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1.
Modulation-doped and uniformly doped GaAs/GaAs1-xPx strained-layer superlattices (SLS’s) have been prepared by metal organic chemical vapor deposition in a vertical, atmospheric
pressure, quartz reaction chamber. The layers were doped with Se or Si by using a H2Se or SiH4 source and by using a vent-run valve-configuration to minimize dopant tailing. Carrier concentrations and mobilities were
determined from Hall measurements at 300 and 77 K. The Se modulation-doped SLS’s with carrier concentrations in the range
of 1016 to 1018 cm-13 exhibited enhanced transport properties when compared to the properties of epitaxial GaAs prepared under the same conditions.
The use of molecular sieves to purify the arsine or the use of SiH4 resulted in lower mobilities for the SLS’s and the epitaxial GaAs layers. The presence of surface cracking or a large residual
strain in the SLS’s also caused the modulation-doped SLS’s to have lower mobilities. 相似文献
2.
We report on the electrical characteristics of the two-dimensional electron gas (2DEG) formed in an InAlAs/InAsxP1-x/InP pseudomorphic composite-channel modulation-doped (MD) structure grown by solid source (arsenic and phosphorus) molecular
beam epitaxy (SSMBE). The As composition, x, of strained InAsxP1-x was determined by x-ray diffraction analysis of InP/InAsxP1-x/InP multi-quantum wells (MQWs) with compositions of x=0.14 to x=0.72. As the As composition increases, the room temperature
sheet resistance of InAlAs/InAsxP1-x/InP composite-channel MD structures grown over a range of As compositions decreased from 510 to 250 Ω/cm2, resulting from the greater 2DEG confinement and lower electron effective mass in the InAsxP1-x channel as x increases. The influence of growth conditions and epitaxial layer designs on the 2DEG mobility and concentration
were investigated using 300 K and 77 K Hall measurements. As the exposure time of the As4 flux on the growth front of InAsxP1-x increased during growth interruptions, the 2DEG mobility, in particular the 77K mobility, was considerably degraded due to
increased roughness at the InAlAs/InAsxP1-x interface. For the InAlAs/InAs0.6P0.4/InP composite-channel MD structure with a spacer thickness of 8 nm, the room temperature 2DEG mobility and density were 7200
cm2/Vs and 2.5 × 1012 cm−2, respectively. These results show the great potential of the InAlAs/InAsxP1-x/InP pseudomorphic composite-channel MD heterostructure for high frequency, power device applications. 相似文献
3.
In this paper we show that pseudomorphically strained heterostructures of InAs
x
P1−x
/InP may be an alternative to lattice-matched heterostructures of In1−x
Ga
x
As
y
P1−y
/InP for optoelectronic applications. We first studied the group-V composition control in the gas-source molecular beam epitaxy
(GSMBE) of the GaAs1-x
P
x
/GaAs system. Then we studied GSMBE of strained InAs
x
P1−x
/InP multiple quantum wells with the ternary well layer in the composition range 0.15 <x < 0.75. Structural and optical properties were characterized by high-resolution x-ray rocking curves, transmission electron
microscopy, absorption and low-temperature photoluminescence measurements. High-quality multiple-quantum-well structures were
obtained even for highly strained (up to 2.5%) samples. The achievement of sharp excitonic absorptions at 1.06, 1.3 and 1.55μm at room temperature from InAs
x
P1−x
/InP quantum wells suggests the possibility of long-wavelength optoelectronic applications. 相似文献
4.
M. Razeghi M. A. Poisson J. P. Larivain J. P. Duchemin 《Journal of Electronic Materials》1983,12(2):371-395
The low pressure metalorganic chemical vapor deposition epitaxial growth and characterization of InP, Ga0.47In0.53 As and GaxIn1-xAsyP1-y, lattice-matched to InP substrate are described. The layers were found to have the same etch pit density (EPD) as the substrate.
The best mobility obtained for InP was 5300 cm2 V−1S−1 at 300 K and 58 900 cm2 V−1 S−1 at 772K, and for GaInAs was 11900 cm2 V−1 S−1 at 300 K, 54 600 cm2 V−1 S−1 at 77 K and 90 000 cm V−1S−1 at 2°K. We report the first successful growth of a GaInAs-InP superlattice and the enhanced mobility of a two dimensional
electron gas at a GaInAs -InP heterojunction grown by LP-MO CVD. LP MO CVD material has been used for GaInAsPInP, DH lasers
emitting at 1.3 um and 1.5 um. These devices exhibit a low threshold current, a slightly higher than liquid phase epitaxy
devices and a high differential quantum efficiency of 60%. Fundamental transverse mode oscillation has been achieved up to
a power outpout of 10 mW. Threshold currents as low as 200 mA dc have been measured for devices with a stripe width of 9 um
and a cavity length of 300 um for emission at 1.5 um. Values of T in the range 64–80 C have been obtained. Preliminary life
testing has been carried out at room temperature on a few laser diodes (λ = 1.5μm). Operation at constant current for severalthousand
hours has been achieved with no change in the threshold current. 相似文献
5.
We report an OMVPE growth process for InP using trimethylindium (TMI) and tertiarybutylphosphine (TBP), a V/III ratio of 15,
and a TBP partial pressure of 0.5 Torr. Growth is initiated with a 0.1 μm buffer layer employing a ramped TBP flow. Results
are presented for InP grown with two different samples of both TMI and TBP and compared to previous experimental results and
theoretical predictions. Good surface morphology is obtained from 540 to 600° C. The net carrier concentrations, Nd-Na, decrease with increasing growth temperature—but never fall below 1.3 × 1016 cm-3. Mobilities of 3990 and 11200 cm2/V.sec are observed at 300 and 77 K, respectively. At 77 K, we infer a compensation ratio of ∼0.4, independent of Nd-Na. Photoluminescence measurements at 6 K show intense near bandgap emission with a full width half maximum proportional to
Nd-Na. Weak emission is also observed from carbon acceptors, independent of growth temperature. Secondary ion mass spectroscopy
measurements are performed on an InP wafer grown with four different temperatures. The observed sulfur concentration drops
from 1 × 1018 to 6 × 1016 cm-3 with increasing growth temperature. This confirms that sulfur is an important residual impurity in TBP. The observed carbon
concentration is 4–6 × 1016 cm-3, regardless of growth temperature. 相似文献
6.
A. Mircea R. Azoulay L. Dugrand R. Mellet K. Rao M. Sacilotti 《Journal of Electronic Materials》1984,13(3):603-620
We present a procedure for the MOVPE of InP as simple as the one currently used for GaAs. InP and InGaAsP alloys are grown
on InP substrates using trimethy1indium (TMI), phosphine, trimethylgallium (TMG) and arsine. The choice of carrier gas is
important ; a mixture of hydrogen and nitrogen allowed us to grow uniform layers over large areas at atmospheric pressure,
without pyrolizing the phosphine or separating the input reactants. Preliminary characterization results are presented.
Most information contained in this paper was presented at the 1983 Electron Materials Conference as paper Cl. 相似文献
7.
Rong -Ting Huang Ching -Long Jiang Ami Appelbaum Daniel Renner Stanley W. Zehr 《Journal of Electronic Materials》1990,19(11):1313-1317
The effects of indium sources, mask materials and etched mesa profiles on growth mor-phology of Fe-doped semi-insulating InP
on patterned, nonplanar InP substrates were studied for low-pressure organometallic vapor phase epitaxy (OMVPE). The presence
or absence of polycrystalline InP layers deposited on the mask was found to depend on the indium source but not on the mask
material. Trimethylindium was found to be the preferable indium source for prevention of polycrystalline InP deposits on the
mask. The etched mesa shape was found to dominate the final geometry of the OMVPE re-grown InP layer. Inclusion of an interfacial
layer of 1.16 μm bandgap wavelength InGaAsP between the dielectric mask and InP substrate produces a favorable mesa shape
by con-trolling the level of undercut during mesa etching, so as to form a smooth mesa profile. After selective regrowth of
InP over the resulting mesa, a planar surface is typically achieved for mesa stripes with a mask overhang length as long as
2.6 μm and a mesa height as high as 4 μm. 相似文献
8.
K. L. Fry C. P. Kuo C. A. Larsen R. M. Cohen G. B. Stringfellow A. Melas 《Journal of Electronic Materials》1986,15(2):91-96
We report the organometallic vapor phase epitaxial (OMVPE) growth of InP and Ga0.47In0.53As using a new organometallic indium source, ethyldimethylindium (EDMIn), rather than the traditional sources triethylindium
(TEIn) or trimethylindium (TMIn). EDMIn is a liquid at room temperature and its vapor pressure at 17° C was found to be 0.85
Torr using thermal decomposition experiments. The growth results using EDMIn were compared to those using TMIn in the same
atmospheric pressure reactor. For InP, use of EDMIn resulted in a high growth efficiency of 1.3 × 104 μm/ mole, which was independent of the growth temperature and comparable to the growth efficiency obtained with TMIn. The
high growth efficiency is consistent with the observation of no visible parasitic gas phase reactions upstream of the substrate.
The 4K photoluminescence (PL) spectra consist of a peak due to bound excitons and an impurity related peak 38 meV lower in
energy. This impurity peak is ascribed to conduction band to acceptor transitions from carbon, due to the decreasing relative
intensity of this peak with increasing V/III ratio. The relative intensity of the C impurity peak decreases by five times
when the growth temperature is increased from 575 to 675° C, with a corresponding increase in the room temperature electron
mobility from 725 to 3875 cm2/ Vs. For GalnAs lattice-matched to InP, use of EDMIn also resulted in a temperatureindependent high growth efficiency of
1.0 x 104 μm/mole, indicating negligible parasitic reactions with AsH3. The In distribution coefficient was nearly constant at a value of 0.9, however the run to run composition variation was
slightly higher for EDMIn than for TMIn. The 4K PL showed donor-acceptor pair transitions due to C and Zn. The C impurity
peak intensity decreased dramatically with increasing growth temperature, accompanied by an increase in the room temperature
electron mobility to 5200 cm2/Vs. Overall, the growth of both InP and GalnAs using EDMIn was qualitatively similar to that using TMIn, although the room
temperature electron mobilities were lower for the new source than for our highest purity bottle of TMIn. 相似文献
9.
This paper reports the results of atmospheric pressure organometallic vapor phase epitaxial growth of (Al
x
Ga1-x
)0.51
0.49P thin films using tertiarybutylphosphine (TBP) as the phosphorus source. The trimethylalkyls were used as group III sources.
The growth temperature was 680° C. It was observed that V/III ratio dramatically affected the surface morphology and photoluminescence
(PL). The epilayers grown at a V/III ratio lower than 60 had rough surfaces and weak PL emission. An input V/III ratio larger
than 70 was required to obtain good surfaces and strong PL emission. Good quality (AlxGa1-x
)0.51
0.49P epilayers forx ≤ 0.62 were obtained at a V/III ratio of 85. The surface morphologies were smooth except for the occurrence of dense oval-shaped
hillocks forx > 0.42. The Al distribution coefficient using TBP is the same as for phosphine (PH3), which was used as the phosphorus source in previous AlGalnP growth. No parasitic reactions between TBP and trimethylalkyls
were observed. 10 and 300 K PL emission was observed for all epilayers withx ≤ 0.62. However, the PL peak energy did not follow the band gap, as obtained for (AlxGa1-x
)0.51
0.49P epilayers grown using PH3. The PL peak energy at both 10 and 300 K increased with increasingx forx ≤ 0.35, and then became nearly constant with further increases inx. In this region the PL is believed to be from a process involving a deep energy level, induced by an impurity from the TBP,
bound to theX conduction band minimum. It was concluded that TBP has the potential to replace PH3 for OMVPE growth of Al-containing compounds, although the purity needs to be improved. 相似文献
10.
M. Peter J. Forker K. Winkler K. H. Bachem J. Wagner 《Journal of Electronic Materials》1995,24(11):1551-1555
Two types of quantum well (QW) structures grown lattice matched on (100) GaAs have been studied. The first type of structure
consists of pseudomorphic GaAsxSb1-x/GaAs (x≤0.3) SQWs which show emission wavelengths longer than those reported for pseudomorphic InyGa1−yAs/GaAs QWs. However, the attractive emission wavelength of 1.3 μm has not been achieved. To reach this goal, a novel type
of bilayer QW (BQW) has been grown consisting of a stack of two adjacent pseudomorphic layers of GaAsxSb1−x and In Ga1-y As embedded between GaAs confinement layers. In this BQW, a type-II heterojunction is formed between GaAsxSb1−x and InyGa1−yAs, resulting in a spatially indirect radiative recombination of electrons and holes at emission wavelengths longer than those
achieved in the GaAsxSb1−x/GaAs and IiyGa1−yAs/GaAs SQWs. The longest 300K emission wavelength observed so far was 1.332 μm. 相似文献
11.
In order to better understand the electrical and optical properties of GaAs and AlxGa1-x As used in making double heterojunction lasers, we have studied the Hall coefficient, resistivity and photoluminescence behavior
of doped epitaxial samples of these materials. In particular, we report results on Ge-doped GaAs and Alx Ga1-x As, Sn-doped AlxGa1-x As and Si-Te-doped GaAs single crystal layers which were grown on GaAs substrates by the liquid phase epitaxial method. The
effects of impurities in the solution on the carrier concentration, mobility, photoluminescence spectra and possible recombination
processes in these layers are discussed. 相似文献
12.
CVD growth conditions, particularly growth temperature and partial pressures of the reactant gases, strongly affect the growth
characteristics and properties of GaAs0.6P0.4 epitaxial layers grown on GaAs substrates. For LED’s the most important properties of the material are B/J (brightness per
unit current density) and surface morphology. This paper presents the results of a systematic study of the effect of temperature
and reactant gas partial pressure (at a fixed III/V ratio) on B/J, surface morphology, growth rate, impurity doping and layer
composition. Growth conditions which yield the optimum properties for LED’s are determined. The results are interpreted on
the basis of kinetic and thermodynamic mechanisms controlling the growth process under various growth conditions. At constant
temperature and constant III/V ratio, increasing the partial pressures causes the growth process to change from mass transport
limited, where the growth rate increases with increasing partial pressures, to kinetically limited, where the growth rate
is independent of partial pressures. Good morphology layers are obtained over a range of partial pressures around the transition
from mass transport limited to kinetically limited growth. The B/J peaks at a value of partial pressure in the kinetically
limited regime at which good morphology layers are obtained. Although B/J increases with increasing growth rate in the mass
transport regime, the maximum B/J occurs in the region where growth rate is independent of partial pressures so that growth
rate alone is not sufficient to determine B/J. In contrast to the “parabolic≓ dependence of growth rate on growth temperature,
caused by the transition from the mass transport regime to the kinetic regime, the relative incorporation of As, P, and Te
varies with temperature in the manner predicted from thermodynamics in both regimes. This behavior is consistent with the
growth rate in the kinetic regime being limited by the desorption of chlorine atoms from the growth surface, with the reaction
of As, P, and Te with the Ga proceeding thermodynamically at all temperatures. 相似文献
13.
E. R. Gertner A. M. Andrews L. O. Bubulac D. T. Cheung M. J. Ludowise R. A. Riedel 《Journal of Electronic Materials》1979,8(4):545-554
Reported here, for the first time, is the lattice matched growth of InAs1-xSbx on GaSb. The thermodynamic incompatibility of the system, i.e., the strong tendency for the In-As-Sb liquid to dissolve the
GaSb substrate, was solved via a novel liquid phase epitaxial growth technique. Liquid compositions for lattice matching conditions
have been determined in the 400-600°C range. Epitaxial growth has been examined for (100), (111)B and (111)A orientations.
Dislocation etch pit densities for lattice matched, and near lattice matched conditions are shown to be less than 104-cm−2 and 105-cm−4, respectively. The composition of the epitaxial layers are determined by the Gandolfi X-ray diffraction technique and compositional
homogeneity has been confirmed by SEM X-ray analysis. Some material related device properties which demonstrate the reproducibility
of the growth technique are presented. 相似文献
14.
The organometallic vapor phase epitaxial (OM-VPE) growth of AlxGa1-xPyAs1-y on graded GaPyAs1-yGaAs in the compositional range 0 < x < 0.9 and 0 < y < 0.6 is reported. It is found that composition control can be easily
achieved, and that the vapor phase ratio of trimethylaluminum to trimethylgallium strongly influences the incorporation of
P in the solid. A model is developed which explains this in terms of competing reaction rates. The model gives a good fit
to the experimental data. 相似文献
15.
M. E. Heimbuch A. L. Holmes C. M. Reaves M. P. Mack S. P. Denbaars L. A. Coldren 《Journal of Electronic Materials》1994,23(2):87-91
Tertiarybutylarsine (TBA) and teriarybutylphosphine (TBP) are liquid organometallic sources that are a safer alternative to
arsine and phosphine. In this work, we have grown high-quality In0.53Ga0.47As/InP quantum wells at a temperature of 590° with TBA and TBP partial pressures of 0.4 and 2.5 Torr, respectively. A low-temperature
photoluminescence study indicated optimized column V growth interruption times of 0.5 s for In0.53Ga0.47As wells with InP barriers. Using the optimized growth conditions, we have obtained lattice matched In0.53Ga0.47As/InxGa1-xAsyP1-x single quantum-well lasers emitting at 1.55 μm. Broad-area devices with a length of 3.5 mm exhibit a low threshold current
density of 220A/cm2. Broad-area lasers containing four quantum wells had a threshold current density of 300A/cm2 for a 3.0 mm cavity length and CW powers of 40 mW per facet for an as-cleaved 4 × 750 μm device. 相似文献
16.
Investigation of GaAs]-x_x P crystals using the pseudo-kossel X-ray and photoluminescence techniques
Two indirect methods of determining composition in GaAs1-x xP films grown epitaxially on GaAs substrates are discussed in this paper. In the first method precision lattice parameters, obtained using the pseudo-Kossel technique in back reflection, are compared to compositions determined with the electron microprobe. A plot of corrected lattice parameter vs. %GaP (microprobe) over the range of composition investigated (0.10 < x < 0.55) shows that Vegard’s law holds very closely in this system. The slope of the line is -0.002042 Å/%GaP while the intercept is within 0.028% of the established lattice parameter for GaAs. No point lies farther than 0.003 Å from the line describing Vegard’s law. 相似文献
17.
T. Kuno T. Akane S. Jinno T. Hirata Y. Yang Y. Isogai N. Watanabe Y. Fujiwara A. Nakamura Y. Takeda 《Materials Science in Semiconductor Processing》2003,6(5-6):461-464
ErP has been grown on InP (0 0 1), (1 1 1)A and (1 1 1)B substrates by low-pressure organometallic vapor-phase epitaxy. The morphological change with growth temperature has been explored by atomic force microscope. On all the substrates, ErP is grown in island structure. Height and area size of the ErP islands on (1 1 1)A substrate exhibit an obvious dependence on growth temperature. ErP islands grown at 540°C, that is the suitable temperature for ErP formation, gather to step edges to make wires. 相似文献
18.
Large, high-quality crystals of various Pb-salt compounds and alloys have been grown from the vapor by a horizontal, unseeded,
closed-tube method. The optimum growth conditions have been experimentally determined. The crystalline imperfections and electrical
properties of the crystals were examined. In a series of growth experiments on PbTe, the source materials were prepared by
adding small quantities of Pb to much larger quantities of zone-melted PbTe. This method makes it possible to control the
source and as-grown crystal compositions for excess Pb or Te concentrations in the 1018/cm3 range. From the results of these experiments it was found that the composition of zone-melted PbTe (i. e., the maximum-melting
point composition of PbTe) corresponds to a hole concentration of approximately 1 x l019/cm3.
This work was sponsored by the Department of the Air Force. 相似文献
19.
采用MOCVD生长技术在InP衬底上成功实现了晶格失配的3μm In0.68 Ga0.32As薄膜生长.通过As组分的改变,利用张应变和压应变交替补偿的InAsxP1-x应变缓冲层结构来释放由于晶格失配所产生的应力,在InP衬底上得到了与In0.68Ga0.32 As晶格匹配的InAsxP1-x“虚拟”衬底,通过对缓冲层厚度的优化,使应力能够在“虚拟”衬底上完全豫弛.通过原子力显微镜(AFM)、高分辨XRD、透射电镜(TEM)和光致发光(PL)等测试分析表明,这种释放应力的方法能够有效提高In0.68 Ga0.32 As外延层的晶体质量. 相似文献
20.
Using the molecular beam epitaxial (MBE) technique, CdTe and Hg1-xCdxTe have been grown on Cr-doped GaAs (100) sub-strates. A single effusion cell charged with polycrystal-line CdTe is used for the growth of CdTe films. The CdTe films grown at 200 °C with a growth rate of ~ 2 μm/hr show both streaked and “Kikuchi” patterns, indicating single crystalline CdTe films are smoothly grown on the GaAs sub-strates. A sharp emission peak is observed at near band-edge (7865 Å, 1.577 eV) in the photoluminescence spectrum at 77 K. For the growth of Hg1-xCdxTe films, separate sources of HgTe, Cd and Te are used. Hg0.6Cd0.4Te films are grown at 50 °C with a growth rate of 1.7 μm/hr. The surfaces are mirror-smooth and the interfaces between the films and the substrates are very flat and smooth. As-grown Hg0.6Cd0.4Te films are p-type and converted into n-type by annealing in Hg pressure. Carrier concentration and Hall mobility of an annealed Hg0.6Cd0.4Te film are 1 × 1017 cm?3 and 1000 cm2/V-sec at 77 K, respectively. 相似文献