We have studied the morphology and crystallographic angular discontinuities of subboundaries and defect trails in zone‐melting‐recrystallized Si films. These subboundaries and defect trails, which originate at the interior corners of the faceted solidification front, are classified into seven types. Evidence is presented that in‐plane stress due to temperature gradients plays a major role in causing such defects. Various schemes for entraining subboundaries and defect trails are described.