摘要:

Bulk, undoped, semi‐insulating, liquid encapsulated Czochralski GaAs crystals have been annealed under controlled arsenic pressures, and the uniformities of EL2 concentration and resistivity were investigated. Crystals were grown from different melt compositions from Ga rich to As rich. Arsenic pressure was changed from 0 (vacuum) to 3.4×103Torr. As a result, it was found that both EL2 concentration and resistivity in the crystal grown from As‐rich melt have the lowest fluctuations around 530 Torr arsenic pressure.

ISSN:0003-6951    

DOI:10.1063/1.97944

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The amount of carbon in GaAs and (Al,Ga)As films depends on the orientation of crystals grown by metalorganic chemical vapor deposition. We investigated the relation between the incorporation of carbon and the orientation of crystals using (100), (311)A, and (311)Bsubstrates. The concentration of electrons on (311)Bsubstrates of unintentionally doped films was higher than those of the films on (100) and (311)Asubstrates. The films grown on (311)Bsubstrates did not showp‐type behavior even when they were grown with a fairly low V/III ratio. The relative intensity of the free‐to‐carbon acceptor luminescence of the films grown on (311)Bsubstrates was smaller than that of films grown on the other substrates. This is consistent with the results of carbon contamination indicated by secondary ion mass spectra. Furthermore, a reduced peak in photoluminescence caused by defects was observed when (311)Bsubstrates were used.

ISSN:0003-6951    

DOI:10.1063/1.97945

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We have investigated the states produced at the Si‐SiO2interface by Fowler–Nordheim tunneling and by UV photoinjection at low temperature (90 K). After the interface states are generated, subsequent application of a negative gate bias (5–6 MV/cm) converts them entirely into trapped negative charge. The reverse conversion into interface states occurs if a positive gate bias (5–6 MV/cm) is applied. Cycling of the defects between interface states and trapped negative charge is observed in both experiments. The data strongly suggest that both low‐temperature Fowler–Nordheim tunneling and UV photoinjection generate essentially the same structural defect at the interface between Si and SiO2.

ISSN:0003-6951    

DOI:10.1063/1.97946

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Broadband tapered slot antennas monolithically integrated on ion damaged silicon‐on‐sapphire substrates are driven by picosecond photoconductivity to generate and detect millimeter waves. The time‐dependent electromagnetic impulse response of these transceivers is modeled by relating the antenna structure and the shape of the exciting pulse. The far‐field response is observed to consist of a traveling‐wave component and a standing‐wave component, which is also predicted by the model.

ISSN:0003-6951    

DOI:10.1063/1.97947

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A planar InP/InGaAsP avalanche photodiode with a reduced junction curvature and lowp‐type doping was fabricated by Be+implantation through a photoelectrochemically etched InGaAs mask. A uniform gain as high as 15 was obtained without edge or surface breakdown. The device had a separated absorption and multiplication structure grown by vapor phase epitaxy. Then−‐InP top layer and guard ring conventionally used for planar devices were not needed. Two‐dimensional device modeling indicates that the reduced junction curvature and low doping can prevent edge breakdown and greatly suppress the surface field.

ISSN:0003-6951    

DOI:10.1063/1.97948

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Undoped metalorganic chemical vapor deposited GaAs layers on Si substrates were implanted with29Si ions (5×1012cm−2dose at 100 keV energy) to form a shallown‐type region. The net donor activation (74%) and electron mobility (3014 cm2 V−1 s−1) after rapid thermal annealing (900 °C, 10 s) were compared to those obtained for similar implants into bulk GaAs. There was a slight improvement in the proton backscattering yield from the GaAs‐Si interface region after the annealing cycle, consistent with cross‐sectional transmission electron microscopy data showing an alignment of defects in annealed samples.

ISSN:0003-6951    

DOI:10.1063/1.97949

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We present a procedure whereby a sheet of donor atoms is incorporated in (100) Si during molecular beam epitaxial growth. Analysis by secondary ion mass spectroscopy and transmission electron microscopy shows that the width of such &dgr;‐function doping layers is only a few lattice planes. Tunneling spectroscopy and transport measurements give evidence for quantum confinement of the electronic charge in the layer and thus confirm the narrow width.

ISSN:0003-6951    

DOI:10.1063/1.97950

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Thermal oxide layers grown on polycrystalline and amorphous silicon films have been analyzed and compared by using scanning electron microscope (SEM) photographs, ramp‐voltage‐stressed current‐voltage (I‐V) measurements, and constant current stress. The asperity effect observed from SEM photographs and the ramp‐voltage‐stressedI‐Vtechnique is found to be less serious for the thermal oxides grown on the amorphous silicon films, resulting in a smaller leakage current and a larger electron fluence endurance. These superior characteristics enable the amorphous silicon to be a good candidate for further scaled nonvolatile memory device applications.

ISSN:0003-6951    

DOI:10.1063/1.97951

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We report the operation of the first Ga0.47In0.53As/InP superlattice avalanche photodiode grown by metalorganic chemical vapor deposition. The undoped region of thep‐i‐nstructure consists of 100 periods of alternating InP and Ga0.47In0.53As layers 100 A˚ thick with no intentional doping. dc multiplication higher than 20 and high‐speed response with full width at half‐maximum of 200 ps have been measured.

ISSN:0003-6951    

DOI:10.1063/1.97952

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The properties of several III‐V compound semiconductor alloys, namely, GaAs, AlGaAs, and GaInP, have been studied at high temperatures using Raman spectroscopy. The temperature range used for these measurements includes the thermal dissociation temperatures for GaAs and GaInP in vacuum. The Raman spectra taken from the thermally dissociated surface yield information on the crystallinity (or lack of it) after decomposition in vacuum occurs. These data establish the feasibility to acquire Raman spectra of these materials and deduce their alloy composition and layer thickness during epitaxial growth. We have determined the phonon frequency shifts with temperature, and found that the linewidth broadening of the Raman peaks at high temperatures (700 °C) is minimal.

ISSN:0003-6951    

DOI:10.1063/1.97953

出版商:AIP    

年代:1987

数据来源: AIP