A study of the formation of epitaxial stacking faults in 2 in. diameter, dislocation‐free (111) silicon wafers used in the fabrication of standard buried collector transistors has been made. The nucleation sites for the epitaxial faults are introduced during the initial oxidation of the wafer and are correlated with the presence of a high density of shallow, flat‐bottomed, saucer‐shaped etch pits. The saucer pits are selectively annihilated in the diffused or implanted regions during the fabrication of the Sb‐doped buried collectors. For the ion‐implanted process the annihilation of saucer pits extends laterally from 50 to 100 μm beyond the boundaries of the collectors. Following epitaxial growth, epitaxial stacking faults, at a density of 104 cm−2, are only found in those nonburied layer regions which have a saucer pit density of 106–107 cm−2 before epitaxy. Therefore, epi stacking faults are not found in ion‐implanted material with a separation between buried collectors of 100 μm or less. Most 3 in. diameter, and the central regions of 2 in. diameter wafers do not have saucer pits or epi stacking faults. This is attributed to anin situ gettering of nucleation sites by precipitates, which are known to form in wafers, or regions of wafers, with a high initial oxygen concentration. Additional procedures for deliberately suppressing or gettering the nucleation sites are presented. These include deliberate abrasion, deposition of strained layers, introduction of misfit dislocations, and the use of an Sb ion implant, which are performed on the back side of wafers before the initial masking oxidation.