Formation of extended defects in 4H‐SiC epitaxial growth and development of a fast growth technique

Abstract

AbstractThis paper surveys extended defects in 4H‐SiC epilayers and reports recent results concerning fast epitaxial growth. Synchrotron X‐ray topography, transmission electron microscopy, Nomarski optical microscopy and defect selective etching analysis are applied to investigate the nucleation and propagation of carrot defects, basal plane Frank‐type defects, polytype inclusions and basal plane dislocations (BPDs) in 4H‐SiC epitaxial growth. In the development of the 4H‐SiC fast epitaxial growth technique, a very high growth rate of up to 250 μm/h is obtained in a newly developed vertical hot‐wall‐type reactor under low system pressure using a H2 + SiH4 + C3H8 system. Good thickness and impurity doping uniformity are also obtained simultaneously over a large area, with the retention of a high growth rate. A 4H‐SiC epilayer virtually free from BPDs is obtained on a 4° off Si‐face substrate. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)