摘要:

Nonstoichiometry in undoped semi‐insulating GaAs grown by the liquid‐encapsulated Czochralski technique has been evaluated by absolute lattice parameter measurements using the Bond method. The lattice parameter increases with increasing As atom fraction in the initial melt. The observed range of lattice parameters and the variation along the growth direction suggest that the solidus curve in the phase diagram extends to the As‐rich side than to the Ga‐rich side, and the congruent point is located on the stoichiometric point or the slightly As‐rich side.

ISSN:0003-6951    

DOI:10.1063/1.97377

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Electron paramagnetic resonance studies on as‐grown semi‐insulating liquid encapsulation Czochralski (LEC) GaAs at 35 GHz have revealed a new resonance labeled FR3. It is consistently present in LEC material but usually unobservable in Bridgman samples, thus strongly indicating that the defect involved contains boron. The center has trigonal symmetry and is electrically active. Its spectrum indicates ad 9orp5one‐hole configuration. We tentatively identify FR3 with a Ga antisite complex, Ga−As‐B0Ga.

ISSN:0003-6951    

DOI:10.1063/1.97378

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

We have studied the electrical characteristics ofp‐GaAs/n‐Si (100) heterojunction diodes grown by molecular beam epitaxy in an effort to determine the interface polarity. A Ga or As pre‐exposure was used prior to the growth ofp‐GaAs onn‐Si substrates to prevent antiphase domains. The Ga prelayer induces a shift in the built‐in voltage of −0.2 V, while the As prelayer shifts it as much as +2.0 V depending upon the As coverage. From the shift, the electrical charge and its polarity can be determined which is not possible by structural analysis. These electrical measurements are very sensitive to the interface charge properties and show very clearly that even with a submonolayer pre‐exposure, antiphase domain‐free material can be obtained.

ISSN:0003-6951    

DOI:10.1063/1.97379

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

We report the first operating bipolar transistor built with an AlGaAs/GaAs superlattice base. High current gain is measured with a suitable design of the bipolar transistor structure. Experimental results are in good agreement with a Bloch to hopping transition which is very sensitive to the AlGaAs barrier thickness. This interpretation is supported by a detailed numerical simulation reproducing the staticIc(Vce,Ib) transistor transfer data.

ISSN:0003-6951    

DOI:10.1063/1.97380

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

We established that the contact resistance to the two‐dimensional electron gas (2DEG) in selectively dopedn‐AlGaAs/GaAs heterostructure is crystal orientation dependent. The contact resistance in the [011] direction is the lowest and that in the [01¯1] direction is the highest. The contact resistance monotonically changes between the [011] and [01¯1] directions. We also find the sheet resistance dependence of the contact resistance.

ISSN:0003-6951    

DOI:10.1063/1.97381

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The first stages of the formation of the so called ‘‘new donors’’ is studied by annealing initiallyn‐type Czochralski silicon at 580 °C for 24–360 h. The analysis of electrical properties using the admittance spectroscopy technique reveals that the freezing of carriers is controlled by an activation energy of 20 meV, and a discrete level is detected at 19 meV. These effects are tentatively ascribed to levels localized within quantum wells surrounding small positively charged oxide precipitates.

ISSN:0003-6951    

DOI:10.1063/1.97627

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The problems of residual extended defects due to end‐of‐range ion implantation damage and mask edge lateral damage have been solved in this study for shallow boron junctions preamorphized via germanium ion implantation. Defect elimination has been achieved by adjusting the germanium ion energy, dose, and annealing temperature and ambient to minimize the local interstitial point defect concentration and optimize the role of the free surface in defect annihilation. For the combination of shallow, low dose 40 or 60 keV/2×1014cm−2Ge+and 8 keV/1×1015cm−2B+implants, a defect‐free structure was obtained following a 1050 °C, 10 s rapid thermal anneal (RTA) in a nonoxidizing Ar ambient. For these samples, boron profiles determined using secondary ion mass spectroscopy (SIMS) showed the junction depth to be approximately 0.17 &mgr;m at a background doping of 1×1017cm−3with a sheet resistance of 136 &OHgr;/&laplac;.

ISSN:0003-6951    

DOI:10.1063/1.97382

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Amorphous SiNx:H films were prepared by rf glow discharge (GD) of SiH4‐N2‐H2mixtures at 300 °C using a new decomposition technique. The optical gapEgincreases slowly with the ratio N2/SiH4up to a critical gapEgcof 2.5–3.0 eV, and then rapidly increases up to 5.3 eV. The spin densityNsfrom electron spin resonance of Si dangling bonds increases with N2/SiH4untilEgreachesEgc. AboveEgc,Nsrapidly decreases in contrast with that of conventional GD films, but in similarity to pyrolytic films. The slopeBin Tauc equation for optical absorption corresponds well withNs.

ISSN:0003-6951    

DOI:10.1063/1.97383

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Carrier confinement to one and zero degrees of freedom has been achieved in artificial quantum well wires and boxes fabricated in the GaAs‐GaAlAs system. Low‐temperature cathodoluminescence measurements show new luminescence lines attributed to transitions arising from ground and excited levels of electrons within these low dimensional structures.

ISSN:0003-6951    

DOI:10.1063/1.97384

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The effect of emitter grading on the injection barrier of Al0.3Ga0.7As/GaAs heterojunction bipolar transistor grown by metalorganic chemical vapor deposition was studied. The barrier height for electrons injected from the emitter was determined from the temperature dependence of collector current. It has been directly confirmed that the barriers for graded heterojunction and GaAs homojunction are comparable. However, the grading enhanced the recombination at the emitter‐base depletion region, which suggests that the hole confinement was reduced.

ISSN:0003-6951    

DOI:10.1063/1.97385

出版商:AIP    

年代:1986

数据来源: AIP