摘要:

Output energy of a discharge‐pumped F2molecular laser has been greatly increased by an extremely intense excitation in a sufficiently high‐pressure laser gas mixture. The maximum vacuum ultraviolet output energy was 112 mJ for an 8 atm laser gas mixture, which is almost an order of magnitude larger than that obtained so far with discharge devices. The peak power deposition into the discharge plasma was estimated to be 23 MW/cm3for the maximum output energy. Use of a short electrode spacing was found to be effective to increase the output energy.

ISSN:0003-6951    

DOI:10.1063/1.100889

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

We use the active‐layer photomixing technique to directly modulate the output of a GaAs semiconductor laser operating at temperatures as low as 4.2 K. The technique produces modulation with nearly perfect immunity to device parasitic effects, revealing the laser diode’s intrinsic modulation response. At 4.2 K the parasitic corner frequency is estimated to be 410 MHz, yet the response appears ideal out to 15 GHz. We measure the dynamical parameters governing the response function, the relaxation resonance frequency, and the damping rate, and discuss their low‐temperature behavior.

ISSN:0003-6951    

DOI:10.1063/1.100890

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

Transient‐enhanced diffusion of boron is studied by comparing through‐oxide and direct boron implants. Some of the directly implanted wafers are differentially anodized and etched to depths equal to the thicknesses of the thermal oxides. Spreading resistance profiles after annealing reveal that transient‐enhanced diffusion of boron can be prevented by implantation through oxide. The result indicates that the presence of recoiled oxygen in the through‐oxide implanted silicon can be important in reducing dopant‐enhanced diffusion.

ISSN:0003-6951    

DOI:10.1063/1.100891

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The threshold voltage (VT) shift of hydrogenated amorphous silicon thin‐film transistors (a‐Si:H TFTs) by boron doping has been investigated. In TFTs with a uniformly doped structure (SiN/B‐dopeda‐Si:H),VTshifts to a positive voltage by boron doping, while the field‐effect mobility decreases markedly. By using a step‐doped structure (SiN/undopeda‐Si:H/B‐dopeda‐Si:H), the degradation of the field‐effect mobility by boron doping becomes less than that of a uniformly doped TFT with the sameVTshift, and aVTshift of 3.5 V was obtained without degradation of the field‐effect mobility.

ISSN:0003-6951    

DOI:10.1063/1.100892

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The Franz–Keldysh oscillations induced by the electric field in the depleted zone below the GaAs surface are studied by photoreflectance spectroscopy. The electric field is precisely controlled by a molecular beam epitaxy grown buried highly doped layer and the pinned position of the Fermi level at the surface. It is shown that the electric field value as derived from theory is in disagreement with the value derived from electrostatic calculations. Consequently a determination of the Fermi level pinning is only possible from a measurement of bothn‐ andp‐doped samples.

ISSN:0003-6951    

DOI:10.1063/1.100893

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The combined use of rapid thermal annealing and deep level transient spectroscopy is described as an efficient means to reveal chromium profiles in silicon wafer after various thermal treatments. The proposed method has been successfully applied to observe the depletion of chromium atoms at the near‐surface region of intentionally contaminated Czochralski‐grown silicon reslting from a conventional three‐step gettering cycle.

ISSN:0003-6951    

DOI:10.1063/1.100894

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The intervalley electron‐phonon deformation potentials between the lowest &Ggr;−,X‐ andL‐conduction band valleys in zinc blende semiconductors are calculated using empirical pseudopotentials for the electrons and realistic shell models for the phonons. The intervalley scattering rates computed using these deformation potentials are in agreement with experiments.

ISSN:0003-6951    

DOI:10.1063/1.100895

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The physical and electronic structure of hydrogenated amorphous silicon carbide (a‐SiC:H) are identified by measuring its photoluminescence and infrared spectra at various stages of thermal annealing. It is found that Brodsky’s [Solid State Commun.36, 55 (1980)] quantum well model can be successfully applied to explain the observed results, such as the double peak structure in photoluminescence spectrum and the physical origin of the optical gap widening due to carbon incorporation.

ISSN:0003-6951    

DOI:10.1063/1.100896

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The stability of thin‐film transistors (TFTs) fabricated from undoped low‐pressure chemical vapor deposited polycrystalline silicon under stress conditions (dc voltage and temperature) is investigated. It is demonstrated that the Si‐SiO2interface morphology is critical for the TFT device performance. Device degradation and threshold voltage instabilities are mainly attributed to the roughened Si‐SiO2interface.

ISSN:0003-6951    

DOI:10.1063/1.100897

出版商:AIP    

年代:1989

数据来源: AIP

摘要:

The influence of group V:III flux ratio on the molecular beam epitaxy growth process of AlGaAs/GaAs quantum wells is studied by means of photoluminescence, using a careful line shape analysis. Upon enlarged group V flux, a sublinear increase of the growth rate and a reduction of shallow impurity incorporation is found, with, however, an increase of deep trap concentration, attributed to EL2.

ISSN:0003-6951    

DOI:10.1063/1.100898

出版商:AIP    

年代:1989

数据来源: AIP