Growth of Si whiskers on Au/Si(1 1 1) substrate by gas source molecular beam epitaxy (MBE)

The vapor-liquid-solid growth of Si whiskers from disilane has been studied in a gas source MBE system. The wire-like Si crystals are grown on Si(1 1 1) substrates in a temperature range of 600-800 degrees C, a disilane pressure between 1 x 10(-4) and 1 x 10(-7) Torr, and using Au as a growth-promoting agent. The morphology of the Si whiskers is investigated. It is found that the growth rate of the vertical wires is independent of the wire diameter (i.e. whiskers with different diameters have the same growth rate). The growth rate of the wires in the vertical direction increases with increasing substrate temperature and disilane pressure, and is about 8-10 times larger than the growth rate of the planar film on the substrate and the width of the whiskers. (C) 1999 Elsevier Science B.V. All rights reserved.