摘要:

The crystallinity and regrowth mechanism of a seeded‐lateral epitaxial layer of Si on a SiO2substrate is evaluated using a newly developed microprobe reflection high‐energy electron diffraction method. Measurements with a spatial resolution of 0.1 &mgr;m reveal that the lateral seeding process actually occurs in the regrowth process and that the seeding area is indispensable to the process, though a seed length of less than 0.5 &mgr;m is required.

ISSN:0003-6951    

DOI:10.1063/1.93375

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

We provide experimental evidence of electrical activity correlated with residual boron impurities and native point defects in undoped liquid‐encapsulated Czochralski GaAs crystals. In Ga‐rich samples containing ≥1017cm−3boron, an 0.073‐eV acceptor level is observed in which the concentration increases with Ga and B content. An approximately quadratic increase in the concentration of the 0.073‐eV defect acceptor is observed with increasing boron concentration, suggesting that a complex involving boron with an intrinsic defect (VAs, Gai, or GaAs) is responsible for the observed acceptor behavior. No evidence of electrically active boron or boron complexes was found in semi‐insulating GaAs pulled from stoichiometric or As‐rich melts.

ISSN:0003-6951    

DOI:10.1063/1.93376

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

We report the first successful preparation of current injection GaInAsP/InP double heterostructure lasers operating at 1.3 &mgr;m by molecular beam epitaxy. The median threshold current densityJthis 3.5 kA/cm2, while the lowestJthis 1.8 kA/cm2for broad‐area Fabry–Perot diodes of 380×200 &mgr;m and an active layer thickness of 0.2 &mgr;m. The threshold current‐temperature dependence is described very closely by exp (T/T0) withT0of 70–87 K in the temperature range 10°–65 °C. Elemental As and P (red phosphorus) were used as the primary molecular beam sources for deriving the As2and P2beams. In addition, the As and P ovens were equipped with recharge interlock systems. As a result, the growth chamber was always maintained in ultrahigh vacuum condition even during As and P recharge.

ISSN:0003-6951    

DOI:10.1063/1.93377

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

All hard Josephson tunnel junctions, whose base and counter electrodes are composed of double‐layered niobium nitride (NbN) and niobium (Nb) films, have been successfully fabricated by isolating a junction sandwich formed on a whole silicon wafer with a reactive ion etching technique. The reactive ion etching technique has been used for patterning both base and counterelectrodes, and self‐aligning definition of junction areas has been performed. The fabricated junctions show good quality single‐particle tunneling characteristics and excellent uniformity in critical currents.

ISSN:0003-6951    

DOI:10.1063/1.93378

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Conversion electron Mo¨ssbauer spectroscopy has been used to study irradiation effects in the near surface region of type 304 stainless steel after 40 keV helium ion bombardment; a ferromagnetic phase in the paramagnetic matrix was observed after the irradiation to 8×1017ion/cm2at 200 °C. The amount of ferromagnetic phase was found to increase with increasing helium ion fluence.

ISSN:0003-6951    

DOI:10.1063/1.93379

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Polished silicon substrates weree‐gun deposited with 100‐nm films of CaF2in a molecular beam epitaxy vacuum station. Measurements of this material system reveal a factor of 35 reduction in reflectivity for films exposed to electron irradiation. Exposure is accomplished by simply viewing the desired area using a 3‐kV Auger electron microprobe. It is further reported that this exposed inorganic material can be developed (selectively washed away) in H2O. In addition, both over and under exposures have been observed. Optimum electron exposure dose has been determined to be 0.1–0.2 C/cm2.

ISSN:0003-6951    

DOI:10.1063/1.93380

出版商:AIP    

年代:1982

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.93719

出版商:AIP    

年代:1982

数据来源: AIP