Thin films of W-N alloys have been prepared by reactive rf sputtering from a W target. Alloy compositions up to about 65at.%N, amorphous phases are formed with crystallization temperatures up to above 600°C. All the films gradually release N upon vacuum annealing and decompose into αW between 700 and 800°C in vacuo. Application of W-N alloys as diffusion barriers in a Si metallization scheme is discussed.

A relatively simple technique of surface x-ray diffraction (S-XRD) has been developed for the detection and identification of thin crystalline materials. The technique provides an abundance of diffraction lines with enhanced ability to detect and identify thin phases and to follow the sequence of phase formation within multiple-phase metal silicide structures.

The crystallinity for silicon and germanium films deposited by ion beam sputtering (IBS) as a function of substrate temperatures was determined using Raman spectroscopy, spectroscopic ellipsometry, electrical conductivity and x-ray diffraction measurements. The results show that IBS silicon crystallizes between 300–350°C while germanium crystallizes between 20–200°C. Reasonably good agreement is obtained among the four distinctively different characterization techniques in identifying the onset of crystallinity. A direct relationship is observed between the substrate temperature required for crystallization and the log of the operating pressure for various deposition techniques. Energetic particle stimulation during film growth appears to reduce the crystallization temperature at a given operating pressure. Raman data show that the crystallization temperature depends on the deposition rate. A graded structure is observed in films deposited above 300°C, probably due to oxygen contamination.

Thin films of hard, diamond-like, carbon have been deposited on glass, silicon and sapphire substrates using three different ion beam deposition techniques: (a) ion beam sputter-deposition from a graphite target, (b) sputter-deposition with simultaneous bombardment of the growing film using a second ion beam, (c) primary ion deposition using a beam extracted from an Ar-hydrocarbon plasma. Structural, mechanical optical and electrical properties were measured. It was found that the hydrogen content controlled the internal (compressive) stress and that relatively stress-free films contained ,∼ 30 atomic % H (average). The H content could be correlated with the H/C arrival ratio from the gas phase. Optical absorption and luminescence measurements gave a band gap of '∼, 1 ev with band-tailing. Resistivity measurements and their temperature dependence fitted variable range hopping models. Hardnesses were ≿ 7 Mohs. The properties of the films were consistent with a mixture of sp3 and sp2 bonds in an amorphous, hydrogenated structure.

We have used a 30 kHz ac glow discharge formed from methane gas to grow carbon films on InP substrates. Both the growth rate, and the relative Ar ion sputtering rate at 3 keV varied monotonically with deposition power. The Ar ion etchigg rate of the films decreased with deposition power. Results from the 15N nuclear reaction profile experiments indicated a slight drop in the hyorogen concentration as more energy was dissipated in the ac discharge. Values for the inoex of refraction and extinction coefficient ranged from 1.721 to 1.910 and 0 to -0.188, respectively. Optical bandgaps as high as 2.34 eV were determined.

ESCA valence band and core level loss results have been determined that appear to be directly related to the degree of covalency/ionicity and other bonding features of certain semi-conductor systems. Specific applications are presented that aid in the characterization of the key chemistry of dielectric oxide/semiconductor interfaces and also may help to determine the relative metastability of the solid solution of Group IV elements (e.g., Ge) into certain III-V lattices (e.g., GaAs). It is shown that these features are not detectable through conventional core level shift arguments, and that the aforementioned novel approaches often require high resolution ESCA.

The effects of 1 to 5 keV Ar+ sputtering of (100) GaAs doped with >3 × 1018 cm−3 or <2 × 1017 cm−3 Si and contacted with 1000 Å of Au have been studied. Sputtering caused the contacts on highly doped GaAs to change from ohmic to rectifying, while it caused the Schottky barrier height on moderately doped GaAs to decrease. For both doping densities, barrier heights of ∼0.6 eV were measured. Inverse Laplace transform analysis of angle-resolved X-ray photoelectron spectroscopy data showed that As was preferentially sputtered, probably by a damage-assisted Gibbsian surface segregation mechanism. Modifications of the electrical contacts were explained by sputter-induced self-compensation by Si rearrangement and by damage-created shallow donors with a density of >2 × 1017 cm−3.

This paper addresses the current status of thin film HgCdTe and limitations in the currently achievable thin film properties. The emphasis is placed on Hg1−xCdxTe since this material is presently most seriously considered for infrared devices and particularly resistant to high quality film preparation due to large elemental vapor pressure differences. The current status of thin film HgCdTe is reviewed and the various thin film deposition techniques utilized to prepare HgCdTe thin films are compared. Finally, results are reviewed which still support the claim.that the less investigated technique of bias-sputtering, modified to accommodate deposition in a high partial pressure background of Hg vapor, can yield structurally high quality Hg1−xCdxTe films with device-worthy properties. Significant is the fact that the deposition process still provides the simple and systematic control over all relevant film properties without post-deposition treatment. Such control is required to achieve the desired material for device application. As is also reviewed here, this work was one of the first to demonstrate the ability to use low cost foreign substrates for HgCdTe thin film device fabrication.

Thin alternating layers of InAs and GaAs have been grown by MBE on buffer layers lattice matched to InP. The layer structure was evaluated by transmission electron microscopy (TEM) and low angle X-ray scattering. Commensurate epitaxial layers approximately 15Å thick were obtained in spite of the large lattice mismatch (7%). These results and their implication for growth conditions of strained-layer superlattices will be discussed.

It is shown that the properties of sprayed (Cd, Zn)S layers obtained by means of a pneumatic nozzle depend dramatically on the type of flow gas used (air or nitrogen). The role of chemisorbed oxygen is demonstrated. Independently of the various heat treatments applied the resulting CuxS obtained has always a coefficient x closer to 2 when the flow gas is nitrogen. A subsequent annealing of the (Cd, Zn)S layers is found to increase the CuxS growth speed.

It is also shown that the quality of (Cd, Zn)S layers determines to a great extent that of the cuprous sulfide in (Cd, Zn)S-CuxS heterojunctions. The data are interpreted in terms of the modification of the layers structure, composition and charge carrier concentration.

Stoichiometric amorphous GaAs films with intrinsic properties have beer produced by R.F. Sputtering in pure argon at high substrate temperature of 290°C. The electronic and the optical properties of this material have been modified by the molybdenium co-sputtering. This paper reports: on several modified material parameters including the electrical conductivity, thermal activation energy and optical gap. Atomic Mo concentrations up to 1.24% have been investigated. It is observed that the room temperature conductivity can be controlled over about six orders of magnitude, which corresponds to a shift in the Fermi level of 0.45 eV towards the conduction band edge. For optical parameters, the optical gap has been reduced by 0.1 eV. An additional absorption tail due to localized states introduced by doping atoms is observed. It is concluded that our a-GaAs have the main requirement, i. e low density of defect gap states, for effective doping with analogy to a-Si prepared either by glow discharge or by sputtering in argon-hydrogen plasma.