摘要:

The structural changes in Pd and Pd–Ru alloys induced by the repeated absorption–desorption of hydrogen have been studied. It is found that absorption–desorption cycles produce structural changes in Pd whereas the addition of small amounts of Ru inhibits these hydrogen‐induced changes. The experimental results show that bulk hydrogen absorption occurs in Pd, while hydrogen surface adsorption becomes dominant over bulk absorption, in the Pd–Ru alloy. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113241

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A Mg‐ion indiffusion process was applied to the lithium niobate single‐crystal substrates deposited with magnesium oxide thin film. By means of x‐ray diffraction analysis and differential thermal analysis, we find that the magnesium diffused layer exhibits the crystal structure of an unknown compound of the Mg‐Li‐Nb‐O ternary system. It is proposed, that this unknown compound and MgNb2O6are the real sources for the Mg‐ion indiffusion. The changes in Curie temperature with diffusion parameters such as diffusion temperature, diffusion times, and the thickness of magnesium oxide film are noted. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113242

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A normal‐incident normally on GaAs/AlAs multiple‐quantum well Fabry–Perot transmission modulator is reported. The fabricated modulator achieves ON/OFF transmittance changes larger than 30% and ON/OFF contrast ratios larger than 7.4 at the wavelength of 842.5 nm with a reverse bias voltage of 9 V. ©1995 American Institute of Physics. 

ISSN:0003-6951    

DOI:10.1063/1.113243

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The impact of nitrogen (N) concentration and distribution on the electrical and reliability properties of rapid‐thermally NO‐annealed oxides is studied. The use of NO‐annealing of thermally grown SiO2provides an excellent way to isolate the effects of N, since this method allows for the incorporation of varying N profiles in the oxide without a simultaneous increase in dielectric thickness. Results show that the electrical properties of the dielectric under gate and substrate Fowler–Nordheim injection are highly sensitive to the N profile in the dielectric. While interface endurance (&Dgr;Dit) is seen to improve monotonically with increasing N concentrations for both +Vgand −Vg, the same is not observed for charge‐to‐breakdown (QBD) properties. It is found that althoughQBDimproves with NO nitridation under +Vg, it shows a turnaround behavior under −Vg, i.e., for a 10‐s NO‐annealed oxide theQBDvalue is improved over control oxide while further nitridation is seen to degradeQBDunder −Vg. The presence of bulk N and the nonuniform N distribution in the dielectric is responsible for this behavior. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113244

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

An in‐plane gate field‐effect transistor is characterized by ultrafast electro‐optic sampling. The transistor is monolithically integrated with photoconductive switches in coplanar waveguide and <0.5 ps measurement time resolution is achieved. The gate‐drain capacitance of the transistor is obtained as 1.8 fF at zero drain voltage from displacement current transients. The gate‐drain capacitance is dominated by parasitic capacitance and the intrinsic gate‐drain capacitance is estimated as less than 0.2 fF. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113245

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Hydrogen implantation and subsequent thermal annealing is found to result in a well‐defined band of cavities in Si. This band is an extremely efficient gettering layer for Cu which is also introduced into the near surface of Si by ion implantation. Profiling of implanted Cu indicates that ∼95% of an initial 3×1015cm−2Cu implant is redistributed following annealing at a temperature of 780 °C from a near‐surface damaged layer to a narrow band of cavities of width ∼1000 A˚ at a depth of ∼1 &mgr;m. Furthermore, the Si between the surface and the cavity band is essentially defect‐free and that some cavities contain the bulk Cu3Si phase. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113246

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We have fabricated and characterized resonant tunneling diode pillar arrays. The array resistance switches between two stable states with a maximum room temperature current peak to valley ratio of 500:1. Both the high and the low resistance states are stable at zero bias suggesting that the device may be used for non‐volatile memory storage. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113247

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A quantitative analysis based on the Luryi and Suhir model [Appl. Phys. Lett.49, 140 (1986)] has shown that the growth of strain relaxed and low dislocation density SixGe1−xand InxGa1−xAs buffer layers on Si and GaAs substrates, respectively, is feasible despite the layer/substrate lattice mismatch. A successful growth of such layers is possible on partially masked substrates by selective lateral overgrowth method. In this case, the buffer layer/substrate misfit stress is of limited lateral extent, in accordance with Saint‐Venant’s principle, and its effective length does not exceed 15% of the seeding window width even for very thick buffer layers. High threading dislocation density in the buffer layer can be avoided by reducing the window width such that the effective stress zone length is comparable with the critical layer thickness for misfit dislocation formation. However, a thin alloy layer deposited by molecular beam epitaxy or metalorganic chemical vapor deposition on both the Si and GaAs substrates, prior to coating with SiO2mask and patterning with oxide‐free seeding windows, is required for a quite broad range of alloy compositions ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113248

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We report a new type photochemical hole burning material; organic dye, zinc porphyrin, doped in inorganic semiconductor, titanium dioxide. The hole burning mechanism of this system is concluded to be photoionization via single‐photon process. The small temperature dependence of Debye–Waller factor was indicated by cyclic annealing experiment. A hole could be burned and observed at 140 K. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113249

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Successful growth of silicon in a liquid phase epitaxial (LPE) system requires preventing the formation of a native oxide more than a few monolayers thick. It has been found that the desorption of oxygen and water vapor from the ends of the furnace tube can lead to oxidation of silicon wafers located in the tube center, thus inhibiting epitaxy. A simple method to avoid this problem and eliminate the need for long flush times is described. Evidence is presented that indium, a common solvent in LPE of silicon, plays a catalytic role in the oxidation of silicon. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.113250

出版商:AIP    

年代:1995

数据来源: AIP