摘要:

We have measured the electric field distribution in the cathode sheath of an electron beam He glow discharge. Laser saturation spectroscopy was used to determine the quadratic Stark shift produced by the electric field. The experimental results are in good agreement with the calculations of a collisional model of the cathode sheath.

ISSN:0003-6951    

DOI:10.1063/1.98405

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We find the equilibrium temperature for intrinsic glow discharge amorphous silicon to be 195–200 °C. Defects left behind after fast cooling result in a temperature‐dependent dc photoconductivity which shows small differences in the tail state recombination kinetics when compared to defects left behind in the same number after light soaking. Finally anneal kinetics of fast cool defects follow neither singly activated, mono‐, nor bimolecular kinetics with a temperature dependence indicating activation energies from 1.0 to 1.4 eV. Unlike the distribution of defects left behind in similar number as a result of light soaking at room temperature, the distribution of defects resulting from fast cooling from higher temperature is shifted to higher energies and requires much longer anneal times.

ISSN:0003-6951    

DOI:10.1063/1.98406

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Laser irradiation at fluences below the damage threshold level of antireflection‐coated BK7 (grade A borosilicate crown glass) samples temporarily increases the measured laser‐induced damage threshold by about 40%. Because the surface damage threshold is sensitive to the irradiation history, it is necessary to control the test procedure to ensure reproducible and accurate measurements. Preliminary results indicate that adsorption of water is a principal factor involved in the deactivation of the conditioning enhanced laser damage thresholds.

ISSN:0003-6951    

DOI:10.1063/1.98407

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

It is found that the characteristic infrared spectra of thermally grown silicon dioxide in the 1075 cm−1region for films in the thickness range 28–450 A˚ mathematically deconvolute consistently into two distinctly separate Gaussian profiles. The derived peaks are found around 1050 cm−1with a full width at half‐maximum transmission value (FWHM) of 65 cm−1, and near 1085 cm−1with a FWHM of 35 cm−1. The relative band areas of these two features are consistently found to be approximately 0.76 and 0.24, respectively. These observations could be supportive of at least two structural models of amorphous silicon dioxide disclaiming the generally accepted continuous random network arrangement.

ISSN:0003-6951    

DOI:10.1063/1.98408

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The thermal stability of CrSi2fine lines on undoped chemical vapor deposited polycrystalline silicon was investigated. Heat treatments were in vacuum at temperatures between 500 and 950 °C. Hillock growth resulting from dissolution of silicon and subsequent regrowth in the silicide resulted in degradation at temperatures as low as 650 °C. We found that the degradation occurs preferentially at line edges. It is suggested that the edge preference is due to silicide deformation that is required at recrystallization sites.

ISSN:0003-6951    

DOI:10.1063/1.98409

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Al films deposited on Pt layers developed voids after annealing between 200 and 300 °C. Void formation in the Al was also observed when the Pt layer was deposited above the Al film. The amount of Al surrounding the voids increased as the voids grew. The void growth seems to saturate when all the Pt is consumed to form Pt2Al3, and the rate of void growth decreases as the thickness of the initial Al film increases. We believe the controlling mechanism is diffusion along the Al/Pt interface made possible by compound formation there.

ISSN:0003-6951    

DOI:10.1063/1.98410

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We demonstrate that second harmonic generation is a sensitive probe of thin‐film deposition conditions.

ISSN:0003-6951    

DOI:10.1063/1.98411

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We have measured the saturation of optical absorption in GaSb at wavelengths close to the band gap, and have determined the nonlinear absorption (&agr;2) and refraction (n2) coefficients. At liquid‐helium temperature a sharp free‐exciton absorption line is observed which saturates with increasing incident laser intensity; we obtain values ‖&agr;2‖=70 cm W−1and ‖n2‖≊0.2 cm2 kW−1. At room temperature we do not observe a well‐defined exciton; saturation of the residual interband absorption occurs at much higher intensity, and it is found to be obscured by strong thermal effects.

ISSN:0003-6951    

DOI:10.1063/1.98412

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The relation between generation of neutral electron trap centers and hole trapping in thermally grown SiO2under Fowler–Nordheim tunneling stress has been investigated. The experimental results show that the density of neutral electron trap centers is proportional to the density of trapped holes under Fowler–Nordheim tunneling stress with various electric fields and the total number of electrons injected into the oxide. The generation mechanism is explained by a model based on strained bonds.

ISSN:0003-6951    

DOI:10.1063/1.98413

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The interaction of the surface acoustic wave (SAW) with the GaAs/AlAs superlattice is investigated using a separate‐medium convolver structure. The magnitude and polarity of the acoustoelectric voltages exhibit strong temperature and SAW frequency dependences, a phenomenon that is not observed in homogeneous semiconductors. Possible SAW‐superlattice interaction models that tentatively explain the observed data are discussed.

ISSN:0003-6951    

DOI:10.1063/1.98414

出版商:AIP    

年代:1987

数据来源: AIP