摘要:

We have used a simple, analytically solvable model to analyze the characteristics of dual-gate metal-oxide-semiconductor field-effect transistors (MOSFETs) with 10 nm-scale channel lengthL. The model assumes ballistic dynamics of two-dimensional electrons in an undoped channel between highly doped source and drain. When applied to siliconn-MOSFETs, calculations show that the voltage gain (necessary for logic applications) drops sharply atL∼10 nm,while the conductance modulation remains sufficient for memory applications untilL∼4 nm.©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120473

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Hole induced dielectric breakdown of thin gate oxide films is investigated using substrate hot hole (SHH) injection technique. The breakdown characteristics due to SHH stress differ from the case of Fowler-Nordheim (FN) tunneling current stress; the gate current increases gradually just before the breakdown. Measured hole-fluences-to-breakdown,2–30 C/cm2,which are much larger than that observed in FN stress,0.1 C/cm2,depend on hole current density. Moreover, the oxide breakdown due to FN stress is accelerated for the oxides subjected to prior hole injection. ©1997 American Institute of Physics. 

ISSN:0003-6951    

DOI:10.1063/1.120474

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

A tunnel diode was formed from GaAs containing excess arsenic incorporated by molecular beam epitaxy at reduced substrate temperatures. The incorporation of excess arsenic during growth results in a more efficient incorporation of silicon on donor sites and beryllium on acceptor sites. The better dopant incorporation, along with trap assisted tunneling through deep levels associated with the excess arsenic, results in a tunnel junction with record peak current density of over1800 A/cm2,zero-bias specific resistance of under1×10−4 &OHgr; cm,and a room-temperature peak-to-valley current ratio of 28. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120475

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Organic contaminants adsorbed on the surface of silicon wafers do not always cause the degradation of gate-oxide integrity (GOI) degradation but very little information is available on the ambient atmosphere when wafers are loaded in an oxidation furnace. It has been found in this work that GOI is degraded when wafers having organic contamination are loaded in a nitrogen atmosphere, but that GOI degradation does not occur when the wafers are loaded in an oxygen-containing ambient. In a high-temperature nitrogen atmosphere, carbon remains in silicon dioxides, while in an oxygen-containing ambient, the organic contaminants will be oxidatively degraded and evaporated, so carbon does not remain on the surface. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120476

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

We report on a high positive turn-on voltage (close to 2.5 V) of the gate-source leakage current in AlGaN/GaN high electron mobility transistors (HEMTs). The piezoeffect, the barrier, and channel doping result in the electron sheet concentration as high as1013 cm−2.A larger conduction band discontinuity and a larger electron effective mass (compared to AlGaAs/GaAs HEMTs) lead to a lower gate current and to a higher turn-on voltage. This means that AlGaN/GaN technology can be suitable for applications in digital and mixed-mode integrated circuits. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120477

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Thermal quenching of photoluminescence from SiGe/Si quantum wells (QWs) grown by low-temperature molecular beam epitaxy is shown to be significantly improved by postgrowth thermal annealing. The dominant mechanism responsible for this improvement is shown to be a reduction of grown-in nonradiative defects, such as vacancy-related complexes. Postgrowth hydrogenation is demonstrated to be less effective as compared to thermal annealing in removing the nonradiative defects. Selective optical excitation has been used to determine the relative contributions of nonradiative recombination channels present in the SiGe QWs and the Si barriers. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120478

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Hydrogenated amorphous SiEr (a-SiEr:H) thin films were deposited by cosputtering. Oxygen and nitrogen were employed as impurity enhancers ofEr3+emission of light at 1540 nm, and photoluminescence, infrared absorption, and Raman spectroscopies were performed as a function of various annealing temperatures. As-deposited O-contaminated and N-dopeda-SiEr:H samples exhibitEr3+related photoluminescence, low intensity at room temperature, and maximum intensity after thermal annealing at∼500 °C.In addition to the enhancement of theEr3+emission of light, thermal annealing provokes the outdiffusion of hydrogen bonded to silicon atoms. The experimental data suggest that both hydrogen and thermal treatments improve theEr3+related photoluminescence by decreasing the occurrence of nonradiative processes. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120479

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The time-dependent-dielectric-breakdown (TDDB) distributions measured on a series of identical oxides at the same voltages have been shown to depend on the resistance and capacitance of the measurement test equipment. The TDDB distributions were shifted to shorter times if the impedance of the test equipment was lowered and/or the capacitance of the test equipment was raised. The lower resistances and higher capacitances allowed the nonshorting early electric breakdowns to develop into shorting, thermal, dielectric breakdowns. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120480

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The aluminum gallium nitride (AlGaN) alloy is uniquely suited for fabricating optoelectronic devices in the ultraviolet and visible bands of the spectrum. Its synthesis in a nanometer scale may potentially open the way for applications such as tunable optoelectronic devices. Presently, results concerning the synthesis and microstructural and optical characterization of nanometer-sized AlGaN imbedded in a poly-methylmethacrylate (PMMA) matrix are reported. Our optical measurement showed that the AlGaN/PMMA nanoparticle/polymer composite efficiently emits in the violet-blue region, while the microstructural characterization confirms the formation of defect-free zinc blende AlGaN nanoparticles. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120481

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

High resolution electron energy loss spectroscopy, dielectric theory simulations, and charge profile calculations have been used to study the accumulation layer and surface plasmon excitations at the In-terminated(001)-(4×1)and(111)A-(2×2)surfaces of InAs. For the (001) surface, the surface state density is4.0±2.0×1011 cm−2,while for the(111)Asurface it is7.5±2.0×1011 cm−2,these values being independent of the surface preparation procedure, bulk doping level, and substrate temperature. Changes of the bulk Fermi level with temperature and bulk doping level do, however, alter the position of the surface Fermi level. Ion bombardment and annealing of the surface affect the accumulation layer only through changes in the effective bulk doping level and the bulk momentum scattering rate, with no discernible changes in the surface charge density. ©1997 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.120482

出版商:AIP    

年代:1997

数据来源: AIP