摘要:

The charge behavior of dielectric films on silicon is particularly important in device and integrated circuit technology because of surface effects. Models for ionic migration, fixed-interface charge, and injection trapping are reviewed for insulators used in silicon technology: thermally-grown silicon dioxide and chemical vapor-deposited silicon dioxide and silicon nitride. The distinctive characteristics of insulator charge related to these mechanisms are applied in the case of reactively sputteredSiO2andTa2O5. Ion migration and injection-trapping behavior are found under certain conditions of preparation for both materials. A degree of interface charge control is indicated in the study of sputtered silicon dioxide. More work is needed to establish the future utility of these materials.

ISSN:0022-5355    

DOI:10.1116/1.1492613

出版商:American Vacuum Society    

年代:1969

数据来源: AIP

摘要:

The limitations of dc measurements on doped thin film metal-insulator-metal structures are discussed, particularly in regard to the identification of the band structure of such systems. It is shown that the use of ac techniques provides a much wider scope of measurements which can be used to determine information about the energy diagram of thin film insulators. Furthermore such measurements have prominent characteristics which may be related to the band structure of the sample. The technique has been applied to evaporatedAu–MoO3–Ausamples, the capacitance of which are found to be extremely temperature sensitive; capacitance changes of 50:1 over 100 °C temperature range are reported. At low temperature the capacitance corresponds to the geometric capacitance, but at high temperatures isindependentof the film thickness. The results are explained in terms of Schottky barriers at theAu–MoO3interfaces, and the energy diagram of the system clarified. The doping density in theMoO6is estimated to be about1018 cm−3.

ISSN:0022-5355    

DOI:10.1116/1.1492614

出版商:American Vacuum Society    

年代:1969

数据来源: AIP

摘要:

Photoresists can be classified as either positive resists or negative resists depending on their mode of interaction with light. With the exception of photomasking, the process handling considerations for these two classes are similar. Photoresist performance is highly dependent on processing techniques. Typical processing procedures are discussed along with process problems and performance limitations of currently available materials. General materials chemistry of typical photoresists is discussed, and possible photomechanisms, development mechanisms, and adhesion mechanisms are considered. Substrates to which a resist is applied introduce another variable for consideration when evaluating resist performance.

ISSN:0022-5355    

DOI:10.1116/1.1492615

出版商:American Vacuum Society    

年代:1969

数据来源: AIP

ISSN:0022-5355    

DOI:10.1116/1.1492616

出版商:American Vacuum Society    

年代:1969

数据来源: AIP

摘要:

Dielectric films are used extensively in semiconductor technology for masking against the diffusion of dopants into semiconductors, fabrication of active and passive components, electrical isolation between components, and surface passivation of devices. Silica is the most widely used dielectric in silicon devices at present, the preparation and properties of silica films are reviewed. However, silica is structurally porous, resulting in the high permeability of silica films toward impurities and the migration of impurity ions in silica films. Considerable efforts have been made to investigate other dielectrics during the past few years. The preparation and properties of several important dielectric films are discussed. Silicon nitride and aluminum oxide have been shown to be superior to silica in several respects. Various silica-silicon nitride and silica-alumina combinations have provided new and improved devices.

ISSN:0022-5355    

DOI:10.1116/1.1492617

出版商:American Vacuum Society    

年代:1969

数据来源: AIP

摘要:

A series of sublimation titanium getter-ion pumps with directly heated titanium evaporators has been described by the authors in earlier publications. The pumps have pumping speed capability of 500–5000 liter/sec. The pumps find an application in thin-film technology, in the manufacture of vacuum electron tubes, in the metallurgy of extra-pure metals, and in particle accelerators. The present work reports results of the development of sublimation pumps which offer higher capacity and can operate under more rigid temperature conditions.

ISSN:0022-5355    

DOI:10.1116/1.1492618

出版商:American Vacuum Society    

年代:1969

数据来源: AIP

摘要:

Sorption of nitrogen by a Zr–Al alloy has been measured at constant temperatures at 300 °C and 500 °C and for nitrogen pressures in the range10−6to 1 Torr. The pumping speed of the Zr–Al alloy for nitrogen decreases as the nitrogen pressure is increased and increases with temperature. For a constant nitrogen pressure the pumping speed tends to decrease with time owing to increase in surface concentration. After sorption has been completed the pumping speed can be partially or entirely restored to its initial value by maintaining the active surface at the operating temperature under a low nitrogen partial pressure, e.g.,10−6Torr. During this recovery process nitrogen compounds at the surface migrate towards the interior of the Zr–Al alloy. The data obtained facilitate, at least qualitatively, the measurement of the diffusion of nitrogen from the surface to the bulk metal as a function of time at constant temperature. The data can also be used to predict the behavior of Zr–Al based getter pumps during and after high throughput applications.

ISSN:0022-5355    

DOI:10.1116/1.1492619

出版商:American Vacuum Society    

年代:1969

数据来源: AIP

摘要:

Since the first commercial application of getter-ion pumping, a single metal, such as titanium, has usually been employed for this purpose. However, data obtained several years ago for bulk gettering,i.e., volume absorption of gases by heated materials, showed considerable increases in gettering rates for certain binary alloy compositions over the rate for either component alone. These results suggest that comparable effects might be observed in getterion pumps. This paper reports the results of experiments on the use of two reactive metals in a sputter-ion pump. Residual gas analyses are given and conclusions stated for titanium-zirconium and certain gases. The data indicate the superiority of two-component films, compared with titanium, for pumping in the milliTorr range. The differences in base pressures and residual gas spectra were minor.

ISSN:0022-5355    

DOI:10.1116/1.1492620

出版商:American Vacuum Society    

年代:1969

数据来源: AIP

摘要:

A new diode sputter-ion pump employing cathode posts which protrude within the anode cell is described. For suitable post geometry and material, stable pumping of argon at equilibrium speeds in excess of 25% of the nitrogen speed of the pump has been demonstrated. Effects of post geometry and material are explored with respect to optimizing argon speed. Pumping of noble gases is analyzed in terms of the “high-energy neutrals” hypothesis. Memory effects are shown to be reduced due to the enhancement of permanent pumping mechanisms. Field emission from the post results in greatly enhanced starting at extreme high vacuum.

ISSN:0022-5355    

DOI:10.1116/1.1492621

出版商:American Vacuum Society    

年代:1969

数据来源: AIP

摘要:

A commonly accepted method for determining the activity of a barium getter film within vacuum devices requires the measurement of pressure over the film. The getter pumping speed may be calculated from this measurement when the gas inlet rate and manifold pressure are known. In this work an attempt is made to evaluate the utility of determining getter activity as a function of emission decay of an oxide cathode. Mass spectrometer and emission decay data obtained from experiments carried out using either new or operated color picture tubes indicate that decay to an arbitrary level of 80%, induced by slow oxygen-poisioning, occurs rapidly within a narrow pressure range. This indicates that determination of oxygen getter capacity based on oxide-cathode emission decay may serve as an alternate method for comparing relative getter film activities.

ISSN:0022-5355    

DOI:10.1116/1.1492622

出版商:American Vacuum Society    

年代:1969

数据来源: AIP