摘要:

The temperature dependence of the local mode absorption of CAsat 580 cm−1is reexamined using high‐resolution Fourier transform spectroscopy. A new carbon‐related line is detected at room temperature on the low‐energy side of the main carbon peak at 576.6 cm−1. It follows that the integrated absorption of the whole band is independent of temperature in the temperature range between 77 and 300 K. Calibration factors are given for 77 and 300 K, providing a consistent interpretation of previous data. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114183

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A quantitative three‐dimensional measurement of sidewall roughness of InP etched by chlorine‐based reactive ion beam etching (RIBE) is presented. An electron probe surface roughness analyzer using four secondary electron detectors was employed. The minimum value of average sidewall roughness under the optimized etching condition was as small as 1 nm, where the etching condition was an ion extraction voltage of 400 V and a Cl2gas pressure of 1.2×10−3Torr. It is found that the etched sidewall roughness can be reduced by lowering ion extraction voltage with a relatively higher gas pressure. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114184

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We use spectrally resolved measurements of spontaneous emission to investigate the temperature characteristics of strained and lattice matched InGaAsP multiquantum well lasers. Carrier overflow into the barriers and separate confinement layers and the resulting recombination are demonstrated to be an important factor limiting high temperature performances in these devices. The barrier recombination does not saturate above threshold, instead it increases with the drive current. This effect is further enhanced with increased temperature. We show that the reduction in the barrier recombination correlates quantitatively with increased high temperature slope efficiency. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114185

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The photoluminescence of strained Si1−xCxalloys grown at low temperature by rapid thermal chemical vapor deposition is investigated. The photoluminescence spectra are mainly characterized by a deep level broadband at low energy which subsists up to room temperature. This low energy emission is associated with the low‐temperature growth process required for the incorporation of carbon into substitutional sites. The stability of the layers after thermal annealing is monitored using this low energy radiative recombination. A blue shift of the photoluminescence energy peak is observed and the peak intensity presents a maximum versus annealing time. The blue shift and the associated increased linewidth is explained in terms of the local strain induced band‐gap fluctuations. Infrared transmission spectra of the annealed samples suggest that silicon carbide precipitates appear during the anneal and that oxygen and carbon complexes contribute to the formation of the deep level band. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114186

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The factors affecting the channel mobility of metal–oxide–semiconductor transistors fabricated using as‐deposited rapid thermal chemical vapor deposition (RTCVD) of silicon dioxide are investigated and compared to thermal silicon dioxide at various temperatures. The results indicate that the observed differences in the mobility values of thermal and rapid thermal chemical vapor deposed oxides at channel concentrations where Coulombic scattering is important is due to increased oxide trapping in the RTCVD films. It was also observed that the rapid thermal chemical vapor deposited oxides exhibited slightly larger mobility degradation rates at high fields when compared to thermal oxides. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114149

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Electron‐beam evaporation was used as a low‐temperature deposition process of boron and boron/amorphous‐silicon layers as dopant sources in rapid thermal diffusion. High efficiency of doping is attributed to high dopant supply from the boron layer to the silicon substrate. Oxygen ambient leads to layer consumption and thus opens possibility for the source removal after diffusion. Dopant activation results in high carrier concentration within the junctions. High concentrations of dopant cause generation of precipitates at the B/Si substrate interface but not at the B/Si cap interface. The process is compatible with the complementary‐metal‐oxide‐semiconductor technology since the low temperature of the source deposition facilitates masking of the dopant by a patterned photoresist and its subsequent lift‐off removal from the silicon surface. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114150

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A nonlinear switch formed by the integration of an overmoded multi‐quantum‐well (MQW) section with disordered input and output branching waveguides is presented. The area‐selective disordering of GaAs/AlGaAs MQWs is achieved by diffusion of group III vacancies generated by etching of the surface oxide. The absorption edge of the disordered MQW regions was shifted by 71 nm and the disordered ridge waveguides had a loss figure of 8 dB/cm. Time‐resolved optical pump‐probe measurements were performed on an integrated switch that had more than a 5:1 power split between the two output ports. The measured signal recovery of the switch had a time constant of 110 ps. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114151

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The ultrafast carrier dynamics in GaSb are studied using optical transmission‐correlation spectroscopy with sub‐100‐fs pulses. The laser wavelength was tuned between 1.50 and 1.72 &mgr;m in order to differentiate between different scattering processes. The carriers scatter out of the initial distribution in 2–2.5 ps with a 200–350 fs component also observed. This faster component, usually attributed to phonon scattering, is observed below the assumed phonon emission threshold. When the laser is tuned above the intervalley scattering threshold a large fraction of the carriers rapidly scatter to theLvalley. Saturation of the absorption is measured versus the pump power near the band edge. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114153

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Hydrogenated amorphous silicon films were deposited from 100% silane and disilane gases by a pulsed radio‐frequency plasma chemical vapor deposition method in which a nonzero low power level was maintained. The pulse parameters were varied to study their effect on the deposition rate. It was found that the deposition rate depends both on the high power level and the dwell time. For a given high power level, the deposition rate is less than that of a continuous wave discharge up to a certain dwell time and increases beyond this value in both silane and disilane discharges. Onset of powder formation was observed beyond this crossover point. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114154

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The threshold voltage recovery (‘‘fading’’) ofP‐channel metal–oxide–semiconductor dosimeters irradiated to 10 Gy(Si), after 3500 h room‐temperature annealing, has been investigated. The obtained results have shown that fading decreases with the increase of the absolute value of gate voltage as well as with the increase of gate oxide thickness. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114155

出版商:AIP    

年代:1995

数据来源: AIP