摘要:

The form imposed by the existence of a logarithmic transient to the relaxation times distribution has been deduced in a very general way. This distribution is found to be proportional to the inverse of the relaxation time. This result is then applied to analyze the particular case of a logarithmic capacitance transient originated from a thermally activated emission process.

ISSN:0021-8979    

DOI:10.1063/1.345348

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

High‐temperature stability of the F+‐ or BF+2‐implanted PtSi thin film was investigated. For the PtSi films that received F+implantation, the film characteristics remain unchanged even after annealing at 800 °C for 90 min, while for those without F+implantation, the film properties begin to degrade after annealing at 750 °C as observed by scanning electron microscopic inspection, Auger electron spectroscopy analysis, Rutherford backscattering spectroscopy analysis, and sheet resistance measurement. The secondary ion mass spectroscopy analysis indicates that the fluorine atoms are segregated to the PtSi/Si interface. A fluorine barrier model is proposed to explain the absence of Pt in‐diffusion induced deterioration for the F+‐implanted PtSi film.

ISSN:0021-8979    

DOI:10.1063/1.345327

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A prominent Urbach tail is introduced in the absorption spectra of In0.72Ga0.28As0.60P0.40, by Ge doping, due to transitions from disorder‐induced localized states at the valence‐band edge to conduction band. Different components of the disorder have been considered. A model calculation, considering multiphonon emission, has been made.

ISSN:0021-8979    

DOI:10.1063/1.345328

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Reported here are the results of investigations carried out on the mechanism of electrical conduction in CdSexTe1−xthin films between 300 and 125 K in vacuum. All the films showed a transition from grain boundary limited conduction in the conduction/valence band to phonon assisted hopping via the impurity band (impurity band conduction) at around 280–290 K. The grain boundary limited conduction showed an activation energy equal to about 0.14 eV and conduction via impurity band showed an activation energy of about 0.02 eV, which is characteristic of phonon assisted hopping conduction.

ISSN:0021-8979    

DOI:10.1063/1.345329

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A Fourier transform infrared study of Fe‐donor B‐acceptor complexes formed in iron‐implanted B‐doped Czochralski‐grown silicon crystals is performed by monitoring the behavior of boron‐acceptor excitation spectrum lines. The effect of the iron presence on absorption spectra due to B‐acceptor hydrogenlike systems, related to electronic transitions from the ground to excited states associated with the siliconP3/2valence band, was analyzed in a wide range of fluences. Low‐temperature optical data are reported and discussed comparing optical results with secondary‐ion mass spectroscopy and spreading resistance measurements, supporting the existence of a fluence threshold that controls iron diffusion into the bulk.

ISSN:0021-8979    

DOI:10.1063/1.345302

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Depth uniformity of electrical properties has been evaluated for neutron‐transmutation‐doped (NTD), semi‐insulating GaAs irradiated with thermal neutrons of 1.5×1018cm−2by the van der Pauw method combined with iterative etching of the surface. In NTD‐GaAs wafers (thickness ∼410 &mgr;m) annealed for 30 min at 700 °C, the depth profiles of the resistivity, the carrier concentration, and the Hall mobility show constant values of 1×10−2&OHgr; cm, 2.0×1017cm−3, and 3100 cm2/V s, respectively, within an experimental error of 5%. In an annealing process, the redistribution and/or the segregation of NTD impurities is not observed. We also discuss the limitations of low‐level NTD in semi‐insulating GaAs. It is suggested that the activation of the NTD‐impurities below ∼1×1016cm−3is mainly restricted by the presence of the midgap electron trap (EL2).

ISSN:0021-8979    

DOI:10.1063/1.345303

出版商:AIP    

年代:1990

数据来源: AIP