摘要:

(001) GaAs surfaces treated with ultrasonic‐running de‐ionized water (U‐RDIW) after NH4OH/H2O2/H2O etching are investigated by reflection high‐energy electron diffraction (RHEED) and by x‐ray photoelectron spectroscopy (XPS). RHEED observations show a spotty (1×1) pattern lying on the 0‐th Laue circle at room temperature, a (2×4) streaky pattern at 310 °C, and a spotty (3×6) pattern after annealing at 370 °C. We discuss the difference in surface stoichiometry after U‐RDIW between the H2SO4‐ and NH4OH‐etched surfaces based on the results of XPS. The experimental results indicate the possibility of controlling the surface stoichiometry of the U‐RDIW‐treated GaAs surfaces by varying the etching solution.

ISSN:0003-6951    

DOI:10.1063/1.105691

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

A new transistor effect is demonstrated in a 120 nm base, bipolar quantum‐well, resonant‐tunneling transistor (BiQuaRTT). In this BiQuaRTT, a strong, multiple negative differential resistance (NDR) characteristic is obtained at room temperature with high‐current gain (≳50). The effect is shown to be the consequence of an asymmetric, quantum‐well‐base heterostructure whose shape is controlled by the base/collector bias. Changes in the quantum‐well shape lead to large modulations of the transmission coefficient for quasi‐thermalized minority electrons crossing the quantum‐well base. In this letter, we describe the transport characteristics of these transistors, including also temperature and magnetic field dependence.

ISSN:0003-6951    

DOI:10.1063/1.105692

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

By the use of ac conductance measurements, we have observed two distinct defects with different capture cross sections at the x‐ray irradiated (100)Si/SiO2interface. The capture cross section for one defect is a strong function of energy, while the other one is basically independent of energy. There is a strong possibility that these two interface defects correspond to the Pb0and Pb1centers seen in the electron spin resonance experiments. The fact that we do not observe the same behavior on (111) samples lends support to this hypothesis.

ISSN:0003-6951    

DOI:10.1063/1.105693

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The growth of Si(001) from a gas source molecular‐beam epitaxy system (Si‐GSMBE) using disilane (Si2H6) was investigated. The surface reconstructions occurring between 100–775 °C were studied as a function of both substrate temperature and surface coverage. Further, we report the first observation of (2×2) andc(4×4) reconstructions during growth at substrate temperatures near 645 °C using Si2H6. All growth was found to be initiated by the formation of 3D islands which coalesce at substrate temperatures above 600 °C, following which, growth proceeds in a two‐dimensional (2D) fashion. The Si surface was found to have undergone a series of reconstructions which were related to the number of hydrogen adatoms and Si dimers covering the surface.

ISSN:0003-6951    

DOI:10.1063/1.105694

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

X‐ray reflectivity has been utilized in a study of the SiO2/Si interfacial structure for dry oxides grown at room temperature on highly ordered Si(001) surfaces. Scattering near (±110) demonstrates the Si lattice termination of the wafers studied is characterized by a highly ordered array of terraces separated by monoatomic steps. Specular reflectivity data indicate the ‘‘native’’ dry oxide thickness is approximately 5 A˚ with a 1‐A˚ vacuum interface width. Residual laminar order in the oxide electron density along the oxide/Si interfacial normal decays exponentially from the oxide/Si interface with a ∼2.7‐A˚ decay length.

ISSN:0003-6951    

DOI:10.1063/1.105695

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The density of Si dangling bond defects in plasma‐deposited Si‐richa‐Si1−xCx:H anda‐Si1−xNx:H is argued to depend primarily on deposition temperature via the hydrogen diffusion rate. The optimum temperature equals about 0.62 of the bulk‐bonded hydrogen evolution temperature, or about 500 °C fora‐Si3N4:H. A model of hydrogen diffusion in alloys is proposed.

ISSN:0003-6951    

DOI:10.1063/1.105696

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The effect of free edges on the thermal stress distribution in square‐patterned GaAs/Si (100) is studied by three‐dimensional finite‐element elastic analysis. The results are discussed in comparison with previous analytical and numerical calculations. Finally the stress in the most important central portion of the square is calculated as a function of width to thickness ratio in the range 1 to 40. Results are presented in a form appropriate for interpretation of 4.2‐K photoluminescence (PL) measurements and device optimization.

ISSN:0003-6951    

DOI:10.1063/1.105697

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The common emitter current gain of InP/Ga0.47In0.53As heterojunction bipolar transitors having a base doping level of 7×1019cm−3is found to increase monotonically with decreasing base thickness in the range of 200–1000 A˚. The variation of the gain with base thicknessWBis proportional to 1×W2B, as expected for diffusive base transport, and a high injection efficiency.

ISSN:0003-6951    

DOI:10.1063/1.105698

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The optical properties of Cd0.3Zn0.7S/ZnS strained‐layer superlattices grown on (100) GaAs substrates by low‐pressure metalorganic chemical vapor deposition, were investigated by means of photoluminescence excitation spectroscopy and through the effect of an electric field on exciton emission. A multiple longitudinal optical‐phonon emission process, related to the relaxation of excitons, has been observed for the first time in the excitation spectra. The localization of excitons has been found to be the dominant cause of the linewidth broadening. The effects on an axial electric field on exciton emission intensity and peak position have revealed that the dissociation of the localized excitons on the low‐energy side of the spectrum principally takes place due to impact ionization.

ISSN:0003-6951    

DOI:10.1063/1.106396

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Using a modified electron spin resonance technique known as spin‐dependent recombination, we have found that channel hot hole injection innchannel metal oxide silicon (MOS) transistors creates the trivalent silicon dangling bond defect known as thePbocenter. This letter reports the first direct identification of the atomic structure of interfacial point defects created by channel hot carrier stressing in MOS transistors.

ISSN:0003-6951    

DOI:10.1063/1.105699

出版商:AIP    

年代:1991

数据来源: AIP