摘要:

Defects with deep electronic energy levels induced by electron irradiation at room temperature or plastic deformation at 450°C in GaAs in which grown-in EL2 defects are previously eliminated by heat-treatment are investigated by means of measurements of the optical absorption and the Hall effect. Thermal stabilities of the induced defects are studied by tracing the changes mainly in the absorption specturm due to isochronal annealing. The absorptions both in deformed and irradiated specimens are mostly photo-unquenchable. Therefore, the defects induced by above two procedures are identified not to be EL2. Semi-insulating orn-type specimens convert top-type by plastic deformation or electron irradiation, showing that high densities of acceptors are generated by the above two procedures.

ISSN:1042-0150    

DOI:10.1080/10420158908213016

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This work is devoted to an “old” defect and its annealing characteristics, namely the divacancy centre in silicon. Infrared spectroscopy is applied to study the annealing kinetics of divacancy-related absorption peaks in electron-irradiated Czochralski-grown samples doped with boron. In all specimens the kinetics show an exponential decay (first-order process) and a model taking into account both diffusion and dissociation as annihilation mechanisms gives excellent quantitative agreement with the experimental results. Activation energy values extracted for diffusion and dissociation are 1.28 eV and 1.71 eV, respectively. In highly boron doped samples (0.1 °Cm), a strong dependence of the absorption bands on the Fermi-level position is observed during annealing below ∼ 200°C and concurrently, a change of the divacancy charge state from neutral to singly positive takes place.

ISSN:1042-0150    

DOI:10.1080/10420158908213017

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

EFG silicon ribbon and two kinds of polycrystalline silicon (SILSO and HEM) obtained by casting techniques, with different concentrations of oxygen and carbon impurities have undergone thermal treatments in the temperature range from 450 to 1300°C. Infrared spectroscopy was used to monitor changes in the concentration and configuration of various defects. The carbon-to-oxygen concentration ratio and the thermal history of the investigated materials proved to be of the paramount importance in the nucleation and growth of various precipitation phenomena at higher temperatures. As distinct from single crystal silicon, grain boundaries and high dislocation densities offer an additional source of impurities which may be seen by the infrared techniques upon their activation at higher temperatures.

ISSN:1042-0150    

DOI:10.1080/10420158908213018

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:1042-0150    

DOI:10.1080/10420158908213019

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A possible atomic mechanism of amorphization-crystallization processes in irradiated diamond-type semiconductors is proposed in the present work. This mechanism is based on the concept of a phase transition into a new state with participation of point defects and can be considered as a basis for the kinetic description of amorphization-crystallization processes in semiconductors during irradiation.

ISSN:1042-0150    

DOI:10.1080/10420158908213020

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The non-monotonic distribution of secondary defects after two-step annealing of silicon implanted with boron ions is investigated using the TEM technique and the method of mercury probe along a bevel which was made chemically. Possible mechanisms of multilayer structure formation are discussed.

ISSN:1042-0150    

DOI:10.1080/10420158908213021

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

It was investigated that, when an Al evaporated layer on a GaP (GaAs, GaAs1−yPy) substrate was bombarded with total fluences of 0.1−1.0 × 1018electrons cm−2at 7 MeV and at 50°C, a thin heteroepitaxial layer of AlxGa1−xP (AlxGa1−xAs, AlxGa1−xAs1−yPy) crystal was grown on S-doped (111), (100) and (110) GaP [(110) Cr, O-doped GaAs, (100) Te-doped GaAS1−yPy] substrates.

ISSN:1042-0150    

DOI:10.1080/10420158908213022

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Two optical absorption bands are identified as arising from the negative charge state of each of the P-, As-, and Sb-vacancy pairs in silicon. The more prominent band for each is at 6150, 6000, and 5500 cm−1, respectively. A second broader partially overlapping band at ∼8500 cm−1is also present for each. Dichroism produced in the bands by uniaxial stress reveals a static Jahn-Teller distortion of opposite sign to that for the neutral state previously studied by EPR. The absorption bands can be identified as electron transitions from filled to empty orbitals of a simple one-electron molecular orbital model for the defect.

ISSN:1042-0150    

DOI:10.1080/10420158908213023

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:1042-0150    

DOI:10.1080/10420158908213024

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor