The growth of submonolayer Pb-films on Cu (100) and (111) was investigated by a 3-dimensional Monte Carlo simulation based on the Metropolis technique. The system Cu/Pb was studied because of its known immiscibility. Two different types of potentials have been chosen to simulate the interaction of deposited film atoms mutually and with the substrate surface: (a) Morse- and (b) Embedded Atom (EAM)-potential. Especially by varying the unknown Morse-potential parameters of the Cu-Pb interaction we observed all stages from layer-by-layer growth to surface alloying. At the Cu (111) surface both potentials led to a preferred adsorption site by decorating a Cu step with Pb atoms. Also a seam of embedded Pb atoms parallel to the step edge on the upper side of a monoatomic Cu step was observed. The early stages of a Pb film growing on Cu (100) are characterized by forming different types of superstructures. Surface total energy calculations were performed and compared with STM results. Most of the results are in accordance with experimental results and observations by scanning tunnel microscopy.

We present measurements of specular and nonspecular x-ray scattering from interfacial roughness in ND/Al2O3 multilayers grown by rf-sputtering on a sapphire substrate at different Ar pressures. The rms-roughness of the interfaces is found to increase drastically if the Ar pessure is raised above a critical value corresponding to the thermalization of the impinging atoms. At the same time the height-height correlation function of the interfaces changes from a non-self-affine to a self-affine form. This result can be deduced from the structure factor of the diffuse scattering measured over a wide range in parallel momentum transfer.

The structure obtained on annealing sub-monolayer of Au deposited on clean Si(100) surfaces at room temperature was studied using mainly ultrahigh vacuum transmission electron imaging (UHV-HREM). Spots suggesting a 5×1 type reconstruction and faint 1/2 order streaks were seen in the diffraction patterns. The reconstructed wave shows pairs of Au-rows which correspond to the “trenches” reported in an earlier STM study. Lateral disorder across the rows was seen to be responsible for the streaks in the patterns.

The atomic structure of thin epitaxial erbium suicides on Si(111) substrates has been studied in situ by means of surface X-ray diffraction and medium-energy ion scattering. In the sub-monolayer range, a two-dimensional (2D) suicide is formed within a 1 × 1 unit cell, with the Er atoms occupying T4 sites and a Si bilayer on top which is 180° rotated with respect to the bulk (5-type). Suicide layers with a thickness of 3 monolayers exhibit a regular network of Si vacancies which release the compressive strain of the graphite-like Si layers between adjacent Er layers. This results in a √3 × √3 R 30° unit cell, in which 3 out of 5 Si atoms are displaced towards the vacancy, and in which 3 Er atoms relax away from the vacancy.

A variable temperature scanning tunnelling microscope (STM) in UHV has been used to investigate the growth, morphology and surface atomic structure of ultrathin titanium suicide films on Si(100) and Si(111) substrates. Three stages of suicide growth have been identified based on microstructural considerations. They occur over similar temperature ranges for both substrates and may be summarised as: agglomeration and the formation of disordered islands, crystallite formation, and crystallite growth. Additionally, island burial is found for Si(100) substrates (950°C), and preferential crystallite growth is observed for high temperature processing (1200°C) of titanium silicide on Si(111).

Methods for STM crystallography have been developed and used to identify possible epitaxial silicide/silicon relationships based on morphological considerations. Atomic resolution images of titanium silicide crystallites have identified a 2×2 silicon termination of a C54-TiSi2(111) surface, a 2×2 silicon terminated C54-TiSi2(010) surface, and a reconstructed C54-TiSi2(311) surface. It has been concluded that unambiguous identification of epitaxial relationships requires images of the atomic structure of the silicide crystallite surfaces in addition to morphological information.

The structure of Ga overlayers on stepped Si(112) surfaces is investigated using the technique of Auger electron diffraction (AED). Although previous studies suggest that the Ga adatoms form well-ordered chains along the stepped Si(112) surface, no studies to date have determined the exact Ga adsorption sites on the Si(112) surface. However, low energy AED measurements on adsorbate structures are very sensitive to the adsorption site position and geometry due to strong backscattering from substrate atoms. In this work, low energy Ga AED data is analyzed using single scattering cluster (SSC) calculations. The analysis is able to differentiate between step edge and terrace adsorption site models for the Ga/Si(112) structure, as well as determine the detailed adsórbate geometry on the surface. The Ga overlayer model deduced from the data places the Ga adatoms 1.0 Å below the substitutions step edge sites of the non-primitive Si(112) surface.

The morphology of Si1-χGeχ films is studied using atomic force microscopy (AFM) and scanning tunneling microscopy (STM). Depending on growth temperature and Ge content, growth proceeds in either a layer-by-layer mode or by me growth of 3-dimensional coherent islands. In the former case strain relaxation occurs by formation and multiplication of misfit dislo-cations, leading to a cross-hatched surface morphology. In the latter case the rough morphology leads to a higher density of nucleation sites, and reduced glide efficiency, for the dislocations. A Fourier transform based method for analyzing the morphology is introduced, and is compared with other, existing roughness analysis methods.

We review the principles of magnetic force microscopy and describe recent advances in imaging methods and probes. Some current applications of MFM in experimental micromag-netism and materials development are also discussed, as well as challenges in image interpretation and in using MFM for quantitative work.

Titanium nitride (TiN) films serve an important function as an adhesion layer and diffusion barrier in contact and via plug structures of ULSI devices. In this work, TiN films were deposited by chemical vapor deposition (CVD) at atmospheric pressure using the tetrakis (dimethylamido) titanium (TDMAT) and tetrakis (diethylamido) titanium (TDEAT) organic precursors over a range of temperatures and ammonia partial pressures. The step coverage and morphology of these films was evaluated at these various conditions by SEM of cross-sectioned contacts. In addition, material properties such as resistivity. surface roughness, and stoichiometry were assessed at some of the operating conditions.

When silicon killed steels are galvanized in a pure zinc bath at 450°C, the first Fe-Zn compound to precipitate is ξ-compound. If the silicon content is higher than 0.07 wt%, the reactivity of steel in the liquid leads to thick coating and is clearly due to a silicon super-saturated liquid layer near the substrate. In this case, anarchical growth of ξ-crystals is observed.

In order to validate the model proposed for this mechanism, zinc vapor deposition on different substrates has been used. In this case it was shown that the first intermetallic compound which precipitates is no more ξ-compound but the iron richest one: Γ. This result shows that the reactivity of the different steels facing the zinc vapor is the same. In fact, silicon present in the substrate can be totally dissolved in the Γ-phase according to the Fe-Zn-Si phase diagram at 450°C and Si does not play any more its role in preventing the formation of the ξ-compound.

Thin platinum films were deposited at several different deposition rates and with varying thickness on (OOl)-cut MgO single crystal substrates by electron beam evaporation. A mixture of two epitaxial Pt orientations were detected in the films by X-ray diffraction and planar ion channeling experiments: (001) [100] Pt // (001) [100] MgO (the “cube-on-cube” orientation) and (111) [110] Pt // (001) [110] MgO. The effect of deposition rate on film orientation indicated the (111) Pt orientation was preferred under conditions of high driving force for nucleation. The volume fraction of the films occupied by the (111) orientation increased with nominal film thickness, at a constant substrate temperature and deposition rate. This result indicates crystallites having the (111) Pt orientation grew more quickly following nucleation than the (001). The mosaic spread of the Pt orientations decreased markedly as the nominal film thickness increased from ∼ 1.5 nm (isolated islands) to 20 nm (continuous film).

The crystallite size of the chemical vapor deposited Cu film is usually so large that the Cu film does not fill contact holes or via holes in ultra large scaled integrated circuits well. Therefore it is very important to make the grain size of the Cu film small enough to fill small contact holes with high aspect ratio. Pretreatment of the substrate surface with Ar plasma has been found to be effective in making the grain size of the Cu film smaller and in enhancing the deposition rate of the Cu film. The Cu film deposited on the borophosphosilicate glass (BPSG) has the characteristics of smaller grain size, lower resistivity, and higher degree of (111) preferred orientation, but slightly lower deposition rate than that on the SiO2 glass. The higher resistivity of the Cu film on SiO2 may be due to the formation of the intermetallic compound CU15Si4 at about 400°C which is not formed at the Cu-BPSG interface at the same temperature. Also the dependence of some properties of the Cu film on the substrate material is discussed.

Easy axis orientation of rf magnetron sputtered barium hexaferrite films plays an important role in their usefulness as recording media. Processing variables included substrate temperature, pressure, composition, and duration of sputtering, as well as secondary heat-treatment schedule. As-deposited films were primarily amorphous; after secondary heat-treatment, barium hexaferrite devitrified with a crystal size of ∼200 nm. The c-axis of crystalline grains formed parallel to the heat-treated film surface when the substrate was at 620°C during deposition. A perpendicular c-axis orientation was measured using an argon atmosphere at 1.33 Pa and a substrate temperature of 720°C. This film showed the highest remnance (4.781 × 10-3 emu). The coercivity of such films ranged from 0.8 -2KOe.

The surface characteristics of ZnS and Zn2SiO4powders were evaluated by scanning force microscopy (SFM) to optimize the coating process. The different characteristics of uncoated and coated powder are presented.

The physical properties of a thin metal film are highly dependent on the process by which the film is formed. Using the Multiple Expansion Cluster Source (MECS), it is possible to form an inert gas aerosol containing neutral metal clusters with uniform diameters in the nanometer size range. Cluster-based (CBD) films can be deposited directly from this aerosol or can be formed from colloidal clusters captured from the aerosol. We present TEM data comparing the initial microstructure of gold films formed by these two CBD processes and also by vacuum-evaporation (PVD). Electrical resistivity versus nominal thickness are also presented for the aerosol deposited CBD and the PVD cases.

The evolution of microstructure during Au-mediated solid phase epitaxial growth of a SiGe alloy film on Si(001) (c-Si) was investigated by in situ resistance measurements, X-ray diffraction, conventional and high-resolution transmission electron microscopy, and chemical microanalyis. Annealing a-Ge/Au bilayers on c-Si to temperatures below 120°C caused changes primarily in the microstructure of the Au film. Increases in temperature to ≃150°C resulted in the diffusion of Ge through the grain boundaries of Au. The Au, displaced by crystalline Ge at the grain boundaries, diffused along columnar voids of amorphous Ge (a-Ge) leading to the formation of Au-rich crystallites in the top layer. Results indicate that the Ge that had reached the Au/c-Si interface grew epitaxially on c-Si at temperatures below 150°C. As the temperature was further increased, some Si from the substrate dissolved into Au and got incorporated in the growing epilayer. At 310°C, the initial Au film was displaced completely by a laterally continuous Siξ Gei.ξ (ξ ∼ 0.2) epilayer whose thickness was limited by that of the initial Au film. Twins, and residual amounts of Au near the SiGe/c-Si interface, were the predominant defects observed in the SiGe epilayer.

Root mean square measurements of the Si(001)/SiO2 interface have been performed with a variety of techniques. Using X-ray diffraction to represent the diffraction class of techniques, and atomic force microscopy to represent imaging techniques, we discuss the effect that limitations of each technique have on experimental results.

The surface roughness of deposited SiO2 has become increasingly important as integrated circuit (IC's) device dimensions approach the low sub-micron regime. The impact of roughness is consistent with that of gross paniculate contamination such that both contribute to device failure and low yield. SiO2 deposited from nitrous oxide (N2O) and silane (SiH4) addresses other stringent process requirement such as conformity and step coverage but, certain process conditions result in rough surface textures. For this study SiO2 was deposited at a pressure of 400 mTorr and at a temperature of 800°C in a vertical diffusion furnace (VDF) from SiH4 and N2O. Atomic force microscopy (AFM) was used to investigate the film's surfaces for roughness. We have found that the surface roughness is a strong function of deposition pressure, total gas flow, and N2O/SiH4 flow ratio. In this paper, film roughness is presented as measured by the AFM and laser-based particle detector. The possible impact of roughness on device failure and hence low yield is also investigated.

Techniques developed over recent years have progressively refined the interlamellar spacing to produce harder, more wear resistant pearlitic steels. This study aims to explain the mechanisms for the wear performance by observing how the microstructure adapts to the wear loading. Four pearlitic steels, with similar chemical composition but with different interlamenar spacings, have been examined. Wear test have been conducted under both pure sliding and rolling-sliding conditions. The worn surfaces and the plastically deformed subsurface regions have been examined by optical metallography and scanning electron microscopy. It was observed that the plastic deformation produced considerable fracturing and realignment of the hard cementite lamellae. The softer ferrite matrix was severely deformed, allowing a reduction in the interlamellar spacing on approaching the worn surface. The effect of these realignments on the surface was to present an increased area fraction of hard cementite lamellae on planes parallel to the surface.

The surface roughness, ρ, of alloyed AuGeNi metallizations to n-type InP have been measured and compared to the specific contact resistance, rc. It was found that p was large for annealing temperatures above 370°C. Below 370°C the surface was smooth. The maximum value of p (120 nm) coincided with the minimum value of rc (7×10-8 Ωcm2) at 420°C annealing. In addition, outgrowths (∼2–4 μm in height), devastating for any further device processing, were observed for annealing temperatures between above 410°C. Using AES it was found that the outgrowths contained a large amount of Au, In and P with the original, as-deposited AuGeNi metallization lying on top. A two step annealing process was developed in order to overcome the outgrowth problem. In the first step the AuGeNi metallization was annealed for long times at a low temperature 370°C, which is the onset of low rc and large p. In the second step a short annealing at 500°C was employed to congruently melt the Au-In binary phase formed at 370°C. It was found that p remained in the order of 120 nm, but no outgrowths were observed and rc was further reduced to 5×10-8 Ωcm2.