摘要:

Methods for studying semiconductor surface chemistry are presented. It is shown that adsorption and desorption kinetic measurements, when combined with Auger spectroscopy, can give useful insights into fundamental elementary surface kinetic processes which are important in understanding the behavior of complex chemical vapor deposition, plasma vapor deposition, or reactive ion etching processes. Techniques for crystal preparation, mounting, temperature control, and reaction kinetic measurements are given using examples from the adsorption and reaction of propylene with Si(100). An illustration of the manipulation of active site availability on Si(100) is described.

ISSN:0734-2101    

DOI:10.1116/1.574131

出版商:American Vacuum Society    

年代:1987

数据来源: AIP

摘要:

A method for removing ion yield transients from the beginning of secondary ion mass spectrometry (SIMS) depth profiles is evaluated. Ion yield transients, which result from the concentration buildup of yield enhancing primary ion species, may be characterized by depth profiling standards which are bulk doped with the element of interest. The transients of B+and B−in Si were characterized using an O+2and Cs+primary ion beam, respectively. The resulting transient correction functions were used to correct depth profiles of 10 and 4 keV B implants in Si.

ISSN:0734-2101    

DOI:10.1116/1.574825

出版商:American Vacuum Society    

年代:1987

数据来源: AIP

摘要:

Emission from the plasma generated when a pulsed CO2laser is used to evaporate dielectric materials is analyzed in the 200–900 nm region by means of an optical multichannel analyzer. Atomic spectra consisting of excited neutral and singly, doubly, and triply ionized species were observed from laser irradiation of Al2O3, SiO2, ZnO, PbF2, TiO2, and HfO2. Emission from theB–Xtransition of AlO was observed under vacuum conditions becoming more intense in the presence of added gases. Assuming local thermal equilibrium, plasma temperatures were calculated using the emission intensities of several selected atomic species. Possible effects of the observed phenomena on the properties of thin films deposited by laser‐assisted deposition are discussed.

ISSN:0734-2101    

DOI:10.1116/1.574130

出版商:American Vacuum Society    

年代:1987

数据来源: AIP

摘要:

The energy of Ti neutrals and Ti+ions was determined in the region of the cathode spot of a Ti vacuum arc by measurement of the Doppler broadened profiles of Ti(I) and Ti(II) emission lines using Fabry‐Perot interferometry. Energy analysis of Ti+and Ti++was carried out at a distance from the cathode using an electrostatic analyzer. The emission lines showed that the neutrals had energies corresponding to approximately 0.4 eV while the Ti+ions had a most probable energy of 3 eV. The energy analyzer showed that remote from the cathode spot Ti+had a most probable energy of 80 eV. This large difference is explained in terms of a simple model for the arc which includes a potential ‘‘hump’’ near the cathode. The charge fraction of the evaporant was measured to be approximately 0.5, and the effect of nitrogen background gas on the energy distribution was observed. Deposited films of Ti and TiN were prepared and the influence of substrate bias investigated. It was found that under high negative bias the Ti films exhibited a preferred 〈110〉 orientation consistent with previous studies of ion‐beam‐induced textures.

ISSN:0734-2101    

DOI:10.1116/1.574132

出版商:American Vacuum Society    

年代:1987

数据来源: AIP

摘要:

We have measured the composition distribution of positive silane ions in a dc silane glow discharge as a function of pressure, flow, and cathode‐to‐anode separation. The ions were sampled through the anode and were analyzed by a mass spectrometer. When the sampling aperture is close to the negative glow, the monosilane ions are dominant, whereas when the aperture is moved further from the negative glow, successively larger ions are found to dominate. The physical properties of the amorphous silicon films which are deposited on the anode also depend on the distance to the cathode. Correlations between the properties of the films and the ionic composition of the plasma have been made and we have discussed the implications of these results with regard to the mechanism by which the solid film is formed from gaseous species.

ISSN:0734-2101    

DOI:10.1116/1.574133

出版商:American Vacuum Society    

年代:1987

数据来源: AIP

摘要:

An aluminum alloy molecular beam epitaxy chamber has been constructed and its vacuum properties tested. Prior to the construction an oil‐free lathing technique was developed and was applied to the inner surface of the chamber, which resulted in an extremely low outgassing rate of the order of 10−11Torr 1/s cm2before bakeout and less than 1×10−13Torr 1/s cm2after a 100 °C, 45‐h bakeout. This low outgassing rate of the material enabled the chamber to be pumped down from atmospheric pressure to the order of 10−10Torr in 23 h of evacuation without bakeout and in only 6 h with bakeout. With this short pumpdown time and its great reduction in bakeout temperature and time together with its reduced weight and the low cost, the aluminum alloy ultrahigh vacuum system provides us with a remarkably convenient tool to access the ultrahigh vacuum region.

ISSN:0734-2101    

DOI:10.1116/1.574134

出版商:American Vacuum Society    

年代:1987

数据来源: AIP

摘要:

Energetic ion bombardment of a sputtering target often results in a significant fraction of incident ions being reflected as energetic neutrals in the direction of the growing film. Experiments are described which test the degree to which bombardment by these energetic backscattered neutrals can influence the microstructure of a growing film. As anticipated, microstructural changes of the film are influenced by the reflection coefficient and energy exchange of a given energetic gas ion at the sputtering target which in turn depends on the mass ratio of the sputtering gas to that of the target. Whereas the sputtered metal species leave the target with a near cosine distribution, evidence for a strong noncosine reflection preference in the forward direction for the energetic backscattered neutrals will be given. Very careful x‐ray diffraction studies show that films grown in a Ne/Pd system give rise to lattice dilation in the (111) lattice planes resulting in a 1% increase in the lattice parameter over Pd bulk values. On the other hand, in the Xe/Cu system no significant changes from bulk unit cell dimensions were observed. Data are also presented to show lattice distortions induced by deliberate energeticionbombardment during film growth involving normalized energies much greater than that obtainable by energetic neturals. X‐ray data show that lattice distortions and preferred crystallographic orientation induced by equivalent energetic particle bombardment differs significantly for different metals.

ISSN:0734-2101    

DOI:10.1116/1.574135

出版商:American Vacuum Society    

年代:1987

数据来源: AIP

摘要:

In the opposed‐targets sputtering system (OTSS), plasma is focused in the space between opposed targets by magnetic and electric fields. Usually, since an equal potential is applied to the targets, the discharge is in the balanced potential mode. In this study, unbalanced potential (UP) modes of discharge characteristics are investigated for the OTSS. Discharge characteristics strongly depend on the unbalanced voltage applied to the opposed targets. UP is seen to promote strong ionization just as the plasma confinement field and other discharge parameters do.

ISSN:0734-2101    

DOI:10.1116/1.574136

出版商:American Vacuum Society    

年代:1987

数据来源: AIP

摘要:

The design and operation of an electron beam roll coating machine, utilizing oblique angle incidence of the evaporant, for the production of magnetic tape is outlined. The use of a magnetic bending system and backscattered electron confinement is discussed with respect to the particular problems associated with the coating of thin polymer films. Preliminary results are reported for magnetic tape produced on such a machine with respect to magnetic and structural properties which indicate that the product exhibits characteristics suitable for video recording.

ISSN:0734-2101    

DOI:10.1116/1.574137

出版商:American Vacuum Society    

年代:1987

数据来源: AIP

摘要:

This paper reports on the results of experimental investigation into the preferred orientation of Ni–Fe film formed by ion beam sputtering. Through experiments concerning ion bombardment and substrate temperature, argon ion bombardment is found to increase the amount of the (111) crystal texture in addition to contributing to the texture orientation itself. In terms of film morphology, the fracture cross section indicates a more obvious columnar structure with the film surface becoming slightly rougher as the amount of argon ion bombardment increases. Conversely, nitrogen and oxygen‐mixed ion bombardment weakens the (111) preferred orientation, and the effect becomes more notable when the ion has a higher energy. On the other hand, although the substrate temperature increase makes the (111) texture better oriented, the amount of the crystal texture becomes smaller due to this temperature increase. Additionally, the observed lattice distortion corresponds well to that estimated by the internal stress.

ISSN:0734-2101    

DOI:10.1116/1.574138

出版商:American Vacuum Society    

年代:1987

数据来源: AIP