Abstract
Two types of crystal defects, stacking fault induced by a nitrogen-doped substrate (N-SF) and elliptical pit (E-pit), are generated in the epitaxial layer due to grown-in defects in a nitrogen-doped Czochralski-grown silicon (CZ-Si) substrate. We investigate the dependence of N-SF and E-pit formation on the quality of nitrogen-doped substrates. It was revealed that the control of both nitrogen concentration and crystal growth parameter of the CZ-Si ingot is effective for suppressing N-SF and E-pit formation. We also examined crystal defect in the epitaxial layer on a nitrogen and carbon co-doped substrate, which is the other candidate for realizing the epitaxial wafer having a high intrinsic gettering ability. It was clarified that carbon co-doping in addition to nitrogen doping suppresses N-SF and E-pit generation.