Microstructure and property of Czochralski-grown Si-TaSi₂ eutectic in situ composite for field emission

Directional solidification of eutectic alloys yields various kinds of in situ composites with interesting and excellent properties, among which the semiconductor-metal eutectic with three-dimensional array of Schottky junctions grown in the composite is useful in electronic applications. This paper reports the experimental research on the Si/TaSi₂ rod-like eutectic composite for field emission. By the Czochralski crystal growth technique, the composite with highly oriented TaSi₂ fibres embedded in the (1 1 1) monocrystal n-type Si matrix is obtained. The average fibre diameter is 1.79 μm, the average fibre spacing is 10.0 μm and the average fibre density is 9.25×10⁵/cm². The fibre distribution characteristic is also studied. The TaSi₂ fibres with hexagonal crystal structure present various cross-section shapes. Furthermore, the composite is preferentially etched to form the cone-shaped TaSi₂ field emission array protruding above the Si matrix and the field emission property measurement shows that the turn-on field is about 4.4 MV/m which is quite well.