摘要:

The generalized analysis of the grain‐boundary diffusion by surface accumulation method has been extended by incorporating the effects of an electric field along the grain boundary. General expressions for the average surface concentration have been derived and the effects of an electric field on its time dependence have been investigated in some detail.

ISSN:0021-8979    

DOI:10.1063/1.327648

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

The formation of buried layers of silicon nitride by nitrogen‐ion implantation in single‐crystal silicon is studied. He+backscattering, x‐ray diffraction, scanning and transmission electron microscopies, and infrared absorption measurements were used for the physico‐chemical characterization; sheet resistivity determination, spreading‐resistance profile, and current‐voltage characteristics for the electrical characterization. It is shown that, for 180‐keV nitrogen ions, a fluence about 1018N/cm2must be implanted in order to obtain a continuous layer of silicon nitride and that annealing must be performed at 1200 °C to make it homogeneous and electrically insulating. The Si3N4layer obtained crystallizes in the &agr; phase and presents properties nearly similar to those of deposited layers. It is demonstrated that the conditions of implantation (energy, substrate temperature, beam intensity) play a fundamental role in the structure of the superficial silicon layer: the substrate must not be amorphized up to the surface during the implantation to obtain, after annealing, a monocrystalline surface layer suitable, for instance, for further epitaxy.

ISSN:0021-8979    

DOI:10.1063/1.327649

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

A method for the direct calculation of primary ion and recoil range distributions, as well as energy deposition profiles in multilayered targets, is presented. The technique is based on stepwise numerical integration of the Boltzmann transport equation. Range distributions for arsenic, phosphorus, and boron and damage density distributions resulting from antimony and boron implants in silicon are found to compare favorably with other calculations and experimental results. Oxygen recoil fluxes from SiO2into Si also agree well with experiment. Silicon and nitrogen recoil range distributions resulting from a 400‐keV selenium implantation through 1000 A˚ of Si3N4on GaAs are calculated and are shown to have a significant effect on doping profiles determined from electrical measurements.

ISSN:0021-8979    

DOI:10.1063/1.327650

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

A high‐temperature treatment in a chlorine containing oxidizing ambient can be used to achieve a shrinkage or a complete annihilation of the oxidation‐induced stacking faults (OSF’s). This paper discusses in more detail the efficiency of a trichloroethane (C33) oxidation to inhibit the OSF nucleation during a prolonged oxidation or a reoxidation in dry and wet oxygen, respectively. Preferential‐etching studies demonstrate that one has to be very careful in interpreting the results available in the literature. Dependent on the parameters (temperature, time, and gas atmosphere) of both the first and the second oxidation, the OSF’s are annihilated either throughout the entire volume of the wafer or only in a near‐surface region. The influence of different oxidation cycles on the leakage current ofp+ndiodes is analyzed.

ISSN:0021-8979    

DOI:10.1063/1.327651

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

The energy‐focused time‐of‐flight atom‐probe field‐ion microscope (FIM) is employed to study surface segregation of a Ni‐Cu alloy in nitrogen and oxygen. In nitrogen, in addition to the normal enrichment of Cu to the top surface layer as in the vacuum annealing case, highly Cu‐rich regions are formed near plane edges of the top surface layer. In oxygen, no Cu enrichment at the surface is found. Both the composition depth profiles and the spatial distributions of alloy species within an atomic layer can be obtained by the atom‐probe (FIM) with depth and spatial resolution of a few angstroms.

ISSN:0021-8979    

DOI:10.1063/1.327652

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

Precipitation of Ni3Si in undersaturatedNiSi solid solutions is shown to be triggered by high‐energy electron irradiations at very low displacement rates. The results are compared to those previously obtained under high‐flux irradiations. A simple interpretation is proposed for the temperature shift of the dose rate threshold for radiation‐induced precipitation in this system.

ISSN:0021-8979    

DOI:10.1063/1.327653

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

One of the singular features of amorphous selenium films is their position‐dependent crystallization rates. A new model is proposed which attributes the 100‐fold variation in rate to stress fields surrounding some of the polycrystalline cylindrites. The mechanism by which these fields can enhance the crystallization rate is discussed and some critical tests are suggested.

ISSN:0021-8979    

DOI:10.1063/1.327654

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

The changes in the absolute values as well as in the temperature dependences of the elastic constantsC11,C44,C′, andCLas a function of dissolved hydrogen up to 1.7 at. %, in palladium single crystals have been determined. The measurements were performed in the temperature range between 140 and 310 K, using both longitudinal and shear 10‐MHz ultrasonic waves. In the &agr; phase, the changes in the absolute values of the elastic constantsC11,C44, andCLwere very small, while a larger effect of −1.2%/ at. % H was obtained in the case of the shear constantC′. The relative changes in the computed bulk modulus and Voight‐Reuss average Young’s modulus in that phase are, respectively, +0.2% and −0.5%/ at. % H. The effects of hydrogen in the &agr; phase on the temperature dependences of the elastic constants, however, are found to be significantly large in the case ofC11andCLand small in the case of the shear constantsC′ andC44. These effects are discussed in terms of the volume expansion due to H in Pd, the possible electronic effect due to the addition of H to Pd, and finally the hydrogen contributions to the higher‐order elastic constants. From this analysis, it is concluded that hydrogen in the &agr; phase contributes primarily to the short‐range ion core repulsive interactions in palladium.

ISSN:0021-8979    

DOI:10.1063/1.327603

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

Quantitative experimental measurements have been made in the study of thermoelastic generation of elastic waves in a metal by unfocused laser radiation. A calibrated wide‐band detection system, incorporating a capacitance transducer, has enabled acoustic waveforms to be recorded with a minimum of distortion. From these measurements, a theoretical model has been developed. The transfer function of the metal block has been deconvoluted to give the acoustic source function, which was modeled as a rapidly expanding point volume of material. The thermoelastic source generated longitudinal (L) and (S) waves, but the latter predominated at the epicenter, where, in experiments presented here, both wave amplitudesLandSwere proportional to the total absorbed energy in the laser pulse.

ISSN:0021-8979    

DOI:10.1063/1.327601

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

The electrical resistance behavior under pressure of an Fe85B14Si1alloy in the as‐cast amorphous condition and in three different annealed states with different degrees of crystallinity was studied. We found that in the as‐cast amorphous sample there is no measurable resistance‐jump with application of pressure up to about 300 kbar. Subsequent annealing of the amorphous sample for different lengths of time results in the reappearance of the resistance‐jump with different amplitudes.

ISSN:0021-8979    

DOI:10.1063/1.327604

出版商:AIP    

年代:1980

数据来源: AIP