Incorporating silicon into resist materials is a well known method for providing resistance to oxygen reactive ion etching. However, silicon containing materials don't have good resistance to fluorine dry etching. Incorporation of tin into resist imparts resistance to both oxygen and fluorine dry etching. Therefore, we have studied the synthesis of block copolymers in which one block contains tin. Our goal is to facilitate production of imprint templates for manufacturing of hard disk devices with bit patterned media, which requires patterning fused silica(SiO2) imprint templates.  The tin materials enable high aspect ratio etching into the fused silica, but they are easily stripped with H2 plasma.  Our first approach involved use of trimethylstannylstyrene.  We made the homopolymer of the tin compound, and confirmed that it has better resistance to both oxygen and fluorine dry etching than polystyrene and the silicon analog. Next, we made polystyrene-block-polytrimethylstannylstyrene by various polymerization methods including Nitroxide Mediated Polymerization(NMP), Activator Regenerated by Electron Transfer Atom Transfer Radical Polymerization (ARGET ATRP), and anionic polymerization.  However, none of these controlled polymerization methods worked. We found Reversible Addition Fragmentation chain Transfer (RAFT) worked for this tin monomer and made various Mw tin containing block copolymers were successfully synthesized and characterized.Incorporating silicon into resist materials is a well known method for providing resistance to oxygen reactive ion etching. However, silicon containing materials don't have good resistance to fluorine dry etching. Incorporation of tin into resist imparts resistance to both oxygen and fluorine dry etching. Therefore, we have studied the synthesis of block copolymers in which one block contains tin. Our goal is to facilitate production of imprint templates for manufacturing of hard disk devices with bit patterned media, which requires patterning fused silica(SiO2) imprint templates.  The tin materials enable high aspect ratio etching into the fused silica, but they are easily stripped with H2 plasma.  Our first approach involved use of trimethylstannylstyrene.  We made the homopolymer of the tin compound, and confirmed that it has better resistance to both oxygen and fluorine dry etching than polystyrene and the silicon analog. Next, we made polystyrene-block-polytrimethylstannylstyrene by various polymerization methods including Nitroxide Mediated Polymerization(NMP), Activator Regenerated by Electron Transfer Atom Transfer Radical Polymerization (ARGET ATRP), and anionic polymerization.  However, none of these controlled polymerization methods worked. We found Reversible Addition Fragmentation chain Transfer (RAFT) worked for this tin monomer and made various Mw tin containing block copolymers were successfully synthesized and characterized.

Synthesis of tin-containing block copolymer

247th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.