摘要:

Data are presented demonstrating the optically coupled operation of a 3×3 two‐dimensional array of AlxGa1−xAs‐GaAs vertical‐cavity surface‐emitting lasers. Room‐temperature threshold current for the array is 90 mA, with the device geometry allowing for light emission from the epitaxial side of the device.

ISSN:0003-6951    

DOI:10.1063/1.102981

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

An integrated optic circuit on silicon, which can be used in balanced polarization diversity detection, is demonstrated. The device consists of a 3 dB coupler and two polarization splitters. It has excess losses of 1.8 and 3.0 dB for TM and TE polarizations, respectively, and around −22 dB rejection of the unwanted polarizations at each output.

ISSN:0003-6951    

DOI:10.1063/1.102982

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Artificial multilayers of amorphous Si and amorphous Si containing 0.7 at. % Au, with repeat lengths between 44 and 48A, were fabricated by ion beam sputtering. The change, with annealing time in the intensity of the first‐order x‐ray diffraction peak resulting from the composition modulation, is used to determine the diffusivity of Au in amorphous Si. Diffusion lengths on the order of an interatomic distance have been measured. The diffusivities over the temperature range 200–260 °C have an Arrhenius‐type temperature dependence with an activation enthalpy of about 1.3 eV, and are in agreement with the extrapolation of published higher temperature data.

ISSN:0003-6951    

DOI:10.1063/1.102983

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Raman spectroscopy is used as a probe of the state of amorphous Si (a‐Si) and damaged crystalline Si. MeV ion beams have been used to irradiate structurally relaxeda‐Si. When the density of Si atoms displaced by nuclear collisions exceeds 5%, thea‐Si is ‘‘de‐relaxed’’, and thus returns to its as‐implanted state. This behavior is an indication that point defect complexes exist ina‐Si and play an important role in the process of structural relaxation.

ISSN:0003-6951    

DOI:10.1063/1.102984

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We have imaged, in ultrahigh vacuum, the (001) surface of NaCl using an optical‐beam‐deflectin force microscope operating in the short‐range repulsive regime. The design and performance characteristics of the microscope are given, and the observed atomic corrugations are compared with those deduced from He‐atom scattering experiments.

ISSN:0003-6951    

DOI:10.1063/1.102985

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The kinetics for the thermal emission of electrons fromDXlevels are shown to be exponential in heavily Si‐doped GaAs. Isothermal voltage transients, obtained atconstantcapacitance, show a perfect exponential behavior. In contrast, a clear deviation from a single exponential function is observed when the transients are recorded at constant voltage, due to the nonuniform doping profile in these structures. The exponential emission kinetics seen in GaAs support the proposal that nonexponential emission kinetics observed atconstantcapacitancein AlxGa1−xAs are due to different emission rates forDXlevels having different local atomic configurations in the alloy.

ISSN:0003-6951    

DOI:10.1063/1.102986

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

This letter presents results of high structural quality epi/oxide boundaries of selective epitaxy grown on (100) oxide patterned Si wafers by ultralow pressure chemical vapor deposition from SiH4/H2at 800 °C using growth‐sputter cycles. The epitaxial films were characterized by cross‐sectional transmission electron microscopy and Nomarski optical microscope. About 2.1 &mgr;m silicon epitaxy was grown on the exposed silicon windows with about 0.27 &mgr;m lateral epitaxial growth over the oxide near {011} epi/oxide sidewalls. Almost no lateral epitaxial overgrowth was observed near {010} sidewalls. The epi/oxide boundary and the epitaxy grown over the oxide were found to be of high structural quality and defect‐free.

ISSN:0003-6951    

DOI:10.1063/1.103232

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The electronic states of Si(111), (110), and (100) surfaces in the early oxidation stages are examined using high‐resolution photoelectron spectroscopy (&Dgr;E<0.3 eV) with synchrotron radiation. The experimental results reveal stronger intensities of Si3+and Si4+oxide components for the Si(111) surface oxidation than for the Si(110) and (100) surface oxidations. Additionally, the depth distribution of intermediary components (SiOx: 0<x≤2) obtained from the tunability of synchrotron radiation shows that the Si3+and Si4+oxidation states form at the first and second outermost layers of the Si(111) surface. Features of the oxidation process are also discussed.

ISSN:0003-6951    

DOI:10.1063/1.102987

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We have observed an electron paramagnetic resonance signal corresponding to a neutral fourfold coordinated nitrogen in plasma‐enhanced chemical vapor deposited SiO2films fabricated under certain conditions. The same films containE’centers (positive oxygen vacancies) in an equal quantity. Our data support a model in which these two paramagnetic centers are created simultaneously by an electron transfer, starting from a positive fourfold nitrogen and a neutral oxygen vacancy. This model allows an earlier observation of an apparently neutralE’variant to be interpreted as a normal positiveE’plus a nitrogen center to conserve charge.

ISSN:0003-6951    

DOI:10.1063/1.103233

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Transmission spectra of ZnTe‐ZnSe strained‐layer superlattices grown on GaAs (001) have been measured for the first time and step‐like optical‐absorption spectra between conduction and valence subbands have been observed. The GaAs substrates with a narrower band gap than the superlattices were partially removed by a chemical etching method. For the ZnTe‐ZnSe superlattices with a type II band structure, the transmission spectra provide a powerful tool for determining the effective band gap and band offset, because the spatial indirect transition of separately confined electrons and holes is very weak and therefore difficult to observe in photoluminescence measurements. The absorption thresholds observed in the transmission spectra agree very well with the exciton emissions that appeared in photoluminescence data.

ISSN:0003-6951    

DOI:10.1063/1.102988

出版商:AIP    

年代:1990

数据来源: AIP