Amorphous silicon nitride fibers grown from the vapor phase

Using high reactor pressures (>1 bar) and a unique rate control mechanism, three fibers were recently obtained by laser assisted chemical vapor deposition (LCVD) having elemental (i.e., boron, carbon, and silicon) compositions, small diameters (>9 μm), and surprisingly high growth rates (0.3–1.1 mm/s). By reacting silane and ammonia at high pressures (>1 bar) near the focus of a Nd-YAG laser beam, we have now obtained the first LCVD fibers with binary (i.e., silicon-nitrogen and silicon nitride) compositions having small diameters and high growth rates (0.34–0.74 mm/s). These fibers were amorphous.