Removal of SU8 fine patterns with N-Methyl-2-Pyrrolidone doped

Abstract

SU8 is a negative photoresist shows superior characteristics of heat resistance and chemical resistance. And, it is used to make high-aspect ratio micro structures such as master of electroforming. However, it is extremely difficult to remove SU8 from substrate. Researchers have investigated a means of SU8 removal. Therefore we proposed a new SU8 removal method “DI water (H2O) and lithium chloride (LiCl) doped NMP” which promises swelling furtherance of SU8, and we demonstrated that the new method could remove fine SU8 patters from substrate at proper level. The mechanism of SU8 fine patterns removal is presented as follows. A doped NMP broadens the width of SU8 patterns by swelling effect and reduces buckling stress of SU8 patterns. SU8 patterns reducing buckling stress increases the potential of buckling.

Keywords

• su8
• remove
• nmp
• licl
• h2o