摘要:

The near-band-gap low-temperature photoluminescence (PL) in a pure film of GaAs in the presence of surface acoustic waves (SAW) has been studied experimentally. The complex behavior of the PL peak intensities with SAW power in the excitonic and acceptor spectral regions results from a charge bunching due to the piezoelectric field of SAW. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119180

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Diffusion of indium markers atT=900 °Chave been measured in undoped and Te-doped GaAs epilayers grown by organometallic vapor phase epitaxy. The diffusivity was found to be a linear function of electron concentration over the rangen=2×1017–1.5×1019 cm−3.The results are consistent with the interdiffusion of AlAs–GaAs superlattices, and the diffusivities of In and Al in GaAs at 900 °C are found to be essentially identical within experimental noise. The results strongly suggest that group III interdiffusion in GaAs is controlled by a Ga vacancy with a charge of−1.©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119181

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Vertical-cavity surface-emitting laser (VCSEL) structures have been grown on GaAs (311)B substrates by metalorganic chemical vapor deposition. C-doped GaAs and AlAs layers with smooth surface morphology and a hole concentration of1018 cm−3were obtained by optimizing the growth conditions; these conditions contributed to high-qualityp-type distributed Bragg reflectors (DBRs). The devices on the (311)B substrates exhibited a threshold current of 9.6 mA, voltage of 2.1 V, and maximum power of 4.1 mW at a 20 &mgr;m &fgr; size; these characteristics are similar to those obtained on (100) substrates. The polarization was aligned to [2¯33¯]. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119182

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

A novel method for measuring ultrathin (2–12 nm)SiO2film thickness is discussed. The process consists of: (1) formation of octadecyltrichlorosilane (OTS) self-assembled-monolayer (SAM) islands onSiO2of which thickness to be measured, (2) removal of theSiO2layers not covered by the OTS-SAM islands, and (3) measurement of the height difference between the etched and nonetched areas by atomic-force-microscopy. The OTS film is good resist against HF and its islands can be regarded as self-patterned-mask. Practical usefulness is demonstrated not only by the compatibility of the measured values but also by the short measurement period resulting from the directness of the method. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119183

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Self-consistent Hartree–Fock energy levels of mesoscopic voids in tetrahedrally bonded semiconductors are calculated within the Haldane–Anderson model revealing a high-multiplicity Coulomb ladder of discrete charge-state energies distributed across the semiconductor band gap. These discrete states can compensate shallow dopants. In GaAs, voids with radii of only 5 nm can compensate as many as 25 charges of either sign, producing depletion spheres around the voids in dopedn-type orp-type material. The compensation and depletion behavior of the voids is similar to the behavior of metallic precipitates in nonstoichiometric GaAs. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119184

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Silicon has been anodized such that the porous layer is passivated with a homogeneous stretching phase by incorporatingH2O2in the anodization mixture. Fourier transform infrared spectroscopy measurements show that the Si–H stretching mode oriented perpendicular to the surface at∼2100 cm−1dominates the spectrum with negligible contribution from the bending modes in the600–900 cm−1region. Material analysis using Auger electron spectroscopy shows that the samples have very little impurities, and that the luminescent layer is very thin (5–10 nm). Scanning electron microscopy shows that the surface is smoother with features smaller than those of conventional samples. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119185

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Stress-induced leakage current (SILC) in ultrathin oxide metal–oxide–semiconductor devices has been quantitatively modeled by the trap-assisted tunneling mechanism. These results are compared with experimental data on samples with oxide thickness ranging from 40 to 80 Å. This model accurately describes the electric-field dependence of SILC, and also predicts the increase, then decrease in SILC, with decreasing oxide thickness, which is observed experimentally. ©1997 American Institute of Physics. 

ISSN:0003-6951    

DOI:10.1063/1.119186

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We present evidence for anomalously large, strain-dependent interdiffusion inInAs1−xPxlayers grown on InP(001) substrates by organometallic vapor phase epitaxy at 620 °C. Specifically, there are strong indications for the existence of a “critical strain:” if the strain is∼1.9&percent;or more, much P–As mixing occurs, but for smaller strain the mixing is greatly decreased. The interdiffusion is also highly sensitive to temperature. A set of samples grown at 580 °C exhibits a factor of∼2decrease in P–As mixing compared to a set grown at 620 °C. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119187

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We have used admittance spectroscopy to measure conduction-band and valence-band offsets inSi/Si1−xGexandSi/Si1−x−yGexCyheterostructures grown by solid-source molecular-beam epitaxy. Valence-band offsets measured forSi/Si1−xGexheterojunctions were in excellent agreement with previously reported values. Incorporation of C intoSi1−x−yGexCylowers the valence- and conduction-band-edge energies compared to those inSi1−xGexwith the same Ge concentration. Comparison of our measured band offsets with previously reported measurements of energy band gaps inSi1−x−yGexCyandSi1−yCyalloy layers indicate that the band alignment is Type I for the compositions we have studied and that our measured band offsets are in quantitative agreement with these previously reported results. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119188

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

A novel fabrication process of ferroelectric-semiconductor heterostructures based on direct wafer bonding has been demonstrated. PolycrystallineBi4Ti3O12ferroelectric thin films were deposited on 3 in. silicon wafers using chemical solution deposition. The films were polished and then directly bonded to silicon wafers in a micro-cleanroom. After thermal annealing in air at 500 °C for 12 h, the bonding energy increases up to1.5 J/m2.High resolution transmission electron microscopy shows the difference between the bonded and reacted interfaces. Obtaining a metal-ferroelectric-silicon (MFS) structure containing the ferroelectric-Si bonded interface was achieved by polishing down and etching the handling wafer. TheBi4Ti3O12film kept its ferroelectric properties as shown byC–Vmeasurement. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.119189

出版商:AIP    

年代:1997

数据来源: AIP