摘要:

We have developed a very controllable fabrication process of an extremely narrow (∼10 nm) quantum wire metal‐oxide‐semiconductor field‐effect transistor (MOSFET) on a separation‐by‐implanted‐oxygen (SIMOX) substrate using anisotropic etching and selective oxidation technique. The drain current versus gate voltage characteristics show oscillations caused by Coulomb blockade even at room temperature. The oscillations split into several sharp peaks when the temperature is decreased, indicating that the channel is separated by several serial coupled quantum dots and that the quantum levels of these dots correspond to the observed fine peaks. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116645

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Electrical and structural properties of platinum monosilicide (PtSi) in deep submicron lines are reported. The sheet resistance of the silicide films was found to be rather independent of the linewidth down to dimensions as small as 0.15 &mgr;m. Plan‐view and cross‐sectional transmission electron microscopy was performed to study the structural properties of these films, including their gain structures and lateral growth. The insensitive nature of the electrical properties of the silicide films to the linewidths is correlated with their structural properties. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116646

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Conduction‐band offsets in wide‐band‐gap CdZnSSe/ZnSSe single quantum well structures have been characterized by deep level transient spectroscopy (DLTS) measurements. 50 A˚ thick Cd0.3Zn0.7S0.06Se0.94single quantum wells with ZnS0.06Se0.94barriers were grown by molecular beam epitaxy on GaAs substrates. A thermal emission energy from the quaternary wells of 179±10 meV was measured. This corresponds to a conduction‐band offset energy of ∼251±20 meV. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116647

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Hydrogen‐free diamond‐like carbon (DLC) films were deposited by the layer‐by‐layer technique using plasma enhanced chemical vapor deposition (PECVD), i.e., the alternative deposition of thin DLC layer and subsequent CF4plasma exposure on its surface. The hydrogen‐free DLC could be grown on the Si wafer by repeated deposition of the 5 nm DLC layer and subsequent 200 s CF4plasma exposure on its surface. On the other hand, the conventional DLC deposited by PECVD contains 25 at. % hydrogen inside. The CF4plasma exposure on the thin DLC layer appears to etch weak C–C bonds and break hydrogen bonds, resulting in a widening optical band gap and increasing conductivity activation energy. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116648

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Single InGaAs quantum wires were fabricated by low pressure metal organic chemical vapor deposition on V‐grooved InP substrates. For substrate patterning a new wet chemical etching process that leads to high quality V‐grooves with {111}A facets was used. The growth parameters of the InP buffer layer have a strong impact on the quantum wire formation. Scanning electron microscopy, photoluminescence, and spatially resolved cathodoluminescence experiments have been performed to characterize the structures. The crescent shaped InGaAs quantum wires have dimensions of about 13 nm height and 100 nm width. The wire luminescence is found to be at &lgr;=1575 nm (FWHM=17 meV). ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116649

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We present the current–voltage characteristics of a T‐shaped semiconductor electron waveguide structure in the nonlinear regime. This system is interesting as a potential quantum interference transistor. Calculated zero‐temperatureI–Vcharacteristics are with multiple peaks and exhibit regions of negative‐differential resistance. The peak‐to‐valley ratio has maximum value of 3:1. The calculated values of the transconductance and the differential drain conductance are small, which suggests limited abilities for conventional applications of the transistor. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116650

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We report the observation of a field‐emission effect in SiO2/Si samples assisted by the presence of photons. Electric fields in the oxide of the order of 10 MV/cm−1are attained by photocharging during x‐ray illumination and bring the vacuum level to a position below the equilibrium Fermi level. Hot electrons are injected from the Si substrate, traverse the SiO2layer, and are emitted directly into vacuum. The large photocharging effect is related to the surface topography, consisting of multiple Si tips of about 1 &mgr;m high. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116651

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The recombination velocity at oxide–GaAs interfaces fabricated byinsitumultiple‐chamber molecular beam epitaxy has been investigated. Ga2O3, Al2O3, SiO2, and MgO films have been deposited on clean, atomically orderedn‐ andp‐type (100) GaAs surfaces using molecular beams of Ga–, Al–, Si–, and Mg oxide, respectively. Based on the internal quantum efficiency measured for incident light power densities 1≤P0≤104W/cm2, the interface recombination velocityShas been inferred using a self‐consistent numerical heterostructure device model. While Al2O3–, SiO2–, and MgO–GaAs structures are characterized by an interface recombination velocity which is comparable to that of a bare GaAs surface (&bartil; 107cm/s),Sobserved at Ga2O3–GaAs interfaces is as low as 4000–5000 cm/s. The excellent Ga2O3–GaAs interface recombination velocity is consistent with the previously reported low interface state density in the mid 1010cm−2 eV−1range. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.116652

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We have synthesized, via molecular beam epitaxy alloys of SixSnyC1−x−ywith symmetric strain. In this work we report the growth of systems with varying compositions/band gaps including the first silicon‐based quaternary (Si/Ge/Sn/C) system, which offers an additional degree of freedom for strain and band gap engineering in Si‐based alloys. We report the growth of Si.955Sn.03C.015alloys up to 4500 A˚ in thickness and quaternaries of composition in the neighborhood of Si.835Ge.125Sn.03C.01. Infrared absorption spectroscopy and photoluminescence data have provided evidence of the potential for significant band gap modification in these alloys. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115745

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We have investigated the polarization dependence of subband absorption and photoconductivity in Si/SiGe quantum wells. For samples with a hole concentration ofps=2.8×1012cm−2both transverse magnetic and transverse electric polarized absorptions have been observed, and transitions to several excited states are clearly identified by comparison with self‐consistent Luttinger–Kohn type calculations. The photoconductivity is surprisingly little sensitive to the polarization, which indicates the importance of the subsequent transport process on the photocurrent responsivity. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115746

出版商:AIP    

年代:1996

数据来源: AIP