Fabricating SiC whiskers of different sizes by controlling only the CVD deposition position

Silicon carbide (SiC) whiskers were produced at different positions in the chemical vapor deposition (CVD) furnace. The effect of shifts in specimen position on vaporsolid (VS) whisker growth was studied. First, we confirmed the major factors influencing CVD whisker growth by controlling the specimen position. The source reactant depletion effect and temperature gradient acted to reduce the whisker diameter by 33.3 and 61.7%, but the gas residence time only accounted for 4.2% of whisker diameter reduction. The specimen upon which all three factors acted showed a 74.2% decrease in diameter. Transmission electron microscopy (TEM) observation showed that all whiskers had highly crystalline FCC structures. The front perpendicular specimen showed higher stacking fault densities, whereas the back horizontal specimen possessed no stacking faults. These results suggest that position variation led to a growth rate difference, which affected the stability of whisker growth. Based on this idea, we confirmed the possibility of synthesizing whiskers of two different diameters on the same substrate. This can propose a new network structure consisting of combined whiskers. This report focuses on varying the whisker deposition size by controlling the deposition position instead of changing the deposition conditions as is common.