摘要:

A photoemission electron microscope has been used to generate spatial maps of silicon surfaces, along with chemical spectroscopy of the silicon core levels at micron‐scale spatial resolution. The electron optics permits scanned photon energy imaging of the sample surface, with image capture at video rates in a 512×512 pixel buffer memory. The image is generated primarily by low‐energy secondary electrons produced by photoabsorption. Near‐edge structure in the image photoyield as a function of photon energy is used to determine the oxidation state of microscopic regions of the surface of a single‐crystal Si(111) sample. These measurements show that spectroscopic imaging with 100‐nm resolution will be possible using undulator generated synchrotron radiation.

ISSN:0734-2101    

DOI:10.1116/1.575760

出版商:American Vacuum Society    

年代:1989

数据来源: AIP

摘要:

Ge(3d) and Si(2p) core level photoemission intensities were measured to monitor the coverage of Ge(001) and Ge(111) surfaces during the interrupted deposition of a thin Si film at room temperature and upon annealing. Annealing treatments were performed at temperatures up to a maximum of 880 K and interrupted a few times to allow for core level measurements. The Ge(3d) core level intensity was found to almost recover to its initial value upon annealing while the Si(2p) intensity decreased ∼60%. Intensity changes were observed at temperatures from 680 K upwards. It is concluded that above 680 K a significant diffusion of Si into Ge occurs, although at higher temperatures island formation or surface roughening also takes place.

ISSN:0734-2101    

DOI:10.1116/1.575733

出版商:American Vacuum Society    

年代:1989

数据来源: AIP

摘要:

The Auger electron spectroscopy (AES) peak heights, sputtering yields, and line shapes of well‐characterized TiSiyfilms were examined. Analysis of AES peak‐to‐peak heights showed that the total correction factor (KT) used for quantification varied linearly by a factor of 10 as the mole fraction of Si (XSi) changes from 0 to 1. TheKTvariation was attributed primarily to preferential sputtering although line‐shape variations also had some effect. The line shapes of the derivative SiLVVand TiLVVspectra were examined as a function ofXSi. The TiLVVline shape did not change significantly with composition. However, the characteristic features (peak height, peak width, skewdness, etc.) of the SiLVVline shape were shown to vary linearly with silicide composition. The average sputtering rates and yields of the titanium silicides were shown to vary by a factor of 2 asXSivaries from 0 to 1. The average sputtering yields of the silicides varied linearly with composition while the sputtering rates did not. The use of peak height, line‐shape, and sputtering yield calibration lines for quantitative concentration and depth determinations is discussed.

ISSN:0734-2101    

DOI:10.1116/1.575739

出版商:American Vacuum Society    

年代:1989

数据来源: AIP

摘要:

A commercial sputtered neutral mass spectrometer, using a rf‐generated plasma for both sputtering and postionization of sputtered particles, has been modified to improve sensitivity for trace analysis. The modified instrument has been used to depth profile zinc‐implanted gallium arsenide. A detection limit of 20 ppma was attained for zinc under conditions of maximum depth resolution from an analyzed sample area of 0.2 cm2with a useful yield of 5 to 7×10−10. The results have been compared with those of secondary ion mass spectrometry. Sputtered neutral mass spectrometry (SNMS) depth profiles revealed zinc redistribution in one heavily implanted sample, leading to the discovery of unusual structural damage through transmission electron microscopy. This investigation is discussed as an example of the usefulness of the SNMS technique in practical applications.

ISSN:0734-2101    

DOI:10.1116/1.575759

出版商:American Vacuum Society    

年代:1989

数据来源: AIP

摘要:

Aninsituspectroscopic erosion yield measurement is developed and used to monitor material surface erosion during bombardment by a plasma. The experiments are performed in a plasma that has the characteristics of a fusion tokamak boundary plasma but the technique is applicable to many processes where plasma erosion is important. Erosion yield of materials bombarded in a high flux (up to 1018ion/cm2 s) plasma environment has been previously studied using weight loss measurements. In the present study, the sputtered flux from a material is monitored by the line emission intensities of atoms eroded from the surface. The line intensities can be used to infer erosion yields after proper calibration. The method agrees well with results from weight loss measurements. Earlier work established that the material surface structure can substantially influence the erosion yield. When a change of surface morphology (e.g., cone formation) occurs, weight loss methods cannot be used to determine the erosion yield. However, theinsituerosion measurement is suitable and is used to investigate the relation between the onset of morphology changes and alternations in erosion yield during plasma bombardment. Experiments are reported for copper, as an example of a pure material, and stainless steel, as an example of an alloy system. The formation of surface cones is observed only when both the sample temperature is above a critical value and surface impurities exist. If the source of impurities is removed, or the sample temperature is lowered below the critical value, a surface rough with cones will be returned to a smooth state.

ISSN:0734-2101    

DOI:10.1116/1.575761

出版商:American Vacuum Society    

年代:1989

数据来源: AIP

摘要:

The deposition of copper into the through holes and vias of printed wiring boards (PWB’s) has been done using vacuum processing techniques such as evaporation and sputtering. One of the most important limiting factors for any deposition process is the substrate heating. The temperature of epoxy‐glass PWB’s should not exceed 180 °C (350 °F). For evaporation, there are two major contributions, the heat of condensation and radiant heating, with the heat of condensation dominating at deposition rates>2 μm/min. The radiant heating is very dependent on α ε, the product of the substrate absorptivity and the source emissivity. Sputter deposition has two main sources of substrate heating: the heat of condensation and the kinetic energy of the incident atoms and ions. The experimental apparatus used to measure the power absorbed by a PWB substrate is described. Data are presented for the power absorbed by the substrate as a function of deposition rate for sputtered copper. These data are compared with the results obtained by other investigators for evaporated aluminum and sputtered aluminum and copper. The various contributions to substrate heating are theoretically determined for both evaporation and sputtering systems. The absorbed power per unit area is calculated as a function of deposition rate and agrees very well with experimental results. It is discovered that the heating rate of a substrate is very similar for evaporation or sputtering of copper for deposition rates ≲3 μm/min. Sputtering heats the substrate more than evaporation at higher deposition rates, primarily because of heating by energetic atoms and ions.

ISSN:0734-2101    

DOI:10.1116/1.575762

出版商:American Vacuum Society    

年代:1989

数据来源: AIP

摘要:

Titanium nitride (TiN) films were deposited onto tool steels and cemented carbide cutting tools by plasma enhanced chemical vapor deposition (PECVD) using a gaseous mixture of TiCl4, N2, H2, and Ar in order to find out the effects of the deposition temperature and rf power density on the deposition rate and properties of deposited TiN. The deposition rate and crystallinity of the deposited TiN was affected by the deposition temperature as well as the plasma power density. The deposition rate was decreased with an increase in deposition temperature between 270 and 430 °C. The crystallinity of deposited TiN was improved by an increase in deposition temperature as well as rf power density. Crystalline TiN was obtained above 300 °C and showed a strong crystallographic preferred orientation of 〈200〉. TiN layers deposited by PECVD using TiCl4as a reactant contained chlorine, the content of which was increased with a decrease in deposition temperature. Oxygen at the interface between the TiN deposited layer and the substrate excluded nitrogen and chlorine. The surface morphology of the deposited TiN is a dome‐shaped cluster composed of many fine grains.

ISSN:0734-2101    

DOI:10.1116/1.575763

出版商:American Vacuum Society    

年代:1989

数据来源: AIP

摘要:

Diamond thin films were formed by deflecting the flow of CH+4using a magnetic field. The possibility of involvement of neutral particles and their effects on film formation were examined. The results show (i) the estimated amount of the neutral particle involved during the ionized deposition was nearly 30%, (ii) the surface morphology of the film prepared by the deposition of the deflecting ion was very smooth when it was examined by scanning electron microscopy, and (iii) transmission electron diffraction and transmission electron microscopy indicated relatively large grain polycrystalline diamond films.

ISSN:0734-2101    

DOI:10.1116/1.575764

出版商:American Vacuum Society    

年代:1989

数据来源: AIP

摘要:

This investigation centers around the impregnation of plasma grown alumina films using the incipient wetness technique for introduction of ruthenium chloride to the surface. The modeling of bulk alumina catalysts by use of planar alumina films necessitates investigation of the impregnation of these films. It has been found that very different products are formed by slight changes in the process used for impregnation. The impregnation was found to yield a product ranging from a highly dispersed ruthenium species to the dispersion of relatively large metal islands on the surface of the alumina. Characterization by x‐ray photoelectron spectroscopy, scanning electron microscopy, and energy dispersive spectroscopy indicates that the products containing highly dispersed metal are suitable for further investigation in the modeling of bulk ruthenium catalysts.

ISSN:0734-2101    

DOI:10.1116/1.575729

出版商:American Vacuum Society    

年代:1989

数据来源: AIP

摘要:

Here we present some results of transmission electron microscopy and secondary ion mass spectroscopy of thermally oxidized gallium arsenide with different types of dopants. At temperatures below 400 °C an amorphous oxide is formed. Oxidation at temperatures between 500 and 600 °C initially produces an epitaxial film of γ‐Ga2O3. As the reaction proceeds, this film becomes polycrystalline and then transforms to β‐Ga2O3. This film contains small crystallites of As2O5and As2O3in the case of the chromium doped samples, whereas only the former was detected in the case of silicon and tellurium doped samples. Elemental arsenic was always found at the interface between the oxide and GaAs. Chromium doped gallium also exhibited a slower oxidation kinetics than the other materials.

ISSN:0734-2101    

DOI:10.1116/1.575730

出版商:American Vacuum Society    

年代:1989

数据来源: AIP