Optimization of 150 mm 4H SiC Substrate Crystal Quality

Abstract

Continuous optimization of bulk 4H SiC PVT crystal growth processes has yielded an improvement in 150 mm wafer shape, as well as a marked reduction in stacking fault density. Mean wafer bow and warp decreased by 26% and 14%, respectively, while stacking faults were nearly eliminated from wafers produced using the refined process. These quality enhancements corresponded to an adjustment to key thermal parameters predicted to control intrinsic crystal stresses, and a reduction in crystal dome curvature.