摘要:

On the occasion of the 30th anniversary of the founding of the American Vacuum Society, we have prepared a history of the past decade which is intended to update a history of the first 20 years of the Society published in 1973. Included is information on growth in all areas and changes in administration and operations intended to poise the Society to better serve the technical community. Also recounted are data related to membership, symposia, publications, education, awards, scholarships, international activities, and interactions with various elements of the U.S. Government.

ISSN:0734-2101    

DOI:10.1116/1.572022

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

Reactive sputtering has been investigated by a number of workers, but no clear, generalized picture of the method or the phenomena involved has emerged. It is shown that the variation observed in the partial pressure of O2during both reactive and nonreactive Ta depositions is a sensitive measure of reactive surface activity in the plasma. A detailed examination of the O2behavior is made as the degree of activity of either target or substrate is systematically changed. A correlation is made between observed O2partial pressure variations and resulting compositional variations of the collected films using Auger electron spectroscopy, Auger sputter profiling, and transmission electron microscopy. Most importantly, we describe the reactive sputtering of Ta in O2in terms of two inverse reactions at two reactive surfaces; a dissociative reaction proceeds at the target while its inverse proceeds at the substrate. A generalized process in which a metal oxide dissociates to a less‐stable suboxide at the target, transfers to the substrate as the suboxide, and recombines to form the original target compound, is suggested for the reactive sputtering of any metal oxide which exhibits preferential sputtering effects.

ISSN:0734-2101    

DOI:10.1116/1.572023

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

Transparent conducting layers for liquid crystal displays and plastic substrates must be deposited without significant heating. A planar magnetron sputtering process which provides a suitable combination of resistivity and transparency on unheated substrates has been developed. Transparent conducting films of ZnO and indium tin oxide (ITO) have been deposited by sputtering Zn and In0.9Sn0.1targets in a planar magnetron system modified to introduce oxygen near the substrate and to reduce the conductance for oxygen to the target. As the oxygen flow ratef2increased, the dc voltageVa, required to maintain constant sputtering current, first increased and then decreased rapidly as the critical flow ratef2c, at which the target oxidizes, is approached. In the ZnO case,Vahad a maximum value of 525 V and was 355 V after the target oxidized; transparent conducting films were obtained at 435 V but the best films were obtained by activating an rf discharge close to the substrate to increase the oxidation rate. These polycrystalline films had a transmittance of 80% and a resistivity of 0.03 Ω cm but their chemical stability was too poor for useful application. In the ITO case, the rf discharge was necessary to obtain transparent conducting films. Even atf2/f2c=0.94, films were opaque in the absence of this extra oxidation mechanism. Films with a transmittance of 79% and a resistivity of 1×10−4Ω cm were obtained by coupling an rf power of 105 W to the substrate holder, with a substrate self‐bias voltage less than 5 V, atf2/f2c=0.77. These films are amorphous and chemically stable. This sputtering process provides a maximum deposition rate of 48 nm/min on unheated substrates and is suitable for fabricating MIM‐addressed liquid crystal displays.

ISSN:0734-2101    

DOI:10.1116/1.572024

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

Insight on the deposition mechanism of hydrogenated amorphous silicon (a‐Si:H) can be gained by inspecting the consumption rates of SiH4by various species in the plasma since essentially all the silicon in the silane consumed is incorporated in the solid. Chemical chain reactions eliminating H2are thermodynamically allowed as the replacement of two Si–H bonds with H–H and Si–Si bonds is thermoneutral or exothermic. In the case where the chain carriers are positive ions, the chain reaction is known to proceed at collisional rates. The relative rate of SiH4removal by electron impact induced fragmentation can be estimated for various plasma conditions by making appropriate assumptions for the distribution function, mean electron energy, and fragmentation cross section. It is found that under most conditions used for the deposition ofa‐Si:H, the species arising from chain reactions are more important in silicon transport than fragments directly formed in electron impact.

ISSN:0734-2101    

DOI:10.1116/1.572025

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

Thin films of photoresist material (PMMA and AZ 1450J) have been irradiated by H+and He+ions in the low MeV energy region. The composition and thickness of the irradiated layers were determined by RBS techniques. It was found that the composition of the PMMA layer is subject to a drastic change in the initial state of the ion bombardment. The erosion rates of the polymer materials were also measured and were found to vary between 100–20 000 atoms/incoming ion. This could not be explained by conventional sputtering theories. It is assumed that these high erosion rates and compositional changes are connected with the electronic losses of the bombarding ions, giving rise to a bond breaking phenomenon of the resist molecules.

ISSN:0734-2101    

DOI:10.1116/1.572026

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

The sputtering of negative carbon ions from graphite targets bombarded with Cs+ions has been studied. The energy of the Cs+ions has been varied from 200 V to 20 kV. The targets studied were polycrystalline, pyrolytic and vitreous graphite. The negative ion yield strongly depends on the amount of cesium adsorbed on the surface and intercalated into the bulk of the graphite. The optimum C−ion yield is 0.5 to 0.6 C−ions per incident Cs+ions for a bombarding energy of 10 keV and for a target temperature of 200 °C. The yield is independent of the graphite structure. In addition to C−ions, negatively charged clusters of carbon ions up to C−19were sputtered from polycrystalline and pyrolytic graphite. Sputtering from vitreous graphite produces only light clusters, up to C−4.

ISSN:0734-2101    

DOI:10.1116/1.572027

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

Experimental thickness profiles of thin films deposited on substrates perpendicular to the target being sputtered show maxima whose position depends on the sputtering gas pressure. A simple model of particle slowing down in the transport stage accounts for this fact. The influence of diffusional transport on thin film profiles deposited on substrates both parallel and perpendicular to the target, can be estimated comparing experimental data with model predictions.

ISSN:0734-2101    

DOI:10.1116/1.572028

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

The bombardment of surfaces with energetic ions has led to the development of various types of surface topography. In one special case, that of graphite, ion bombardment is responsible for the formation of whiskerlike structures. Whiskers formed under ion bombardment exhibit an initial rapid growth process followed by a slower, diffusion‐fed process. The rates of lengthening and thickening during the diffusion‐fed process appear to be constant in time. Whisker length increases nonlinearly with beam energy; population density decreases as beam energy increases. Whiskers grow parallel to the ion beam. Their alignment is apparently dominated by the destruction of nonparallel whiskers rather than electric field effects. Simultaneous impurity seeding inhibits whisker formation and can totally suppress formation if sufficient flux is present. A growth model involving stress relief at recrystallization front junctures qualitatively fits many experimental observations.

ISSN:0734-2101    

DOI:10.1116/1.572029

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

An apparatus is described for the rapid and reliable measurement of the angular evaporation characteristics of sources. It consists of a moving and a stationary quartz crystal evaporation rate monitor, and it can be operated at any chosen azimuth angle. The instrument has been used to demonstrate the effect of source design, rate of evaporation, external obstructions, and evaporant material on the angular evaporation characteristics of high rate, high capacity evaporation sources.

ISSN:0734-2101    

DOI:10.1116/1.572030

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

In a previous paper, techniques were developed to obtain hexagonal‐close‐packed (27–32 wt.% Bi) Pb–Bi alloy films by evaporating from an alloy source. For the work reported here, Pb–Bi films were prepared under various evaporation rates, substrate temperatures, and residual gas pressures with a goal to obtain smooth and fine‐grained films. Contrary to what is generally expected, the grain size, as measured at room temperature after sample warm up, increased by a factor of 3 to 5 when the substrate temperatureTswas lowered from 273 to ∼180 K and below. Evidence to be presented suggests that although fine grains were obtained at lowTs, significant grain growth had occurred when the films were warmed fromTs<200 K to room temperature. Grain sizes of Pb–Bi films prepared at 77 K were reduced when the films were doped with H20 during deposition or seeded with 5–10 nm thick layers of Pb–Bi or O2‐doped Pb. But no grain size reduction was observed for films doped with O2at 77 K or seeded with Au or Pd at 273 K. The dependence of film morphology on composition, deposition rate, and substrate temperature were also investigated. For fine‐grained Pb–Bi films prepared as described above, hillocks and/or holes were typically observed.

ISSN:0734-2101    

DOI:10.1116/1.572031

出版商:American Vacuum Society    

年代:1983

数据来源: AIP