Authors: C. Wang, K. Malladi and M. Madou
Affilation: University Of California, Irvine, United States
Pages: 660 - 662
Keywords: Si nanowire, Ni catalyst, nano corners, shape, size
One dimensional structure with nanometer diameters, such as Si nanowires, have great potential for understanding and testing fundamental concepts about the roles of dimensionality in optical, electrical and mechanical properties and for applications ranging from nanoelectronics to bio sensing. Recently we successfully grew high aspect ratio Si nanowires using Ni catalyst and SLS mechanism. Figure 1 shows a typical SEM picture of Si nanowires. Detailed microscopy results showed that in our case catalyst particle size has no relation with the diameter of Si nanowires. At high temperature, we found that Ni catalyst layer changed to irregular starfish like structure. Most Si wires grew form the irregular catalyst tentacles. In this work, we are aiming to understand how catalyst size and shape affect Si wires formation. Using EB writer and lift-off process we made various types of Ni nano corners. Figure 2 showes an array of Ni nano corners formed by EB writer and lift-off process. After heating at 900oC in forming gas environment, shape transition of Ni catalyst from one structure to many smaller domains was observed. This domain size increase was determined by variation of initial catalyst shape and size. Figure 3 showed a SEM image of a nanowire grown from a catalyst particle. Detailed experimental results and discussion will be presented in this meeting.