Ion bombardment can release densely active intermediates within a cylindrical area along the passage of a single ion. The cylindrical area, in which high-energy is deposited from projectile ion, is sometimes called an "ion track". The high energy charged particle irradiation of a polycarbosilane (PCS) film causes cross-linking reactions, leading to the formation of a polymer gel containing cylindrical nanostructures (nanowires). The diameter and length of the nanowires were completely controlled by changing several parameters. PCS is also a well-known a precursor of silicon carbide (SiC), and the PCS nanowires formed by the present techniques were heated at 1,000 oC in Ar gas. A SiC ceramic wire, which has a higher heat resistance than polymers, was obtained on a Si substrate by conversion from the PCS nanowires. In this paper, the crystal structure and phase of the SiC nanowires obtained are discussed.

Keywords: Ion beam, Polycarbosilane, Silicon carbide (SiC), and Nanowire.