共查询到20条相似文献,搜索用时 484 毫秒
1.
S. V. Rendakova I. P. Nikitina A. S. Tregubova V. A. Dmitriev 《Journal of Electronic Materials》1998,27(4):292-295
We investigated silicon carbide (SiC) epitaxial layers grown by liquid phase epitaxy (LPE). The layers were grown on 6H-SiC
and 4H-SiC well-oriented (0001) 35 mm diameter commercial wafers as well as on 6H-SiC Lely crystals. A few experiments were
also done on off-axis 6H-SiC and 4H-SiC substrates. Layer thickness and growth rate ranged from 0.5 to 50 microns and 0.5
to 10 μm/h, respectively. Layers were investigated by x-ray diffraction, x-ray topography, and selective chemical etching
in molten KOH. It was found that dislocation and micropipe density in LPE grown epitaxial layers were significantly reduced
compared with the defect densities in the substrates. 相似文献
2.
Microstructure and enhanced morphology of planar nonpolar m-plane GaN grown by hydride vapor phase epitaxy 总被引:1,自引:0,他引:1
Benjamin A. Haskell Arpan Chakraborty Feng Wu Hideo Sasano Paul T. Fini Steven P. Denbaars James S. Speck Shuji Nakamura 《Journal of Electronic Materials》2005,34(4):357-360
Nonpolar (
) m-plane gallium nitride has been grown heteroepitaxially on (100) γ-LiAlO2 by several groups. Previous attempts to grow m-plane GaN by hydride vapor phase epitaxy (HVPE) yielded films unsuitable for
subsequent device regrowth because of the high densities of faceted voids intersecting the films’ free surfaces. We report
here on the growth of planar m-plane GaN films on (100) γ-LiAlO2 and elimination of bulk and surface defects. The morphology achieved is smooth enough to allow for fabrication of m-plane
GaN templates and free-standing substrates for nonpolar device regrowth. The GaN films were grown in a horizontal HVPE reactor
at 860–890°C. Growth rates ranged from 30 μm/h to 240 μm/h, yielding free-standing films up to 250-μm thickness. The m-plane
GaN films were optically specular and mirror-like, with undulations having 50–200-nm peak-to-valley heights over millimeter
length scales. Atomic force microscopy revealed a striated surface morphology, similar to that observed in m-plane GaN films
grown by molecular beam epitaxy (MBE). Root-mean-square (RMS) roughness was 0.636 nm over 25-μm2 areas. Transmission electron microscopy (TEM) was performed on the m-plane GaN films to quantify microstructural defect densities.
Basal-plane stacking faults of 1×105 cm−1 were observed, while 4×109 cm−2 threading dislocations were observed in the g=0002 diffraction condition. 相似文献
3.
G. Kipshidze S. Nikishin V. Kuryatkov K. Choi Ìu. Gherasoiu T. Prokofyeva M. Holtz H. Temkin K. D. Hobart F. J. Kub M. Fatemi 《Journal of Electronic Materials》2001,30(7):825-828
Epitaxial layers of AlN and GaN were grown by gas source molecular-beam epitaxy on a composite substrate consisting of a thin
(250 nm) layer of silicon (111) bonded to a polycrystalline SiC substrate. Two dimensional growth modes of AlN and GaN were
observed. We show that the plastic deformation of the thin Si layer results in initial relaxation of the AlN buffer layer
and thus eliminates cracking of the epitaxial layer of GaN. Raman, x-ray diffraction, and cathodoluminescence measurements
confirm the wurtzite structure of the GaN epilayer and the c-axis crystal growth orientation. The average stress in the GaN
layer is estimated at 320 MPa. This is a factor of two less than the stress reported for HVPE growth on 6H-SiC (0001). 相似文献
4.
Kai Qiu X.H. Li F. Zhong Z.J. Yin X.D. Luo C.J. Ji Q.F. Han J.R. Chen X.C. Cao X.J. Xie Y.Q. Wang 《Journal of Electronic Materials》2007,36(4):436-441
This paper reports the properties of GaN grown by the hydride vapor-phase epitaxy (HVPE) technique on buffer layers with different
polarities. The N-, mixed-, and Ga-polarity buffer layers were grown by molecular-beam epitaxy (MBE) on sapphire (0001) substrates;
then, thicker GaN epilayers were grown on these by HVPE. The surface morphology, structural, and optical properties of these
HVPE-GaN epilayers were characterized by atomic force microscopy (AFM), x-ray diffraction (XRD), scanning electron microscopy,
and photoluminescence (PL) spectroscopy. The results indicate that the crystallinity of these HVPE-GaN epilayers depends on
the polarity of the buffer layer. 相似文献
5.
Halide vapor phase epitaxy(HVPE) is widely used in the semiconductor industry for the growth of Si, GaAs, GaN, etc.HVPE is a non-organic chemical vapor deposition(CVD) technique, characterized by high quality growth of epitaxial layers with fast growth rate, which is versatile for the fabrication of both substrates and devices with wide applications. In this paper, we review the usage of HVPE for the growth and device applications of Ga_2O_3, with detailed discussions on a variety of technological aspects of HVPE. It is concluded that HVPE is a promising candidate for the epitaxy of large-area Ga_2O_3 substrates and for the fabrication of high power β-Ga_2O_3 devices. 相似文献
6.
M. A. L. Johnson Shizuo Fujita W. H. Rowland W. C. Hughes Y. W. He N. A. El-Masry J. W. Cook J. F. Schetzina J. Ren J. A. Edmond 《Journal of Electronic Materials》1996,25(5):793-797
The growth of GaN and AlGaN by molecular beam epitaxy (MBE) has been studied using GaN/SiC substrates. The GaN/SiC substrates
consisted of ∼3 μm thick GaN buffer layers grown on 6H-SiC wafers by metalorganic vapor phase epitaxy (MOVPE) at Crée Research,
Inc. The MBE-grown GaN films exhibit excellent structural and optical properties—comparable to the best GaN grown by MOVPE.
AlxGa1−xN films (x ∼ 0.06-0.08) and AlxGa1−xN/GaN multi-quantum-well structures which display good optical properties were also grown by MBE on GaN/SiC substrates. 相似文献
7.
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
8.
G. P. Yablonskii A. L. Gurskii E. V. Lutsenko I. P. Marko B. Schineller A. Guttzeit O. Schön M. Heuken K. Heime R. Beccard D. Schmitz H. Juergensen 《Journal of Electronic Materials》1998,27(4):222-228
Photoluminescence (PL) and reflection spectra of undoped and Mg-doped GaN single layers grown on sapphire substrates by metalorganic
vapor phase epitaxy (MOVPE) were investigated in a wide range of temperatures, excitation intensities, and doping levels.
The undoped layers show n-type conductivity (μ=400 cm2/Vs, n=3×1017 cm−3). After annealing at T=600–700°C, the Mg-doped layers showed p-type conductivity determined by the potential-profiling technique.
A small value of the full width at half maximum (FWHM=2.8 meV) of the excitonic emission and a high ratio between excitonic
and deep level emission (≈5300) are evidences of the high layer quality. Two donor centers with activation energies of 35
and 22 meV were observed in undoped layers. A fine structure of the PL band with two narrow lines in the spectral range of
the donor-acceptor pair (DAP) recombination was found in undoped layers. An anomaly was established in the temperature behavior
of two groups of PL lines in the acceptor-bound exciton and in donor-acceptor pair regions in Mg doped layers. The lower energy
line quenched with increasing temperature appreciably faster than the high energy ones. Our data does not agree with the DAP
recombination model. It suggests that new approaches are required to explain the recombination mechanisms in undoped and Mg-doped
GaN epitaxial layers. 相似文献
9.
Ok-Hyun Nam Tsvetanka S. Zheleva Michael D. Bremser Robert F. Davis 《Journal of Electronic Materials》1998,27(4):233-237
Lateral epitaxial growth and coalescence of GaN regions over SiO2 masks previously deposited on GaN/AlN/6H-SiC(0001) substrates and containing 3 μm wide rectangular windows spaced 7 μm apart
have been achieved. The extent and microstructural characteristics of these regions of lateral overgrowth were a complex function
of stripe orientation, growth temperature, and triethylgallium (TEG) flow rate. The most successful growths were obtained
from stripes oriented along 〈1
00〉 at 1100°C and a TEG flow rate of 26 μmol/min. A density of ∼109 cm−2 threading dislocations, originating from the underlying GaN/AlN interface, were contained in the GaN grown in the window
regions. The overgrowth regions, by contrast, contained a very low density of dislocations. The surfaces of the coalesced
layers had a terrace structure and an average root mean square roughness of 0.26 nm. 相似文献
10.
Jun Hu Hongyuan Wei Shaoyan Yang Chengming Li Huijie Li Xianglin Liu Lianshan Wang Zhanguo Wang 《半导体学报》2019,40(10):85-94
Due to the remarkable growth rate compared to another growth methods for gallium nitride(GaN)growth,hydride vapor phase epitaxy(HVPE)is now the only method for mass product GaN substrates.In this review,commercial HVPE systems and the GaN crystals grown by them are demonstrated.This article also illustrates some innovative attempts to develop homebuilt HVPE systems.Finally,the prospects for the further development of HVPE for GaN crystal growth in the future are also discussed. 相似文献
11.
12.
M. Milanova T. Cholakova L. Bedikjan N. Stanev 《Journal of Electronic Materials》1994,23(11):1235-1237
Indium-doped GaAs layers are investigated by low-field Hall effect, photoluminescence, and double crystal x-ray diffraction
in order to study the influence of the In concentration on the electrical, optical, and crystallographic properties. The layers
were grown by liquid phase epitaxy from solution with In concentrations in the range 0–10 at.%. It was found that epitaxial
growth from the melt with 7 at.% In content produces the highest quality epitaxial layers. 相似文献
13.
额外HCl和氮化对HVPE GaN生长的影响 总被引:2,自引:0,他引:2
在氢化物气相外延(HVPE)生长Ga N过程中,发现了一种在成核阶段向生长区添加额外HCl来改善Ga N外延薄膜质量的方法,并且讨论了额外HCl和氮化对Ga N形貌和质量的影响.两种方法都可以大幅度地改善Ga N的晶体质量和性质,但机理不同.氮化是通过在衬底表面形成Al N小岛,促进了衬底表面的成核和薄膜的融合;而添加额外HCl则被认为是通过改变生长表面的过饱和度引起快速成核从而促进薄膜的生长而改善晶体质量和性质的 相似文献
14.
Thomas Gehrke Kevin J. Linthicum Edward Preble Pradeep Rajagopal Carsten Ronning Christian Zorman Mehran Mehregany Robert F. Davis 《Journal of Electronic Materials》2000,29(3):306-310
Pendeo-epitaxy (PE)1 from raised, [0001] oriented GaN stripes covered with silicon nitride masks has been employed for the growth of coalesced
films of GaN(0001) with markedly reduced densities of line and planar defects on Si(111)-based substrates. Each substrate
contained previously deposited 3C-SiC(111) and AlN(0001) transition layers and a GaN seed layer from which the stripes were
etched. The 3C-SiC transition layer eliminated chemical reactions between the Si and the NH3 and the Ga metal from the decomposition of triethylgallium. The 3C-SiC and the GaN seed layers, each 0.5 μm thick, were also
used to minimize the cracking and warping of the GaN/SiC/silicon assembly caused primarily by the stresses generated on cooling
due to the mismatches in the coefficients of thermal expansion. Tilting in the coalesced GaN epilayers of 0.2° was confined
to areas of lateral overgrowth over the masks; no tilting was observed in the material suspended above the trenches. The strong,
low-temperature PL band-edge peak at 3.456 eV with a FWHM of 17 meV was comparable to that observed in PE GaN films grown
on AlN/6H-SiC(0001) substrates. 相似文献
15.
Direct growth of CdZnTe/Si substrates for large-area HgCdTe infrared focal plane arrays 总被引:1,自引:0,他引:1
S. M. Johnson T. J. de Lyon C. A. Cockrum W. J. Hamilton T. Tung F. I. Gesswein B. A. Baumgratz L. M. Ruzicka O. K. Wu J. A. Roth 《Journal of Electronic Materials》1995,24(5):467-473
Direct epitaxial growth of high-quality 100lCdZnTe on 3 inch diameter vicinal {100}Si substrates has been achieved using molecular
beam epitaxy (MBE); a ZnTe initial layer was used to maintain the {100} Si substrate orientation. The properties of these
substrates and associated HgCdTe layers grown by liquid phase epitaxy (LPE) and subsequently processed long wavelength infrared
(LWIR) detectors were compared directly with our related efforts using CdZnTe/ GaAs/Si substrates grown by metalorganic chemical
vapor deposition (MOCVD). The MBE-grown CdZnTe layers are highly specular and have both excellent thickness and compositional
uniformity. The x-ray full-width at half-maximum (FWHM) of the MBE-grown CdZnTe/Si increases with composition, which is a
characteristic of CdZnTe grown by vapor phase epitaxy, and is essentially equivalent to our results obtained on CdZnTe/GaAs/Si.
As we have previously observed, the x-ray FWHM of LPE-grown HgCdTe decreases, particularly for CdZnTe compositions near the
lattice matching condition to HgCdTe; so far the best value we have achieved is 54 arc-s. Using these MBE-grown substrates,
we have fabricated the first high-performance LWIR HgCdTe detectors and 256 x 256 arrays using substrates consisting of CdZnTe
grown directly on Si without the use of an intermediate GaAs buffer layer. We find first that there is no significant difference
between arrays fabricated on either CdZnTe/Si or CdZnTe/GaAs/Si and second that the results on these Si-based substrates are
comparable with results on bulk CdZnTe substrates at 78K. Further improvements in detector performance on Si-based substrates
require a decrease in the dislocation density. 相似文献
16.
17.
G. Attolini P. Franzosi C. Pelosi L. Lazzarini G. Salviati 《Journal of Electronic Materials》1994,23(2):153-158
Highly mismatched GaAs epitaxial layers with thickness ranging from 15 nm to 7 μm have been grown on InP substrates by atomospheric
pressure metalorganic vapor phase epitaxy. Layers thinner than 30 nm exhibited 3-D growth mechanism; in the thicker layers,
the islands coalesced and then the growth followed the layer by layer mechanism. The elastic strain and the extended defects
have been studied by high resolution x-ray diffraction and transmission electron microscopy, respectively. The common observation
of planar defects, misfit, and threading dislocations in the layers has been confirmed. The results on the elastic strain
release have been discussed on the basis of the equilibrium theory. 相似文献
18.
In-Tae Bae Tae-Yeon Seong Young Ju Park Eun Kyu Kim 《Journal of Electronic Materials》1999,28(7):873-877
Detailed transmission electron microscope (TEM) and transmission electron diffraction (TED) examination has been performed
on organometallic vapor phase epitaxial GaN layers grown on (001) GaAs substrate to investigate microstructures and phase
stability. TED and TEM results exhibit the occurrence of a mixed phase of GaN. The wurtzite (α) phase grains are embedded
in the zinc-blende (β) phase matrix. It is shown that there are two types of the wurtzite GaN phase, namely, the epitaxial
wurtzite and the tilted wurtzite. The tilted wurtzite grains are rotated some degrees ranging from ∼5° to ∼35° regarding the
GaAs substrate. A simple model is presented to describe the occurrence of the mixed phases and the two types of the wurtzite
phase. 相似文献
19.
GaN纳米材料因具有优异的晶体质量和突出的光学性能及发射性能,日益受到关注.研究了一种利用氢化物气相外廷(HVPE)系统生长高质量的GaN纳米柱的方法.使用镍作为催化剂,在蓝宝石衬底上生长出了GaN纳米柱.在不同生长时间和不同HC1体积流量下制备了多组样品,使用扫描电子显微镜(SEM)、X射线衍射(XRD)和光致发光(PL)谱对样品进行了分析表征.测试结果表明,在较低的HC1体积流量下,生长2 min的样品具有较高的晶体质量和较好的光学性质.讨论了不同生长阶段的GaN纳米结构发光特性的变化规律,认为纳米结构所产生的表面态密度大小差异会造成带边峰位的红移和展宽. 相似文献
20.
The initial growth conditions of a 100 nm thick GaN layer and Mg-surfactant on the quality of the GaN epilayer grown on a 6H-SiC substrate by metal-organic vapor phase epitaxy have been investigated in this research. Experimental results have shown that a high Ⅴ/Ⅲ ratio and the initially low growth rate of the GaN layer are favorable for two-dimension growth and surface morphology of GaN and the formation of a smoother growth surface. Mg-surfactant occurring during GaN growth can reduce the dislocations density of the GaN epilayer but increase the surface RMS, which are attributed to the change of growth mode. 相似文献