摘要:

In order to quantify the contributions of atomic and molecular chlorine during the plasma etching of aluminum, a discharge‐flow system was used to generate chlorine atoms upstream of a parallel‐plate reactor in which aluminum samples were etched with the afterglow. Molecular dissociation in excess of 70% was achieved. Dissociation was measured in the parallel‐plate reactor by gas‐phase titration of the chlorine atoms with NOC1 using the chemiluminescent emission resulting from atom recombination as an end point indicator. Molecules etched aluminum at least four times faster than atoms and displayed an activation energy near zero (0.02–0.04 eV/molecule) between 35 and 150 °C. Below 25 °C etching was quenched due to the inability of products and/or contaminants to desorb. The higher molecular etch rate is believed to be the result of an enhanced sticking coefficient on the chlorinated surface. Calculation of molecular sticking coefficients based on the assumption of adsorption‐limited etching are in good agreement with reported values. Temperature‐dependent atom recombination on theinsituelectrodes prevented accurate determination of the molecule/atom etch rate ratio and masked the activation energy for atom etching.

ISSN:0021-8979    

DOI:10.1063/1.336567

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Silver complex oxide thin films, which contain V, Cr, Mo, W, Si, Sn, P, Te, and I as constituent elements, are synthesized by anodic oxidation of silver metal films. It is found that Ag3VO4, Ag4SiO4, and Ag3PO4films show good photochromic properties. An x‐ray photoelectron spectroscopy study on a Ag3PO4film shows that the silver ions are reduced and PO4tetrahedra are condensed by visible light irradiation and that the inverse reaction is produced by heating.

ISSN:0021-8979    

DOI:10.1063/1.336568

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

A relation for the short‐circuit current near a grain boundary perpendicular to the surface of the solar cell is given. In the analysis a point‐generation source is assumed. The grain parameters such as the lifetime and the diffusivity of the minority carriers and the effective recombination velocity are determined from the decay curve of the short‐circuit current induced by the electron beam. Since the depletion layer capacitanceCand the series resistanceRin the solar cell are large, the parameterRCis taken into account in the analysis of the short‐circuit current.

ISSN:0021-8979    

DOI:10.1063/1.336569

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Activity coefficients of the Hg and Cd components have been qualitatively calculated for a tellurium‐rich Hg‐Cd‐Te ternary liquid‐phase‐epitaxy growth solution for the growth of (Hg,Cd)Te. A comparison of these values with the corresponding values for HgTe(s), CdTe(s), and binary Hg‐Cd alloys indicates that the activity coefficient for the Cd component is closer to the value for tellurium‐rich CdTe(s), while that for the Hg component lies between the value for Te‐rich HgTe(s), and binary Hg‐Cd alloy of a similar composition.

ISSN:0021-8979    

DOI:10.1063/1.336570

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Mixed systems of graphite carbon and polyethylene glycol are found to show an anomalous increase in electrical resistance at certain temperatures. Making use of this property, we have made plane heaters of these graphite carbon‐polyethylene glycol mixed systems. These heaters, when the power was supplied, maintained constant temperature without any temperature control device. It is also found that the constant temperature depends upon the molecular weight of polyethylene glycol used. This makes it possible to obtain a heater which maintains a desired intrinsic constant temperature without any temperature control device.

ISSN:0021-8979    

DOI:10.1063/1.336571

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

It is pointed out that carrier collection in a quantum well becomes very effective when the quantum well thickness satisfies a transmission resonance condition. This is attributable to the fact that an electron wave dwells on the quantum well for a long time under resonance condition.

ISSN:0021-8979    

DOI:10.1063/1.336572

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Calculations of the high‐field properties of holes in Al0.45Ga0.55As are presented based on the ensemble Monte Carlo technique. It is shown that the hole drift velocity in AlGaAs is significantly below that in GaAs until saturation occurs. Despite the much larger energy band gap in Al0.45Ga0.55As, the hole ionization rate approaches that of GaAs at very high electric fields, >600 kV/cm. No significant hole impact ionization is observed below 300 kV/cm in Al0.45Ga0.55As. This is of importance to superlattice avalanche photodiodes made from the GaAs/AlGaAs material system.

ISSN:0021-8979    

DOI:10.1063/1.336573

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

We have studied the surface composition of gallium arsenide and indium phosphide under conditions of physical sputtering and reactive ion beam etching. Samples of Fe‐doped (100) GaAs and InP were bombarded with 1‐keV Ne+ions under a varying amount of Cl2dose. Low‐energy ion scattering spectroscopy and sputtered neutral mass spectrometry indicate an increase of the Group V element at the surface upon addition of Cl2to the system. This effect is believed to be due to segregation of the As and P due to an altered chemical potential at the surface/vacuum interface resulting from chlorine adsorption. The segregation and subsequent volatilization of PClxspecies leaves aggregates of In/InClxspecies at the surface, resulting in a roughened surface.

ISSN:0021-8979    

DOI:10.1063/1.336574

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

This paper presents a theoretical study of suppression of undesired higher‐order thickness modes excited in magnetostatic forward volume delay lines. This can be done by using the exciting and receiving transducers deposited directly on the top of an yttrium iron garnet film. Though this geometry has been used before, this paper describes more detailed investigation. Numerical results obtained are quite useful and encouraging. The magnetostatic volume wave delay lines have potential applications in microwave signal processing with larger operating bandwidth directly at microwave frequencies.

ISSN:0021-8979    

DOI:10.1063/1.336575

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Previously reported nitrogen distributions in SiO2films on Si which have been thermally nitrided at 1000 °C have been explained by a kinetic model of the nitridation process which rests upon the effects of interfacial strain. A critical test of this kinetic model is the validity of the predictions regarding nitrogen distributions obtained at other nitridation temperatures. In this work, nitrogen distributions determined via x‐ray photoelectron spectroscopy are reported for samples nitrided at 800 and 1150 °C, and are shown to be consistent with the kinetic model. In addition, the intensity of a fluorine marker is found to correlate with the nitrogen distribution, and is postulated to be related to kinetically generated defects in the dielectric film, consistent with the strain‐dependent energy of formation of defects proposed recently to explain electrical data.

ISSN:0021-8979    

DOI:10.1063/1.336576

出版商:AIP    

年代:1986

数据来源: AIP