摘要:

The development of altered surface layers due to preferential sputtering can be modeled by an algorithm based on the diffusion theory of atomic mixing using a depth‐dependent diffusion coefficient. Application of the model to typical SIMS depth profiles of buried layers indicates that the effects of atomic mixing and preferential sputtering can be separated by analysis of the shift and broadening of the measured peaks.

ISSN:0734-2101    

DOI:10.1116/1.572380

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

The influence of an O2atmosphere on oxygen‐isotope analysis by means of secondary ion mass spectrometry (SIMS) was studied in detail using various standard metal oxides enriched with a stable isotope18O. The secondary ion intensities of16O−and18O−were examined under different16O‐oxygen pressures and primary Ar+beam currents. The deviation in the isotope ratio became prominent at an oxygen pressure over about 1×10−4Pa, and in the sequence of CuO

ISSN:0734-2101    

DOI:10.1116/1.572381

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

By ratioing multiple Auger intensities and plotting a two‐dimensional occupational scatter diagram while digitally scanning across an area, the number and elemental association of surface phases can be determined. This can prove a useful tool in scanning Auger microscopic analysis of complex materials. The technique is illustrated by results from an anomalous region on the reaction zone of a SiC/Ti–6A1–4V metal matrix composite material. The anomalous region is shown to be a single phase associated with sulphur and phosphorus impurities. Imaging of a selected phase from the ratioed scatter diagram is possible and may be a useful technique for presenting multiple scanning Auger images.

ISSN:0734-2101    

DOI:10.1116/1.572382

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

The process of segregation of titanium oxides onto the surface of Pt3Ti upon the exposure to oxygen at different pressures and temperatures was studied by LEED and AES. Oriented [111] and [100]monocrystals as well as polycrystals were synthesized for study. Qualitatively similar behavior was observed with all three types of surfaces, with three stages of oxidation observed on each surface. A layer of stoichiometry close to TiO segregated onto the surface in the initial stage of oxidation, depleting the subsurface region of the alloy in Ti. The TiO formed a compact, epitaxial monolayer which completely blocked the metallic surface for chemisorption by carbon monoxide. Further oxidation caused formation of a multilayer of TiO1.2, an oxide with an orthorhombic structure derived from TiO by removing Ti atoms to form an ordered vacancy lattice. Finally, oxidation at the relatively extreme conditions of atmosphere pressure at high (>1000 K) temperature caused formation of thick TiO2(rutile) overlayers.

ISSN:0734-2101    

DOI:10.1116/1.572384

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

The oxidation kinetics and morphology of very thin (<10 nm) mixed Cu/CuO films obtained by exposing very thin discontinuous Cu films to atomic oxygen plasma were investigated by electron diffraction and dark field electron microscopy. The oxidation process is characterized by an initial stage of oxide logarithmic growth which goes on until about 50% of the initial Cu is oxidized. The morphology of the films during the oxidation evolves from a situation characterized by discontinuous metallic islands covered with an oxide layer to another one in which metallic grains are embedded in a continuous oxide film.

ISSN:0734-2101    

DOI:10.1116/1.572385

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

When silicon is crushed in ultrahigh vacuum (UHV) the well known electron paramagnetic resonances signal calledA, atg=2.0055, and width 5–7 G is produced. Upon annealing to above the 700 °C regions,Ais gradually replaced byA1, a new signal atg=2.0020 with width about 10 G and height about 1% ofA. Heating above 900 °C destroysA1and all subsequent gas effects. Exposure of silicon withA1to oxygen or parabenzoquinone (PBQ), causesA1to increase and the appearance of a new sharp signalCatg=2.0024 and width about 2 G. However in the case of oxygen only, another new signal calledE, atg=2.0000, and width about 1 G, appears on pumpingoutthe oxygen. This is reversible. The behavior under variations of gas exposure and of microwave power indicated that the signals are all associated with cracks and fissures, and thatCis probably due to ‘‘free’’ electrons along lines of O2or PBQ at fissure ends. The similarity ofAwith the EPR signal from amorphous hydrogenated silicon is now ascribed toAresulting from classical dangling bonds at the ends of fissures where the strain prevents surface reconstructions on the crack surfaces.

ISSN:0734-2101    

DOI:10.1116/1.572386

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

Measurement of the nonequilibrium surface concentration in a Fe–10 at. % Si (110) sample as an function of temperature reveals specific interrelated segregation behavior. A review of the initial processes in this single crystal shows the existence of certain interactions. In agreement with work on the other ternary systems, evidence has been found that carbon and silicon show a repulsive interaction in the segregation process. At lower temperatures the surface free energy favors the carbon and above a transition temperature, the silicon on the surface. On the other hand, silicon and phosphorus cosegregate, which is indicative of an attractive interaction. This has the effect that much less phosphorus is available for segregation to the surface or grain boundaries than in a pure Fe–P system. The LEED pattern for the silicon covered surface is the same as for a 1% Si sample viz. ac(7×1) superstructure with reference to thec(a×(2a)1/2) surface net, whereais the unit cell parameter in the [001] direction. Elongation of the spot in one direction indicates a change of order in the [001]direction in agreement with the silicon island formation. The pattern of the phosphorus covered surface shows a maximum surface coverage by phosphorus in good agreement with the observed value as determined by AES.

ISSN:0734-2101    

DOI:10.1116/1.572387

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

This paper describes negative resistance switching inn‐type silicon film resistors which contain linear arrays of grain boundaries. These linear arrays have been predictably located in the active region by a laser recrystallization procedure. The grain boundaries are made to bisect the resistors. Effects of parameters such as grain boundary number and grain‐dopant concentration have been examined. We show that quasisaturated and asymmetricalI–Vcharacteristics are exhibited by our resistors. This is evidence that the voltages across the depletion region and across the grain boundary layer are not equally divided on each side of the junction, and that dopants are nonuniformly incorporated in the grains during laser recrystallization.

ISSN:0734-2101    

DOI:10.1116/1.572388

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

Temperature dependence, in the range 150–450 K, of the resistivity and Hall mobility were studied on polycrystalline sputtered CdS thin films. The room‐temperature values of analyzed samples for resistivities and Hall mobilities ranged between 1–108Ω cm and 2–8 cm2/V s. The results showed a major scattering mechanism controlled by the intergrain barrier height, the carriers being thermally activated. A temperature dependence of the barrier height φB=φ0(1+αT) has been observed which allows fitting a general expression for Hall mobility of the form μH=11.6 exp(26.8 φ0) exp(−φ0/kT). A theoretical calculation of the μ0parameter has been performed. The results show good agreement with the experimental data.

ISSN:0734-2101    

DOI:10.1116/1.572389

出版商:American Vacuum Society    

年代:1984

数据来源: AIP

摘要:

The phenomenon of explosive recrystallization has been studied in Si+and Cu+implanted amorphous silicon layers by electron microscopy and Rutherford backscattering techniques (RBS). Cross‐section and plan‐view electron microscopy techniques (TEM) have been used to obtain a detailed characterization of microstructures associated with the explosive mode of recrystallization. RBS and analytical TEM studies on segregation of copper provided information on the mechanism of explosive recrystallization involving a thin liquid film interposed between crystallized and uncrystallized regions.

ISSN:0734-2101    

DOI:10.1116/1.572390

出版商:American Vacuum Society    

年代:1984

数据来源: AIP