SYNTHESIS AND BULK, SURFACE, AND MICROLITHOGRAPHIC CHARACTERIZATION OF POLY(1-BUTENE SULFONE)-G-POLY(DIMETHYLSILOXANE)

Hexenyl-functionalized poly(dimethylsiloxane) (PDMS) macromonomers were synthesized by the anionic ring-opening polymerization of hexamethylcyclotrisiloxane. These macromonomers were terpolymerized under free-radical conditions with 1-butene and sulfur dioxide to form the title graft copolymers. The molar masses of the macromonomers were varied from 1K to 20K g/mol, and the copolymer compositions ranged from 5 to 20 wt % PDMS. The bulk and surface phase morphologies were investigated by using DSC, TEM, XPS, and water contact angle measurements. The graft copolymers were evaluated as electron-beam resists; their sensitivity was ca. 4.5-mu-C/cm2 at 25 kV, and their etch rate ratio during oxygen reactive ion etching relative to a cross-linked novolac resin was 1:29.