Effect of surface treatments on interfacial adhesion energy between UV-curable resist and glass wafer

The interfacial adhesion energy between the resist and the substrate is very important in nanoimprinting because of problems with the resist sticking or pulling off during separation of the mold from the substrate. Substrate surface treatments with a self-assembled monolayer or oxygen plasma provide good adhesion between a resist coating and a silica substrate. In this paper, we describe the adhesion properties of a resist and a glass wafer measured using the four-point bending test. The interfacial adhesion energy between the resist and the glass wafer was evaluated for various substrate surface treatments of adhesion promoters and anti-sticking layers. The interfacial fracture energy without treatment was 1.23 J/m2, and was in the range 0.49–2.57 J/m2 for the other treatments tested. The interfacial fracture surfaces were also investigated by field emission scanning electron microscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy to determine the fracture mode at the interfaces.