摘要:

In a dc sputtering system only the cathode is bombarded by positive ions. However, in a two‐electrode rf sputtering system, both electrodes are bombarded. In both sputter deposition and sputter etching this bombardment must be controlled for control of contamination and film properties. The ratio of ion bombardment energies at the two electrodes has been studied here by an indirect method using measurements of the rf and induced dc voltages between the electrodes. The behavior of this voltage ratio, and of the corresponding ion energy ratio, has been studied as a function of the electrode area ratio (varied between 0.3 and 1), the electrode material (SiO2and stainless steel), the rf voltage on the electrodes (varied from 300 to 2000Vpp), the gas (He, Ne, Ar, Xe, and CF4), and its pressure (from 0.1 to 100 Pa). The results show that while it is easy to obtain roughly equal ion bombardment of the rf electrodes, large ion bombardment energy ratios are difficult to obtain and require careful system design. In particular the dependence of the ion bombardment ratio on the fourth power of the electrode area ratio, which has been widely assumed in the past, has not been confirmed. The analysis also describes the effect of the dc bias voltage and the rf peak‐to‐peak voltage on target etch rates.

ISSN:0734-2101    

DOI:10.1116/1.572311

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

The results of an optical emission study of neon and oxygen species which exist in Ne/O2rf diode sputtering glow discharges are presented. Comparing emission intensities in pure Ne and Ne/O2mixtures at constant total gas pressure, it was found that the addition of O2to the sputtering gas quenches Ne i emission and increases emission from O i and O+2species to a greater extent than that which would be expected from the relative changes in neon and oxygen concentrations, respectively. Although this effect could be caused by a change in the electron density and electron energy distribution function, the correlation between Ne i, O i, and O+2emission suggests that metastable neon atoms may interact directly with ground state diatomic oxygen molecules in two competing ways: (1) by Penning ionization which produces O+2, and (2) by a quasiresonant transfer of excitation which leads to the production of O. The results are compared to those previously obtained for Ar/O2discharges using identical sputtering conditions, where the dominant interaction between the rare gas and O2leads entirely to the production of monatomic oxygen.

ISSN:0734-2101    

DOI:10.1116/1.572312

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

A new sputtering apparatus for taking thin sections from solid‐state diffusion samples is described. New features include the use of a Kaufman‐type ion gun, high‐yield chamber geometry, and a catcher‐foil advance mechanism capable of taking 32 sections without breaking vacuum. The apparatus can also be used as a general laboratory facility for ion milling.

ISSN:0734-2101    

DOI:10.1116/1.572313

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

A three target dc magnetron sputtering system has been constructed. The main feature of the system is a unique rotating substrate table which permits deposition onto continuously heated or cooled substrates while they are rotating. With this setup, Nb‐based tunnel junctions with thin Al overlayers, multilayered materials, and a variety of alloys have been prepared.

ISSN:0734-2101    

DOI:10.1116/1.572314

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

The interfacing of a UTI 100C quadrupole mass spectrometer to an inexpensive microcomputer system (the Commodore 32K Pet) is described. The system is capable of selecting and monitoring up to 13 masses simultaneously (on a time scale of 1 s). An example is given of the utilization of this system in the temperature‐programmed decomposition of dimethyltetrazine on a platinum surface.

ISSN:0734-2101    

DOI:10.1116/1.572316

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

A simulation method to obtain the pressure distribution in a complex vacuum system has been proposed. The method introduces a new concept with regard to the function of each component of the vacuum system. The vacuum pump is regarded as a ‘‘vacuum resistor’’ connected at one side to the perfect vacuum. The gas source is regarded as a pressure generator connected to the vacuum. The conducting pipe is regarded as a vacuum resistor between the above elements. The vacuum sides of the pump element and the gas source element are assumed to be connected together by an imaginary route, and thus the vacuum system can be regarded as a closed vacuum circuit network. Such a vacuum circuit network may be replaced by an electric circuit network of a simulator for the vacuum system. The simulator was employed for the high vacuum system of an electron microscope in order to obtain the pressure distribution. The results obtained were in good agreement with the actually measured pressure distribution.

ISSN:0734-2101    

DOI:10.1116/1.572317

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

The design and performance of a modified extractor gauge for ultrahigh vacuum pressure measurement is described. The open end construction of the grid cage prevents the x rays from striking the ion collector directly except for those minor indirect x rays that are reflected at respective electrodes. The sensitivity factor is about 8.3×10−2Pa−1(11 Torr−1) at an electron current of 1 mA corresponding to the residual gases. Pressure measurements were carried out in the range of 1×10−6to 9×10−10Pa (1×10−8to 7×10−12Torr). It is confirmed that the x‐ray limit of the gauge is lower than that of the nude‐type B–A gauge. Description is also given of the modified design of the gauge for high vacuum pressure measurements facilitated by the cap electrode mounted on the top of the grid cage.

ISSN:0734-2101    

DOI:10.1116/1.572318

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

Outgassing characteristics of POCO graphite coated with TiC by chemical vapor deposition are reported. Results obtained from fully TiC‐coated samples showed that the coating layers are not completely gas tight. The air included in the porous part of the graphite was gradually released at an outgassing rate on the order of 10−10Torr⋅l/s⋅cm2. After exposing a part of the graphite surface, the outgassing rate was reduced to the order of 10−12Torr⋅l/s⋅cm2, after vacuum baking at 250 °C for 24 h.

ISSN:0734-2101    

DOI:10.1116/1.572319

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

ISSN:0734-2101    

DOI:10.1116/1.572320

出版商:American Vacuum Society    

年代:1983

数据来源: AIP

摘要:

The adsorption of D2O on clean polycrystalline rhenium has been studied by x‐ray photoelectron spectroscopy. At 305 K, only dissociative adsorption occurs; at 135 K, D2O adsorbs molecularly with the formation of multilayer ice at high converges. The molecular D2O desorbs at 180 K with the formation of an OD complex.

ISSN:0734-2101    

DOI:10.1116/1.572321

出版商:American Vacuum Society    

年代:1983

数据来源: AIP