Thick Epitaxial Films Research Articles

Measurement of the physical thickness and refractive index of thin epitaxial garnet films

A technique for the measurement of refractive index and physical film thickness of epitaxial garnet films is described which utilizes variable wavelength measurements. Experimental results are presented for gadolinium gallium garnet substrates and two different bubble domain film compositions. From these results, it is concluded that the technique is not applicable to wafers with films on both sides due to the differences in film thickness of the two films. For single sided wafers, the refractive index can be determined with an accuracy of ±0.3 percent.

P-i-n epitaxial structures for high power devices

p-i-n structures have been made with avalanche blocking voltages between 1200 and 5100 V, using an Al-diffusion profile and a thick epitaxial film to obtain the buffering n-layer. The device areas are between 2.5 and 10 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Epitaxial films of ∼50-µm thickness with a very low defect density have been obtained after an in situ gas phase etching with SF <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> of approximately 30 µm. The application of these p-i-n structures as a basic element for the development of very fast high voltage reverse non-blocking thyristors is briefly discussed.

Diffusion of silver through epitaxial films of copper and nickel on silver (111): the formation of an equilibrium layer of silver

Thick (>2000 AA) epitaxial films of nickel and copper grown on silver (111) have been annealed in ultra-high vacuum at temperatures in the range 500-600K. This annealing procedure appears to cause diffusion of silver to the outer surface to take place, with the formation of an 'equilibrium layer' of silver. The silver layer appears to be strained in each case to give an integral ratio matching with the nickel or copper, the matching being 6:7 for Ag:Ni and 8:9 for Ag:Cu. A comparative study was made for thin films of silver deposited directly on to copper (111). LEED, RHEED and Auger spectroscopy were used throughout the study. Extra non-primary satellite beams in both LEED and RHEED from thin layers of Ag on Cu or Ni are believed to result from a combination of multiple diffraction and periodic deformations in the overlayer.

On the problem of measurement of thickness of epitaxial semiconductor films on semiconductor substrates by the ellipsometric method in the far infrared region: K K Svitashev et al, Mikroelektronika, 2 (5), 1973, 454–460 ( in Russian)

On the problem of measurement of thickness of epitaxial semiconductor films on semiconductor substrates by the ellipsometric method in the far infrared region: K K Svitashev et al, Mikroelektronika, 2 (5), 1973, 454–460 ( in Russian)

Thickness measurements of films on transparent substrates by photoelectric detection of interference fringes

Apparatus for epitaxial film thickness measurement by photoelectric detection of interference fringes is described. The apparatus features high speed, immunity to noise from ambient light and the ability to distinguish between films grown on opposite sides of a transparent substrate, and is implemented with a minimum of components.

On the growth of thick epitaxial platinum films with various orientations

The growth of epitaxial films of Pt with thicknesses up to 20 μm and selected orientations is reported. The substrates are thin films of Ag deposited on rocksalt.

Electron and impurity distributions in epitaxial n-type gallium arsenide

The electron, donor, and acceptor distributions along the thickness of epitaxial gallium arsenide films were studied as functions of the nature and orientation of the substrate. There is a discussion of mechanisms which may be responsible for these distributions.

A method to determine the thickness and magnetization of thin uniaxial magnetic films

A method is described whereby the thickness and magnetization of thin epitaxial magnetic films can be estimated from a measurement of the initial slope of the magnetic flux vs magnetic field curve and the zero-field domain period, respectively. The method is based on an analysis of the parallel-stripe-domain configuration as an approximation to the real domain configuration. Data is shown comparing the calculated thickness to that obtained by optically observing edge polished specimens, for a number of films.

Far-Infrared Interference Technique for Determining Epitaxial Silicon Thickness

Interference technique in the frequency range 30–200 cm−1 has been used for the first time to determine the thickness of low-conductivity epitaxial films deposited on a highly conducting silicon substrate. It is shown that for thick epitaxial films (d≥4 μm) the frequency at which half-order minimum occurs is highly sensitive to the epilayer-substrate interface carrier concentration profile. In general the far ir thickness is close to that obtained by angle-stain technique. A combination of ir and far-ir measurements therefore yields valuable information regarding the interface carrier concentration profile. The far-ir technique can replace the costly and destructive methods presently used, such as angle stain, and capacitance-voltage measurements made on specially fabricated diodes. The paper also discusses the optical constants of silicon in the far ir. The calculations show that it is necessary to use the energy-dependent anisotropic scattering time to correctly evaluate the optical constant in the far ir.

Some electrical properties of epitaxial germanium films deposited on semi-insulating gallium arsenide substrate

Conductivity and Hall constant were measured on thick epitaxial Ge films (0.7 to 5 micro m). The effects of film thickness, substrate temperature and deposition rate upon the electrical parameters mentioned and Hall mobility were investigated. The temperature dependence of these parameters was measured within the range 90°–500 °K and variation with heat treatment investigated.

Thick Epitaxial Films of Pb1−xSnxTe

During the past several years attempts have been made to grow thick epitaxial films of PbS, PbTe, PbSe, and their alloys with tin on alkali halide substrates. The thickest films which have been achieved using conventional evaporation techniques were limited to 10–15 μ m. We have developed a quasiequilibrium system which has yielded thick films of Pb1−xSnxTe ranging up to 328 μm. When combined with appropriate substrate preparations, this technique yields films having optical quality surfaces and good adherence to the substrate. In addition, the films may be easily removed from their substrates, intact and undistorted, by dissolving the substrates. Various electrical, optical, and thermal measurements on these thick films show that they are homogeneous. X-ray data indicate that the films are of high crystalline quality.

Thick Epitaxial Films of Cubic ZnSe and ZnS by Vapor Phase Transport

Films of cubic and have been grown epitaxially on [100] oriented substrates by vapor phase transport in flowing hydrogen. Thicknesses up to 200 µm over areas up to 5 cm2 have been obtained. The films are superior in crystalline quality to the films. The films exhibit low birefringent strain, good optical transmission, high resistivity, and near‐bulk electro‐optic constants. These properties make them suitable for use in information storage devices utilizing the longitudinal linear electro‐optic effect.

Determining the thickness of epitaxial films by an infra-red interference method: L Fejes, Magyar Fizikai Folyoirat, 17 (6), 1969, 477–494 ( in Hungarian)

Determining the thickness of epitaxial films by an infra-red interference method: L Fejes, Magyar Fizikai Folyoirat, 17 (6), 1969, 477–494 ( in Hungarian)

Thick Epitaxial Films of Cubic Zinc Sulfide Deposited by a Hot Wall Technique

A vacuum technique is described which permits the deposition of epitaxial films of ZnS in thicknesses up to 100 μ. Results of electron diffraction and observations of the surface morphology are described. The films can be used in devices which are based upon electro-optic effects.

282. Determination of epitaxial film thickness with the aid of an infrared interference method: L Fejes, Acta Tech Acad Sci Hung, 65 (1–2), 1969, 179–195

282. Determination of epitaxial film thickness with the aid of an infrared interference method: L Fejes, Acta Tech Acad Sci Hung, 65 (1–2), 1969, 179–195

MOBILE CYLINDRICAL DOMAINS IN EPITAXIAL Ga: YIG FILMS

The properties of mobile cylindrical ``bubble'' magnetic domains observed in gallium-substituted epitaxial yttrium iron garnet films are discussed. At epitaxial film thickness of 5 μm, cylindrical domain diameters of 8 μm are measured at a bias magnetic field of 19 Oe.

919. Measurement of the thickness of epitaxial films on silicon: V V Livshits and T P Komleva, Zav Lab, (6), 1965, 718, (in Russian)

919. Measurement of the thickness of epitaxial films on silicon: V V Livshits and T P Komleva, Zav Lab, (6), 1965, 718, (in Russian)

Measurements of the thickness of epitaxial films on silicon

Measurements of the thickness of epitaxial films on silicon