Rapid Structural Defect Mapping of Bulk II-VI Semiconductors Using White-Beam Synchrotron Topography and X-ray Rocking Curve Analysis

1992 ◽  
Vol 262 ◽  
Author(s):  
Don Di Marzio ◽  
Louis G. Casagrande ◽  
Myung B. Lee ◽  
Thomas Fanning ◽  
Michael Dudley
Keyword(s):  
Semiconductor Industry ◽  
Defect Analysis ◽  
Etch Pit Density ◽  
Ir Detector ◽  
Rocking Curve ◽  
X Ray ◽  
Etch Pit ◽  
White Beam ◽  
Device Structures ◽  
Nondestructive Characterization

ABSTRACTNondestructive characterization techniques for substrates, epilayers, and device structures are becoming increasingly important in the semiconductor industry. Synchrotron-based white-beam x-ray topography, x-ray rocking curve measurements, and etch pit density were used to map the defect structure in a variety of CdTe and CdZnTe single crystal substrates, which are important for IR detector applications involving HgCdTe. Defects such as low angle grain boundaries have been successfully correlated using topography, rocking curves, and etch pit density, and twins have been observed using topography and rocking curves. The effectiveness of white-beam synchrotron topography for rapid and nondestructive defect analysis and substrate screening is discussed.

Mosaicity and Wafer Bending in SiC Wafers as Measured by Double and Triple Crystal X-Ray Rocking Curve and Peak Position Maps

2007 ◽  
Vol 556-557 ◽  
pp. 213-218 ◽  
Author(s):  
K.W. Kirchner ◽  
Kenneth A. Jones ◽  
Michael A. Derenge ◽  
Michael Dudley ◽  
Adrian R. Powell
Keyword(s):  
Laser Light ◽  
Peak Position ◽  
Etch Pit Density ◽  
Normal Position ◽  
Rocking Curve ◽  
X Ray ◽  
Etch Pit ◽  
Density Map ◽  
Beam Transmission ◽  
Si Wafer

Double and triple crystal rocking curve and peak position maps are constructed for a 4HSiC wafer for the symmetric (0 0 0 8) reflection in the normal position, the same reflection for a sample rotated 90º, and an asymmetric (1 23 6) reflection for the wafer in the normal position. These measurements were corrected for the ‘wobble’ in the instrument by scanning a 4” (1 1 1) Si wafer and assuming that the Si wafer was perfect and attributing the variations in the measurements to instrumental error. The x-ray measurements are correlated with a cross polar image, etch pit density map, white beam transmission x-ray topograph, and a laser light scan.

Life Time Predictions through X-Ray Defect Analysis of MEMS Devices

2008 ◽  
Vol 584-586 ◽  
pp. 518-522 ◽  
Author(s):  
Antonia Neels ◽  
Philippe Niedermann ◽  
Alex Dommann
Keyword(s):  
Single Crystal Silicon ◽  
Life Time ◽  
Defect Analysis ◽  
Mems Devices ◽  
X Ray Diffraction ◽  
Reciprocal Space Mapping ◽  
Crystal Silicon ◽  
Rocking Curve ◽  
X Ray ◽  
Curve Method

In single crystal silicon (SCSi) MEMS devices, crystalline imperfection is recognized to favor failure. A DRIE etched SCSi structure was built to study the crystal strain profile in dependence of the SCSi deformation by applying a mechanical force. High resolution X-ray diffraction methods such as the rocking curve method and reciprocal space mapping were used to determine the strain as well as the defect concentration in the crystal. The investigations also include the numerical simulation of deformations.

Subsurface Micro-Lattice Strain Mapping

1986 ◽  
Vol 90 ◽  
Author(s):  
T. S. Ananthanarayanan ◽  
R. G. Rosemeier ◽  
W. E. Mayo ◽  
P. Becla
Keyword(s):  
Diffraction Method ◽  
Epitaxial Films ◽  
Depth Of Penetration ◽  
Ir Detector ◽  
Strain Mapping ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray ◽  
Microplastic Strain ◽  
Invaluable Tool

SYNOPSISDefect morphology and distribution up to depths of 20um have been shown to be critical to device performance in micro-electronic applications. A unique and novel x-ray diffraction method called DARC (Digital Automated Rocking Curve) topography has been effectively utilized to map crystalline micro-lattice strains in various substrates and epitaxial films. The spatial resolution of this technique is in the the order of 100um and the analysis time for a 2cm2 area is about 10 secs. DARC topography incorporates state-ofthe- art 1-dimensional and 2-dimensional X-ray detectors to modify a conventional Double Crystal Diffractometer to obtain color x-ray rocking curve topographs.This technique, being non-destructive and non-intrusive in nature, is an invaluable tool in materials’ quality control for IR detector fabrication. The DARC topographs clearly delineate areas of microplastic strain inhomogeniety. Materials analyzed using this technique include HgMnTe, HgCdTe, BaF2, PbSe, PbS both substrates and epitaxial films. By varying the incident x-ray beam wavelength the depth of penetration can be adjusted from a 1–2 micron up to 15–20um. This can easily be achieved in a synchrotron.

Growth of Iii-Nitrides by Rf-Assisted Molecular Beam Epitaxy

1998 ◽  
Vol 512 ◽  
Author(s):  
E. C. Piquette ◽  
P. M. Bridger ◽  
Z. Z. Bandić ◽  
T. C. Mcgill
Keyword(s):  
Electric Fields ◽  
Molecular Beam ◽  
Plasma Source ◽  
Rf Plasma ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Wide Range ◽  
Device Structures ◽  
Hall Technique

ABSTRACTGaN, AlGaN, AIN were grown on (0001) A1203 substrates by MBE using a RF plasma source and employing an AIN buffer layer. The films were characterized by RHEED, AFM, and x-ray diffraction, and electrical properties were measured by Hall technique. RHEED observations indicate that the polarity of the films is likely predominantly N-face, although Ga-face inversion domains can be observed in some films by AFM. Symmetric x-ray rocking curve widths as low as 39 arcseconds are achieved for some layers, while asymmetric peaks show widths of 240–300 arcsec. Control of Si doping over a wide range is demonstrated, which is important for design of high power device structures. Gold Schottky barrier m-v-n+diodes were fabricated which achieve high reverse electric fields before edge breakdown.

X-Ray, Photoluminescence and Etching Studies of Indium-Doped LPE GaAs Layers

1988 ◽  
Vol 144 ◽  
Author(s):  
J.F. Chen ◽  
C. R. Wie ◽  
F. A. Junga
Keyword(s):  
Phase Diagram ◽  
Sharp Increase ◽  
Emission Spectra ◽  
Etch Pit Density ◽  
Double Crystal ◽  
X Ray ◽  
Etch Pit ◽  
In Doping ◽  
Good Crystalline Quality ◽  
Pseudobinary Phase Diagram

ABSTRACTThe effects of In doping on the structural properties of liquid phase epitaxially (LPE) grown GaAs layers are studied. The distribution coefficient of In in the GaAs at 800 ° C was determined to be 0.033 which was consistent with the value calculated from the pseudobinary phase diagram of the ternary system at a dilute In concentration. The full widths at halfmaximum (FWHM) of x-ray double crystal rocking curves show that a GaAs epi-layer of good crystalline quality can be obtained by doping In to a concentration up to 4.3 × 1019 cm−3, beyond which a sharp increase in the FWHM is observed. Etch pit density (EPD) measurement shows that the dislocation density is reduced by doping the epi-layer with In. At the optimal In concentration of 2.4 × 1019 cm−3, the EPD is reduced by a factor of 20 when measured at the surface of a 9 um thick epilayer.Photoluminesce measurements made at 15 K show two sharp emission spectra near the bandedge. The relative intensities of the two emissions, I(l.49eV)/I(l.5eV) are reduced with increasing In content. This suggests that incorporation of Carbon acceptors is suppressed by In doping in the GaAs epilayers. The FWHM as small as 5 meV of the bandedge transition was obtained for the epi-layer doped with In concentration of 2.4 × 1019 cm−3.

Growth of Boron Carbide Crystals from a Copper Flux

2009 ◽  
Vol 1164 ◽  
Author(s):  
Yi Zhang ◽  
James Edgar ◽  
Jack Plummer ◽  
Clinton Whiteley ◽  
Hui Chen ◽  
...  
Keyword(s):  
Boron Carbide ◽  
Potassium Hydroxide ◽  
Crystal Size ◽  
Optical Microscope ◽  
Etch Pit Density ◽  
Bulk Crystals ◽  
Limited Growth ◽  
Etch Pits ◽  
X Ray ◽  
Etch Pit

AbstractBoron carbide crystals ranging in size from 50 microns to several millimeters have been grown from a copper-boron carbide flux at temperatures from 1500°C to 1750°C. The crystal size increased with growth temperature although copper evaporation limited growth at the higher temperatures. Synchrotron X-ray Laue patterns were indexed according to (001) orientation boron carbide structure, indicating the bulk crystals were single crystalline with {001} growth facets. Raman spectrum of boron carbide indicates an improved crystal quality compared to the source powder, but peaks of crystals grown from 11B -enriched source shifted to the lower energy by 1-4 cm−1 from literature values, possibly due to the boron isotope dependency. Five fold symmetry defects and twin planes were common as observed by optical microscope and scanning electron microscope. Raindrop shape etch pits were formed after defect selective etching in molten potassium hydroxide at 600°C for 6 minutes. Typically, the etch pit density was on the order of 106/cm2.

Use of Synchrotron White Beam X-Ray Topography to Characterize IR Detector Manufacturing Processes

1993 ◽  
Vol 324 ◽  
Author(s):  
M. Dudley ◽  
Jun Wu ◽  
D. J. Larson ◽  
D. Dimarzio
Keyword(s):  
Focal Plane ◽  
Depth Profiling ◽  
Focal Plane Arrays ◽  
Ir Detector ◽  
X Ray ◽  
Ir Microscopy ◽  
White Beam ◽  
Processing Step ◽  
Yield Quality ◽  
Detector Materials

AbstractIt has been have demonstrated that synchrotron white beam x-ray topography can be used to characterize IR detector materials at nearly every stage in the manufacturing cycle, including: as-grown CdZnTe single crystal boules; substrate wafers cut from different positions in the boules; thin films grown on characterized wafers; and HgCdTe focal plane arraystructures. Special diffraction geometries have been developed, taking advantage of the broad wavelength spectrum, large beam size, and high intensity of the synchrotron radiation source, to enable rapid and non-destructive assessment of defect densities and strain distributions after each processing step. This diagnostic method has important implications for increasing the producibility of focal plane arrays. Boule characterization can reveal defects, grain orientation, interfaces and strains, and provides guidance for optimal slicing. Wafer characterization produces multiple topographic images, providing both defect mapping and depth profiling in a single exposure. Finally, x-ray topography of HgCdTe focal plane array test articles reveals subsurface damage not observable by optical or IR microscopy. The applicability of this technique to evaluate yield, quality, and reproducibility will be discussed.

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