r fan r he and p yang nano lett 5 457 2005 and i lombardi a i hochbaum p yang c carraro and r maboudian chem mater 18 988 2006 in embodiments of the present invention the thickness of catalyst is proportional to the diameter of the wires being grown so 500 nm of catalyst material produced u02dc 1 5 u03bcm diameter si wires this relatively thick catalyst layer and or the higher growth temperatures led to a significant problem with catalyst migration if a buffer oxide was not present on the surface in contrast to the hochbaum and lombardi references in which much thinner catalyst layers were used the growth of si microwires according to embodiments of the present invention have optimal growth temperatures of 1000 1050 u00b0 c at 950 u00b0 c and below the wires either did not grow straight grew intermittently straight with kinks or grew straight but not aligned normal to the substrate at 1075 u00b0 c and above the wires grew straight and normal to the substrate but significant destruction of the surface oxide was observed during the growth process leading to a loss of the pattern fidelity see for example fig7 a and 7b fig7 a shows a top down and inset tilted sem views of the au catalyzed si.