Scaling in Early Stage of Metal Assisted Chemical Etching

Abstract

 In the early stage of Si nanowire growth in metal assisted chemical etching (MACE) process, we have investigated the kinetic roughning. The scaling exponents a, b and 1/z are determined using atomic force microscopy. In the formation of Si nanowire, nascent Ag ions plays an important role which will diffuse through the si surface that controls the size of the nanowire. In this system for the first time, we have observed kinetic roughening of the growth front within our detectable range of Si nanowire. We have observed a = 0.74 ± 0.01 at the early stage of growth of Si nanowire. Interface width w increases as a power law of etching time (t),, with growth exponent b = 0.30 ± 0.05 and lateral correlation length x grows as  with 1/z = 0.32 ± 0.05.