摘要:

We report here the formation ofn‐type layers with ion‐implanted nitrogen or antimony inp‐type &agr;‐SiC requiring maximum process temperatures of 1400 and 1600°C respectively for only a few minutes. This is believed to be the first confirmation of donor behavior by antimony in SiC. Electrical characteristics of these implanted layers have been evaluated by Hall and sheet resistivity measurements. Junction devices formed from the implanted layers have shown excellent forward and reverse characteristics at operating temperatures to 400°C.

ISSN:0003-6951    

DOI:10.1063/1.1652838

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

Numerical solutions are presented for a time‐dependent two‐dimensional wave equation in which the nonlinear contribution to the refractive index is governed by a relaxation equation. For input pulse widths comparable to the relaxation time, pulse shapes are asymmetrically distorted and self‐focusing is inhibited but there is no indication of beam size stabilization.

ISSN:0003-6951    

DOI:10.1063/1.1652839

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

A simple method is proposed and demonstrated which provides a direct and reliable observation of the multiplicity of charge states of impurity centers. This is achieved by recording the high‐frequency photocapacitance changes in a reverse‐biasedp‐njunction at a low temperature during monochromatic illuminations at different wavelengths. The photon energy is first chosen so that it is above the threshold required to excite one of the trapped electrons at the impurity center, but below the threshold of exciting the next electron. After the capacitance change is completed, the photon energy is increased to the next range to excite the second trapped electron into the conduction band. The equality of the change of the squared capacitance during these two illumination periods then implies a multiplicity of three of the charge state. The procedure may be repeated for more than three charge states. An example is given for a sulfur‐doped siliconp+njunction whose double donor levels have thermal activation energies of 0.30 and 0.55 eV below the conduction‐band edge.

ISSN:0003-6951    

DOI:10.1063/1.1652840

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

Continuous‐wave chemical laser operation has been observed at 10.6 &mgr; in CO2pumped by vibrational energy released from chemical reactions forming excited DF and HF molecules. A two‐step vibrational energy transfer mechanism is proposed to explain the pumping of CO2by chemically formed HF. The results suggest improved performance occurs when simple chain reactions are operative.

ISSN:0003-6951    

DOI:10.1063/1.1652841

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

The variation of electron and hole diffusivity and drift velocity in the ``warm electron'' range of electric field (1–50 kV/cm) has been measured for ⟨111⟩‐oriented silicon at 300°K. These measurements were obtained from the transient currents produced from a thin layer of electrons or holes propagating through the high‐field region of a reverse‐biasedp+−&ngr;−n+diode. Use of a sampling oscilloscope in conjunction with an analog‐to‐digital converter and averaging system resulted in significant improvement of the resolution and statistics of the measurement and allowed digital readout of the resulting data. Diffusivity of both electrons and holes was found to decrease slightly below the low‐field values in the electric field range of 6–50 kV/cm. Drift velocity versus electric field was measured and found to be reasonably consistent with the literature.

ISSN:0003-6951    

DOI:10.1063/1.1652842

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

Experimental observations of the interaction of the memory in amorphous semiconductors are described. Between two pairs of electrodes located sufficiently close by, memory exchange has been observed, namely, switch‐on or ``lock‐on'' (memory setting) of one pair of electrodes unlocks the memory of the other pair. The results are attributed to the thermal interaction between ``lock‐on'' filament and switch‐on filament.

ISSN:0003-6951    

DOI:10.1063/1.1652843

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

Experimental results on a new type of electronically tunable optical filter are described. Tuning from 7000 to 5500 Å has been obtained by changing an acoustic driving frequency from 750 to 1050 MHz. A band pass of less than 2 Å, a corrected peak transmission of 50%, and an average skirt rejection ratio of about 45 dB have been obtained.

ISSN:0003-6951    

DOI:10.1063/1.1652844

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

Single‐crystalline, colorless, GaN has been prepared by a vapor‐phase growth technique previously used to prepare GaAs, GaP, and GaSb. These crystals are the first reported speciments of GaN suitable for good electrical and optical evaluation of this compound. It has been determined that GaN has adirectenergy bandgap of 3.39 eV, and that undoped crystals prepared by this method have a very high inherent electron concentration, typically above 1019/cm3, which is probably related to a high density of nitrogen vacancies. Conductingp‐type specimens have been prepared using Ge as the dopant; but this result has been difficult to reproduce, and the samples have been electrically inhomogeneous.

ISSN:0003-6951    

DOI:10.1063/1.1652845

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

A series of Nb&sngbnd;Ti&sngbnd;N films have been prepared, with various Nb/Ti ratios, by a high purity, reactive sputtering process. A maximum in transition temperature (at ∼ 15.5°K) has been obtained for a composition ofNb0.5Ti0.5N. Critical field and critical current measurements indicate a degradation in these properties with increasing titanium content, contrary to results reported previously.

ISSN:0003-6951    

DOI:10.1063/1.1652846

出版商:AIP    

年代:1969

数据来源: AIP

摘要:

Iron diffusion in an Fe‐3% Si alloy has been studied by means of the Mo¨ssbauer effect. The results in this iron‐base system agree closely with conventional measurements and do not appear to exhibit the factor of 2 anomaly with the Singwi and Sjo¨lander analysis which Knauer and Mullen observed for iron in dilute solution. The values obtained can be described by the equationD=0.20(−0.15;+0.65) exp[−49 600±3700/RT].

ISSN:0003-6951    

DOI:10.1063/1.1652847

出版商:AIP    

年代:1969

数据来源: AIP