摘要:

The heteroepitaxial growth of ZnSe on GaAsepilayersgrown by molecular beam epitaxy is found to occur via a two‐dimensional growth mechanism. Alternatively, nucleation on a GaAs substrate exhibits three‐dimensional growth characteristics. The differentiation of the type of nucleation is evidenced by reflection high‐energy electron diffraction intensity oscillations, as well as the dynamic behavior of the diffraction patterns. Photoluminescence measurements of pseudomorphic ZnSe epilayers grown on GaAs epilayers provide a direct measurement of ZnSe deformation potentials.

ISSN:0003-6951    

DOI:10.1063/1.98247

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Interface structures in monocrystalline beta‐silicon carbide thin films grown on (001) silicon substrates have been studied by high‐resolution electron microscopy of cross‐sectional specimens. Despite a large lattice mismatch, there is a periodic registry of {111} atom planes across the SiC‐Si interface. Planar defects on SiC {111} planes are grown‐in and arise primarily from lattice and thermal expansion mismatch. Thermal oxidation in wet atmospheres results in preferential attack of the SiC film at sites where planar defects intersect the film surface, whereas oxidation in dry atmospheres does not.

ISSN:0003-6951    

DOI:10.1063/1.97661

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

High quality specular epilayers of GaAs were grown using a plasma enhanced metalorganic chemical vapor deposition process. The GaAs epilayers were grown from trimethyl gallium and arsine at very low pressures (2–3 Torr) using an rf discharge to dissociate arsine. Specular single‐crystal layers of unintentionally dopedn‐type GaAs were deposited on semi‐insulating GaAs substrates both with and without plasma enhancement. The reactor design allowed the group V sources (in this case arsine) to be dissociated by a plasma localized to an area above the substrate. Films deposited with and without an rf plasma had good mobility and photoluminescence, but as the temperature was lowered films deposited with the plasma were better than those deposited without the plasma.

ISSN:0003-6951    

DOI:10.1063/1.97662

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Very shallown+layers have been obtained in InP by using gallium sulfide as a source for sulfur diffusion, and chemically vapor deposited SiO2as a cap. Diffusions were carried out from 585 to 725 °C in an open‐tube system with a nitrogen ambient. The doping profile of sulfur in InP is estimated to be of the complementary error function type with a surface concentration of 5.6×1018/cc and a diffusion constant of 1.1×10−14cm2/s at 670 °C. Diodes made onn+‐pjunctions obtained by this diffusion technique show ideality factors close to unity and saturation current densities as low as 3.4×10−15A/cm2, signifying the presence of a defect‐free junction. These diffusions, with junction depths in the 400–700 A˚ range, are ideal for solar cell applications.

ISSN:0003-6951    

DOI:10.1063/1.97663

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We report the first observation of tunneling through In0.53Ga0.47As‐InP double‐barrier structures at 77 and 4.2 K. The tunneling peaks occur at voltages close to the predicted values of the subband levels of the quantum well. The observed values are symmetrical about zero bias, unlike the results for similar structures in the AlGaAs‐GaAs system. The measured peak‐to‐valley ratios are low, being near to unity. This result is attributed to the presence of a large leakage current caused by conduction at the edges of the devices. We also report the observation of minima in the conductance curves due to the resonance levels in the continuum of states above the quantum well.

ISSN:0003-6951    

DOI:10.1063/1.97664

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We show in this work that the internal photoemission at the semiconductor‐insulator interface in the semiconductor‐insulator‐electrolyte system can be used to initiate localized chemical reactions at the insulator‐electrolyte interface. Using this concept, successful depositions of Cu and Ni films have been obtained on oxidized Si wafers. We have also found that the activation of the SiO2surface with Pd atoms results in an efficient electron transfer at the SiO2‐electrolyte interface and improves the adhesion of the deposited metal.

ISSN:0003-6951    

DOI:10.1063/1.97665

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The use of AsH3in the organometallic vapor phase epitaxial (OMVPE) growth of GaAs and other As containing III/V semiconductors has a number of disadvantages, including toxicity hazard, purity problems associated with storage cylinders, and low pyrolysis rate at the low temperatures often desirable in OMVPE growth. A new organometallic source, tertiarybutylarsine (TBAs), has recently become available. In this letter we report the results of OMVPE growth of GaAs using trimethylgallium (TMGa) and TBAs in a one atmosphere ambient. The major results of the study are (1) the vapor pressure of TBAs is measured to be 96 Torr at 10 °C, (2) the pyrolysis rate of TBAs appears to be greater than that of AsH3under similar conditions, (3) as a consequence of (2), excellent morphology GaAs layers can be grown at lower values of V/III ratio (approximately unity) using TBAs than using AsH3(4) no additional carbon incorporation is produced by the use of the organometallic group V source. These factors make TBAs a promising candidate to replace AsH3in vapor phase epitaxial growth of GaAs.

ISSN:0003-6951    

DOI:10.1063/1.97666

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

When the surface of &bgr;‐SiC, grown epitaxially on (001) silicon by chemical vapor deposition, is chemically etched, boundaries appear which may be observed by optical or scanning electron microscopy. Examination by plan‐view and cross‐sectional transmission electron microscopy shows boundaries in the film which exhibit line or fringe contrast. Convergent beam electron diffraction has been used to show that these boundaries separate domains that are in an antiphase relationship to each other. A model is presented which discusses the formation of these domains from independent nucleation on a stepped substrate surface.

ISSN:0003-6951    

DOI:10.1063/1.97667

出版商:AIP    

年代:1987

数据来源: AIP