TEM and SEM Studies of MOCVD-Grown GaP on Si

1985 ◽  
Vol 62 ◽  
Author(s):  
M. M. Ai-Jassim ◽  
J. M. Olson ◽  
K. M. Jones

ABSTRACTGaP and GaP/GaAsP epitaxial layers have been grown on Si substrates by metal-organic chemical vapor deposition (MOCVD). These layers were characterized by SEM and TEM plan-view and cross-sectional examination. At growth temperatures ranging from 600° C to 800° C, the initial stages of growth were dominated by three-dimensional nucleation. TEM studies showed that at high temperatures the nuclei were generally misoriented with respect to each other yielding, upon coalescence, polycrystalline layers. The growth of single-crystal layers was achieved by nucleating a 30–50 nm layer of GaP at 500° C, followed by annealing and continued growth at 750 ° C. The defect density in these structures was investigated as a function of various growth parameters and substrate conditions. A high density of structural defects was generated at the Si/GaP interface. The use of 2° off (100) Si substrates resulted in GaP layers free of antiphase domains. These results and their implications are discussed.

2019 ◽  
Vol 5 (7) ◽  
pp. eaaw3180 ◽  
Author(s):  
Gangtae Jin ◽  
Chang-Soo Lee ◽  
Xing Liao ◽  
Juho Kim ◽  
Zhen Wang ◽  
...  

We report wafer-scale growth of atomically thin, three-dimensional (3D) van der Waals (vdW) semiconductor membranes. By controlling the growth kinetics in the near-equilibrium limit during metal-organic chemical vapor depositions of MoS2 and WS2 monolayer (ML) crystals, we have achieved conformal ML coverage on diverse 3D texture substrates, such as periodic arrays of nanoscale needles and trenches on quartz and SiO2/Si substrates. The ML semiconductor properties, such as channel resistivity and photoluminescence, are verified to be seamlessly uniform over the 3D textures and are scalable to wafer scale. In addition, we demonstrated that these 3D films can be easily delaminated from the growth substrates to form suspended 3D semiconductor membranes. Our work suggests that vdW ML semiconductor films can be useful platforms for patchable membrane electronics with atomic precision, yet large areas, on arbitrary substrates.


1988 ◽  
Vol 144 ◽  
Author(s):  
J.H. Kim ◽  
S. Sakai ◽  
J.K. Liu ◽  
G. Raohakrishnan ◽  
S.S. Chang ◽  
...  

ABSTRACTWe first report on migration-enhanced molecular beam epitaxial (MEMBE) growth and characterization of the GaAs layers on Si substrates (GaAs/Si). Excellent surface morphology GaAs layers were successfully grown on (100) Sisubstrates misoriented 4 toward [110] direction. The MEMBE growth method isdescribed and material properties are compared with those of normal two-step MBE-grown or in-situ annealed layers. Micrographs of cross-sectional view transmission electron microscopy (TEM) and scanning surface electron microscopy (SEM) of MEMBE-grown GaAs/Si showed dislocation densities of 107 cm-2 over ten times lower than those of two-step MBE-grown or in-situ annealedlayers. AlGaAs/GaAs double heterostructure lasers and light-emitting diodeshave been successfully grown on MEMBE GaAs/Si by both metal organic chemical vapor deposition and liquid phase epitaxy. MOCVD-grown lasers showed peak output power as high as 184 mW/facet, pulsed threshold currents as low as150 mA at 300 K, and differential quantum efficiencies of up to 30 %. The LPE-grown light-emitting diodes showed output powers of 1.5 mW and external quantum efficiencies of 3.3 mW/A per facet.


2016 ◽  
Vol 22 (1) ◽  
pp. 131-139 ◽  
Author(s):  
Katharina I. Gries ◽  
Katharina Werner ◽  
Andreas Beyer ◽  
Wolfgang Stolz ◽  
Kerstin Volz

AbstractMelt-back etching is an effect that can occur for gallium (Ga) containing III/V semiconductors grown on Si. Since this effect influences interfaces between the two compounds and therefore the physical characteristics of the material composition, it is desirable to understand its driving forces. Therefore, we investigated Ga grown on Si (001) via metal organic chemical vapor deposition using trimethyl Ga as a precursor. As a result of the melt-back etching, Ga-containing droplets formed on the Si surface which reach into the Si wafer. The shape of these structures was analyzed by plan view investigation and cross sectional tomography in a (scanning) transmission electron microscope. For plan view preparation a focused ion beam was used to avoid damage to the Ga-containing structures, which are sensitive to the chemicals normally used during conventional plan view preparation. Combining the results of both investigation methods confirms that the Ga-containing structure within the Si exhibits a pyramid shape with facets along the Si {111} lattice planes.


2018 ◽  
Vol 6 (7) ◽  
pp. 1642-1650 ◽  
Author(s):  
Wenliang Wang ◽  
Yunhao Lin ◽  
Yuan Li ◽  
Xiaochan Li ◽  
Liegen Huang ◽  
...  

High-quality GaN-based light-emitting diode (LED) wafers have been grown on Si substrates by metal–organic chemical vapor deposition by designing epitaxial structures with AlN/Al0.24Ga0.76N buffer layers and a three-dimensional (3D) GaN layer.


2001 ◽  
Vol 680 ◽  
Author(s):  
Yoshihiro Irokawa ◽  
Noboru Yamada ◽  
Masahito Kodama ◽  
Tetsu Kachi

ABSTRACTSilicon (Si) substrates having cavities just beneath the surface layer (multi-cavity Si substrates) were examined whether they worked as the stress relaxation structure in 3C-SiC heteroepitaxial growth on Si. Single crystalline 3C-SiC layers were grown on the multi-cavity Si substrates by means of low pressure chemical vapor deposition (LPCVD). The layers' quality was characterized by the cross-sectional TEM observations and the Micro-Raman spectroscopy. The TEM results showed that this structure reduced the defect density in the 3C-SiC layers. The averaged full width at half-maximum (FWHM) of LO Raman mode in the 3C-SiC layerson the multi-cavity Si substrates became narrower than that on the conventional Si substrates. Furthermore, Schottky barrier structures showed that the reverse leakage current of the diodes using the multi-cavity Si substrates is smaller than that using the conventional Si substrates. These results indicate that the multi-cavity Si substrates are effective for stress relaxation in the 3C-SiC layers.


1987 ◽  
Vol 65 (8) ◽  
pp. 897-903
Author(s):  
P. Mandeville ◽  
A. J. SpringThorpe ◽  
C. J. Miner ◽  
R. A. Bruce ◽  
J. F. Currie ◽  
...  

Single-crystal GaAs layers have been grown by molecular beam epitaxy (MBE) on (100) Si substrates. Surface morphology, defect density, and optical and electrical properties have been studied as a function of the growth parameters. The characterization techniques included photoluminescence, Hall effect, cross-sectional transmission electron microscopy, and X-ray diffraction. GaAs metal semiconductor field-effect transitors on Si exhibited transconductances of 128 mS∙mm−1 and current-gain cutoff frequencies as high as 19 GHz. Special heterostructures showed Shubnikov–de Haas oscillations at low temperature and plateaux in the Hall resistance, which confirmed the presence of two-dimensional electron gas in the heterostructure.


1988 ◽  
Vol 116 ◽  
Author(s):  
K.C. Hsieh ◽  
M.S. Feng ◽  
G.E. Stillman ◽  
C.R. Ito ◽  
D.G. McIntyre ◽  
...  

Astract:A systematic study of the structural properties and defect distribution of GaAs layers grown by metalorganic chemical vapor deposition on Si substrates misoriented 1°, 1.5°, 2°, 4°, and 6° from [100] toward [011] is reported. Double crystal x-ray rocking curves, cross-section and plan-view Transmission Electron Microscopy (TEM) are used to characterize the structural strain and defect distribution of as-grown and annealed GaAs layers. Both strain and defect density in the GaAs layers are found to be dependent of the degree of substrate misorientation as well as the direction in which measurements are made. Plan-view TEM shows an asymmetric distribution of microtwins in two perpendicular directions. There exists a correlation between the directionality of the strain and of the defect density. Furnace annealing at 850°C for 30 minutes in an arsine overpressure can reduce significantly the defects, the strain and the strain anisotropy. It is found that microtwins are of the highest density when the substrate is misoriented about 4 degrees for the as-grown samples. Though a reduction of defects after annealing occurs for all samples, the least misoriented one shows the most improvement.


2005 ◽  
Vol 891 ◽  
Author(s):  
Tetsuya D. Mishima ◽  
Madhavie Edirisooriya ◽  
Michael B. Santos

ABSTRACTStructural defects in InSb quantum well (QW) samples have been investigated by transmission electron microscopy (TEM). Using molecular beam epitaxy, an InSb QW with remotely-doped Al0.09In0.91Sb barriers was grown on a GaAs (001) substrate with buffer layers consisting of, in order from the substrate: 1 μm of GaSb, 1 μm of AlSb, 50 nm of GaSb-AlSb strained layer superlattice (SLS), and 3 μm of Al0.09In0.91Sb. Cross-sectional TEM analysis indicates that high densities of threading dislocations (TDs) are created at the two highly lattice-mismatched interfaces, the Al0.09In0.91Sb/GaSb-AlSb SLS and the GaSb/GaAs interfaces. Pairs of stereo images taken from plan-view TEM (PV-TEM) specimens show that TDs propagate through the InSb QW layer. The densities of TDs and micro-twin (MT) defects measured by PV-TEM are 9×108/cm2 and 4×103/cm, respectively. These values are worse than those in an InSb QW layer grown with a different buffer layer by a factor of ∼4. The different buffer layer contains an InSb interlayer that effectively filters out both TDs and MTs. Adopting an interlayer structure and reducing the GaSb and AlSb layer thickness may make it possible to fabricate a lower-defect-density yet thinner InSb QW sample with the type of buffer layer examined in this study.


1990 ◽  
Vol 198 ◽  
Author(s):  
Henry P. Lee ◽  
Thomas George ◽  
Hyunchul Sohn ◽  
Jay Tu ◽  
Eicke R. Weber ◽  
...  

ABSTRACTThe nucleation and interfacial defect structure of thin GaAs films grown on reactive ion etched Si substrates by normal molecular beam epitaxy (MBE) and modulated molecular beam epitaxy (MMBE) at 300°C were studied by plan view and high resolution cross-sectional electron microscopy (TEM). Plan view TEM micrographs show a pronounced three-dimensional (3-d) island type nucleation for the MBE grown sample. A high density of microtwins is also found in these nucleated islands from high resolution cross-sectional TEM micrographs. The 3-d nucleation and the interfacial twinning is suppressed however in the MMBE grown samples. The FWHM of the (400) Bragg peak for 3 μm thick GaAs on Si films shows a reduction of 60 arcseconds when the initial buffer layer is grown by MMBE as compared to normal MBE.


Author(s):  
K.M. Jones ◽  
M.M. Al-Jassim ◽  
J.M. Olson

The epitaxial growth of III-V semiconductors on Si for integrated optoelectronic applications is currently of great interest. GaP, with a lattice constant close to that of Si, is an attractive buffer between Si and, for example, GaAsP. In spite of the good lattice match, the growth of device quality GaP on Si is not without difficulty. The formation of antiphase domains, the difficulty in cleaning the Si substrates prior to growth, and the poor layer morphology are some of the problems encountered. In this work, the structural perfection of GaP layers was investigated as a function of several process variables including growth rate and temperature, and Si substrate orientation. The GaP layers were grown in an atmospheric pressure metal organic chemical vapour deposition (MOCVD) system using trimethylgallium and phosphine in H2. The Si substrates orientations used were (100), 2° off (100) towards (110), (111) and (211).


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