X-Ray Rocking Curve Analysis of S-Implanted GaAs

1988 ◽  
Vol 126 ◽  
Author(s):  
M. Fatemi ◽  
P.E. Thompson ◽  
J. Chaudhuri ◽  
S. Shah

ABSTRACTThe effect of rapid thermal annealing on strain reduction in 1.15 MeV S-implanted GaAs wafers irradiated to a dose of 5 × 1014/cm2 has been studied by double-crystal x-ray diffraction technique. X-ray rocking curves exhibit characteristic thin film fringes between the peak of unstrained GaAs and the major peak of the strained region. The maximum strain, i.e., the separation between the two peaks, as well as the number of minor fringes decreases with increasing RTA temperature, while the relative spacing between the fringes remains constant. At temperatures above 900°C, the main peaks begin to overlap; however, a residual positive strain can be measured for temperatures as high as 1100°C.

1990 ◽  
Vol 208 ◽  
Author(s):  
Neil Loxley ◽  
D. Keith Bowen ◽  
Brian K. Tanner

ABSTRACTReplacement of the pinhole collimator on a double axis X-ray diffractometer with a device incorporating a channel-cut crystal permits the beam to be pre-conditioned in angular divergence. We examine the merits of such devices, known as channel-cut collimators (CCC's), of different materials and reflections. The experimental performance of InP 004 and Si 022 CCC's is presented.With a reference crystal on the first axis, set in the dispersive peometry with respect to the CCC, conditioning in wavelength spread is achieved. Dispersion broadening is effectively eliminated and no resetting of the reference crystal is required when changing specimen materials or reflections. The devices have extremely low background and reduced Bragg tails. Application of the 4-reflection CCC to rocking curve analysis of thin epitaxial layers, ultra-low angle scattering from biological systems, grazing incidence reflectometry and triple axis diffraction of semi-conductors is discussed.


2020 ◽  
Vol 90 (5) ◽  
pp. 795
Author(s):  
Р.В. Селюков ◽  
В.В. Наумов

Textured Pt films with thickness h=20-80 nm were sputter deposited on oxidized c-Si (100) wafers and annealed in vacuum at 500°C/60 min. The thickness dependencies of the crystalline texture parameters and of the fraction of crystalline phase δ are obtained for as-deposited and annealed films using X-ray diffraction. The determination of δ in textured films is carried out by the new method based on rocking curve analysis. It is found that annealing leads to the texture improvement and to the increasing of δ for all h. The less h, the stronger effects of texture improvement and of δ increasing. These results are explained by the annealing-induced formation of large secondary grains whose volume fraction increases as h decreases. The inhomogeneity of the depth distributions of texture parameters and of δ are investigated for the as-deposited Pt films.


1987 ◽  
Vol 31 ◽  
pp. 143-154 ◽  
Author(s):  
M. Fatemi

AbstractThere is considerable interest in the microelectronics industry to obtain high-resolution images, as well as precise measures of defect densities in “ device quality” thin films and substrates. In the field of x-ray diffraction, research groups worldwide are intensely pursuing the relevant applications of computerized x-ray rocking curve analysis and topography. Production-type, on-site rocking curve instrumentation has already been introduced into the market, and potential uses of x-ray topography are also under consideration.In the present study, the merits and limitations of these two techniques are critically evaluated. Possible pitfalls of automated data collection are pointed out and conditions under which meaningful measurements may be made are explored. It is shown that reliable results may nearly always be obtained with reasonable care when each method is applied subject to its own mode of operation. However, extreme caution is needed when digitized data initially collected for topography is subsequently used for rocking curve analysis; otherwise, the correspondence between the interpretation and actual defect configuration may be vitiated. Thus, additional tests will be necessary to ensure the validity of the results.


1999 ◽  
Vol 595 ◽  
Author(s):  
W.L. Sarney ◽  
L. Salamanca-Riba ◽  
V. Ramachandran ◽  
R.M Feenstra ◽  
D.W. Greve

AbstractGaN films grown on SiC (0001) by MBE at various substrate temperatures (600° - 750° C) were characterized by RHEED, STM, x-ray diffraction, AFM and TEM. This work focuses on the TEM analysis of the films' features, such as stacking faults and dislocations, which are related to the substrate temperature. There are several basal plane stacking faults in the form of cubic inclusions for samples grown at low temperatures compared to those grown at high temperatures. The dislocation density is greatest for the film grown at 600°C, and it steadily decreases with increasing growth temperatures. Despite the presence of various defects, x-ray analysis shows that the GaN films are of high quality. The double crystal rocking curve full width at half maximum (FWHM) for the GaN (0002) peak is less than 2 arc-minutes for all of the films we measured and it decreases with increasing growth temperature.


1986 ◽  
Vol 90 ◽  
Author(s):  
I. B. Bhat ◽  
N. R. Taskar ◽  
J. Ayers ◽  
K. Patel ◽  
S. K. Ghandhi

ABSTRACTCadmium telluride layers were grown on InSb substrates by organometallic vapor phase epitaxy and examined using secondary ion mass spectrometry (SIMS), photoluminescence (Pb) and double crystal x-ray diffraction (DCD). The substrate temperature and the nature of the surface prior to growth are shown to be the most important parameters which influence the quality of CdTe layers. Growth on diethyltelluride (DETe) stabilized InSb substrates resulted in CdTe growth with a misorientation of about 4 minutes of arc with respect to the substrates. On the other hand, the grown layers followed the orientation of the substrates when a dimethylcadmium (DMCd) stabilized InSb was used. Growth at 350°C resulted in the smallest x-ray rocking curve (DCRC) full width at half maximum (FWHM) of about 20 arc seconds.


1986 ◽  
Vol 30 ◽  
pp. 527-535 ◽  
Author(s):  
T.S. Ananthanarayanan ◽  
W.E. Mayo ◽  
R.G. Rosemeier

AbstractThis study presents a unique and novel enhancement of the double crystal diffractometer which allows topographic mapping of X-ray diffraction rocking curve half widths at about 100-150μm spatial resolution. This technique can be very effectively utilized to map micro-lattice strain fields in crystalline materials. The current focus will be on the application of a recently developed digital implementation for the rapid characterization of defect structure and distribution in various semiconductor materials.Digital Automated Rocking Curve (DARC) topography has been successfully applied for characterizing defect structure in materials such as: GaAs, Si, AlGaAs, HgMnTe, HgCdTe, CdTe, Al, Inconnel, Steels, BaF2 PbS, PbSe, etc. The non-intrusive (non- contact & non-destructive) nature of the DARC technique allows its use in studing several phenomena such as corrosion fatigue, recrystallization, grain growth, etc., in situ. DARC topography has been used for isolating regions of non-uniform dislocation density on various materials. It is envisioned that this highly sophisticated, yet simple to operate, system will improve semiconductor-device yield significantly.The high strain sensitivity of the technique results from combination of the highly monochromated and collimated X-ray probe beani, the State of the art linear position-sensitive detector (LPSD) and the high-precision specimen goniometer.


2013 ◽  
Vol 1576 ◽  
Author(s):  
Jacob Castilow ◽  
Timothy W Zens ◽  
J. Matthew Mann ◽  
Joseph W. Kolis ◽  
Colin D. McMillen ◽  
...  

ABSTRACTHydrothermal synthesis of ThO2, UxTh1-xO2, and UOx at temperatures between 670°C and 700°C has been demonstrated. Synthesis at these temperatures is 50-80°C below prior growth studies and represents a new lower bound of successful growth. ThO2 single crystals of dimensions 6.49mm x 4.89mm x 3.89 mm and weighing 0.633g have been synthesized at average growth rates near 0.125mm/week. Single crystal UxTh1-xO2 crystals with mole fractions up to x≈0.30 have also been grown. The largest alloyed crystal with mole fraction x≈0.23 has dimensions of 2.97mm x 3.23mm x ∼3mm and recorded average growth rates near 0.2mm/week. Four structures were solved from X-ray diffraction data and their crystallographic data reported here. Rocking curve analysis determined a dislocation density of 1.2×109 cm-2.


1987 ◽  
Vol 91 ◽  
Author(s):  
J.W. Lee ◽  
D.K. Bowen ◽  
J.P. Salerno

ABSTRACTIn an effort to evaluate the near surface crystal quality of GaAs on Si wafers, {224} plane diffraction were investigated using a conventional double crystal x-ray diffractometer without any high intensity radiation source. The x-ray incident angle to wafer surface varied from 3.6 to 9.6 degrees for different {224} planes due to the substrate tilt angle of 3 degrees. The GaAs to Si rocking curve intensity ratio increased significantly as the incident angle decreased. For the diffraction with 3.6 degree incident angle, only the GaAs peak was detected from the 3.5 um thick GaAs on Si wafer and the GaAs peak became narrower. These indicates that this conventional x-ray diffraction technique is applicable for the near surface quality evaluation of GaAs on Si wafers.


1993 ◽  
Vol 312 ◽  
Author(s):  
B. Jenichen ◽  
K. Ploog ◽  
O. Brandt

AbstractThe lateral periodicity of an InAs quantum dot array in a GaAs matrix is measured in the differential rocking curve by triple crystal diffractometry. The quantum dot array was grown by molecular beam epitaxy of submonolayer InAs films on a terraced (001) GaAs substrate. The x-ray diffraction of the array is described in the limits of the kinematical theory. Both the changes in the scattering factor and the tetragonal deformations due to the InAs quantum dots are taken into account. The lateral periodicity of the array along [100] is 8–11nm dependent on the position of the measured region compared with an average of 10nm obtained from the miscut of the sample. In addition the vertical periodicity of the array is measured by comparison of the double crystal rocking curve with the corresponding simulation in the dynamical approximation. The vertical period of the array along [001] is 26.5nm. The coverage of the submonolayer InAs films estimated from the same measurement is 0.4. The absence of plastic relaxation is confirmed by x-ray topography.


1986 ◽  
Vol 69 ◽  
Author(s):  
B. K. Tanner ◽  
Chu Xi ◽  
D. K. Bowen

AbstractA novel technique for high speed X-ray double crystal rocking curve analysis of epitaxial layers is described. It employs specimen rotation about an axis almost normal to the Bragg planes in order to optimize Bragg plane tilts. Very rapid set-up is possible by peak searching using this rotation axis rather than the standard ω scan. A rotation stage suitable for a Bede Scientific Instrument Model 6 diffractometer is described and its performance assessed. Experimental and theoretical values of the shift in centroid of the ω scan rocking curve as a function of rotation angle are in excellent agreement.


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