摘要:

The dynamic behavior of ions ejected by pulsed nitrogen laser irradiation of the single‐crystal CdS have been ivestigated with a dynamic mass spectroscopic method. The energetic ions are generated through a process different from that of slow neutrals. The ion produced below 80 mJ/cm2laser power is created at the surface and accelerated by a Madelung potential, reaching the kinetic energy of 100 eV. At a higher power region, relatively slow cadmium ions showed a Maxwellian velocity distribution suggesting the laser‐generated gaseous plasma. Three possible mechanisms for ion formation are presented.

ISSN:0021-8979    

DOI:10.1063/1.332461

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Band‐to‐band Auger recombination inn+‐type silicon is investigated. A new experimental approach for determining the band‐to‐band Auger coefficient that is based on the hot electrons generated in the recombination process is proposed and theoretically analyzed. Because this method is not sensitive to trap‐assisted Auger recombination, or other types of recombination, it can yield information regarding the fundamental lifetime limits in heavily doped silicon. Experimental results are presented in a companion paper, Part II.

ISSN:0021-8979    

DOI:10.1063/1.332408

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Using a new method based on hot‐electron generation, band‐to‐band Auger recombination inn+silicon is studied experimentally. Using the theory developed in Part I, a conservative analysis demonstrates that this Auger recombination is limited to an electron Auger coefficient smaller than 5×10−32cm6/sec which is in disagreement with some earlier studies reportingCn=2.8×10−31cm6/sec.

ISSN:0021-8979    

DOI:10.1063/1.332409

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

The equilibrium distribution of electrons and holes over shallow impurity states and energy bands of an ultrapure semiconductor is studied for the situation where the semiconductor is continuously illuminated with intrinsic light (i.e., radiation with energies of the order of the gap energy of the semiconductor). The response to additional injection of free minority or majority charge carriers into the energy bands—caused by photothermal ionization of minority or majority impurities, respectively—is separately investigated. The equilibrium and the response have theoretically been analyzed by means of a description with a set of rate of change equations. This analysis explains the usually observed behavior that photothermal ionization of minority impurities in ultrapure germanium under continuous illumination with intrinsic light gives rise to a decrease in electrical conductivity. The measured time evolution of the change in conductivity of an ultrapure germanium sample after the start of the photothermal process revealed a slow (∼5 ms) change, connected with minority impurities only, as well as a fast (<0.5 ms) change. The slow response time has been associated with the electron‐hole recombination time, yielding a value 5×10−12cm3 s−1for the electron‐hole recombination constant. It is demonstrated that in photothermal ionization spectroscopy, when using phase‐sensitive detection techniques by means of a lock‐in amplifier, such a simultaneous presence of a fast and a slow (i.e., of the order of magnitude of the chopping times applied) change in conductivity can cause artefacts in the spectra.

ISSN:0021-8979    

DOI:10.1063/1.332410

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Rod‐like defects in annealed oxygen rich silicon crystals grown by the Czochralski method were investigated by means of transmission electron microscopy. The rod‐like defect has an apparent Burgers vector along ⟨100⟩ and gives a dipole‐like contrast. The rod defect plane is ⟨100⟩ and its character is found to be extrinsic. The clearly resolved dipoles associated with the rod‐like defect consist of perfect dislocations and are interstitial in character. The rod‐like defects are tentatively attributed to some form of SiOxprecipitate.

ISSN:0021-8979    

DOI:10.1063/1.332411

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Ion implantation of P into (111) Si has been investigated by cross‐sectional transmission electron microscopy and secondary ion mass spectrometry. In the dose range 1×1015–2×1016cm−2at 120 keV the formation and width of the amorphous (a) layers were sensitively dependent on wafer temperature. The effect of dynamic annealing on the crystalline (c) to amorphous transformation, and the effect of amorphicity and roughness of thea/cinterface on the formation of microtwins have been studied. It has been observed that the P atoms in the amorphous (a) region do not redistribute on subsequent annealing while the P atoms below thea/crystalline (c) interface diffuse rapidly into the Si substrate. The carrier concentration profiles from the annealed samples were found to follow the atomic profiles almost exactly over the depth range extending from the surface to where the originala/cinterface existed. However, in the deeper regions, the electrical activity was found to be dependent on the annealing temperature used. The different behavior of atomic and carrier concentration redistributions in the amorphous and crystalline regions has been explained by a model that assumes incorporation of impurity atoms on substitutional sites by the movinga/cinterface on recrystallization. The P atoms in the deeper regions are believed to redistribute via an interstitial diffusion mechanism at low temperatures (≤750 °C) and eventually occupy substitutional sites at higher temperatures (>800 °C).

ISSN:0021-8979    

DOI:10.1063/1.332412

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Impurity segregation in explosively crystallizeda‐Si presents two different behaviors depending on whether the intermediate liquid phase in the explosive process is large or narrow. This confirms the theories already published. In other words,a‐Si explodes in a way similar toa‐Ge.a‐Si, however, presents a specific type of explosive crystallization explained by its higher nucleation rate with respect toa‐Ge.

ISSN:0021-8979    

DOI:10.1063/1.332413

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

The step coverage of a dc planar magnetron sputtering system with a revolving substrate is analyzed by both computer simulation and measurement of the step coverage. The model assumes line of sight deposition, no reemission, and the cosine growth law. Good quantitative agreement has been obtained between the model and the experiments. The modeled system does not show the deep cracks typical of the point source planetary system. This is explained by comparing the vapor distribution functions of the planetary and the sputtering systems.

ISSN:0021-8979    

DOI:10.1063/1.332414

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Indium tin oxide (ITO) films have been prepared by the magnetron sputtering technique from a target of a mixture of In2O3and SnO2in the proportion 9:1 by weight. By optimizing the deposition conditions it has been possible to produce highly transparent (transmission ∼90%) and conducting (resistivity ∼10−5&OHgr; cm) ITO films. A resistivity ∼10−4&OHgr; cm has been obtained for films of thickness ∼1000 A˚ at a comparatively low substrate temperature of 50 °C and without using oxygen in the sputtering chamber. To characterize the films, the following properties have been studied, viz., electrical conductivity, thermoelectric power, Hall effect, optical transmission, and band gap. The effect of annealing in air and vacuum on the properties of the films have also been studied.

ISSN:0021-8979    

DOI:10.1063/1.332415

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

An analytical study of anisothermal phase‐transformation kinetics is described. In particular, the familiar Johnson–Mehl–Avrami equation is generalized to the situation for which temperature increases linearly with time. An exact analysis of the problem is carried out, with the general solution being obtained in terms of one of Horn’s confluent hypergeometric functions. In order to facilitate practical application of the analysis, a number of approximate solutions are also obtained, one which is applicable for small relative changes of temperature and two of which are described in terms of certain asymptotic expansions. Two specific numerical examples are considered which serve to illustrate conditions affecting the relative accuracy of the approximate solutions.

ISSN:0021-8979    

DOI:10.1063/1.332416

出版商:AIP    

年代:1983

数据来源: AIP