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 present herein a first comparative analysis of the quality of 50 mm and 75 mmdiameter SiC wafers, purchased directly from vendors across the world, types including the mostwidely available configurations. Large Area White Beam Synchrotron Back Reflection X-RayTopography was used to analyse selected ~1cm2 regions at various locations on up to 10 differentbulk SiC wafers. The study concentrated particularly on the density and distribution of threadingscrew dislocations (TSDs). We also examined all wafers for basal plane dislocation (BPDs)densities and distributions. Alarmingly large variation in wafer quality was observed. TSD densitiesvary from a minimum of 0 cm-2 (in a-plane material) to values as large as over 2,000 cm-2 on somen-type 4H-SiC wafers. TSD densities on individual wafers can also vary by similar magnitudes, e.g.500cm-2 to 2,500 cm-2 on two regions only 2 cm apart on a 50 mm diameter wafer. Computer-basedimage process analysis was used to present a statistical analysis of the distributions of defects. Forexample algorithms created in MATLAB®, Image Processing Toolbox, isolated possible TSDlocations allowing rapid counting to be performed. These counts were confirmed by manualcounting of selected unmodified images
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/17/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.556-557.227.pdf
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