Release Properties and Durability of Release Layer on UV Nanoimprint Lithography

Two photo-curable resins (PAK-01 and PAK-02) have been evaluated by a primitive test and a precise test. The primitive test is simple manual transfer process and the precise test is using UV nanoimprint lithography (UV-NIL) machine. At first, nano order high aspect ratio glassy carbon (GC) molds are prepared and then manual transfers are carried out. Both PAK-01 and PAK-02 have good filling and release properties. Next, a silane coupling agent C(8)F(17)C(2)H(4)SiCl(3) is used for the release treatment of the quartz mold. To investigate of affinity between photo-curable resin and release layer, repetition manual transfers are carried out. In this release layer, durability is not sufficient for PAK-02. Therefore, more precise durability tests are carried out using PAK-01. The release treatment samples with various contact angles are prepared by changing the treatment of the silane coupling agent. The contact angle of less than 10 degrees is obtained by UV ozonation cleaning. The contact angle of 40 degrees is obtained by acetone cleaning. The contact angles of more than 80 degrees are obtained by silane coupling agent at 5 minutes treatment. The contact angles of more than 100 degrees are obtained by silane coupling agent at 2 hours treatment. After the preparation of the mold treatment, repeatedly imprints are carried out using UV-NIL machine. In the case of contact angles with less than 40 degrees, PAK-01 sticks to the surface of the quartz within several imprint times. On the other hand, in the case of contact angles with more than 80 degrees, PAK-01 does not stick on quartz surface more than 1000 times. Therefore, the combination of this release treatment and PAK-01 is suitable for mass-production.