摘要:

We investigate the influence of high frequency microwave radiation on single electron tunneling through a quantum dot. Effective coupling of the radiation to the quantum dot is achieved by an on‐chip integrated broadband antenna. Simulations of the current distribution on the antenna are shown. We find that radiation with a frequency of &ngr;=155 GHz, which corresponds to half of the bare charging energyEc/2 results in an additional conductance peak within the Coulomb blockade regime. This additional resonance is attributed to photon‐assisted tunneling. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114406

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

This letter reports the growth and characterization of ZnSe:N layers by atomic layer epitaxy (ALE) using a nitrogen rf‐plasma source. The ALE‐grown ZnSe:N layers have been investigated in terms ofinsitureflection high electron energy diffraction andexsitucapacitance–voltage profiling and photoluminescence spectroscopy. The net acceptor concentration in the ALE‐grown layer has been obtained as high as 1.2×1018cm−3and the ALE layers of ZnSe:N show reduced number of compensating deep centers compared with the ZnSe:N grown by molecular beam epitaxy. The effects of the Fermi level at a growing surface on the generation of compensating donors with a binding energy of 57 meV are also discussed. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114407

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Carrier recombination centers related with iron complexes inp‐type silicon are studied by microwave and light‐induced absorption techniques. Both thermal‐ and photoactivation are used to decompose iron–boron pairs and to study the impact on the recombination lifetime. Due to photodissociation of iron–boron pairs the lifetime increases for high level injection. Efficient recombination occurs via an acceptor level atEc−0.29 eV as derived from the temperature dependence of carrier lifetime. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114408

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We report electrical properties of undoped and Sb‐doped Si1−xCxalloys grown by molecular beam epitaxy. Nominally undoped alloy layers exhibit electron background levels of 4×1016cm−3with a mobility above 30 000 cm2/V s at low temperatures. The layers can be doped with Sb at low growth temperatures, and the carrier concentrations and mobilities obtained are comparable to similarly doped Si layers. Modulation‐doped Si/Si1−xCx/Si structures with the modulation doping in the Si layer close to the surface exhibit enhanced electron mobilities with peak values of about 10 000 cm2/V s, indicating that Si1−xCxstrained on a silicon substrate forms an electron channel. From the saturation carrier concentration at low temperatures, the electron barrier between Si and Si0.98C0.02is estimated to be about 150 meV. In lightly doped channel structures carrier freeze‐out at low temperatures is observed, indicating a relatively high defect density in the channel. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114409

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

In this work, we demonstrate record low dark current operation of InGaAs (1.55 &mgr;m)p‐i‐nphotodetectors on both silicon and gallium arsenide substrates using a wafer bonding technique. The photodetectors were made by first bonding thep‐i‐nepitaxial layers to the Si and GaAs substrate followed by chemical removal of the host (InP) substrate from thep‐i‐nstructure. The photodetector was then fabricated atop the newly exposedp‐i‐nepilayers. Dark currents of as low as 57 pA on a GaAs substrate and 0.29 nA on a Si substrate were measured under 5 V reverse bias. The responsivity at 1.55 &mgr;m wavelength was measured to be 1 A/W, corresponding to an external quantum efficiency of 80%. The series resistance measured across the bonded interface gave 17 &OHgr; on GaAs and 350 &OHgr; on Si, respectively. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114410

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The development of new high dielectric constant materials is essential for the development of advanced silicon integrated circuits. In this letter, we report preliminary results of lanthanum doped lead zirconate titanate (PLZT) films deposited by dual spectral sources (DSS) rapid isothermal processing (RIP) assisted metalorganic chemical vapor deposition (MOCVD) system. The dielectric constant and leakage current density data reported in this letter represents the best results reported to date. The use of high energy photons play an important role in the deposition of high quality dielectric films ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114411

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We present Schlieren images which show the existence and evolution of current filaments during the very early stages of surface‐related breakdown inside 1 cm siliconp+‐n−‐n+structures. These images confirm our previous finding that breakdown occurs in the silicon rather than in the ambient, and suggest that a streamerlike mechanism may be responsible. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114412

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The structural, electronic, and optical properties of the so‐called local defect layer (LDL), the key feature of the junction near the local defect layer (JNLD) Si solar cell, have been studied aftereachprocessing step using transmission electron microscopy, spreading resistance (SR), and absorption measurements. Our results show that a layer of 20–80 nm sized bubbles is formed beneath the Si surface after proton implantation and a two‐step annealing process. The SR profiles reveal that the implantation‐damaged Si material is almost electronically reconstituted after the second annealing step. This LDL absorbs less than 2% of the sunlight; therefore, the efficiency of a JNLD solar cell cannot be increased by more than 2% (relative) compared to an unimplanted reference cell. However, by using higher implantation doses a buried textured layer is formed which leads to an enhanced absorption and has a similarbeneficialeffect in solar cells as a textured surface. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114413

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The desorption rate of In atoms from an InAs surface and its dependence on surface As coverage is reported. InAs films were grown by molecular beam epitaxy on fully strained 1 monolayer thick In0.75Ga0.25As films deposited on (001) InAs substrates. Using a sensitive technique based on reflection high‐energy electron diffraction, the desorption rate for In is found to be highly dependent on the As coverage. During a sublimation process, where In from an InAs surface is desorbed, the desorption rate at 510 °C is five times greater for a group III stabilized surface than for an As‐stabilized surface. The difference in desorption rate is believed to be related to changes in the In to surface bond strengths. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114414

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Separation by implanted oxygen silicon wafers have been investigated with cross‐sectional transmission electron microscopy after annealing at 1200 °C in argon as well as in hydrogen. It is observed that the buried oxide has experienced little change in the thickness, which is ascribed to the low hydrogen solubility in the crystal (about 3×1015cm−3) and provides a natural mark to measure the thickness variation of the top silicon directly. The evaporation rate as determined in this method is less than 0.1 nm/min with an accuracy of ±0.1 nm/min, at least two orders of magnitude lower than reported in previous investigations. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.114415

出版商:AIP    

年代:1995

数据来源: AIP