Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Defects and ion redistribution in implant-isolated GaAs-based device structures (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 6580-6586 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Implant isolation of thick GaAs based epitaxial structures using either multiple energy keV ions or a single MeV ion implantation is becoming more popular for devices such as heterojunction bipolar transistors or quantum well lasers. We report examples of both types of isolation schemes, using keV F+ and H+ ions, or MeV O+ ions. Post-implant annealing at temperatures in the range 500–600 °C is needed to maximize the resistivity of the implanted material, but this causes redistribution of both F and H (but not O) and accumulation of hydrogen at strained or ion-damaged interfaces. The amount of hydrogen motion is sufficient to cause concerns about dopant passivation occurring in the initially masked, active regions of the devices. The resistance of the ion-implanted regions is stable for periods of ≥50 days at 200 °C, and is controlled by deep level point defects which pin the Fermi level near mid gap.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.355096
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Nonlinear spectroscopy near half-gap in bulk and quantum well GaAs/AlGaAs waveguides (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 1927-1935 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We study the nonlinear properties of bulk AlGaAs and GaAs/AlGaAs multiple quantum wells (MQW) below the half-band-gap energy using subpicosecond pulses between 1.65 and 1.7 μm. In the bulk material we find a value for the nonlinear index n2 = +3.6× 10−14 cm2/W and a two-photon absorption coefficient β = 0.26 × 10−4 cm/MW. In the MQW we measure an n2 up to 2.4 times larger, and we attribute this enhancement to a stronger 1S-exciton intermediate state. The β value is up to 25 times larger in the MQW. This larger value may result from midgap states that resonantly enhance the virtual intermediate state in two-photon absorption and act as a real transition in a two-step absorption process. The resulting figure of merit (2n2/βλ) for the bulk (MQW) material is 17 (1.6), which means that these semiconductors below half band gap are appropriate for all-optical switching and quantum optics applications. We confirm that n2 is instantaneous on the 300 fs time scale of our pulses from self-phase-modulation spectra as well as time-resolved pump-probe measurements. However, we find an intriguing exchange of energy between the two orthogonal axes as evidenced by the signal along the probe axis following the negative derivative of the pump intensity. This result may be explained by self-phase modulation of the pump combined with a low-frequency Raman process that couples the modes along orthogonal axes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.351182
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Photoexcited escape probability, optical gain, and noise in quantum well infrared photodetectors (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 4429-4443 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We present a detailed and thorough study of a wide variety of quantum well infrared photodetectors (QWIPs), which were chosen to have large differences in their optical and transport properties. Both n- and p-doped QWIPs, as well as intersubband transitions based on photoexcitation from bound-to-bound, bound-to-quasicontinuum, and bound-to-continuum quantum well states were investigated. The measurements and theoretical analysis included optical absorption, responsivity, dark current, current noise, optical gain, hot carrier mean free path, net quantum efficiency, quantum well escape probability, quantum well escape time, as well as detectivity. These results allow a better understanding of the optical and transport physics and thus a better optimization of the QWIP performance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.352210
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Carbon-doped long wavelength GaAs/AlxGa1−xAs quantum well infrared photodetectors grown by organometallic vapor phase epitaxy (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 3642-3644 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report p-doped long wavelength GaAs/AlxGa1−xAs quantum well infrared photodetectors (QWIP) grown by organometallic vapor phase epitaxy. The operation of these devices is based on the photocurrent induced through valence-band intersubband absorption by holes and, unlike n-doped QWIPs, can utilize normal incidence illumination. Carbon was used as the p-type dopant in a low-pressure (30 Torr) vertical-geometry reactor. The C-doped QWIPs consisted of fifty periods of 54-nm-thick undoped AlxGa1−xAs (x=0.36 or 0.30) and C-doped GaAs wells (Lz=4 or 5 nm). Using normal incidence illumination, the C-doped QWIP with shorter wavelength response (x=0.36, Lz=4 nm) exhibited a quantum efficiency of η=21.4% and a detectivity at the peak wavelength of Dλ=5.4×109 cm (square root of)Hz/W at 77 K. The peak and cutoff wavelengths were λp=8.1 μm and λco=8.9 μm, respectively. The C-doped QWIP with longer wavelength response (x=0.30, Lz=5 nm) exhibited a normal incidence η=22.1% and D*λ=3.5×108 cm (square root of)Hz/W for λp=10.5 μm (λco=11.7 μm). The detectivity of the C-doped QWIPs is about four times less than n-doped QWIPs for the same λp but have the advantage of utilizing normal incidence illumination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.350899
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Low-threshold GaAs/AlGaAs quantum-well lasers grown by organometallic vapor-phase epitaxy using trimethylamine alane (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 432-435 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have utilized a new aluminum source, trimethylamine alane (TMAA), in the growth of graded-index separate-confinement heterostructure single quantum-well GaAs/AlGaAs laser structures by low pressure (30 Torr) organometallic vapor-phase epitaxy. We find lower carbon and oxygen incorporation in AlGaAs epilayers using TMAA since it does not contain a direct Al–C bond and it is not susceptible to the formation of volatile Al–O containing compounds. The oxygen and carbon concentrations were below the detection limits (〈 5 × 1016 cm−3 and 〈 3 × 1016 cm−3, respectively) of the secondary ion mass spectrometry measurements. Broad-area lasers with 10-nm quantum wells and Al0.45Ga0.55As cladding layers exhibited threshold current densities of 140 A cm−2 for cavity lengths of 1 mm, internal quantum efficiencies of 81%, and intrinsic losses of 1.6 cm−1. These results demonstrate that extremely high-quality AlGaAs and GaAs quantum wells can be grown with TMAA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.350294
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    A photoluminescence study of hydrogenated GaAs grown on an InP substrate by metalorganic chemical vapor deposition (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 68 (1990), S. 902-905 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The effects of hydrogenation on the low-temperature (5 K) photoluminescence properties of GaAs grown on InP substrate by metalorganic chemical vapor deposition are investigated. An emission band at ∼1.4 eV originating from the GaAs/InP interfacial region shows a 30-fold increase in intensity relative to the GaAs band-edge emission after exposure to hydrogen plasma for 30 min at 250 °C. This improvement in intensity is attributed to hydrogen passivation of defects at the heterointerface caused by the large (≈4%) lattice mismatch between GaAs and InP. Annealing the hydrogenated sample at 350 °C nullifies the passivation effect. Further, the 1.4-eV band shifts to higher energy on annealing the sample in the temperature range 150–450 °C with the hydrogenated sample exhibiting a larger shift than the untreated sample. It is suggested that the annealing-induced peak shift arises due to modification of the interface and that it is greater in the hydrogenated sample compared to the untreated sample.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.346757
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Passivation of carbon-doped GaAs layers by hydrogen introduced by annealing and growth ambients (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 3716-3724 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Carbon acceptors in GaAs epitaxial layers grown from metalorganic sources are often partially passivated by hydrogen following growth. Here we examine heavily C-doped GaAs epilayers grown by metalorganic molecular beam epitaxy and metalorganic vapor phase epitaxy by infrared absorption, secondary ion mass spectrometry, and Hall measurements. The concentration of passivated C has been determined by calibrating the intensity of infrared absorption due to C-H complexes. We have investigated the sources of H in the layers and have found that H2 in the growth and annealing ambients is especially effective in passivating C. A brief anneal in an inert ambient at temperatures above 550 °C is sufficient to activate C acceptors that are passivated by H.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.352902
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Isolation properties and experimental ranges of high energy ions in GaAs and InP (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 2663-2668 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The formation of high-resistivity layers in initially highly doped n- and p-type epitaxial GaAs by the passage of 25- to 50-MeV oxygen ions was investigated. The experimentally determined projected ranges of these ions are 14.0 and 28.8 μm, respectively. The sheet resistance of thin (0.5 μm) epitaxial surface layers exposed to such ions increases rapidly with fluence in the range 1013–1015 cm−2 but, depending on the initial doping density, may decrease again at higher doses. The remnant conductivity in the epitaxial layers after implantation is dominated by hopping processes with low activation energies (43–68 meV). Secondary-ion mass spectrometry was used to measure the depth profiles of Si ions implanted into GaAs and InP at energies of 30–70 MeV. The projected ranges are slightly larger (≤10%) than those predicted by current theory, and the activation efficiency of the implanted Si ions in both GaAs and InP is higher than for low-energy (∼100 keV) ions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.351038
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Doping of In0.53Ga0.47As and In0.52Al0.48As by Si+ and Be+ ion implantation (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 215-220 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The activation kinetics and diffusion characteristics of Si+ and Be+ ions implanted into InAlAs and InGaAs were investigated for rapid thermal annealing in the temperature range 600–900 °C. The apparent activation energies for electrical activation of Be are 0.43±0.03 eV in InAlAs and 0.38±0.03 eV in InGaAs, and for Si are 0.58±0.05 eV in InAlAs and 0.64±0.06 eV in InGaAs. Higher activation efficiencies are obtained for both dopants in InGaAs relative to InAlAs and anomalously low activation for low dose Be implants is observed due to a lack of vacant sites for the Be to occupy. Extensive redistribution of Be after annealing at 750 °C, 10 s is observed in both materials, whereas Si shows no motion even for annealing at 850 °C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.350745
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Characteristics of Be+ and O+ or H+ co-implantation in GaAs/AlGaAs heterojunction bipolar transistor structures (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 698-703 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The simultaneous formation of buried external collector and extrinsic base regions in GaAs/AlGaAs heterojunction bipolar transistor (HBT) structures by co-implantation of Be+ together with O+ or H+ ions is described. Oxygen implants at doses of ≥ 1012 cm−2, or proton implants at doses ≥ 1014 cm−2, followed by annealing at 500–550 °C, create fully depleted collector regions, while similar anneals lead to significant Be activation and lowered base resistance. Higher annealing temperatures improve this Be activation but restore the initial doping level in the implanted collector region. For Be+ ion doses ≤ 5≤5× 1014 cm−2 there are no defects visible by transmission electron microscopy in the HBT structure for annealing temperatures below 800 °C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.347352
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...