ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
We have presented a combined method of microscopic measurements between Ramanscattering and polarizing optical microscope to characterize inhomogeneous residual stressdistributions around dislocations in 4H- and 6H-SiC wafers. First, stressed portions were found inwafers by an optical polarizing microscope under a crossed Nicole arrangement. Then, the portionswere examined by Raman-imaging technique for lateral variations of phonon spectra. The residualstresses were quantified from the phonon-peak frequency shift using a known frequency-shift rate for6H-SiC. Characterization to the depth direction was also conducted by surface etching with moltenKOH. The stresses typically amounted to the order of 100 MPa. In a 4H-SiC homoepitaxial wafersample, we observed threading dislocations transferred from the substrate to the epitaxial layer, andfound that larger stress fields existed in the epitaxial layer than the substrate. We also observed stressdistributions around compressively stressed sub-grain boundaries
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/20/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.600-603.337.pdf
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