摘要:

Cones topped by filaments with submicron diameters grow on carbon surfaces when they are bombarded with energetic (e.g., 1 keV) argon ions. It is shown that sputter redeposition is an important process by which cone growth occurs. The possible role of hydrogen in poisoning growth sites and increasing the density of cones at higher temperature is discussed. Several experiments are proposed to clarify growth mechanisms.

ISSN:0734-2101    

DOI:10.1116/1.576418

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

Boron and Ti/B films have been magnetron sputter deposited and characterized using x‐ray diffraction, Auger‐depth profiling, and electron microscopy. The amorphous boron films contain no morphological growth features, unlike those characteristically found in thin films prepared by various plasma vapor deposition processes. The use of a high‐density boron sputter target prepared by hot isostatic pressing was a major factor in controlling the deposition process. Consequently, the radio frequency sputter deposited boron proves feasible for ultrathin band pass filters as well as the low Z element in high Z/low Z mirrors which enhance reflectivity from grazing to normal incidence.

ISSN:0734-2101    

DOI:10.1116/1.576419

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

A sloped etching process for Nb is developed for pilot line operations. Reactive ion etching and plasma processes are compared for a CF4/O2parallel plate etch system. The higher pressure etches were found to have better characteristics for the numerous combinations of independent variables examined. Process settings tested include rf power, chamber pressure, and etchant flow rates. Higher Nb etch rates, photoresist:niobium etch rate selectivity of 1:1, and adequate selectivity over SiO2were obtained with the plasma etches. For both types of processes, control of plasma loading affects were determined to be crucial to accomplish successful patterning. Finally, mathematical models of the etch process were derived from the data and used to determine basic etch mechanisms occurring within the reactor.

ISSN:0734-2101    

DOI:10.1116/1.576420

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

We report for the first time laser‐induced fluorescence measurements of a sputtering magnetron plasma. From these measurements we determined the density, average velocity, and temperature of the ions. The ion density profile is peaked at the same location as the electron density profile, which was measured with a Langmuir probe. The average ion velocity parallel to the cathode surface is less than our detection limit of 93 m/s. The ions at the edge of the discharge are room temperature, while in the center of the discharge they reach a temperature of 0.64 eV. These temperatures are attributed to acceleration of the ions by the electric field in the plasma, together with collisional scattering.

ISSN:0734-2101    

DOI:10.1116/1.576421

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

The ZrO2thin film is deposited by means of a reactive radio frequency diode sputtering from an elemental zirconium target in an argon–oxygen mixture gas. The influence of the deposition process parameters on the microinstructure, composition, film stress, and refractive index is investigated. It is noted that the process parameters, in particular substrate bias, have a profound effect on the structure and properties. The possible mechanism, in terms of bombardment of energetic particles and adatom mobility on the film surface, is discussed.

ISSN:0734-2101    

DOI:10.1116/1.576422

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

The composition and structure of boron nitride films prepared by thermal and plasma enhanced chemical vapor deposition (CVD) using borazine as a precursor have been studied. Thermal CVD at temperatures between 475 and 550 °C using either a hot‐wall or cold‐wall reactor results in amorphous boron‐rich films of approximate composition BN0.67. Plasma enhanced CVD consistently gives films of 1:1 boron to nitrogen stoichiometry, but the hydrogen content of films deposited below 300 °C is so high that the films react with atmospheric moisture. Optimum conditions for the growth of stoichiometric BN with relatively low hydrogen content were found to be low plasma power, hydrogen–borazine gas mixtures, and a substrate temperature of 550 °C. Films deposited under these conditions are mixtures of poorly crystalline hexagonal and cubic boron nitride.

ISSN:0734-2101    

DOI:10.1116/1.576423

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

Micrometer thick layers of ZnSe and other dielectric materials have been grown with high thickness uniformity using the new ultrahigh vacuum (UHV) molecular beam deposition (MBD) technique. Optical techniques have been employed to demonstrate that variations in thickness down to as little as ±0.15% over 90 mm diam can be achieved.

ISSN:0734-2101    

DOI:10.1116/1.576424

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

We present measurements of the oxidation level (Cu+and Cu2+concentration) of copper thin films deposited using a new type of oxygen plasma source. This oxygen plasma source is operated under ultrahigh vacuum, and allows one to oxidize copper up to nearly pure Cu2+oxide at rather low temperature (<500 °C) and low molecular oxygen background pressure (2×10−6Torr). High growth rate and high substrate temperature promote the formation of Cu+oxide, whereas Cu2+oxide is mainly obtained at low growth rate (0.5 Å s−1) and low substrate temperature (450 °C). The active species for oxidation is mostly atomic oxygen produced in the plasma. When the plasma is off, while the oxygen flux remains unchanged, no copper oxide is detected in the films.

ISSN:0734-2101    

DOI:10.1116/1.576425

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

As part of a continuing effort to characterize the influence of plasma environments on metals, tin foil reconstruction in argon, oxygen, and hydrogen plasma afterglows, created with a low power (<250 W) microwave system, was studied. It was found that neither oxygen nor argon plasmas had any apparent impact on the foil morphology. Hydrogen plasma treatments led to a dramatic reconstruction of the foils. Whereas originally the foil samples consisted of large, oriented crystals, following treatment in hydrogen plasmas the foil surfaces became a network of large pores and strings of small randomly oriented crystallites. No weight loss (etching) was observed. Detailed study and modeling work suggested that the reconstruction was the result of the formation of metastable tin hydride and subsequent short range metal transport. In contrast to the etching of other metals, ions, and electrons were found to play no role in the process.

ISSN:0734-2101    

DOI:10.1116/1.576426

出版商:American Vacuum Society    

年代:1990

数据来源: AIP

摘要:

Argon plasma treatment of gold metal in a glass reactor deposited silicon oxide originating from the reactor on the metal surface. The deposited silicon oxide was nonstoichiometric and had a strong exoelectron emission activity. The chemical and structural nature of the emitting centers has been investigated. The thermally stimulated exoelectron emission (TSEE) glow curves for the surfaces exhibited one strong emission peak at ∼170 °C (in a few cases, three peaks at ∼120, 190, and 240 °C ) with increasing temperature. The intensity of the TSEE peak appearing at 170–190 °C varied in parallel to the atomic ratio of Si2p/O1sobtained by x‐ray photoelectron spectroscopy as a function of operational parameters in the plasma treatment. The TSEE peak intensity increased with an increase in the ratio of Si2p/O1s. The emitting centers for the TSEE peak can be related to electron trapping sites located in the neighborhood of the oxygen‐deficient silicon atoms deposited on the metal surface.

ISSN:0734-2101    

DOI:10.1116/1.576427

出版商:American Vacuum Society    

年代:1990

数据来源: AIP