Using in situ reflection high energy electron diffraction and x-ray diffraction, the structure and composition of nickel and titanium multilayer films have been studied. The films were evaporated under UHV conditions at rates of.01 to.1 nm/sec. When deposited on an amorphous NiTi film at 70°C, the individual layers of nickel or titanium are polycrystalline and textured with the close-packed planes perpendicular to the growth direction. The interface between the layers is amorphous and about 2 nm thick. X-ray scattering from the crystalline layers indirectly shows the composition of the amorphous interface to be Ni rich.

We have performed a coordinated experimental and theoretical investigation of the structure and stability of Ti/C multilayers. The samples were prepared by conventional techniques and the lattice structure was characterized by X-ray diffraction. Electron Energy Loss and Auger spectroscopies (EELS,AS), in conjunction with Rutherford Backscattering (RBS) were employed to characterize the chemical composition of the samples. It was observed that the Ti/C interface is isolated by a thin titanium oxide layer. The center of the Ti layer gives a typical EELS spectrum of Ti metal. The carbon shows a graphitic character. We have used total energy calculations to study the crystallographic structure and electronic behavior at the interface in Ti-C superlattices. This involved examining a series of structures in the Ti-C system proceeding from the ground state NaCl structure to superlattices. In particular we performed total energy calculations for an arrangement of atoms designed to allow direct investigation of the competition between Ti-C bonds and C-C bonds. We conclude that the equilibrium structure is dominated by C-C bonding and so we find that the interface has a graphite like atomic arrangement rather than a carbide like arrangement. We than further explored the interactions in this graphitic arrangement and found that the interface does not have a significant Ti-C bonding and that the interface most likely consists of simply a layer of graphite adjoining a titanium surface. This carries important implications for the diffusion and bonding at the interface.

Electrical measurements, including DLTS, I-V, C-V, and C and G versus temperature were carried out on aluminum Schottky diodes fabricated on Ion-etched GaAs surfaces. Fluence variations show little effect at 3keV ion energy, while a definite threshold can be seen at 0.5keV. A chemical etch before Schottky deposition Indicates diode parameter and EL2 deep level recovery after 1000Å removal at 3keV, and after only 100Å removal at 0.5keV. Computer analysis shows that these results are consistent with a previously reported model consisting of lumped R-C components attributable to a damaged and partly amorphous top layer, and to diffused bulk damage.

The microstructural characteristics of sputtered Co-Cr films, such as grain size observed by SEM and the crystallite size estimated by x-ray diffractometry, vary throughout the thickness of the film. The grain and crystallites size become larger, as the film grows. In this study, multilayered Co-Cr thin films with intermediate layers of amorphous carbon have been prepared by Facing Targets Sputtering (FTS) in order to produce films with uniform structure throughout the entire thickness of the film. Amorphous carbon sputtered films have been used as intermediate layers since they are fully continuous, even though they are very thin so that they may not affect the crystallographic structure of Co-Cr thin film successively deposited. The carbon thin layer deposited at Ar gas pressure lower than 2 mTorr did not cause the degradation in c-axis orientation of the Co-Cr crystallites in the Co-Cr thin films. Then, the films composed of ten Co-Cr layers with thickness of 200Å were deposited, varying the thickness of carbon intermediate layers δup to 200 X. The grain size in these multilayered film show same vaiue as that of 200 Å-thick single layer film without intermediate carbon layers. These results indicate that the multilayered films prepared by this technique are composed of fine grains of comparable size.