摘要:

A definitive proof has now been obtained of the existence of a dislocation pinning effect by oxygen atoms in silicon. Ambiguities caused by uncertain material variables in different crystals or different parts of a crystal are avoided in this investigation by making oxygen out‐diffusion from a wafer, creating a continuous variation of oxygen concentration in a ∼60‐&mgr;m‐deep surface layer. Dislocation movement at different depths of this layer was studied using indentation dislocation rosettes (IDR) on a 2° beveled surface. The method of IDR is uniquely suitable for this study because microdislocation half‐loops are generated and confined to move within each ∼10‐&mgr;m‐deep layer in a series of precisely determined microregions down the bevel. The size of IDR increases steadily toward the sample surface, in good correlation with the steady decrease of oxygen concentration toward the same sample surface. The effect at the maximum oxygen concentration in this case increases the critical resolved shear stress in silicon by a factor of 4. This is a most beneficial effect in reducing thermal slip in the practical matter of silicon wafer processing.

ISSN:0003-6951    

DOI:10.1063/1.89580

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

The elastic‐surface‐wave device with a zero first‐order temperature coefficient has been fabricated on Pyrex glass by use of a ZnO thin‐film overlay. The second‐order temperature coefficient of ZnO/Pyrex glass was about 1.24 times as much as that of ST‐cut quartz and was similar in sign. It is shown theoretically that the dispersion is very low at a ZnO film thickness ofhK∼1.7, which gives a zero first‐order temperature coefficient.

ISSN:0003-6951    

DOI:10.1063/1.89588

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Absorption of unpolarized light by a dichroic dye dissolved in a chiral nematic host increased with a decrease in pitch of the host, accompanied by a proportionate increase in contrast ratio, in qualitative agreement with a theoretical analysis by White and Taylor. Identical experimental values of order parameter of the guest‐host system were obtained by two independent methods.

ISSN:0003-6951    

DOI:10.1063/1.89589

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

A new spectroscopic technique for imaging the spatial distribution of nonradiative defects in semiconductor materials is presented. The technique combines the versatility and sensitivity of deep‐level transient spectroscopy (DLTS) with the capability for defect analysis at high resolution of the scanning transmission electron microscope. This scanning DLTS method (SDLTS) is illustrated by observing Cu‐related defect centers in Ga1−xAlxAs epitaxial layers. A high sensitivity (3×1015Cu defects cm−3have been detected) and a spatial resolution of 2 &mgr; or better illustrate the potential of the technique for the study of the electrical behavior of defects in semiconductor devices.

ISSN:0003-6951    

DOI:10.1063/1.89590

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

A new type of ZnO/Si monolithic convolver has been constructed for the purpose of eliminating unstable memory effects due to the traps in ZnO or due to the SiO2/Si interface states. It has controllingp‐njunctions on the Si surface. It was experimentally verified that by varying the junctions bias, the convolution output can be controlled with a rapid response time and without any hysteresis. The applications of this device to a matched filter have been also demonstrated.

ISSN:0003-6951    

DOI:10.1063/1.89591

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

On the surface of a Cu target irradiated by a uv N2laser (TEA, pulse duration 300 ps, peak power 1 MW) a metallic plasma is generated due to the high brightness of the laser operating at atmospheric pressure. An interferometric study also using subnanosecond pulses from a N2laser (1 bar) demonstrates the development of shock wave and plasma with high temporal and spatial resolution. The plasma with an initial pressure of 2000 bar and a temperature of 30 000 K is capable of igniting a combustible mixture of CH4‐O2. A new method for optical synchronization is well proved, delivering pictures as soon as 30 ns after plasma onset.

ISSN:0003-6951    

DOI:10.1063/1.89592

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Measurements of the asymptotic energy distribution of the different high‐energy ion species at Nd‐laser irradiance 1015–1016W/cm2on a CH2planar target are presented and the acceleration mechanism of these high‐energy ions is discussed. Multipeak structure between 10 and 100 keV is observed on the H+ion distribution. A disproportionate number of H+ions withE/Zhigher than the C+zions is also observed.

ISSN:0003-6951    

DOI:10.1063/1.89593

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

It is shown that the coherent coupling of radiation into metal‐barrier‐metal structures by surface plasmons, which reduces to the usual antenna coupling at low frequencies, can be efficient up to a frequency at least as high as the plasma resonance.

ISSN:0003-6951    

DOI:10.1063/1.89594

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

This paper develops a set of criteria for superradiant emission in x‐ray systems. These new criteria, which must be satisfied in order to obtain efficient x‐ray emission, are given in the form of simple inequalities in terms of experimental parameters.

ISSN:0003-6951    

DOI:10.1063/1.89595

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

A rectangular optical waveguide of homogeneous refractive index (dimensions 0.10×0.14×100 mm3) is designed to provide double self‐imaging of either end face upon the opposite one. We show how to use this guide as a fiber‐optical beamsplitter and, with the addition of a mirror, as a two‐beam interferometer. The operation of the interferometer demonstrates the mutual coherence of the split images. Applications are possible for in‐line fiber‐optical interferometric devices.

ISSN:0003-6951    

DOI:10.1063/1.89596

出版商:AIP    

年代:1977

数据来源: AIP