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:
The move towards commercialization of SiC based devices places increasing demands on thequality of the substrate material. While the industry has steadily decreased the micropipe (MP) levels incommercial SiC substrates over the past years, the achievement of wafers that are entirely free of MPsmarks an important milestone in commercialization of SiC based devices. We present the results of astudy for controlling the nucleation and propagation of MP defects in SiC ingots grown via PVT. Ourstudies confirm that during bulk growth of SiC, foreign polytype nucleation such as 3C-polytype occursat the initial stages of growth (nucleation period) and/or during subsequent growth in the presence offacets. Results in this investigation suggest that polytype instability during crystal growth adverselyimpacts the MP density. Based on this key concept, growth conditions for nucleation and growth stageswere optimized. These conditions were subsequently implemented in an innovative PVT growthenvironment to achieve a growth technique with highly effective polytype control. Under continuouslymodulated growth conditions, MPs induced by seed material and/or formed during the growth wereeliminated. 2-inch and 3-inch diameter MP-free (zero MP density) conducting 4H-SiC ingots wereobtained
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.527-529.39.pdf
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