Impact of curing kinetics and materials properties on imprint characteristics of resists for UV nano-imprint lithography

UV curable resist formulations for nanoimprint must satisfy criteria for cure rate, volatility, viscosity, cohesion of the cured material and release from the template in addition to being successfully imprintable. We describe an investigation of the properties of a series of formulations comprising polyhedral oligomeric silsesquioxane and selected diluents as candidates for imprintable dielectrics. Although all have low viscosity and volatility and are successfully imprinted, significant variations in cure rate, mechanical and adhesion properties with resist composition are found. The trends observed are not all predictable from the literature, indicating that formulation optimization for this application requires a focus on the fundamentals of both materials and processes.

[1]  C. Decker.  Kinetic Study and New Applications of UV Radiation Curing , 2002 .

[2]  Frances A. Houle,et al.  Adhesion between template materials and UV-cured nanoimprint resists , 2006, SPIE Advanced Lithography.

[3]  C. Grant Willson,et al.  Implementation of an imprint damascene process for interconnect fabrication , 2006 .

[4]  Hiroshi Ito,et al.  Vinyl ether resist system for UV-cured nanoimprint lithography , 2006, SPIE Advanced Lithography.

[5]  Bernard Choi,et al.  Step and flash imprint lithography: a new approach to high-resolution patterning , 1999, Advanced Lithography.

[6]  Kwang-Woo Choi,et al.  Photopolymerization Kinetics of Methacrylate Dental Resins , 2003 .

[7]  Hiroshi Ito,et al.  Product Volatilization as a Probe of the Physics and Chemistry of Latent Image Formation in Chemically Amplified Resists , 2002 .

[8]  H. Henning Winter,et al.  Rheological expression of physical gelation in polymers , 1995 .

[9]  J. Stansbury,et al.  Network formation and compositional drift during photo-initiated copolymerization of dimethacrylate monomers , 2001 .

[10]  Richard A. L. Jones,et al.  Polymers at Surfaces and Interfaces , 1999 .

[11]  Hiroshi Ito,et al.  Molecular resists based on polyhedral oligomeric silsesquioxanes (POSS) , 2005, SPIE Advanced Lithography.

[12]  Pedro Guerrero,et al.  Fracture behavior–morphology relationships in an unsaturated polyester resin modified with a liquid oligomer , 1999 .

[13]  David Wang,et al.  Direct imprinting of dielectric materials for dual damascene processing , 2005, SPIE Advanced Lithography.

[14]  Saad A. Khan,et al.  Rheology and Photo-Cross-Linking of Thiol−Ene Polymers , 1996 .

[15]  Igor V. Khudyakov,et al.  Kinetics of Photopolymerization of Acrylates with Functionality of 1−6 , 1999 .