Amplification of Misorientation of Ge Films on Si (100) During Ion-Assisted Molecular Beam Epitaxy

1992 ◽  
Vol 280 ◽  
Author(s):  
Cho-Jen Tsai ◽  
Harry A. Atwater

ABSTRACTWe have observed significant increases in the misorientation of Ge films on Si (001) grown by ion-assisted molecular beam epitaxy. The misorientation between the Ge films and Si substrates was found to be a function of the ion-to-atom flux ratio and growth temperature. The parametric dependence of the misorientation on the growth conditions suggests that defects generated by low energy ion bombardment are responsible for the observed increase in misorientation. The amplification of misorientation produced by concurrent low energy ion bombardment during epitaxial growth was attributed to an increase in the fraction of misfit strain accommodated by threading dislocations.

1991 ◽  
Vol 237 ◽  
Author(s):  
T. George ◽  
R. W. Fathauer

ABSTRACTThe stability of CoSi2/Si interfaces was examined in this study using columnar suicide structures grown on (111) Si substrates. In the first set of experiments, Co and Si were co-deposited (1:7 flux ratio) using molecular beam epitaxy at 800°C and the resulting columnar suicide layer was capped by epitaxial Si. Deposition of Co on the surface of the Si capping layer at 800°C results in the growth of the buried suicide columns. The buried columns grow by subsurface diffusion of the deposited Co, suppressing the formation of surface islands of CoSi2. The columns' sidewalls appear to be less stable than the top and bottom interfaces, resulting in preferential lateral growth and ultimately in the coalescence of the columns to form a continuous buried CoSi2 layer.In the second set of experiments, annealing of a 250nm-thick buried columnar layer at 1000°C under a 100nm-thick Si capping layer results in the formation of a surface layer of CoSi2 with a reduction in the sizes of the CoSi2 columns. For a sample having a thicker (500nm) Si capping layer the annealing leads to Ostwald ripening producing buried equiaxed columns. The' high CoSi2/Si interfacial strain could provide the driving force for the observed behavior of the buried columns under high-temperature annealing.


2013 ◽  
Vol 740-742 ◽  
pp. 339-343 ◽  
Author(s):  
Shota Sambonsuge ◽  
Eiji Saito ◽  
Myung Ho Jung ◽  
Hirokazu Fukidome ◽  
Sergey Filimonov ◽  
...  

3C-SiC is the only polytype that grows heteroepitaxially on Si substrates and, therefore, it is of high interest for various potentail applications. However, the large (~20 %) lattice mismatch of SiC with the Si substrate causes a serious problem. In this respect, rotated epitaxy of 3C-SiC(111) on the Si(110) substrate is highly promising because it allows reduction of the lattice mismatch down to a few percent. We have systematically searched the growth conditions for the onset of this rotated epitaxy, and have found that the rotaed epitaxy occurrs at higher growth temperatures and at lower source-gas pressures. This result indicates that the rotated epitaxy occurs under growth conditions that are close to the equilibrium and is thefore thermodynamically, rather than kinetically, driven.


1990 ◽  
Vol 201 ◽  
Author(s):  
C. J. Tsai ◽  
H. A. Atwater ◽  
T. Vreeland

AbstractSignificant changes in strain are produced in SixGe1−x epitaxial films grown on Si and Ge (001) substrates as a result of low energy ion beam assisted molecular beam epitaxy (IAMBE). Films grown with concurrent Ar+ or Xe+ ion bombardment are coherent and uniformly strained in the growth direction by up to 1.5% in Ge films and 0.5% in Si films and contain no dislocations. The dependence of the films strain perpendicular to the growth surface on ion-atom flux ratio, and ion energy can be explained by the injection of uniformly distributed point defects. Post-growth isochronal annealing of SixGe1−x films suggests that the existing defects in the IAMBE films are defect complexes and that the strain relaxation path is determined by the overall thermodynamic driving force toward the strain-relieved state.


2008 ◽  
Vol 1080 ◽  
Author(s):  
Kevin Goodman ◽  
Kejia Wang ◽  
Xiangning Luo ◽  
John Simon ◽  
Tom Kosel ◽  
...  

ABSTRACTMolecular beam epitaxy growth of GaN and InGaN nanowires is accomplished on Si (111) substrates using Ga-droplet nucleation. Typical diameters range from 25-80 nm and lengths can be varied by increasing the growth time; the growth rate is ∼0.25 microns/hour. The nanowires have been characterized structurally and optically. Photoluminescence spectra show band-edge emission of GaN nanowires centered at 362 nm at 290 K. Transmission electron microscopy images unveil that the nanowires are highly crystalline, and grow along the 0001 polar direction. Indium has also been successfully incorporated into GaN nanowires by modifying the growth conditions; the InGaN nanowires emit at ∼520 nm, which provides a possible route to solving strain related problems of high In-composition InGaN based efficient green emitters.


1995 ◽  
Vol 77 (1) ◽  
pp. 146-152 ◽  
Author(s):  
Tsutomu Iida ◽  
Yunosuke Makita ◽  
Shinji Kimura ◽  
Stefan Winter ◽  
Akimasa Yamada ◽  
...  

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