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

24 Oct 1994

Volume 65, Issue 17, pp. 2121-2234

Page 2 of 2 Pages Previous Page | Jump to Page

Optical monitoring of the growth of heavily doped GaAs by chemical beam epitaxy and of the in situ etching of GaAs using CBr4

T. B. Joyce, T. J. Bullough, and T. Farrell

Appl. Phys. Lett. 65, 2193 (1994); http://dx.doi.org/10.1063/1.112759 (3 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
We report the in situ optical monitoring of the growth of heavily doped GaAs by chemical beam epitaxy. The normal incidence reflectance of a 670 nm semiconductor laser was monitored in real time using dynamic optical reflectivity (DOR). Oscillations in the reflectance of the growing film arising from small changes in the refractive index due to doping were observed for carbon doping in the range 2×1019–6×1020 cm−3. No oscillations were obtained for samples with carbon or sulphur doping levels in the range 1018–1019 cm−3. A reduction in growth rate was observed for carbon concentrations above 1020 cm−3 and this was attributed to etching by the CBr4 dopant source. In situ etching of GaAs layers by CBr4 prior to growth was also monitored using DOR. © 1994 American Institute of Physics.
Show PACS
68.55.-a Thin film structure and morphology
07.60.Hv Refractometers and reflectometers

Design of high‐performance quantum well electron transfer modulators via self‐consistent modeling

Jin Wang, J. E. Zucker, J. P. Leburton, T. Y. Chang, and N. J. Sauer

Appl. Phys. Lett. 65, 2196 (1994); http://dx.doi.org/10.1063/1.112964 (3 pages)

Full Text: | Download PDF

Show Abstract
We successfully use a self‐consistent physical model to predict device performance in a chopped quantum well electron transfer modulator. Large built‐in electric fields for this structure cause delocalization of the electron wave function, requiring a careful evaluation of excitonic effects. Our calculations of both the electrical and electro‐optic properties are in remarkably good agreement with the experimental data once Coulomb interactions are properly taken into account. © 1994 American Institute of Physics.
Show PACS
42.79.Hp Optical processors, correlators, and modulators
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
78.66.-w Optical properties of specific thin films
85.30.De Semiconductor-device characterization, design, and modeling

Observation of sulfur‐terminated GaAs(001)‐(2×6) reconstruction by scanning tunneling microscopy

Shiro Tsukamoto and Nobuyuki Koguchi

Appl. Phys. Lett. 65, 2199 (1994); http://dx.doi.org/10.1063/1.112760 (3 pages) | Cited 16 times

Full Text: | Download PDF

Show Abstract
Scanning tunneling microscopy (STM) images of smooth, in situ prepared, sulfur‐terminated (S‐terminated) GaAs(001) surface reconstruction are presented. It is found that (2×6) surface reconstruction is dominant on the S‐terminated GaAs(001) surface. This (2×6) reconstruction, of which the cell contains five S‐S adatom dimers, is determined by both STM and reflection high‐energy electron diffraction. The atomic model, which is consistent with both STM images and electron counting heuristics, is also shown. Moreover, this (2×6) reconstruction is also observed in the case of an (NH4)2Sx‐treated surface. © 1994 American Institute of Physics.
Show PACS
68.35.B- Structure of clean surfaces (and surface reconstruction)
81.65.-b Surface treatments

Measurement of nonuniform distribution of strain in InGaAs/GaAs quantum wires

Yu‐Pei Chen, Jason D. Reed, William J. Schaff, and Lester F. Eastman

Appl. Phys. Lett. 65, 2202 (1994); http://dx.doi.org/10.1063/1.112761 (3 pages) | Cited 12 times

Full Text: | Download PDF

Show Abstract
Nonuniform strain distribution in In0.2Ga0.8As/GaAs strained wires has been observed by measuring the lattice spacing from the lattice image of the cross section of a single 10 nm×400 nm wire. It was found that in the wire, the region near the wire sidewall was under a larger compressive strain in the growth direction (vertical strain) than the center of the wire. In the barrier, near the wire sidewall, GaAs was under a vertical tensile strain by the In0.2Ga0.8As wire. This observation explains experimental observation of quantum confinement in strained InGaAs/GaAs quantum wires where the possibility of nonconfining band offsets was previously hypothesized. The assumptions underlying theory which predicts the absence of quantum confinement can now be modified to include actual strain variations. The nonuniform strain distribution observed also has ramifications for stability of strained quantum wire, or buried quantum well lasers. © 1994 American Institute of Physics.
Show PACS
68.55.-a Thin film structure and morphology

Carbon doping of AlAs using CCl4 and CBr4 during growth by metalorganic molecular‐beam epitaxy

C. R. Abernathy, J. D. MacKenzie, W. S. Hobson, and P. W. Wisk

Appl. Phys. Lett. 65, 2205 (1994); http://dx.doi.org/10.1063/1.112762 (3 pages) | Cited 2 times

Full Text: | Download PDF

Show Abstract
CBr4 and CCl4 have been investigated as carbon doing sources for deposition of AlAs:C by metalorganic molecular‐beam epitaxy. Through the use of CBr4, hole concentrations up to 4.5×1019 cm−3 were achieved in as‐deposited AlAs layers. Attempts to increase the hole concentration in as‐grown material beyond this level resulted in a decrease in the hole concentration even though (SIMS) and (XRD) analysis show the carbon concentration to increase with increasing dopant flow. By annealing the AlAs after growth, the maximum achievable hole concentration could be increased to 1.1×1020 cm−3, which is the highest yet reported for AlAs:C. This increase in p after annealing is believed due to removal of hydrogen from the lattice which passivates the carbon acceptor. Neither carbon source increased the oxygen background beyond the level of ∼5×1017 cm−3 normally observed in AlAs grown under similar conditions. These compounds do introduce Cl and Br, and reduce the Al incorporation rate due to parasitic etching reactions with the adsorbed halogen. © 1994 American Institute of Physics.
Show PACS
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Electrically active subthreshold damage in Si ion implanted with Si, Ge, and Sn

P. Kringhøj, J. S. Williams, and C. Jagadish

Appl. Phys. Lett. 65, 2208 (1994); http://dx.doi.org/10.1063/1.112763 (3 pages) | Cited 6 times

Full Text: | Download PDF

Show Abstract
The residual damage in Si after Si, Ge, and Sn implantation and annealing at elevated temperatures has been studied with capacitance‐voltage measurements and deep level transient spectroscopy. We present a critical dose, specific to the implanted species and energy, below which no electrically active defects are found within our detection limit (2×10−5 of the background doping). This critical dose is found to scale with the number of beam‐induced vacancies and is in remarkable agreement with the critical dose established previously for observation of structural defects (dislocation loops) with transmission electron microscopy. © 1994 American Institute of Physics.
Show PACS
61.80.Jh Ion radiation effects
61.72.uf Ge and Si
71.55.Cn Elemental semiconductors

Determination of the GaN/AlN band offset via the (‐/0) acceptor level of iron

J. Baur, K. Maier, M. Kunzer, U. Kaufmann, and J. Schneider

Appl. Phys. Lett. 65, 2211 (1994); http://dx.doi.org/10.1063/1.112764 (3 pages) | Cited 70 times

Full Text: | Download PDF

Show Abstract
A characteristic infrared luminescence spectrum, dominated by a zero‐phonon line at 1.30 eV, has been observed on AlN polycrystalline material. It is assigned to the spin‐forbidden internal 3d–3d transition 4T1(G)→6A1(S) of Fe3+Al(3d5). By photoluminescence excitation spectroscopy the (‐/0) acceptor level of iron in AlN could be located at EV+3.0 eV. The corresponding value for iron in GaN is EV+2.5 eV. From these values, the valence‐band offset in AlN/GaN heterojunctions is predicted as ΔEV=0.5 eV, the conduction‐band offset as ΔEC=2.3 eV. © 1994 American Institute of Physics.  
Show PACS
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
78.55.Cr III-V semiconductors
71.55.Eq III-V semiconductors

Conduction‐band engineering in piezoelectric [111] multiple quantum well p‐i‐n photodiodes

J. L. Sánchez‐Rojas, A. Sacedón, F. Calle, E. Calleja, and E. Muñoz

Appl. Phys. Lett. 65, 2214 (1994); http://dx.doi.org/10.1063/1.112765 (3 pages) | Cited 20 times

Full Text: | Download PDF

Show Abstract
The influence of the design parameters on the conduction‐band profile and optoelectronic properties of [111]‐oriented InGaAs/GaAs p‐i(MQW)‐n diodes is presented. An analytical expression for the average electric field (AEF) in the p‐i‐n active region (MQWs within the intrinsic region) is obtained. The existence of two different potential envelopes, corresponding to a positive or to a negative sign of the AEF, and giving rise to clearly different optical and electronic properties, is demonstrated. In samples with negative AEF, as compared to structures with positive AEF, larger reverse voltages are needed to quench the photoluminescence and to enhance the p‐i‐n photocurrent. An analysis of both transition energies and intensities, versus bias, clearly indicates that in samples with a negative AEF carriers accumulate at the extremes of the active region, giving rise to a long‐range screening effect of the field in the wells. © 1994 American Institute of Physics.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
78.66.Fd III-V semiconductors
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

Selective epitaxial growth of GaInP by low‐pressure metal‐organic chemical‐vapor deposition using ethyldimethylindium as In source

Shih‐Hsiung Chan, Simon Ming Sze, Chun‐Yen Chang, and Wei‐I Lee

Appl. Phys. Lett. 65, 2217 (1994); http://dx.doi.org/10.1063/1.113039 (3 pages)

Full Text: | Download PDF

Show Abstract
We have demonstrated the feasibility of selective epitaxial growth (SEG) of GaInP using low‐pressure metal‐organic chemical‐vapor deposition (LPMOCVD) with the combination of ethyldimethylindium (EDMIn) and triethylgallium (TEGa) as the group‐III sources. Complete selective epitaxy can be achieved at a growth temperature of 675 °C and a growth pressure of 40 Torr. The deposition of Ga‐rich polycrystalline GaInP on Si3N4 film occurs at lower temperatures. Although the incorporation efficiency of TEGa into GaInP is much lower than that of trimethylgallium, the combination of EDMIn and TEGa has been found to be a good candidate for SEG of GaInP. Low‐temperature photoluminescence shows that the selectively grown epitaxial layer has good optical quality and is useful for light emitting device applications. © 1994 American Institute of Physics.
Show PACS
68.55.-a Thin film structure and morphology
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
78.55.Cr III-V semiconductors

Magnetron sputter epitaxy of SimGen/Si(001) strained‐layer superlattices

P. Sutter, C. Schwarz, E. Müller, V. Zelezny, S. Goncalves‐Conto, and H. von Känel

Appl. Phys. Lett. 65, 2220 (1994); http://dx.doi.org/10.1063/1.112766 (3 pages) | Cited 16 times

Full Text: | Download PDF

Show Abstract
Epitaxial growth of SimGen/Si(001) strained‐layer superlattices by magnetron sputter epitaxy is reported. Films of excellent crystal quality resulted from low‐temperature sputter growth at TS=350 °C, as is evidenced by Rutherford backscattering spectrometry minimum channeling yields χmin=3%. The absence of relaxation was demonstrated by Raman spectroscopy. Raman results on the first‐order longitudinal‐optical Ge–Ge phonon proved pure Ge to be present in a Si30Ge6 superlattice, which indicates an interface broadening of the order of 2 monolayers. High resolution transmission electron microscopy confirmed the formation of smooth and well‐defined interfaces between subsequent Si and Ge layers. © 1994 American Institute of Physics
Show PACS
68.55.-a Thin film structure and morphology
81.15.Cd Deposition by sputtering

Bandwidth enhanced metal‐semiconductor‐metal photodetectors based on backgated ip structures

E. Greger, K. Reingruber, P. Riel, G. H. Döhler, J. Rosenzweig, and M. Ludwig

Appl. Phys. Lett. 65, 2223 (1994); http://dx.doi.org/10.1063/1.112767 (3 pages) | Cited 9 times

Full Text: | Download PDF

Show Abstract
We report on theoretical and experimental results on a novel metal‐semiconductor‐metal (MSM) photodetector with a backgate provided by a p‐doped layer. The backgate allows extremely short sweep‐out times for the holes, due to strong electric fields normal to the surface. Thus, long tails due to slow moving holes and screening of the external drift fields by hole space charge accumulation at high optical power, which lead to a degradation of the time response of conventional MSM photodetectors, are avoided. The high frequency performance measured up to 8 GHz in the time and frequency domain showed a significant reduction of the bandwidth limiting hole tail compared to standard MSM photodetectors. © 1994 American Institute of Physics.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
42.79.Pw Imaging detectors and sensors
73.40.Sx Metal-semiconductor-metal structures

Infrared absorption of holes in a parabolic quantum well

M. Sundaram, S. J. Allen, M. R. Geller, P. F. Hopkins, K. L. Campman, and A. C. Gossard

Appl. Phys. Lett. 65, 2226 (1994); http://dx.doi.org/10.1063/1.112771 (3 pages) | Cited 2 times

Full Text: | Download PDF

Show Abstract
We observe the infrared absorption of holes in a wide graded AlxGa1−xAs parabolic quantum well to be at a single frequency, independent of the number of holes in the well. The resonant absorption frequency appears to be determined by the light hole mass, not the heavy hole mass.
Show PACS
78.66.Fd III-V semiconductors
78.30.Fs III-V and II-VI semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems

Oxidation of silicon nitride prepared by plasma‐enhanced chemical vapor deposition at low temperature

Wen‐Shiang Liao, Chi‐Huei Lin, and Si‐Chen Lee

Appl. Phys. Lett. 65, 2229 (1994); http://dx.doi.org/10.1063/1.112772 (3 pages) | Cited 33 times

Full Text: | Download PDF

Show Abstract
Hydrogenated amorphous silicon nitride (a‐SiNx:H) films have been fabricated by plasma‐enhanced chemical vapor deposition at temperatures ranging from 50 to 250 °C. It is found that as soon as the samples are taken out from the reaction chamber and exposed to the atmosphere, the a‐SiNx:H films start to oxide. The oxidation processes are monitored using infrared absorption spectroscopy. A model of porous ‘‘fractal‐like network’’ structure, which is probably inherent in low‐temperature deposition, is proposed to explain why moisture (H2O) in the air can percolate through numerous microvoids into these films. The H2O molecules which percolate into these porous films are active to react with the —Si—N—Si—, —Si—N—H, and —N—Si—‐H bonds and to form more chemically stabilized —Si—O—Si—, —Si—O—H, and H—O—H bond configurations with the result of eventual oxidization of the entire nitride films. © 1994 American Institute of Physics.  
Show PACS
81.65.-b Surface treatments
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.

Insulating boundary layer and magnetic scattering in YBa2Cu3O7−δ /Ag interfaces over a contact resistivity range of 10−8–10−3 Ω cm2

S. C. Sanders, S. E. Russek, C. C. Clickner, and J. W. Ekin

Appl. Phys. Lett. 65, 2232 (1994); http://dx.doi.org/10.1063/1.112773 (3 pages) | Cited 19 times

Full Text: | Download PDF

Show Abstract
We have measured interface transport in thin‐film YBa2Cu3O7−δ /Ag interfaces having resistivities ranging from 10−8 to 10−3 Ω cm2. Analysis of the interface I‐V data indicates that tunneling is the predominant transport mechanism even for the in situ interfaces having contact resistivities of 1–7×10−8 Ω cm2. Zero‐bias conductance peaks are also observed for the entire range of interface resistivity. The similarity of the zero‐bias conductance peaks among these widely varying interfaces suggests that the low‐temperature interface transport is governed by the same mechanism in each case. These conductance peaks are analyzed in the framework of the Appelbaum–Anderson model for tunneling assisted by magnetic scattering from isolated magnetic spins in the interface. © 1994 American Institute of Physics.
Show PACS
74.50.+r Tunneling phenomena; Josephson effects
74.45.+c Proximity effects; Andreev reflection; SN and SNS junctions
74.78.-w Superconducting films and low-dimensional structures
Page 2 of 2 Pages Previous Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close