Solid Phase Recrystallization and Strain Relaxation in Ion-Implanted Strained Si on SiGe Heterostructures

2005 ◽  
Vol 864 ◽  
Author(s):  
M.S. Phen ◽  
R. T. Crosby ◽  
V. Craciun ◽  
K. S. Jones ◽  
M.E. Law ◽  
...  

AbstractThe relaxation process of strained silicon films on silicon-rich relaxed SiGe alloys has been studied. Experimental structures were grown via Molecular Beam Epitaxy (MBE) growth techniques and contain a strained silicon capping layer approximately 50 nm thick. The relaxed SiGe alloy compositions range from 0 to 30 at.% germanium. A 12 keV Si+ implant at a dose of 1×1015 atoms/cm2 was used to generate an amorphous layer ∼30 nm thick, which was confined within the strained silicon capping layer. Upon annealing at 500 °C, it was found that the solid phase epitaxial regrowth process of the amorphous silicon breaks down for high strain levels and regrowth related defects were observed in the regrown layer. In addition, high-resolution X-Ray diffraction results indicate a reduction in strain for the silicon capping layer. This study addresses the critical strain regime necessary for the breakdown of solid phase epitaxial recrystallization in silicon.

2000 ◽  
Vol 647 ◽  
Author(s):  
J. Rodriguez-Viejo ◽  
Zakia el-Felk

AbstractThe strain and damage produced on Si substrates by high-dose ion implantation of Si and C is investigated after thermal treatments by double and triple crystal X-ray diffraction, high ressolution transmission electron microscopy (HRTEM) and Secondary Ion Mass Spectrometry (SIMS). Si implantation (180 keV, 5×1015 Si at cm−2) at liquid nitrogen temperature forms a buried amorphous layer. Annealing at temperatures close to 650°C results in epitaxial films with significant defect recovery. X-ray rocking curves show the existence of interference fringes on the left hand side of the 004 Si peak indicating the presence of tensile strained Si layers due to the generation of Si interstitials during the implantation process. C implantation, at 60 keV, 7×1015 cm−2 and 450°C, in the preamorphized Si wafers results in the growth of Si1-yCy epitaxial films with a low amount of substitutional carbon (y≍ 0.1%). Rapid thermal annealing at 750°C results in highly defective epitaxial films with a maximum carbon content close to 0.4%.The high density of defects is responsible for the partial strain relaxation observed in those layers. The amount of substitutional Si also decreases drastically with increasing temperature. Profile fitting of rocking curves using dynamical X-ray theory is used to estimate the C concentration and the strain and disorder profiles of the heterostructures.


2004 ◽  
Vol 810 ◽  
Author(s):  
R. T. Crosby ◽  
K. S. Jones ◽  
M. E. Law ◽  
A. F. Saavedra ◽  
J. L. Hansen ◽  
...  

ABSTRACTThe relaxation processes of strained silicon films on silicon-rich relaxed SiGe alloys have been studied. Experimental structures were generated via Molecular Beam Epitaxial (MBE) growth techniques and contain a strained silicon capping layer of approximately 50 nm. The relaxed SiGe alloy compositions range from 0 to 30 atomic% germanium. Samples received two distinct types of silicon implants. A 12 keV Si+ implant at a dose of 1×1015 atoms/cm2 was used to generate an amorphous layer strictly confined within the strained Si cap. An alternate 60 keV Si+ implant at a dose of 1×1015 atoms/cm2 was employed to create a continuous amorphous layer extending from the sample surface to a position 50 nm into the bulk SiGe material. The strain relaxation and regrowth processes are quantified through High Resolution X-Ray Diffraction (HRXRD) rocking curves and Cross-sectional Transmission Electron Microscopy (XTEM). The role of injected silicon interstitials upon the strain relaxation processes at the Si/SiGe interface after annealing at 600°C is investigated.


1989 ◽  
Vol 159 ◽  
Author(s):  
Koichi Akimoto ◽  
Jun'Ichiro Mizuki ◽  
Ichiro Hirosawa ◽  
Junji Matsui

ABSTRACTSurface superstructures (reconstructed structures) have been observed by many authors. However, it is not easy to confirm that a superstructure does exist at an interface between two solid layers. The present paper reports a direct observation, by a grazing incidence x-ray diffraction technique with use of synchrotron radiation, of superstructures at the interface. Firstly, the boron-induced R30° reconstruction at the Si interface has been investigated. At the a Si/Si(111) interface, boron atoms at 1/3 ML are substituted for silicon atoms, thus forming a R30° lattice. Even at the interface between a solid phase epitaxial Si(111) layer and a Si(111) substrate, the boron-induced R30° reconstruction has been also observed. Secondly, SiO2/Si(100)-2×l interfacial superstructures have been investigated. Interfacial superstructures have been only observed in the samples of which SiO2 layers have been deposited with a molecular beam deposition method. Finally, the interfaces of MOCVD-grown AIN/GaAs(100) have been shown to have 1×4 and 1×6 superstructures.


2003 ◽  
Vol 799 ◽  
Author(s):  
W. K. Cheah ◽  
W. J. Fan ◽  
S. F. Yoon ◽  
S. Wicaksono ◽  
R. Liu ◽  
...  

ABSTRACTLow temperature (4.5K) photoluminescence (PL) measurements of GaAs(N):Sb on GaAs grown by solid source molecular beam epitaxy (MBE) show a Sb-related defect peak at ∼1017nm (1.22eV). The magnitude of the Sb-related impurity PL peak corresponds in intensity with the prominence of the additional two-dimensional [115] high-resolution x-ray diffraction (HRXRD) defect peaks. The elimination of these defects can be a measure of the improvement in crystal quality of GaAsN:Sb and a Sb flux ≥ 1.3×10−8 Torr is needed to invoke the surfactant behavior in III-V dilute nitride MBE growth for a growth rate of 1μm/hr.


SPIN ◽  
2014 ◽  
Vol 04 (04) ◽  
pp. 1440025 ◽  
Author(s):  
GAVIN R. BELL ◽  
CHRISTOPHER W. BURROWS ◽  
THOMAS P. A. HASE ◽  
MARK J. ASHWIN ◽  
SEAN R. C. MCMITCHELL ◽  
...  

The cubic polymorph of the binary transition metal pnictide (TMP) MnSb , c- MnSb , has been predicted to be a robust half-metallic ferromagnetic (HMF) material with minority spin gap ≳1 eV. Here, MnSb epilayers are grown by molecular beam epitaxy (MBE) on GaAs and In 0.5 Ga 0.5 As (111) substrates and analyzed using synchrotron radiation X-ray diffraction. We find polymorphic growth of MnSb on both substrates, where c- MnSb co-exists with the ordinary niccolite n- MnSb polymorph. The grain size of the c- MnSb is of the order of tens of nanometer on both substrates and its appearance during MBE growth is independent of the very different epitaxial strain from the GaAs (3.1%) and In 0.5 Ga 0.5 As (0.31%) substrates.


2010 ◽  
Vol 24 (22) ◽  
pp. 4225-4231
Author(s):  
W. S. TAN ◽  
H. L. CAI ◽  
X. S. WU ◽  
K. M. DENG ◽  
H. H. CHENG

In this paper, with solid source molecular beam epitaxy technique, Si 1-x Ge x( SiGe ) virtual substrates were deposited on low-temperature-grown Si (LT- Si ) buffer layer, which was doped with Sb . The strain in SiGe virtual substrate was characterized by high resolution X-ray diffraction. Results indicated that Sb -doping in LT- Si can effectively modulate the degree of strain relaxation in SiGe virtual substrate. The segregated Sb on the surface of LT- Si layer acts as surfactant and results in abrupt strain relaxation.


Author(s):  
M. E. Twigg ◽  
B. R. Bennett ◽  
J. R. Waterman ◽  
J. L. Davis ◽  
B. V. Shanabrook ◽  
...  

Recently, the GaSb/InAs superlattice system has received renewed attention. The interest stems from a model demonstrating that short period Ga1-xInxSb/InAs superlattices will have both a band gap less than 100 meV and high optical absorption coefficients, principal requirements for infrared detector applications. Because this superlattice system contains two species of cations and anions, it is possible to prepare either InSb-like or GaAs-like interfaces. As such, the system presents a unique opportunity to examine interfacial properties.We used molecular beam epitaxy (MBE) to prepare an extensive set of GaSb/InAs superlattices grown on an GaSb buffer, which, in turn had been grown on a (100) GaAs substrate. Through appropriate shutter sequences, the interfaces were directed to assume either an InSb-like or GaAs-like character. These superlattices were then studied with a variety of ex-situ probes such as x-ray diffraction and Raman spectroscopy. These probes confirmed that, indeed, predominantly InSb-like and GaAs-like interfaces had been achieved.


1989 ◽  
Vol 160 ◽  
Author(s):  
T. L. Lin ◽  
C. W. Nieh

AbstractEpitaxial IrSi3 films have been grown on Si (111) by molecular beam epitaxy (MBE) at temperatures ranging from 630 to 800 °C and by solid phase epitaxy (SPE) at 500 °C. Good surface morphology was observed for IrSi3 layers grown by MBE at temperatures below 680 °C, and an increasing tendency to form islands is noted in samples grown at higher temperatures. Transmission electron microscopy (TEM) analysis reveals that the IrSi3 layers grow epitaxially on Si(111) with three epitaxial modes depending on the growth conditions. For IrSi3 layers grown by MBE at 630 °C, two epitaxial modes were observed with ~ 50% area coverage for each mode. Single mode epitaxial growth was achieved at a higher MBE growth temperature, but with island formation in the IrSi3 layer. A template technique was used with MBE to improve the IrSi3 surface morphology at higher growth temperatures. Furthermore, single-crystal IrSi3 was grown on Si(111) at 500 °C by SPE, with annealing performed in-situ in a TEM chamber.


Polymer ◽  
2004 ◽  
Vol 45 (18) ◽  
pp. 6341-6348 ◽  
Author(s):  
S. Stoeva ◽  
A. Popov ◽  
R. Rodriguez

2001 ◽  
Vol 696 ◽  
Author(s):  
Gu Hyun Kim ◽  
Jung Bum Choi ◽  
Joo In Lee ◽  
Se-Kyung Kang ◽  
Seung Il Ban ◽  
...  

AbstractWe have studied infrared photoluminescence (PL) and x-ray diffraction (XRD) of 400 nm and 1500 nm thick InAs epilayers on GaAs, and 4 nm thick InAs on graded InGaAs layer with total thickness of 300 nm grown by molecular beam epitaxy. The PL peak positions of 400 nm, 1500 nm and 4 nm InAs epilayer measured at 10 K are blue-shifted from that of InAs bulk by 6.5, 4.5, and 6 meV, respectively, which can be largely explained by the residual strain in the epilayer. The residual strain caused by the lattice mismatch between InAs and GaAs or graded InGaAs/GaAs was observed from XRD measurements. While the PL peak position of 400 nm thick InAs layer is linearly shifted toward higher energy with increase in excitation intensity ranging from 10 to 140 mW, those of 4 nm InAs epilayer on InGaAs and 1500 nm InAs layer on GaAs is gradually blue-shifted and then, saturated above a power of 75 mW. These results suggest that adopting a graded InGaAs layer between InAs and GaAs can efficiently reduce the strain due to lattice mismatch in the structure of InAs/GaAs.


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