SILICON-NITRIDE MEMBRANE SUBSTRATES FOR THE INVESTIGATION OF LOCAL-STRUCTURE IN POLYMER THIN-FILMS

The fabrication of silicon nitride membrane substrates and their use i n studies of polymer thin films are described. As an integral part of a wafer, these membranes are both self-supporting and transparent for transmission electron microscopy (TEM). Therefore, the same polymer fi lm can be spin-cast on the substrate and, without being removed, studi ed by a variety of techniques, including TEM, and atomic force microsc opy (AFM). To demonstrate the utility of these substrates in character izing both global and local film morphology, experimental results are presented on polystyrene-polymethylmethacrylate diblock copolymers in the ultrathin him limit, using optical microscopy together with combin ations of AFM and TEM at the same location. The addition of microfabri cated structures to these substrates, such as planar electrodes is als o discussed. (C) 1998 Published by Elsevier Science Ltd. All rights re served.