FABRICATION AND PROPERTIES OF FREESTANDING C60 MEMBRANES

Van der Waals forces that bind C60 molecular solids are found to be sufficiently strong to allow the reproducible fabrication of free-standing C60 membranes on (100) silicon wafers. Membranes, 2000 to 6000 angstroms thick, were fabricated by a modified silicon micromachining process and were found to be smooth, flat, and mechanically robust. An important aspect of the silicon-compatible fabrication procedure is the demonstration that C60 films can be uniformly and nondestructively thinned in a CF4 plasma. Young's modulus and fracture strength measurements were made on membranes with areas larger than 6 millimeters by 6 millimeters. It may be possible to use C60 membranes for physical property measurements and applications.