ABSTRACT
By using a statistic electroless metal deposition (SEMD) method, here we report the
morphological controllability of single crystalline silicon nanowires (SiNWs) with respect
to their orientations, diameters, and lengths. The growth axis of single crystalline
SiNWs on three oriented Si wafers- (100), (110) and (111)- is the [100] direction.
Furthermore, the consistent results examined based on the arrays of SiNWs evidently
indicate that the [100] direction is the preferential axial orientation of fabricated SiNWs
in all cases. Notice that our observation is different from the previous reports, and such
a corresponding formation mechanism of anisotropic SiNWs can be successfully
elucidated by both lattice configuration of oriented Si surfaces and the passivation
effect on the H-terminated planes. Next, the diameter control of SiNWs is achieved by
employing the Taguchi methods, proving the capability of controlling the diameter with
narrow distribution and comprehension of the influences from all process factors. The
length of SiNWs presents fast and linear dependence with the immersion time. In
addition to the morphological control of SiNWs, our statistic EMD technique provides
further advantages such as almost room-temperature operation and catalyst/dopant
free, paving a way towards the implementation of SiNWs in nanoelectronics, nanoscale
optoelectronics, nano-electro-mechanical systems, and biological detection.