摘要:

The cluster-Bethe-lattice method is used to investigate SiH bond-bending modes of theHSi-(OSi)3group ina-SiO2:Halloys. When theHSi-(OSi)3group hasC3symmetry, the SiH bond-bending mode has a double degenerate frequency at 876cm−1as found by experiments. But when theHSi-(OSi)3group does not haveC3symmetry, the nonsymmetrical coupling between SiH and its local bonding environment may cause the SiH bond-bending mode to split off and have an additional feature in the spectrum that is not revealed by experiments. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118367

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We report the observation of a ferroelectric field effect in the conducting oxide SrRuO3using Pb(Zr0.52Ti0.48)O3/SrRuO3epitaxial heterostructures. Upon reversing the polarization of the ferroelectric Pb(Zr0.52Ti0.48)O3layer, we measured a 9&percent; change in the resistance of a nominally 30 Å SrRuO3film at room temperature. This change was nonvolatile for a period of several days. Conductivity measurements taken between 4.2 and 300 K are consistent withn-type conduction throughout this temperature range. Hall effect measurements also yieldn-type conduction, withn≈2×1022electrons/cm3, and furthermore allow us to understand quantitatively the magnitude of the observed resistivity change. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118203

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The temperature coefficient of resistance (TCR) for an as-deposited RuO2.2thin film resistor changes from −131.6 to 1007.95 ppm/°C after the annealing at 600 °C for 30 min. Typically, a near zero TCR about 0±0.12 ppm/°C can be obtained after annealing at 300 °C for 30 min in an Ar ambient. The changes of TCR from negative to positive is attributed to the grain growth ofRuOxfilms from fine grain (30–40Å)to a larger one (500–800Å)during the annealing process. Rutherford backscattering spectroscopy andin situx-ray photoemission spectroscopy show that the ratio of O/Ru in the RuOxfilm decreases from 2.2 to 2.0, due to the out diffusion of oxygen during the annealing process, which is independent of the changes in TCR. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118368

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We report on the electronic structure of a delta-doped quantum well of B in Si as a function of temperature from 0 K to room temperature. The calculation is carried out self-consistently in the framework of a Hartree approximation. The energy levels and the occupation number of the discrete states is reported. We conclude that the temperature is not an important factor below 60 K. If temperature is greater than 80 K the level positions are shifted but the changes in carrier concentration are not significant. We give a possible qualitative explanation of the widths of the intersubband absorption peaks. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118369

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We report measurements of electron transfer in real space inGaAs/AlxGa1−xAsasymmetric double quantum wells under an electric field by far-infrared cyclotron resonance (CR). Due to nonparabolicity, the asymmetric quantum structure results in well-resolved CR lines, which allow contactless measurements of the electron density in each well. Our results show that electrons tunnel through the barrier from one well to the other at the level anticrossing of their ground states. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118361

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Electron cyclotron resonance plasma oxidation of strained Si on relaxedSi1−xGexbuffer layers inO2ambient at room temperature is reported. The electrical properties of grown oxide have been characterized and compared with thermally grown oxides using a metal-oxide semiconductor structure. At a low field, the accumulation of holes in the buriedSi1−xGexlayer, due to the type-II band offset, has been observed. The experimental results from thermally grown oxides have been compared with the simulation results obtained using a heterostructure Poisson solver. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118370

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

A sensitive optical speed sensor has been developed utilizing the transient lateral photoeffect induced in a Si thin-filmp–i–nphotodetector by a moving light spot. The local time dependent illumination changes the lateral photocurrent and modulates the potential barrier across the junction allowing the sensing of the light spot velocity. The performances of an amorphous(a-Si:H)and a microcrystalline(&mgr;c-Si:H)silicon-based sensor will be compared and discussed taking into account the differences in material properties and device geometry. The&mgr;c-p–i–nstructure has the advantage of faster response, high current capability, and excellent stability under illumination when compared with the amorphous counterpart. ©1997 American Institute of Physics. 

ISSN:0003-6951    

DOI:10.1063/1.118371

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Polycrystalline &bgr;-SiC, with grain size up to 1500 Å, has been room-temperature-deposited on Si substrates by electron cyclotron resonance chemical vapor deposition. Microwave power and the hydrogen carrier gas are the key parameters to lower the deposition temperature. According to the results of the cross-sectional transmission electron microscopy, the grain size appeared to be in the same scale as that deposited at 500 °C while a large amount of plasma-induced defects were observed in the Si substrate for the room-temperature-deposited samples. Hence, aCH4-plasma treatment prior to the &bgr;-SiC film growth was adopted, forming a SiC-like interfacial layer to suppress the substrate damages. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118372

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We deposited hydrogenated amorphous silicon-based thin film transistors using dc reactive magnetron sputtering at a substrate temperature of 125 °C. We characterize the structural properties of the a-Si:H channel and a-SiNx:Hdielectric layers using infra-red absorption, thermal hydrogen evolution, and refractive index measurements, and evaluate the electrical quality using conductivity, capacitance–voltage, and leakage current measurements. Inverted staggered thin film transistors made with these layers exhibit a field effect mobility of 0.3cm2/V s, aIon/Ioffratio of5×105, a subthreshold slope of 0.8 V/decade, and a threshold voltage of 3 V. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118373

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We report the discovery that the [111] strained Si (∼10 Å) as an interlayer betweenSi3N4and (111) GaAs may allow the Fermi level to fully scan the GaAs conduction band and induce inversion electrons in GaAs. The band structure calculations indicate that the strained Si on (111) GaAs or (111) AlGaAs has a much wider band gap (0.87 eV) than the strained Si on (001) GaAs (0.34 eV). The energy levels in the quantum well formed bySi3N4/Si/(111)GaAsare almost unconfined and those ofSi3N4/Si/Al0.3Ga0.7As/(111)GaAsare confined, but the confined energy level in Si conduction band is ∼0.1 eV higher than the GaAs conduction band. Both structures may induce inversion electrons in GaAs potentially paving the way for the realization of GaAs basedn-channel inversion mode metal-insulator-semiconductor transistors. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.118374

出版商:AIP    

年代:1997

数据来源: AIP