Elektron Tekh Tekhnol Organiz Proizv, 5, 1970, 70–74 ( in Russian)

A packed-column gas-chromatograph/mass-spectrometer (GC/MS), Hewlett-Packard 5982, was modified to accommodate fused silica capillary columns. The original GC/MS interface and chemical-ionization sample-line in the ion-source were changed to allow the end of a fused silica capillary column to enter the ion-chamber directly. For chemical-ionization operation, the reagent gas was brought into the MS through the direct-insertion probe port. The calibration compound was introduced through the electron-impact sample-inlet, which simplified the operation. The modified system yields higher sensitivity and more efficient separation, as well as simpler operation, without sacrificing any original instrument functions.

142. A feed adapter for continuous automatic transfer of solutions into vacuum evaporation systems: R E Bailey,J Lipid Res, 6 (3), 1965, 436–438

142. A feed adapter for continuous automatic transfer of solutions into vacuum evaporation systems: R E Bailey,J Lipid Res, 6 (3), 1965, 436–438

A feed adapter for continuous automatic transfer of solutions into vacuum evaporation systems

The design of a simply constructed feed adapter for continuous transportation of solutions into a vacuum evaporation system is described.

Sources of surface contamination in vacuum evaporation systems : L. Holland, Vacuum13, 173 (May 1963)

Sources of surface contamination in vacuum evaporation systems : L. Holland, Vacuum13, 173 (May 1963)

784. Sources of surface contamination in vacuum evaporation systems: L. Holland, Vacuum, 13 (5), May 1963, 173–180

784. Sources of surface contamination in vacuum evaporation systems: L. Holland, Vacuum, 13 (5), May 1963, 173–180

Sources of surface contamination in vacuum evaporation systems

Sources of surface contamination in vacuum evaporation systems