Impurity and Stoichiometry Control in Atomic Layer Epitaxy

1992 ◽  
Vol 262 ◽  
Author(s):  
H. Yokoyama ◽  
K. Ikuta ◽  
N. Inoue
Keyword(s):  
Point Defects ◽  
Resonant Tunneling ◽  
Room Temperature ◽  
Defect Density ◽  
Atomic Layer ◽  
Negative Resistance ◽  
Atomic Layer Epitaxy ◽  
Tunneling Diode ◽  
Order Of Magnitude ◽  
Stoichiometry Control

ABSTRACTWe investigate the intrinsic point defects in epilayers grown by atomic layer epitaxy (ALE). Ga vacancies and antisite As atoms in the epilayers are detected by photoluminescence spectroscopy. This shows that the ALE epilayer was grown under As-rich conditions. We propose increasing the TMG flux to reduce the number of point defects. With this method, the number of point defects in ALE epilayers can be decreased to less than that in conventionally grown epilayers. Moreover, it is'found that these point defects are formed by the incomplete Ga coverage, not by the steric hindrance as previously suggested. The carbon concentration is decreased by one order of magnitude by using nitrogen instead of hydrogen as the carrier gas. As an application of this low defect density, we fabricated a GaAs/AlAs resonant tunneling diode and observed the negative resistance at room temperature.

Room Temperature Oscillation in Si/Si1-xGex Resonant Tunneling Diode

2007 ◽  
Author(s):  
Yoshiyuki Suda ◽  
Hirotaka Maekawa ◽  
Naoya Asaoka ◽  
Michihiko Suhara
Keyword(s):  
Resonant Tunneling ◽  
Room Temperature ◽  
Temperature Oscillation ◽  
Resonant Tunneling Diode ◽  
Tunneling Diode

scholarly journals Growth of (110) GaAs/GaAs by Molecular Beam Epitaxy

1985 ◽  
Vol 46 ◽  
Author(s):  
L.T. Parechanian ◽  
E.R. Weber ◽  
T.L. Hierl
Keyword(s):  
Molecular Beam Epitaxy ◽  
Substrate Temperature ◽  
Hall Effect ◽  
Room Temperature ◽  
Molecular Beam ◽  
Defect Density ◽  
Temperature Dependent ◽  
Mbe Growth ◽  
Order Of Magnitude ◽  
Hall Effect Measurements

AbstractThe simultaneous molecular beam epitaxy (MBE) growth of (100) and (110) GaAs/GaAsintentionally doped with Si(∼lE16/cm^3) was studied as a function of substrate temperature, arsenic overpressure, and epitaxial growth rate. The films wereanalyzed by scanning electron and optical microscopy, liquid helium photoluminescence (PL), and electronic characterization.For the (110) epitaxal layers, an increase in morphological defect density and degradation of PL signal was observed with a lowering of the substrate temperature from 570C. Capacitance-voltage (CV) and Hall Effect measurements yield room temperature donor concentrations for the (100) films of n∼l5/cm^3 while the (110) layers exhibit electron concentrations of n∼2El7/cm^3. Hall measurements at 77K on the (100) films show the expected mobility enhancement of Si donors, whereas the (110) epi layers become insulating or greatly compensated. This behavior suggests that room temperature conduction in the (110) films is due to a deeper donor partially compensated by an acceptor level whose concentration is of the same order of magnitude as that of any electrically active Si. Temperature dependent Hall effect indicates that the activation energy of the deeper donor level lies ∼290 meV from the conduction band. PL and Hall effect indicate that the better quality (110) material is grown by increasingthe arsenic flux during MBE growth. The nature of the defects involved with the growth process will be discussed.

Impurities and Point Defects in GaAs and AlAs Grown by Atomic Layer Epitaxy

1993 ◽  
Vol 117-118 ◽  
pp. 291-296
Author(s):  
K. Ikuta ◽  
Haruki Yokoyama ◽  
Naohisa Inoue
Keyword(s):  
Point Defects ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy

OPTICAL PROPERTIES OF CdTe/ZnTe ULTRATHIN QUANTUM WELLS GROWN BY ATOMIC LAYER EPITAXY

2002 ◽  
Vol 09 (05n06) ◽  
pp. 1667-1670 ◽  
Author(s):  
M. GARCÍA-ROCHA ◽  
I. HERNÁNDEZ-CALDERÓN
Keyword(s):  
Optical Properties ◽  
Low Temperature ◽  
Quantum Wells ◽  
Gaas Substrate ◽  
Room Temperature ◽  
Diffusion Length ◽  
Substrate Surface ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Low Temperature Photoluminescence

Ultrathin quantum wells (UTQWs) of CdTe within ZnTe barriers were successfully grown by atomic layer epitaxy (ALE) on GaAs(001) substrates. ALE growth of CdTe was performed by alternate exposure of the substrate surface to individual fluxes of Cd and Te. Two different samples with 2-monolayer (ML) (substrate temperature Ts= 270° C ) and 4 ML (Ts = 290° C ) CdTe QWs were grown. Low temperature photoluminescence (PL) experiments exhibited intense and sharp peaks associated to the 2 ML QWs at 2.26 eV. In the case of the nominally 4-ML-thick QW the PL spectrum presented an intense peak around 2.13 eV and two weak features around 2.04 and 1.91 eV. The first peak is attributed to ~ 3 ML QW and the second one to ~ 4 ML QW. The dominance of the 3 ML peak is mainly attributed to Cd loss in the QW due to its substitution by Zn atoms. Due to a high diffusion length of the photogenerated carriers in the barriers, quite weak signals from the ZnTe barriers were observed in both cases. Room temperature (RT) photoreflectance (PR) spectra showed contributions from the CdTe UTQWs, the ZnTe barriers, and the GaAs substrate.

Highly Strained (InAs)M/(GaAs)N Multiple Quantum Well Based Resonant Tunneling Diodes on GaAs (100) Substrates and Their Application in Optical Switching

1991 ◽  
Vol 228 ◽  
Author(s):  
R. M. Kapre ◽  
Kezhong Hu ◽  
Li Chen ◽  
S. Guha ◽  
A. Madhukar
Keyword(s):  
Quantum Well ◽  
Resonant Tunneling ◽  
Optical Switching ◽  
Room Temperature ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Bistable Switch ◽  
Tunneling Diode ◽  
Short Period ◽  
Highly Strained

ABSTRACTWe report the realization of (a) an optically bistable switch using a strained resonant tunneling diode (RTD) and (b) highly strained RTDs exhibiting simultaneously high peak current densities (Jp) and peak-to-valley current ratios (PVR) suitable for high-speed electronic switching. Both of these make use of RTDs with (InAs)M/(GaAs)N strained short period multiple quantum well regions with AlAs barriers in a triple-well, double barrier structure. For the former, high contrast ratio (20:1) and an on state reflectivity of 46.5 % has been obtained at room temperature in an optically bistable switch involving a strained InGaAs/GaAs (100) multiple quantum well based asymmetric Fabty-Perot reflection modulator, detector, and a strained RTD and a Si field effect transistor. For the latter, we have obtained a Jp of 125 kA/cm2 with a PVR of 4.7 at room temperature.

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