摘要:

A new technique for the deposition of nickel metal films by gas‐phase pyrolysis of nickel tetracarbonyl gas is described. A pulsed CO2laser is used to form a reaction zone adjacent to a cold substrate, resulting in a rapidly quenched film. The technique relies on dielectric breakdown of a mixture of source and carrier gases and therefore lends itself to a variety of source gases and chemistries. Adherence data and compositional and structural analyses are presented.

ISSN:0021-8979    

DOI:10.1063/1.336114

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

The drift velocity of electrons in gallium phosphide has been measured for electric fields ranging from 10 to 280 kV/cm. A novel variation on the conductivity technique was used. The resulting saturated drift velocity, ∼1.25×107cm/sec, agrees with theoretical predictions.

ISSN:0021-8979    

DOI:10.1063/1.336115

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

Radiotracer and secondary‐ion mass spectrometry (SIMS) diffusion profiling techniques in CdxHg1−xTe (CMT) have been compared in order to provide a sounder basis for dopant characterization in this material. Au diffusion profiles were determined by the radiotracer and SIMS techniques after a diffusion anneal of 168 h at 225 °C in a flowing Ar ambient. The profiles obtained using the two different techniques were very similar, indicating the same Au diffusion behavior. It was shown that the radiotracer technique can be used for SIMS calibration of Au in CMT. It was also demonstrated that the two techniques give equally valid diffusion profiles.

ISSN:0021-8979    

DOI:10.1063/1.336090

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

The electron‐beam‐induced current contrast from oxygen‐induced defects in Czochralski silicon is studied. It is shown that positive and negative contrasts from individual defects can appear. In some cases a reversal of the contrast’s sign is observed when one changes the observation conditions (electron beam current, accelerating voltage).

ISSN:0021-8979    

DOI:10.1063/1.336091

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

Hall measurements on liquid phase epitaxial In1−xGaxAsyP1−ylattice matched to InP have been performed in the temperature range 300≤T(K)≤600 °C. The crystals were grown at 640 °C. Anomalous lowering of the mobility and carrier concentration has been observed at these temperatures for certain alloy compositions. It is believed that clustering due to miscibility gaps existing in these solid compositions is responsible for the observed data. Interpretations of the data based on this assumption have been made.

ISSN:0021-8979    

DOI:10.1063/1.336092

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

When Pt silicides are formed in an ambient containing oxygen, or using Pt films containing an appreciable amount of oxygen, the formation rates of the silicides are reduced. In the latter case the reduced rates are attributed to the formation of an oxide layer, from the oxygen contained, between the surface Pt and the Pt2Si and PtSi phases. To remove such difficulties, we use Pt films containing little oxygen, and study the effect of oxygen on the formation of both Pt silicides in an oxygen ambient. It is shown that oxygen diffuses from the ambient into Pt during the stage of Pt2Si formation, and an oxide layer is formed under the surface when the front of the Pt2Si phase meets the oxygen in the film, which hinders further growth of the Pt2Si phase. Subsequent formation of the PtSi phase proceeds until it meets the oxide layer and is hindered from further growth. Accordingly, the oxide layer described has little effect on the bulk growth of these two silicides, and other mechanisms are needed to account for the reduced rates by oxygen for such systems, such as that described by the surface potential model.

ISSN:0021-8979    

DOI:10.1063/1.336093

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

In0.53Ga0.47As lattice matched to InP substrate has been grown by chemical epitaxy (CBE). Epilayers with lattice‐mismatch &Dgr;a/a<1×10−3have been reproducibly obtained with extreme uniformity in both composition and layer thickness over a large area of 3.8 cm diameter (limited by the present substrate holder size) without the need of substrate rotation during growth. Surface morphologies were routinely featureless and mirrorlike as observed by Nomarski phase contrast microscope. Comparing with high‐quality In0.53Ga0.47As epilayers grown by molecular beam epitaxy (MBE), the CBE‐grown In0.53Ga0.47As epilayers have similar linewidths but can have substantially higher 300‐K photoluminescence intensities. The electron concentration and mobilities were found to be related to the source purity of the TMAs used. For epilayers grown with high‐purity TMAs source, room‐temperature electron mobility as high as 9000 cm2/V s and concentrations of ∼7×1015cm−3were produced. Such value represents the highest value obtained by using trimethylarsine as the arsenic source. In general, the electron mobilities were as good as those obtained from low‐pressure metalorganic chemical vapor deposition.

ISSN:0021-8979    

DOI:10.1063/1.336068

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

The dual field effect on the relaxation time of the liquid‐crystal BDH‐E7 has been analyzed and demonstrated experimentally by using static magnetic and pulsed optical fields. The novelty of this effect is in the use of a strong external field to accelerate the molecular relaxation process. An improvement factor on decay time up to 10 or higher depending on the field strength can be achieved. At high fields, this relaxation time is inversely proportional to the external field intensity and is independent of the liquid‐crystal thickness. Since this effect does not rely on the specific properties of liquid crystals, potential applications exist among many nematic liquid‐crystal materials.

ISSN:0021-8979    

DOI:10.1063/1.336069

出版商:AIP    

年代:1985

数据来源: AIP