Semi-crystalline poly(4-methyl-1-pentene) polymers for replication of high aspect ratio diffractive features

Two transparent semi-crystalline poly(4-methyl-1-pentene) copolymers (P4MP1) of different molar mass distributions were used for injection molding of high aspect ratio (height/width) diffractive gratings. High quality sub-micron and micron features with aspect ratios of 1.6:1 were obtained with low mold temperatures. According to SEM and AFM measurements, replication of the features depended on substrate thickness and polymer. The copolymer with lower Mn and Mw penetrated deeper into the feature cavities in thin substrates, but showed poorer thermal stability and replication fidelity.