Analysis and Reduction of Obtuse Triangular Defects on 150-mm 4A degrees 4H-SiC Epitaxial Wafers

作者：Sun Yongqiang; Feng Gan; Kang Junyong; Zhang Jianhui; Qian Weining

来源：Journal of Electronic Materials, 2018, 47(9): 5109-5112.

DOI：10.1007/s11664-018-6476-2

• 4H-SiC
• 150 mm
• epitaxial growth
• obtuse triangular defects
• basal plane dislocation gliding

Triangular defects with an obtuse-angled structure and long base on 150-mm 4A degrees off 4H-SiC epitaxial wafers have been characterized and discussed. The results show that the origins of the obtuse triangular defects (OTDs) are related to substrate defects and foreign particles formed during and/or prior to the epitaxial growth, while the formation of the two wing regions for OTD is believed to be due to the disturbance of step flow growth caused by giant step bunching. Basal plane dislocations (BPDs) gliding in the wing regions have also been observed. BPD gliding is induced by the large strain, which originally existed in the 150-mm substrate and was augmented during the epitaxial growth. Reducing the epitaxial growth rate with an appropriate C-to-Si ratio is confirmed to be one of the effective methods to significantly suppress the formation of OTDs.

• 出版日期2018-9
• 单位厦门大学