APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

14 Sep 1998

Volume 73, Issue 11, pp. 1457-1597

Return to All Sections
back to top
RSS Feeds

Comparison between optical techniques for the measurement of the surface electric field in (100) oriented GaAs

Z. Yang, Y. H. Chen, and Yuqi Wong

Appl. Phys. Lett. 73, 1520 (1998); http://dx.doi.org/10.1063/1.122192 (3 pages) | Cited 5 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Three optical spectroscopic techniques commonly used for the measurement of the surface electric field (SEF) of semiconductors, namely photoreflectance (PR) near the E0 energy and near the E1 energy, and the linear electro-optic (LEO) effect of reflectance difference spectroscopy near the E1 energy, are compared on a series of (100) oriented GaAs layered structures. The LEO strength is found to be linearly proportional to the SEF obtained from the PR oscillation period near the E0 energy for samples with a single space charge region in which the field is uniform over the light penetration depth near E1( ∼ 20 nm). The LEO strength remains proportional to the SEF for samples with multiple space charge regions while the PR period near E0 no longer reflects the true SEF. The SEF value estimated from the line width of PR near the E1 energy is quite unreliable because both the electric field and the impurity scattering broaden the line. © 1998 American Institute of Physics.
Show PACS
78.20.Jq Electro-optical effects
78.20.-e Optical properties of bulk materials and thin films
84.37.+q Measurements in electric variables (including voltage, current, resistance, capacitance, inductance, impedance, and admittance, etc.)

Cathodoluminescence study of degradation in ZnSe-based semiconductor laser diodes

A. Toda, K. Nakano, and A. Ishibashi

Appl. Phys. Lett. 73, 1523 (1998); http://dx.doi.org/10.1063/1.122193 (3 pages) | Cited 16 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
After continuous-wave operation of ZnSe-based semiconductor laser diodes, the degradation of these devices was investigated using cathodoluminescence imaging and spectroscopy. Inside the stripe region, i.e., the carrier injection area, there were several dots in which the peak wavelength of emission from a ZnCdSe strained quantum well (QW) shifted with time to a shorter wavelength (blueshift). We consider that the blueshift is due to Cd/Zn interdiffusion. This interdiffusion is enhanced by the electron–hole recombination process (recombination enhanced interdiffusion). Furthermore, there were dark line defects (DLDs) in the 〈100〉 direction, outside the stripe region and running away from the dots, having emission with a blueshift. The peak wavelength of emission from the QW in the DLDs shifted to a longer wavelength (redshift). We consider that the redshift is due to the relaxation of strain in the QW by existing defects, which may originate in the blueshift dots and move outside the stripe region. © 1998 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
78.60.Hk Cathodoluminescence, ionoluminescence
78.66.Hf II-VI semiconductors
73.61.Ga II-VI semiconductors
68.35.Fx Diffusion; interface formation
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)

Optimization of hydrogenated amorphous silicon p–i–n solar cells with two-step i layers guided by real-time spectroscopic ellipsometry

Joohyun Koh, Yeeheng Lee, H. Fujiwara, C. R. Wronski, and R. W. Collins

Appl. Phys. Lett. 73, 1526 (1998); http://dx.doi.org/10.1063/1.122194 (3 pages) | Cited 90 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Hydrogenated amorphous silicon (a-Si:H) p–i–n solar cell performance has been optimized using a two-step i-layer growth process. This effort has been guided by real-time spectroscopic ellipsometry (RTSE) studies of the nucleation and growth of a-Si:H films by plasma-enhanced chemical vapor deposition at 200 °C using a variable H2-dilution gas flow ratio R = [H2]/[SiH4]. RTSE studies during film growth with R>15 reveal a transition from the amorphous to microcrystalline (a→μc) phase at a critical thickness that decreases with increasing R. From such results, the optimum two-step process was designed such that the initial stage of the i layer (∼200 Å) is deposited at much higher R than the bulk to ensure that the film remains within the amorphous side of the a→μc phase boundary, yet as close as possible to this boundary at low i-layer thicknesses. © 1998 American Institute of Physics.
Show PACS
84.60.Jt Photoelectric conversion
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.05.Cy Elemental semiconductors
81.05.Gc Amorphous semiconductors
52.77.Bn Etching and cleaning
52.77.Dq Plasma-based ion implantation and deposition
68.55.-a Thin film structure and morphology

Arsenic flux dependence of incorporation of excess arsenic in molecular beam epitaxy of GaAs at low temperature

A. Suda and N. Otsuka

Appl. Phys. Lett. 73, 1529 (1998); http://dx.doi.org/10.1063/1.122195 (3 pages) | Cited 14 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Incorporation of excess As in GaAs layers grown by molecular beam epitaxy was studied by varying As fluxes for four different substrate temperatures, 210, 240, 270, and 290 °C. Concentrations of excess As in GaAs layers were estimated by measuring increases of lattice spacings with x-ray diffraction, and the substrate surface temperature was monitored by using a quartz rod connected to an infrared pyrometer with its end placed in the vicinity of the substrate surface. Nearly stoichiometric GaAs layers without any detectable increase of the lattice spacing are grown at all substrate temperatures under the As atom flux equal to the Ga atom flux. With a slight increase of the As flux from the above stoichiometric condition, the concentration of excess As sharply increases for all substrate temperatures. For the substrate temperature of 210 °C, the concentration of excess As is saturated in the range of As atom fluxes more than three times the Ga atom flux, while similar tendencies are observed for other substrate temperatures. The incorporation process of excess As is discussed on the basis of these results. © 1998 American Institute of Physics.
Show PACS
81.05.Ea III-V semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.Nq Composition and phase identification

Fabrication and properties of metal/ferroelectrics/semiconductor diodes on 4H–SiC

D. Mou, C. S. Petersson, J. Linnros, and K. V. Rao

Appl. Phys. Lett. 73, 1532 (1998); http://dx.doi.org/10.1063/1.122196 (3 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Polycrystalline PbTiO3 (PTO) films with pure perovskite phase were deposited directly on 4H n-type SiC substrates by pulsed laser ablation. By subsequent gold metallization, metal/ferroelectrics/semiconductor (MFS) diodes were fabricated. At room temperature the leakage current exhibits ohmic behavior at low voltages (<3 V), but at higher voltages (⩾6 V), it is Schottky emission dominated. Both the dielectric constant and the resistivity of the PTO layers are frequency dependent, decreasing monotonically with the increasing frequency. The capacitance–voltage (C–V) curves of the diodes demonstrate the typical hysteresis loop of a MFS diode structure, and carrier injection and memory effects are observed in the C–V measurements. The investigated MFS diode structure has tentative applications as a gate structure in a SiC field effect transistor or a nonvolatile memory cell on a SiC substrate. © 1998 American Institute of Physics.
Show PACS
85.30.Hi Surface barrier, boundary, and point contact devices
85.30.Kk Junction diodes
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
81.15.Fg Pulsed laser ablation deposition
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
77.22.Ch Permittivity (dielectric function)
77.80.Dj Domain structure; hysteresis
85.50.-n Dielectric, ferroelectric, and piezoelectric devices

Highly regular self-organization of step bunches during growth of SiGe on Si(113)

A. A. Darhuber, J. Zhu, V. Holý, J. Stangl, P. Mikulík, K. Brunner, G. Abstreiter, and G. Bauer

Appl. Phys. Lett. 73, 1535 (1998); http://dx.doi.org/10.1063/1.122197 (3 pages) | Cited 7 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have studied the structural properties of highly periodic arrays of terrace steps in a Si/SiGe multilayer grown on a miscut Si(113) substrate by atomic force microscopy, x-ray reflection and high resolution x-ray diffraction. The data reveal a regular array of step bunches with vertical correlation within the multilayer and periodic surface steps extending over lengths of several tens of microns. The (113)-faceted terraces have a lateral period of about 360 nm which is locally modulated due to a long-range waviness of the surface. © 1998 American Institute of Physics.
Show PACS
68.35.Ct Interface structure and roughness
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
73.40.Lq Other semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
68.55.-a Thin film structure and morphology

Study of impurity states in p-type Hg1−xCdxTe using far-infrared spectroscopy

Biao Li, Yongsheng Gui, Zhanghai Chen, Hongjuan Ye, Junhao Chu, Shanli Wang, Rongbin Ji, and Li He

Appl. Phys. Lett. 73, 1538 (1998); http://dx.doi.org/10.1063/1.122198 (3 pages) | Cited 8 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This letter reports the far-infrared (FIR) transmission spectra of undoped and Sb-doped p-type Hg1−xCdxTe films grown by a liquid-phase epitaxy (LPE) or molecular-beam epitaxy (MBE) technique. The activation energies of cation vacancy acceptor are found to be ∼10–12 meV and are almost independent on Cd composition. The absorption strength per Hg vacancy, useful for evaluating the cation vacancy density from the absorption spectra, is derived as 3.4×10−12 cm. Further, Zeeman splitting resulting from two different acceptors is observed from magnetotransmission measurement for the Sb-doped LPE sample, and light hole effective mass is estimated. FIR transmission seems to be a powerful tool for nondestructive characterization of impurity states in Hg1−xCdxTe. © 1998 American Institute of Physics.
Show PACS
78.66.Hf II-VI semiconductors
78.30.Fs III-V and II-VI semiconductors
71.55.Gs II-VI semiconductors
61.72.J- Point defects and defect clusters
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
78.20.Ls Magneto-optical effects
71.70.Ej Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect

Dynamics of recombination-enhanced defect reaction in a ZnCdSe single quantum well

Minxue Tang, Kai Shum, Linfei Zeng, and Maria C. Tamargo

Appl. Phys. Lett. 73, 1541 (1998); http://dx.doi.org/10.1063/1.122199 (3 pages) | Cited 6 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Room temperature photoluminescence spectra from a ZnCdSe single quantum well have been measured as a function of time in a minute time scale under several photoexcitation levels (4–40 W/cm2). Spectrally integrated photoluminescence intensity increases as the measurement time increases and reaches a maximum level that is 37 times higher than the initial intensity. We attribute this dynamical behavior to recombination-enhanced defect reactions in the vicinities of point defects. These reactions reduce the density of point defects and enhance radiation quantum efficiency. A new point defect reduction rate was discovered to fit our experimental data. © 1998 American Institute of Physics.
Show PACS
78.66.Hf II-VI semiconductors
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
73.40.Lq Other semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
78.55.Et II-VI semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
73.61.Ga II-VI semiconductors
61.72.J- Point defects and defect clusters
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.

Light emission spectra of AlGaAs/GaAs multiquantum wells induced by scanning tunneling microscope

T. Tsuruoka, Y. Ohizumi, S. Ushioda, Y. Ohno, and H. Ohno

Appl. Phys. Lett. 73, 1544 (1998); http://dx.doi.org/10.1063/1.122200 (3 pages) | Cited 24 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have investigated the scanning-tunneling-microscope light emission (STM-LE) spectra of p-Al0.4Ga0.6As/p-GaAs multiquantum wells. The injection current level was kept as low as 0.1–0.5 nA to ensure that the sample is not damaged by the tunneling current. This is the current level ordinarily used for taking STM images. The peak energy of the emission shifts to the high energy side with decreasing well widths. A corresponding peak shift behavior was also observed in the photoluminescence (PL) spectra for the same samples. From comparisons of the STM-LE and the PL spectra, we find that although there is a difference in the excitation process, the final recombination process is identical in both cases. © 1998 American Institute of Physics.
Show PACS
78.66.Fd III-V semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
78.60.Hk Cathodoluminescence, ionoluminescence
78.55.Cr III-V semiconductors

Large blue shifts induced by the quantum confined stark effect in asymmetric quantum wells

R. K. Gug and W. E. Hagston

Appl. Phys. Lett. 73, 1547 (1998); http://dx.doi.org/10.1063/1.122201 (3 pages) | Cited 6 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The quantum-confined stark effect is calculated for an asymmetric AlxGa1−xAs/GaAs double quantum well system. It is shown that, with slight modifications to this system, the resultant blue shift in the one-particle energy separation of the electron and hole can be increased to values exceeding 30 meV. It is also shown that the value of this blue shift is very sensitive to the potential profile of the quantum well. © 1998 American Institute of Physics.
Show PACS
78.66.Fd III-V semiconductors
78.20.Jq Electro-optical effects
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems

Enhancement of the interband Stark effects in strained CdxZn1−xTe/ZnTe coupled double quantum wells

T. W. Kim, K. H. Lee, and H. L. Park

Appl. Phys. Lett. 73, 1550 (1998); http://dx.doi.org/10.1063/1.122202 (3 pages) | Cited 6 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The effects of an electric field on the interband transitions in CdxZn1−xTe/ZnTe coupled double quantum wells have been investigated both experimentally and theoretically. Photoluminescence (PL) measurements have been performed to investigate the excitonic transitions in CdxZn1−xTe/ZnTe coupled double quantum wells. Transmission electron microscopy images show that a 35-Å Cd0.18Zn0.82Te quantum well and a 50-Å Cd0.18Zn0.82Te quantum well are separated by a 35-Å Cd0.1Zn0.9Te potential barrier. PL spectra at 300 K show the excitonic transitions. When an electric field is applied to a coupled double quantum well, the Stark shift of the interband transition energy in the CdxZn1−xTe/ZnTe coupled double quantum wells is much more sensitive to the applied electric field than that of the Cd0.1Zn0.9Te/ZnTe single quantum wells. The electronic subband energies and energy wave functions in the quantum wells are calculated by an envelope function approximation, which takes into account the strain effects. These results indicate that CdxZn1−xTe/ZnTe coupled double quantum wells hold promise for potential applications in optoelectronic devices, such as new types of modulators and tunable lasers. © 1998 American Institute of Physics.
Show PACS
78.66.Hf II-VI semiconductors
78.55.Et II-VI semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
78.20.Jq Electro-optical effects
71.35.Cc Intrinsic properties of excitons; optical absorption spectra

Single-crystal α-GaN grown on a α-Ga2O3 template layer

Nobuhiko P. Kobayashi, Junko T. Kobayashi, Won-Jin Choi, and P. Daniel Dapkus

Appl. Phys. Lett. 73, 1553 (1998); http://dx.doi.org/10.1063/1.122218 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The mechanism for growth of single-crystal GaN on oxidized AlAs (AlOx) formed on a Si(111) substrate by metalorganic chemical vapor deposition has been studied. Cross-sectional transmission electron microscopy (XTEM) indicates that the grown GaN is single-crystal α-GaN in spite of the fact that the AlOx on which the GaN is grown is found to contain predominantly polycrystal γ-Al2O3. Reflection high-energy electron diffraction (RHEED) shows that oriented crystallized α-Ga2O3 is formed between AlOx and the GaAs cap layer during the oxidation process. The α-Ga2O3 acts as a growth template and results in the crystalline orientation of α-GaN on polycrystal γ-Al2O3. Further support for this template is derived from energy dispersive x-ray spectroscopy that shows the existence of Ga atoms on AlOx. Combined XTEM/RHEED analysis suggests that α-GaN is oriented in the growth direction as [0001]α-GaN∥[0001]α-Ga2O3∥[111]Si and the in-plane direction as [2110]α-GaN∥[1math00]α-Ga2O3∥[01math]Si, which can be understood by considering the misfit in the in-plane atomic separation at each interface. © 1998 American Institute of Physics.
Show PACS
81.05.Ea III-V semiconductors
68.35.Ct Interface structure and roughness
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
73.20.At Surface states, band structure, electron density of states
68.55.Nq Composition and phase identification

Hydrogen effusion from epitaxial ZnSe layers grown by metalorganic vapor phase epitaxy

B. Hahn, H. Preis, S. Blümel, and W. Gebhardt

Appl. Phys. Lett. 73, 1556 (1998); http://dx.doi.org/10.1063/1.122203 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The thermal outdiffusion of hydrogen from undoped ZnSe layers grown by metalorganic vapor phase epitaxy has been investigated. The samples were grown using dimethyl-zinc-triethylamine, di-tert.-butylselenide as precursors with hydrogen and nitrogen as carriergas. The typical atomic hydrogen concentrations of the samples is nH = 1018 cm−3, which originates from pyrolysis products of the organometallic precursors. The incorporation from the carrier gas is negligible. Control samples grown by molecular beam epitaxy in the presence of atomic and molecular hydrogen in the growth chamber showed no hydrogen incorporation. The outdiffusion process was investigated using transient effusion experiments. The experiments are explained by diffusion controlled effusion with a diffusion coefficient of D(T) = 1.4×10−11 exp[−0.33(±0.03) eV/(kBT)]cm2/s. © 1998 American Institute of Physics.
Show PACS
81.15.Kk Vapor phase epitaxy; growth from vapor phase
81.05.Dz II-VI semiconductors

Microwave plasma nitridation of silicon dioxide on strained Si

L. K. Bera, H. D. Banerjee, S. K. Ray, M. Mukhopadhyay, and C. K. Maiti

Appl. Phys. Lett. 73, 1559 (1998); http://dx.doi.org/10.1063/1.122204 (3 pages) | Cited 2 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Growth of ultrathin (<100 Å) nitrided SiO2 on strained Si using microwave O2/N2O/NH3 plasma is reported. X-ray photoelectron spectroscopy results indicate a nitrogen-rich layer at the strained Si/SiO2 interface. The electrical properties of the nitrided oxides have been characterized using a metal–insulator–semiconductor structure. N2O plasma treatment of O2/NH3 nitrided SiO2 results in a lower insulator charge density (1.2×1011 cm−2) and a higher breakdown voltage. © 1998 American Institute of Physics.
Show PACS
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
52.77.Bn Etching and cleaning
52.77.Dq Plasma-based ion implantation and deposition
77.22.Jp Dielectric breakdown and space-charge effects
81.05.Je Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)
79.60.Bm Clean metal, semiconductor, and insulator surfaces
79.60.Jv Interfaces; heterostructures; nanostructures

Intermediate temperature grown GaAs/AlGaAs photodetector with low dark current and high sensitivity

James Culp, Bahram Nabet, Francisco Castro, and Amro Anwar

Appl. Phys. Lett. 73, 1562 (1998); http://dx.doi.org/10.1063/1.122219 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A photodetector in which Schottky metal laterally contacts the molecular beam epitaxy grown heterointerface of intermediate-temperature GaAs and Al0.24Ga0.76As is reported. The device processed on 400 °C shows very low dark current, less than 25 fA/μm2 (0.5 pA/μm), with a high dc responsivity of about 10 A/W at low optical power levels. The device is process compatible with high electron mobility transistor technology. © 1998 American Institute of Physics.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
73.61.Ey III-V semiconductors

Nondispersive hole transport in an electroluminescent polyfluorene

M. Redecker, D. D. C. Bradley, M. Inbasekaran, and E. P. Woo

Appl. Phys. Lett. 73, 1565 (1998); http://dx.doi.org/10.1063/1.122205 (3 pages) | Cited 239 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Time-of-flight measurements have been used to study carrier transport in films of poly(9,9-dioctylfluorene). We find nondispersive hole transport with a room-temperature mobility, μp = 4×10−4 cm2/V s at a field of 5×105 V/cm. The field dependence of the mobility is weak: μp = 3×10−4 cm2/V s at 4×104 V/cm and increases only modestly to μp = 4.2×10−4 cm2/V s at 8×105 V/cm. Both the relatively high mobility and weak field dependence point to a high degree of chemical regularity and purity that makes polyfluorene attractive for use as an electroluminescent polymer and for other device applications. We have not been able to measure clean electron current transients, suggesting highly dispersive transport with possible deep trapping, as found in many other conjugated polymers. © 1998 American Institute of Physics.
Show PACS
72.15.Nj Collective modes (e.g., in one-dimensional conductors)
78.60.Fi Electroluminescence
78.66.Qn Polymers; organic compounds
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
73.61.Ph Polymers; organic compounds

The observation of the low-frequency acoustic phonon torsional modes in nanocrystalline silicon

X. L. Wu, G. G. Siu, X. Y. Yuan, N. S. Li, Y. Gu, X. M. Bao, S. S. Jiang, and D. Feng

Appl. Phys. Lett. 73, 1568 (1998); http://dx.doi.org/10.1063/1.122206 (3 pages) | Cited 7 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Low-frequency Raman spectra of the porous structure formed on C+-implanted silicon were examined using the 514.5 and 488 nm lines of Ar+ laser. The sharp low-frequency Raman peaks were observed with narrow linewidth and large intensity. According to usual vibration theory of the elastic body and related symmetry analysis, they are identified as the localized acoustic phonon torsional modes resulting from the surface vibrations of quasifree Si nanocrystals with nonspherical shapes. © 1998 American Institute of Physics.
Show PACS
78.30.Am Elemental semiconductors and insulators
68.35.Ja Surface and interface dynamics and vibrations

Surface, stress, and impurity effects on room-temperature migration of ion-beam-generated point defects

S. Coffa, A. La Magna, V. Privitera, and G. Mannino

Appl. Phys. Lett. 73, 1571 (1998); http://dx.doi.org/10.1063/1.122207 (3 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have analyzed the perturbations produced by recombination at surface, trapping at impurities, and stress fields on the room-temperature migration properties of point defects in Si. A stack consisting of a Si oxide (or a Si nitride) and a polycrystalline Si layer, deposited on Si samples, was patterned to open 2-μm-wide, 10-μm-spaced stripes. A 40-keV Si implantation to fluences of 1×1012–5×1013/cm3, performed through this mask at room temperature, was used to inject point defects into the bulk of the wafer. After implants, defect-induced dopant deactivation, in the cross section orthogonal to the direction of the stripes, has been monitored using two-dimensional spreading resistance profilometry. It has been found that, in highly pure epitaxial Si samples, dopant deactivation extends in depth to several microns beyond the region (∼0.4 μm) directly modified by the ions. Furthermore, the two-dimensional deactivation profiles exhibit a strong recess at the surface and a significant anisotropy, being markedly elongated in the lateral direction. Analysis of the data shows that long-range migration of defects is interrupted by trapping at impurities (C and O) or recombination at the surface, characterized by a coefficient of ∼100 μm−1. Moreover, the lateral elongation of the profiles is tentatively explained assuming an anisotropy in the defect diffusivity tensor produced by the strain field under the mask. © 1998 American Institute of Physics.
Show PACS
61.82.Fk Semiconductors
61.72.uf Ge and Si
61.80.Jh Ion radiation effects
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
61.72.J- Point defects and defect clusters
66.30.J- Diffusion of impurities
71.55.Cn Elemental semiconductors
61.72.Yx Interaction between different crystal defects; gettering effect
72.80.Cw Elemental semiconductors
73.61.Cw Elemental semiconductors
72.20.Fr Low-field transport and mobility; piezoresistance

Study of the optical properties of fused quartz after a sequential implantation with Si and Au ions

A. Oliver, J. C. Cheang-Wong, A. Crespo, J. M. Hernández, C. Solís, E. Muñoz, R. Espejel-Morales, and J. Siejka

Appl. Phys. Lett. 73, 1574 (1998); http://dx.doi.org/10.1063/1.122208 (3 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Implantation of Au ions into Si-implanted fused quartz strongly enhances the photoluminescence (PL) intensity around 630 nm measured after subsequent sample annealing at 900 °C. This effect is attributed to the enhancement of the formation of Si nanocrystals by the presence of Au ions and not by ion-implantation-induced defects. This conclusion was deduced by monitoring the defect formation in fused silica by 2 MeV Si ion implantation with doses ranging from 2×1016 to 1×1017 Si/cm2. Some of the 4×1016 Si/cm2-implanted samples were reimplanted at a similar depth with 10 MeV Au ions at doses of 4×1016 and 1.2×1017 Au/cm2. The absorption spectroscopy, electron paramagnetic resonance and PL measurements show the presence of B2 and E′ matrix point defects in as-prepared Si-implanted samples. As these defects disappear after annealing at 600 °C, the presence of a strong PL peak in samples implanted and annealed at 900 °C strongly suggests that the observed luminescence is produced by Si nanoparticle formation. © 1998 American Institute of Physics.
Show PACS
78.55.Hx Other solid inorganic materials
61.72.up Other materials
61.80.Jh Ion radiation effects
61.72.J- Point defects and defect clusters
61.72.Cc Kinetics of defect formation and annealing
61.46.-w Structure of nanoscale materials
76.30.He Platinum and palladium group (4d and 5d) ions and impurities (Zr-Ag and Hf-Au)
76.30.Lh Other ions and impurities
78.40.Ha Other nonmetallic inorganics

Use of Kubo formalism to study transport beyond the Born approximation: Application to low-temperature transport in Si metal–oxide–semiconductor field-effect transistors

Yifei Zhang and Jasprit Singh

Appl. Phys. Lett. 73, 1577 (1998); http://dx.doi.org/10.1063/1.122209 (3 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A formalism is developed to study transport in semiconductor devices under conditions where the Born approximation and independent scattering approximations break down. The approach based on the Kubo formalism is applied to Si metal–oxide–semiconductor field-effect transistors (MOSFETs) where interface roughness effects cause the approximations mentioned above to break down at low temperatures. Results presented are the outcome of a numerical method based on a three-dimensional approach to examine the interface roughness effects on the electronic spectrum as well as on the transport in the MOSFETs. The dependence of mobility on temperature and gate bias are reported and the shortcomings of the Born approximations are outlined. The approach is general and can be applied to problems where scattering is very strong and localization effects are significant, e.g., in amorphous semiconductor devices. © 1998 American Institute of Physics.
Show PACS
85.30.Tv Field effect devices
73.61.Cw Elemental semiconductors
68.35.Ct Interface structure and roughness
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems

Spin transport in GaAs

D. Hägele, M. Oestreich, W. W. Rühle, N. Nestle, and K. Eberl

Appl. Phys. Lett. 73, 1580 (1998); http://dx.doi.org/10.1063/1.122210 (3 pages) | Cited 122 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present a spectroscopic method for studying spin transport in semiconductors. Our time-resolved experiments have an important implication for spin electronics as they show that spin-polarized electron drift is possible in semiconductors over typical device lengths in high electric fields. We demonstrate an almost complete conservation of the orientation of the electron spin during transport in GaAs over a distance as long as 4 μm and fields up to 6 kV/cm. © 1998 American Institute of Physics.
Show PACS
72.80.Ey III-V and II-VI semiconductors
72.20.Ht High-field and nonlinear effects
73.50.Fq High-field and nonlinear effects
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close