Mechanism of Surface Bump Defect Formation in Phosphorus Doped Polysilicon-Silicon Nitride Film Stack

Formation of bump defect on the surface of silicon nitride film deposited on top of phosphorus doped amorphous silicon layer was studied. The bump defect formation was found to be caused by localized phosphorus segregation on polysilicon surface. Wet chemical treatment of silicon surface involving HF- H
₂
O
₂
chemistries were found to reduce bump defect formation.