共查询到20条相似文献,搜索用时 11 毫秒
1.
E. Calleja F. Sanchez E. Muñoz P. Gibart A. Powell J. S. Roberts 《Journal of Electronic Materials》1995,24(8):1017-1022
A systematic silicon contamination has been detected by deep level transient spectroscopy in undoped and n-type doped (Te,
Se, Sn) AlGaAs layers, grown in two different metalorganic vapor phase epitaxy reactors. DX center generation by substitutional
donors, with very specific capture and emission thermal barriers (fingerprints), is the key to unambiguously identifying their
presence, with detection limits well below the standard secondary ion mass spectroscopy capability. We comment on the potential
sources of Si contamination (most common in this epitaxial technique), and on the relevance of such contamination to interpreting
correctly experimental data related to the microscopic structure of DX centers. 相似文献
2.
F. Bugge A. Knauer S. Gramlich I. Rechenberg G. Beister J. Sebastian H. Wenzel G. Erbert M. Weyers 《Journal of Electronic Materials》2000,29(1):57-61
GaAs-based diode lasers for emission wavelengths between 800 nm and 1060 nm with AlGaAs-cladding and GaInP-waveguide layers
were grown by MOVPE. For wavelengths above 940 nm broad area devices with InGaAs QWs show state-of-the-art threshold current
densities. Ridge-waveguide lasers fabricated by selective etching achieve 200 mW CW monomode output powers. (In)GaAsP QW-based
diode lasers with an emitting wavelengths around 800 nm suffer from problems at the upper GaInP/AlGaAs interface. Asymmetric
structures with a lower AlGaAs/GaInP and an upper AlGaAs/AlGaAs waveguide not only avoid this interface but also offer better
carrier confinement. Such structures show very high slope efficiencies and a high T0. Maximum output powers of 7 W CW are obtained from 4 mm long devices. 相似文献
3.
The growth rates of GaSb by metalorganic vapor phase epitaxy were studied as functions of growth temperatures and partial
pressures of precursors. A Langmuir-Hinshelwood model was used to explain the GaSb growth rate in the chemical reaction controlled
regime. The relationship between growth kinetics and epilayer qualities was discussed and properties of GaSb were obtained. 相似文献
4.
Metalorganic vapor phase epitaxy of InP using the novel P-source ditertiarybutyl phosphine (DitBuPH)
H. Protzmann Z. Spika B. Spill G. Zimmermann W. Stolz E. O. Göbel P. Gimmnich J. Lorberth 《Journal of Electronic Materials》1996,25(3):443-448
In this study, the use of a novel phosphorous precursor for low pressure metalorganic vapor phase epitaxy (LP-MOVPE) application
has been investigated. Ditertiarybutyl phosphine ((C4H9)2-P-H, DitBuPH) as substitute for the standardly used hydrid gas phosphine (PH3) promises apart from strongly reduced toxicity due to the reduction of P-H bonds, an enhancement in cracking efficiency as
well as a reduction in growth temperature. Layer quality has been examined by means of optical and scanning electron microscopy
(SEM), temperature-dependent van der Pauw Hall as well as photoluminescence (PL) measurements. Uncompensated n-type InP-layers
(1.0 x 1.5 cm-3; 59600 cm2Vs)-1 at 77K) are realized using DitBuPH in combination with commercial TMIn. All results are compared with those obtained by using
PH3 and commercial tertiarybutyl phosphine (TBP) as P-source, respectively. 相似文献
5.
A. Knauer F. Bugge G. Erbert H. Wenzel K. Vogel U. Zeimer M. Weyers 《Journal of Electronic Materials》2000,29(1):53-56
We present a detailed study of the MOVPE growth of 800 nm diode laser structures based on the combination of a GaAsP quantum
well with well-established AlGaAs waveguide structures. By optimizing the strain and thickness of the quantum well highly-reliable
diode lasers with low threshold current and high efficiency were demonstrated. 100 μm aperture “broad area” devices mounted
epi-side up achieve a CW output power of 8.9 W with a wall-plug efficiency of 50%. These output powers represent record values
for diode lasers in this wavelength range. Reliability measurements at 1.5 W and 50°C ambient temperature suggest lifetimes
>10 000 h. 相似文献
6.
R. M. Lum M. L. Mc Donald E. M. Mack Williams M.D. F. G. Storz J. Levkoff 《Journal of Electronic Materials》1995,24(11):1577-1581
The influence of growth temperature on the composition of InGaAsP films grown by low pressure metalorganic vapor phase epitaxy
(MOVPE) is reported for quaternary (Q) alloys having bandgap wavelengths of λg = 1.1, 1.3, and 1.5 μn. Films with these different Q-compositions were deposited lattice matched to InP at a growth temperature
of 675°C. Subsequent growth experiments were then performed for each Q-composition in which the input gas flow rates were
kept the same and only the temperature changed in 25°C decrements down to 600°C. Photoluminescence (PL) and lattice mismatch
(LMM) measurements of the resulting films were used to determine the effect of growth temperature on film composition. The
PL data indicate a temperature shift in the PL wavelength of −1.8 nm/ °C for the 1.5Q composition, −2.9 nm/°C for 1.3Q, and
−4.3 nm/°C for 1.1Q. Negative shifts were also observed in LMM of −80 ppm/°C for 1.5Q, −150 ppm/°C for 1.3Q, and −250 ppm/°C
for 1.1Q. The Ga/In and P/As ratios of the Q-filmswere measured by secondary ion mass spectroscopy and correlated with full-wafer
maps of the PL wavelength and lattice mismatch to gain insight into the processes responsible for wafer nonuniformity in MOVPE. 相似文献
7.
M. Heuken C. V. Eichel-Streiber A. Behres B. Schineller K. Heime C. Mendorf G. Brockt H. Lakner 《Journal of Electronic Materials》1997,26(10):1221-1224
We investigated the growth of InPSb on GaSb or InAs by low pressure (20 mbar) metalorganic vapor phase epitaxy (MOVPE). Trimethylindium,
triethylantimony, and phosphine were used as starting materials. High resolution x-ray diffraction, photoluminescence at 10K,
Hall measurements at 300 and 77K as well as scanning electron microscopy and scanning tunneling electron microscopy investigations
were carried out to verify the layer properties. Lattice-matched InPSb layers on InAs substrate grown at 520°C show mirror-like
surfaces and sharp x-ray peaks. N-type doping of InP0.69Sb0.31 was carried out with H2S and p-type doping was achieved with DEZn. Maximum electron concentrations of 2×1019 cm−3 and hole concentrations exceeding 1018 cm−3 were obtained after annealing in N2 ambient. The thermal stability of InPSb was studied during annealing experiments carried out at 500°C up to 30 min. The compositional
integrity of the lattice proves to be stable and the InAs/InPSb interface can be improved. Multiple quantum well structures,
pn-junction diodes and the two-dimensional electron gas at the InPSb/InAs/InPSb quantum wells were investigated to demonstrate
the properties of the material. 相似文献
8.
C. D. Maxey C. L. Jones N. E. Metcalfe R. Catchpole M. R. Houlton A. M. White N. T. Gordon C. T. Elliott 《Journal of Electronic Materials》1996,25(8):1276-1285
Band gap engineered Hg1−xCdxTe (MCT) heterostructures should lead to detectors with improved electro-optic and radiometric performance at elevated operating
temperatures. Growth of such structures was accomplished using metalorganic vapor phase epitaxy (MOVPE). Acceptor doping with
arsenic (As), using phenylarsine (PhAsH2), demonstrated 100% activation and reproducible control over a wide range of concentrations (1 × 1015 to 3.5 × 1017 cm−3). Although vapor from elemental iodine showed the suitability of iodine as a donor in MC.T, problems arose while controlling
low donor concentrations. Initial studies using ethyliodide (EtI) demonstrated that this source could be used successfully
to dope MCT, yielding the properties required for stable heterostructure devices, i.e. ≈100% activation, no memory problems
and low diffusion coefficient. Cryogenic alkyl cooling or very high dilution factors were required to achieve the concentrations
needed for donor doping below ≈1016cm−3 due to the high vapor pressure of the alkyl. A study of an alternative organic iodide source, 2-methylpropyliodide (2 MePrI),
which has a much lower vapor pressure, improved control of low donor concentrations. 2 MePrI demonstrated the same donor source
suitability as EtI and was used to control iodine concentrations from ≈ 1 × 1015 to 5 × 1017cm−3. The iodine from both sources only incorporated during the CdTe cycles of the interdiffused multilayer process (IMP) in a
similar manner to both elemental iodine and As from PhAsH2. High resolution secondary ion mass spectroscopy analysis showed that IMP scale modulations can still be identified after
growth. The magnitude of these oscillations is consistent with a diffusion coefficient of≈7 × 10−16cm2s−1 for iodine in MC.T at 365°C. Extrinsically doped device heterostructures, grown using 2 MePrI, have been intended to operate
at elevated temperatures either for long wavelength (8–12 smm) equilibrium operation at 145K or nonequilibrium operation at
190 and 295K in both the 3–5 μ and 8–12 μ wavelength ranges. Characterization of such device structures will be discussed.
Linear arrays of mesa devices have been fabricated in these layers. Medium wave nonequilibrium device structures have demonstrated
high quantum efficiencies and R0A = 37 Ωcm2 for λco = 4.9 μ at 190K. 相似文献
9.
The growth of nominally undoped GaSb layers by atmospheric pressure metalorganic vapor phase epitaxy on GaSb and GaAs substrates
is studied. Trimethylgallium and trimethylantimony are used as precursors for the growth at 600°C in a horizontal reactor.
The effect of carrier gas flow, V/III-ratio, and trimethylgallium partial pressure on surface morphology, electrical properties
and photoluminescence is investigated. The optimum values for the growth parameters are established. The carrier gas flow
is shown to have a significant effect on the surface morphology. The optimum growth rate is found to be 3–8 μm/ h, which is
higher than previously reported. The 2.5 μm thick GaSb layers on GaAs are p-type, having at optimized growth conditions room-temperature
hole mobility and hole concentration of 800 cm2 V−1 s−1 and 3·1016 cm-3, respectively. The homoepitaxial GaSb layer grown with the same parameters has mirror-like surface and the photoluminescence
spectrum is dominated by strong excitonic lines. 相似文献
10.
J. Giess J. E. Hails A. Graham G. Blackmore M. R. Houlton J. Newey M. L. Young M. G. Astles W. Bell D. J. Cole-Hamilton 《Journal of Electronic Materials》1995,24(9):1149-1153
It has been established that a compound present as an impurity in the propan-2-ol used in the preparation of GaAs (100) substrates
for the metalorganic vapor phase epitaxy growth of (Hg,Cd)Te has a marked effect on the crystalline perfection and surface
morphology of the resulting layers. In particular, the presence of this species, which contains Na, ensures that (i) the epitaxial
overgrowth is of (100) orientation without the need for ZnTe nucleation layers, and (ii) the density of pyramidal hillocks
on the surface can be reproducibly < 10 cm−2. 相似文献
11.
M. A. L. Johnson Zhonghai Yu J. D. Brown N. A. El-Masry J. W. Cook Jr. J. F. Schetzina 《Journal of Electronic Materials》1999,28(3):295-300
Traditional epitaxial growth of GaN by metalorganic vapor phase epitaxy (MOVPE) on mismatched substrates such as sapphire
or SiC produces a columnar material consisting of many hexagonal grains ∼0.2–1.0 μm in diameter. The epitaxial-lateral-overgrowth
(ELO) process for GaN creates a new material: single-crystal GaN. We have studied the ELO process for GaN grown by MOVPE in
a vertical flow rotating substrate reactor. Characterization consisted of plan-view SEM and vertical-cross-section TEM studies,
which revealed a large reduction in dislocation density in the overgrown regions of the GaN. Panchromatic and monochromatic
cathodoluminescence images and spectra were used to study the spatial variation of the optical properties within the GaN ELO
samples. The effects of growth temperature and stripe material on the overgrown layers were examined. Through the use of a
higher substrate temperature during growth and the use of a SiNx stripe material, the overgrown crystal shape has a smooth 2D top surface with vertical sidewalls. Applying a second ELO step,
rotated by 60°, over a fully coalesced ELO layer yields a further reduction of defects in GaN overgrown surfaces. 相似文献
12.
K. Yasuda K. Mori Y. Kubota K. Kojima F. Inukai Y. Asai T. Nimura 《Journal of Electronic Materials》1998,27(8):948-953
Growth characteristics of (100)-oriented CdZnTe layers grown by atmospheric-pressure metalorganic vapor phase epitaxy have
been studied using dimethylzinc (DMZn), dimethylcadmium (DMCd), diethyltelluride (DETe), and dimethyltelluride (DMTe) as precursors.
Variations of Zn composition and layer growth rate were examined by changing the DMZn supply ratio, defined as DMZn/(DMCd+DMZn),
where the precursors are expressed in appropriate units of flow rate, from 0 (no DMZn) to 1.0 (no DMCd), while keeping the
total group II supply rate constant. The growth rate of CdZnTe layers was found to decrease monotonically with increase of
the DMZn supply ratio. On the other hand, the Zn composition x of grown layers increased gradually up to x=0.04 with increase
of the DMZn supply ratio from 0 to 0.8, beyond which the Zn composition increased abruptly to ZnTe. The abrupt transition
of Zn composition was suppressed by increasing the VI/II ratio. The growth mechanism of CdZnTe layers was studied based on
the observed growth characteristics of CdTe and ZnTe. A higher desorption rate from the growth surface for Zn species than
for Cd species, and a higher rate of CdTe formation than ZnTe formation are believed to cause the observed growth characteristics.
CdZnTe layers with high crystal quality were grown in a wide range of Zn compositions. The full-width at half-maximum values
for x-ray double-crystal rocking-curve measurements were lower than 320 arc-sec for x<0.3 and x>0.75. 相似文献
13.
Influence of oxygen in AlGaAs-based laser structures with Al-Free active region on device properties
A. Knauer H. Wenzel G. Erbert B. Sumpf M. Weyers 《Journal of Electronic Materials》2001,30(11):1421-1424
AlGaAs-based lasers with GaAsP active regions for emission wavelengths near 730 nm and 800 nm were studied. Trimethyl aluminum
sources with different levels of oxygen concentration were used for the deposition of the laser structures. The laser data
show that the oxygen level in the AlGaAs wave guides is very critical for the performance of the 730 nm devices, even for
the use of an Al-free active region, while its influence is weak for the 800 nm devices. Using the TMAl source leading to
the lowest O-uptake in the AlGaAs wave guides from such structures, 7 W output power and a degradation rate of 1 10−5h−1 at 2 W cw (100 μm stripe width × 4 mm, 25°C, 2000 h) are achieved for 730 nm emission. 相似文献
14.
High-quality AlxGa1−xAs layers with aluminum arsenide contentx up to 0.34 have been grown in a low pressure metalorganic chemical vapor deposition (MOCVD) system using trimethylgallium
(TMG), trimethylamine alane (TMAA) and arsine. The carbon content in these films depended on growth conditions but was in
general lower than in those obtained with trimethylaluminum (TMA) instead of TMAA in the same reactor under similar conditions.
Unlike TMA grown layers, the TMAA grown AlxGa1−xAs layers, (grown at much lower temperature—down to 650° C), exhibited room temperature photolu-minescence (PL). Low temperature
(25 K) PL from these films showed sharp bound exciton peaks with a line width of 5.1 meV for Al0.25Ga0.75As. A 39 period Al0.28Ga0.72As (5.5 nm)/GaAs (8.0 nm) superlattice grown at 650° C showed a strong PL peak at 25 K with a line width of 5.5 meV attesting
to the high quality of these layers. 相似文献
15.
Douglas F. Foster Christopher Glidewell Gordon R. Woolley David J. Cole-Hamilton 《Journal of Electronic Materials》1995,24(11):1731-1738
The decomposition of o-CH3C6H4AsD2 (o-tolyl AsD2) in the gas phase at 900K gives toluene with 0-3 D atoms in the methyl group and/or D on theortho carbon. These experimental data, together with calculations carried out in the PM3 system show that the only low energy pathway
for decomposition ofo-tolylAsD2 involves loss of D2 followed by reaction ofo-tolylAs with intacto-tolylAsD2 to giveo-tolylAsD•.o-tolylAsD• can reductively eliminate toluene or can undergo a rearrangement too-HDAsC6H4CH2• for which the calculated free energy of activation at 900K is very similar to that for reductive elimination, hence explaining
the multiple deuteriation of the methyl group of toluene. Calculations on the decomposition oftBuAsH2 show that this too decomposes by loss of H2 to givetBuAs with a very low free energy of activation.tBuAs decomposes via β-H abstraction to 2-methylpropene and AsH. There is no unimolecular process with a low free energy of
activation that leads to 2-methylpropane, so it is proposed that this product arises mainly from bimolecular H transfer fromtBuAsH2 totBuAs to givetBuAsH• which can lose 2-methylpropene ortBu•.tBu• abstracts H from an AsH species to give 2-methylpropane. A number of experimental results on the decomposition oftBuAsH2 are rationalized in terms of these mechanistic pathways. 相似文献
16.
S. J. C. Irvine A. Stafford M. U. Ahmed A. Brown H. Kheyrandish 《Journal of Electronic Materials》1997,26(6):723-727
The first detailed comparison has been made of the metalorganic vapor phase epitaxy growth rates of CdTe, ZnTe, and ZnSe,
measured in situ with laser reflectometry. The comparison also includes the photo-assisted growth with visible radiation from
an argon ion laser. Using a standard Group II precursor (DMCd or DMZn.TEN) partial pressure of 1.5 × 10−4 atm, VI/II ratio of 1 and DIPM (M = Te, Se) the maximum growth rates are in the region of 10 to 15 AU/ s. Decrease in growth
rates of ZnTe at higher temperatures or higher laser powers have been attributed to the desorption from the substrate of unreacted
Te precursor. The behavior of DTBSe is quite different from DIPSe for both pyrolytic and photo-assisted growth. The maximum
growth rate is around 1 AU/ s with very little photo-enhancement, except at 300°C. Secondary ion mass spectroscopy analysis
of hydrogen concentration in the ZnSe layers shows high concentrations, up to 5.9 × 1019 atoms cm−3 for DTBSe grown ZnSe under pyrolytic conditions. These results show that the growth kinetics play an important part in the
incorporation of hydrogen and passivation of acceptor doped material. 相似文献
17.
X. G. Zhang S. Kalisetty J. Robinson G. Zhao D. W. Parent J. E. Ayers F. C. Jain 《Journal of Electronic Materials》1997,26(6):697-704
ZnSySe1−yZnSe/GaAs (001) heterostructures have been grown by photoassisted metalorganic vapor phase epitaxy, using the sources dimethylzinc,
dimethylselenium, diethylsulfur, and irradiation by a Hg arc lamp. The solid phase composition vs gas phase composition characteristics
have been determined for ZnSyySe1−y grown with different mole fractions of dimethylselenium and different temperatures. Although the growth is not mass-transport
controlled with respect to the column VI precursors, the solid phase composition vs gas phase composition characteristics
are sufficiently gradual so that good compositional control and lattice matching to GaAs substrates can be readily achieved
by photoassisted growth in the temperature range 360°C ≤ T ≤ 400°C. ZnSe/GaAs (001) single heterostructures were grown by
a two-step process with ZnSe thicknesses in the range from 54 nm to 776 nm. Based on 004 x-ray rocking curve full width at
half maximums (FWHMs), we have determined that the critical layer thickness is hc ≤200 nm. Using the classical method involving strain, lattice relaxation is undetectable in layers thinner than 270 nm for
the growth conditions used here. Therefore, the rocking curve FWHM is a more sensitive indicator of lattice relaxation than
the residual strain. For ZnSySe1−y layers grown on ZnSe buffers at 400°C, the measured dislocation density-thickness product Dh increases monotonically with
the room temperature mismatch. Lower values of the Dh product are obtained for epitaxy on 135 nm buffers compared to the case
of 270 nm buffers. This difference is due to the fact that the 135 nm ZnSe buffers are pseudomorphic as deposited. For ZnSySe1−y layers grown on 135 nm ZnSe buffers at 360°C, the minimum dislocation density corresponds approximately to room-temperature
lattice matching (y ∼ 5.9%), rather than growth temperature lattice matching (y ∼ 7.6%). Epitaxial layers with lower dislocation
densities demonstrated superior optical quality, as judged by the near-band edge/deep level emission peak intensity ratio
and the near band edge absolute peak intensity from 300K photoluminescence measurements. 相似文献
18.
M. Usuda K. Sato R. Takeuchi K. Onuma T. Udagawa 《Journal of Electronic Materials》1996,25(3):407-409
Lattice-matched Ga0.47ln0.53As/InP heterostructure was grown by atmosphericpressure metalorganic vapor phase epitaxy reaction system using monovalent
cyclopentadienyl indium. The lattice-matched heterostructure showed electron mobilities ofμ300K= 12700 cm2/Vs at n8= 4.2 x 1011 cm-2 and μ77K= 108000 cm2/Vs at n8 = 3.9 x 1011 cm-2. The uniformity in electrical properties was measured by Hall element array with 400 μm pitch. Coefficient of variation in
electron mobility was 0.18%. 相似文献
19.
Jiro Temmyo Atsuo Kozen Toshiaki Tamamura Richard Nötzel Takashi Fukui Hideki Hasegawa 《Journal of Electronic Materials》1996,25(3):431-437
We have demonstrated that a self-organization phenomenon occurs in strained InGaAs system on InP (311) substrates grown by
metalorganic vapor phase epitaxy. This suggests that a similar formation process of nanocrystals exists not only on the GaAs
(311)B substrate but also on the InP (311)B substrate. However, the ordering and the size homogeneity of the self-organized
nanocrystals are slightly worse than those of the InGaAs/AlGaAs system on the GaAs (311)B substrate. The tensilely strained
condition of a InGaAs/InP system with growth interruption in a PH3 atmosphere reveals a surface morphology with nanocrystals even on the InP (100) substrate. It was found that strain energy
and high growth temperature are important factors for self-organization on III-V compound semiconductors. Preliminary results
indicate that the self-organized nanostructures in strained InGaAs/InP systems on InP substrates exhibit room temperature
photoluminescent emissions at a wavelength of around 1.3 p.m. 相似文献
20.
K. Yasuda K. Kawamoto T. Maejima M. Minamide K. Kawaguchi H. Maeba 《Journal of Electronic Materials》1996,25(8):1362-1365
Growth characteristics of (100) Cd1−xZnxTe (CZT) have been studied using metalorganic vapor phase epitaxy. CZT layers were grown on (100) GaAs substrates using diisopropylzinc
(DiPZn), dimethylcadmiun (DMCd), and diethyltelluride (DETe) as precursors. Growths were carried out in the temperature range
from 375 to 450°C. Since DiPZn has lower vapor pressure than DMCd, CZT layers with Zn composition below 0.06 were grown with
good compositional control. Layers with uniform Zn composition and thickness over an area of 10 × 15 mm2 were grown. Enhancement of CZT growth rate was observed when a small amount of DiPZn is introduced under fixed flows of DMCd
and DETe. Zn composition increases abruptly for further increase of DiPZn flow rate, where growth rate decreases. Growth mechanisms
for the above growth conditions were also discussed. 相似文献