摘要:

A numerical study of the formation of a radiation‐induced defect cluster center in neutron‐irradiated silicon has been performed by solving a set of semilinear parabolic reaction‐diffusion‐coupled equations. It is found that most of the primary displacement defects [interstitial (I) and vacancy (V)] will be annihilated byI‐Vdirect recombination in an extremely short time. In particular, the formation of four‐vacancy defects is independent of the concentration of sinks and impurities in a sample, and of the energy of the recoil particle relatively. The threshold energy for the formation of a vacancy cluster has also been studied. The results are discussed with the experimental observations.

ISSN:0021-8979    

DOI:10.1063/1.345799

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Electron energy distribution functions (EEDF) in a XeCl laser have been obtained by solving the time‐dependent Boltzmann equation coupled to the circuit equations, plasmachemistry, and photon kinetics. The results show that in some zones of temporal evolution, EEDF does not instantaneously follow the alteration of electric field. Moreover, electron‐electron and superelastic collisions play a non‐negligible role in affecting EEDF and related quantities.

ISSN:0021-8979    

DOI:10.1063/1.345800

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The frequency dependence of capacitance of Schottky barriers on AlxGa1−xAs@B:Si shows evidence of the alloy broadening of the emission and capture rates of theDXcenter. The data are analyzed by assuming a Gaussian distribution for the emission and capture barriers of theDXcenter. The variation of the high‐frequency (1‐MHz) capacitance as a function of temperature suggests a temperature dependence of the ionization energy of theDXcenter that might arise from an entropy contribution to the ionization energy of theDXcenter as suggested by Theisetal. [Mater. Sci. Forum38–41, 1073 (1989)].

ISSN:0021-8979    

DOI:10.1063/1.345801

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The influence of the copper concentration in silicon‐doped gallium arsenide on the photoionization and photoquenching of charge carriers was studied both experimentally and theoretically. The studies indicate that the compensation ratio (NCu/NSi) is an important parameter for the GaAs:Si:Cu switch systems with regard to the turn‐on and turn‐off performance. The optimum copper concentration for the use of GaAs:Si:Cu as an optically controlled closing and opening switch is determined.

ISSN:0021-8979    

DOI:10.1063/1.345780

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A theoretical basis to support the application of the fractal approach in fracture physics is put forward. According to the theory, if Griffith’s criterion is approved, the fractal approach can be used.

ISSN:0021-8979    

DOI:10.1063/1.345781

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

With optimal inductors shunted at the end of the transverse radio‐frequency (rf) discharge waveguide laser, the longitudinal voltage variation across a waveguide channel can be reduced. If multiple inductors are shunted at the appropriate positions, an almost perfect rf uniformity may be attained. All the optimum inductances are derived from the conventional transmission line theory.

ISSN:0021-8979    

DOI:10.1063/1.345782

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The problem of identification of the dominant recombination center in platinum‐doped silicon is investigated using deep‐level transient spectroscopy (DLTS). Measurements using electrical and optical injection on platinum‐dopedntype silicon are reported. Results of measurements show that the recently observed platinum‐related midgap level is an efficient recombination center and is probably responsible for the role of platinum as a lifetime killer. In addition, information is provided on the relative magnitudes of the electron and hole capture cross sections of the hitherto well‐known deep levels assigned to platinum.

ISSN:0021-8979    

DOI:10.1063/1.345783

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

In0.45Ga0.55As/GaAs/AlGaAs quantum well lasers emitting at 1100 nm have been fabricated and evaluated. These devices, which employ a highly strained quantum well region, exhibit low‐ (250 A/cm2) threshold current density and excellent reliability both of which were hitherto unattainable at such high In mole fractions.

ISSN:0021-8979    

DOI:10.1063/1.345758

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Low energy ion beam assisted deposition (IBAD) of refractory tungsten nitride films onto GaAs is attempted for the first time. This ion beam technique provides lower process pressure, and less ion damage to substrates and films than conventional reactive sputter deposition. Schottky diode characteristics of W/ and WNx/GaAs and their thermal stability were investigated by capping the refractory films with SiO2films and subsequent annealing at 700–900 °C for 30 min. While both tungsten and tungsten nitride contacts were stable up to 850 °C, the tungsten nitride contact showed better thermal stability and higher Schottky barrier height. The Schottky barrier heights of W/ and WN0.27/GaAs diodes annealed at 850 °C were 0.71 and 0.84 eV, respectively. These preliminary results are comparable to those of the best results reported with the conventional sputtering methods.

ISSN:0021-8979    

DOI:10.1063/1.345759

出版商:AIP    

年代:1990

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.346116

出版商:AIP    

年代:1990

数据来源: AIP