Laser synthesis of carbon-rich SiC nanoribbons

A nanosecond pulsed laser direct-write and doping (LDWD) technique is used for the fabrication of carbon-rich silicon carbide nanoribbons, heterostructure in a single crystal 4H-SiC wafer. Characterization by high-resolution transmission electron microscope and selected area electron diffraction pattern revealed the presence of nanosize crystalline ribbons with hexagonal graphite structure in the heat-affected zone below the decomposition temperature isotherm in the SiC epilayer. The nanoribbons exist in three layers each being approximately 50-60 nm thick, containing 15-17 individual sheets. The layers are self-aligned on the (0001) plane of the SiC epilayer with their c axis at 87degrees to the incident laser beam. The LDWD technique permits synthesis of heterostructured nanoribbons in a. single step without additional material or catalyst, and effectively eliminates, the need for nanostructure handling and transferring processes. (C) 2003 American Institute of Physics.