Fundamentals of Developer-ResistInteractions for Line-Edge Roughness andCD control in Model 248 nm and 157 nmPhotoresists

摘要

The development step is critical to the fabrication of nanostructuresin chemically amplified photoresist technology.With shrinking criticaldimensions (CD) to sub-100 nm,control of line-edge roughness (LER)is becoming more important and understanding contributions toroughness from the development step requires a improvedmeasurements and theoretical framework that address developer-resistinteraction effects on resist polymer chains.Model photoresist bilayersand single layer resists films on silicon substrates comprising of model248 nm (poly(4-hydroxystyrene) (PHOSt) and poly(4-tertbutoxycarbonyloxystyrene) (t-BOC) and 157 nm (poly(norbornenehexafluoroisopropanol)) materials are developed using a series of polarsolvents and aqueous base.The performance contrast between neutralversus charged polymer (polyelectrolyte) dissolution demonstrates animproved framework to interpret dissolution effects on CD and LERcontrol.