Heteroepitaxy on Silicon by Molecular Beam Epitaxy

1988 ◽  
Vol 116 ◽  
Author(s):  
Leo J. Schowalter

AbstractIn recent years extensive research has been conducted on growing heteroepitaxial layers of insulators, metals, and other semiconductors on silicon. This work promises to extend the use of Si (or, at least, Si substrates) far beyond present day devices into hybred semiconductor devices, optoelectronics, ballistic electron devices, and three-dimensional device structures. However, the “art” of heteroepitaxy is still poorly understood and much work remains to be done to realize most practical applications. Molecular beam epitaxy (MBE) represents an attractive technique for research and development of heteroepitaxy because of its relatively low growth temperatures, flexibility in working with different materials, and by providing a good environment for in-situ observation of the heteroepitaxial process. Using examples from recent heteroepitaxial work by molecular beam epitaxy in the areas of CaF2, NiSi2 and CoSi2, and GaAs on Si, this paper discusses how heteroepitaxial quality is affected by the relative surface free energies and strain (due to both lattice and thermal expansion coefficient mismatch). The goal is to produce better heteroepitaxial layers for device applications by an improved understanding of the process.

Author(s):  
T. S. Kuan ◽  
S. S. Iyer ◽  
E. M. Yeo

GexSi1-x/Si heterostructures have been studied extensively because of their potential device applications. Previous GexSi1-x/Si heteroepitaxy studies have been mostly confined to growth on (100) surfaces and have focused on how growth temperature and GexSi1-x layer thickness affect growth morphology and defect generation. In this work we compare the quality of GexSi1-x/Si superlattices grown on (100)-, (111)-, and (110)-oriented Si substrates. We find that these three growth directions give rise to different growth morphologies and defect structures. Strained GexSi1-x layers in a (100) GexSi1-x/Si superlattice annealed at 450 – 500°C have recently been reported to exhibit a CuPt-type long-range order. Thus, another objective of this work is to explore whether growth along the <110> and/or <111> directions can promote or suppress the onset of ordering.Superlattices consisting of 18 layers of alternating Ge0.5Si0.5 (5 nm) and Si (20 nm) were grown by molecular beam epitaxy (MBE). Before growing the superlattice, a 3D-nm-thick Si buffer layer was grown on the Si substrate.


2008 ◽  
Vol 368-372 ◽  
pp. 345-347
Author(s):  
Kun Zhao ◽  
Hui Bin Lu ◽  
Meng He

Position-sensitive photodetectors, a useful class of sensor with a wide range of applications in automatization and measuring techniques, on the basis of a La0.7Sr0.3MnO3/Si heterojunction have been developed. Thin p-La0.7Sr0.3MnO3 films were grown on n-Si substrates by laser molecular beam epitaxy. The large lateral photovoltaic effect has been observed in response to excitation by ultraviolet laser spot irradiation. The position characteristics are symmetric to the zero and linear between the contacts. The devices work well under unbiased conditions and so are simple to configure for practical applications.


1985 ◽  
Vol 56 ◽  
Author(s):  
E. KASPER ◽  
H.-J. HERZOG ◽  
H.DAEMBKES-a1 ◽  
G. ABSTREITER

AbstractGrowth of Si/SiGe superlattices on Si substrates by molecular beam epitaxy (MBE) is described. Strain symmetrization in the superlattice is achieved with an incommensurate SiGe buffer layer. The concept of strainsymmetrization is explained and properties of buffer and strained layer superlattices are investigated. A twodimensional electron gas with enhanced room temperature mobility and folded phonon modes within the reduced onedimensional Brillouin zone are observed. An n-channel Si/SiGe MODFET demonstrates the device applications of this material concept.


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.


1999 ◽  
Vol 595 ◽  
Author(s):  
U. Hömmerich ◽  
J. T. Seo ◽  
J. D. MacKenzie ◽  
C. R. Abernathy ◽  
R. Birkhahn ◽  
...  

AbstractWe report on the luminescence properties of Er doped GaN grown prepared by metalorganic molecular beam epitaxy (MOMBE) and solid-source molecular beam epitaxy (SSMBE) on Si substrates. Both types of samples emitted characteristic 1.54 µm PL resulting from the intra-4f Er3+ transition 4I13/2→4I15/2. Under below-gap excitation the samples exhibited very similar 1.54 µm PL intensities. On the contrary, under above-gap excitation GaN: Er (SSMBE) showed ∼80 times more intense 1.54 µm PL than GaN: Er (MOMBE). In addition, GaN: Er (SSMBE) also emitted intense green luminescence at 537 nm and 558 nm, which was not observed from GaN: Er (MOMBE). The average lifetime of the green PL was determined to be 10.8 µs at 15 K and 5.5 µs at room temperature. A preliminary lifetime analysis suggests that the decrease in lifetime is mainly due to the strong thermalization between the 2H11/2 and 4S3/2 excited states. Nonradiative decay processes are expected to only weakly affect the green luminescence.


1988 ◽  
Vol 53 (24) ◽  
pp. 2435-2437 ◽  
Author(s):  
Jae‐Hoon Kim ◽  
John K. Liu ◽  
Gouri Radhakrishnan ◽  
Joseph Katz ◽  
Shiro Sakai ◽  
...  

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