Carbon nanotube (CNT) devices have been constructed by a post-synthesis alignment, due to difficulties to form a CNT directly on a substrate, whereas CNTs have been found to grow by irradiating an electron beam onto polyyne-containing carbon. This technique is a candidate to construct a CNT device without a metal catalyst by highly geometrically resolvable electron beam lithography. Two types of polyyne-containing carbon (well-aligned and amorphous) are observed and compared by a transmission electron microscope (TEM), providing insights on the formation mechanism and requirements for the precursor. The results suggest that a substantially aligned and notcondensed morphology is essential to form CNTs. (C) 2004 Published by Elsevier B.V.