Investigation of "fur-like" residues post dry etching of polyimide using aluminum hard etch mask

The authors found that oxygen plasma etching of polyimide (PI) with aluminum (Al) as a hard-etch mask results in lightly textured arbitrary shaped “fur-like” residues. Upon investigation, the presence of Al was detected in these residues. Ruling out several causes of metal contamination that were already reported in literature, a new theory for...