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Electron-beam-stimulated deposition and etching has been investigated as a clean, alternative method for nanoscale selective processing. Depositions using W(CO)6 and hydrocarbon sources have yielded efficient and selective electron-beam deposits. Primarily fluorine-based precursors have been used to etch a variety of materials. Initial results regarding the selective etching of silicon and silicon dioxide suggest that inelastic scattering of the primary electron beam with the gas occurs and is more severe at lower beam energies. The etch rate increases linearly with decreasing electron-beam energy, however, it is not clear if this is due to enhanced primary- or secondary-electron-stimulated processes. Feature sizes as small as 55 nm have been selectively processed.

Single-wall carbon nanotubes (SWNT) were grown to micron lengths by laser-annealing nanoparticulate soot containing short (∼50 nm long) nanotube “seeds.” The “seeded” nanoparticulate soot was produced by restricting the time spent by an ablation plume inside an 800 °C oven following laser vaporization of a C–Ni–Co target. The soot collected from the laser vaporization apparatus was placed inside graphite crucibles under argon, and heated by a CO2 laser. In situ pyrometry was used to estimate the sample temperature. Length distributions of SWNT bundles in the unannealed and annealed samples were measured by transmission electron microscopy and field emission scanning electron microscopy. Annealing treatments exceeding 1600 °C produced no increase in nanotube length, while lower temperatures in the 1000–1300 °C range were optimal for growth. These experiments indicate that SWNT grow by the conversion of condensed phase nanomaterial during annealing, a similar mechanism to that proposed for growth during normal laser–vaporization production.

The monoatomic hydride layer on silicon was used as a prototype for resistless electron beam lithography. Arbitrary patterns with linewidths below 60 nm have been achieved. The variation of the linewidth with electron energy, electron dose, and substrate thickness was studied to determine the mechanisms that govern surface hydrogen desorption and subsequent pattern formation. Unlike in resist based lithography, no resolution enhancement was observed with decreasing substrate thickness. The experimental data in combination with Monte Carlo simulations of the backscattered and transmitted electrons suggest that surface hydrogen desorption and pattern formation are not strongly related to the backscattered electrons and the secondary electrons (energies

Electron holography performed in a transmission electron microscope, has been used to measure the width of 90° domain walls in tetragonal BaTiO3, and to determine the magnitude and distribution of the polarization across these walls. The walls are found to be between 15 and 25 A in width. The polarization and its measured variation are in good agreement with other estimates. Fringe splitting has been observed in some holograms and it is suggested that this is due to the presence of charged oxygen vacancies on the walls.

Microstructural studies of Si‐Si interfaces grown by molecular beam epitaxy reveal pockets of oxygen‐rich material for certain substrate preparation conditions. For Czochralski substrates which are cleaned using an argon ion sputtering technique, a high density (about 1011/cm2) of oxygen‐rich pockets about 30 A in size is observed using cross‐sectional transmission electron microscopy and x‐ray microanalysis for short (less than about 15 s) sputtering times. For longer sputtering times, no significant defect density is observed. Post‐deposition thermal annealing causes a dramatic increase in the density of oxygen‐rich defects, and it is suggested that this is due to trapping of oxygen which has diffused from the bulk of the substrate wafer. For (100) interfaces, no significant dislocation activity is associated with the defects, even for densities up to 1012/cm2. On (111) interfaces, however, a large planar fault density is observed. Ramifications for silicon homoepitaxy are discussed.

Transparent, stable, electrically insulating, crystalline thin films of two aromatic organic dianhydrides, 3,4,9,10‐perylenetetracarboxylic dianhydride C24H8O6 and 1,4,5,8‐naphthalenetetracarboxylic dianhydride C14H4O6, were prepared by vapor deposition. On exposure to an electron beam dose of 0.05 C cm−2 the written areas of the films appeared visually blackened and were electrically conducting. This chemical transformation was found to be both dose and current density dependent. Fine lines with widths of 1000 A were prepared by electron exposure at just above writing threshold doses. The chemical and electrical properties of the materials formed upon e‐beam treatment were found to be notably different from those of the starting anhydrides and useful for semiconductor device fabrication.

Contrast from domain walls in materials with cubic magnetic anisotropy has been observed in scanning electron microscope (SEM) images. This contrast, which is visible in both the backscattered and absorbed current images, with normal electron beam incidence arises from the interaction of the convergent incident electron beam with the domains on either side of the wall.

Measurement of thermionic electron emission values for pointed LaB6 single‐crystal emitter cathodes has shown that 〈110〉 axial orientations yield emission values ten times higher than 〈100〉 orientations at 1545 °K. Minimum values were obtained for the 〈510〉 directions. These findings seem encouraging in achieving perhaps two orders of magnitude higher emission fluxes as compared to tungsten emitters.

We have applied the scanning electron microscopy (SEM) technique of Fathers et al. to a study of domain structure in metallic glasses of the form TM0.75P0.16X0.06Al0.03, where TM denotes Fe, Co, Ni, or an alloy of these and X denotes either B, C, or Si. The domain structure is dominated by the presence of a spatially nonuniform uniaxial anisotropy which is related to the flow processes induced by quenching the molten alloy. The existence of both a magnetostrictive and a directional ordering source of anisotropy is indicated.