An etchant for delineation of flow pattern defects in heavily doped p-type silicon wafers

Secco etchant is conventionally used for delineation of flow pattern defects (FPDs) in lightly-doped Czochralski (Cz) silicon wafers. However, the FPDs in heavily doped p-type silicon wafers cannot be well delineated by Secco etchant. Herein, an etchant based on the CrO3HFH2O system, with an optimized volume ratio of V(CrO3):V(HF)=2:3, where the concentration of CrO3 is 0.25–0.35 M, has been developed for delineation of FPDs with well-defined morphologies for the heavily boron (B)-doped p-type silicon wafers.