Laser-induced gold deposition on p(+)-Si from liquid precursors: A study on the reduction of gold ions through competing Dember and Seebeck effects

摘要

Gold micropatterns are deposited from aqueous solutions of NaAuCl4 on boron-doped Si(100) surfaces (rho = 1.5 x 10(-4) Omega m) using a focused Ar+ laser beam (TEM00, lambda = 488 nm, w(0) = 1.5 mu m, P = 20-80 mW). The finite-element method employed for computing the surface temperature profiles reveals that the maximum temperature at the precursor/silicon interface increases only to the range 316-372 K, which is not high enough for chemical reactions with formaldehyde in the precursor. This suggests a different mechanism to be responsible for the reduction of gold ions, namely, changes in the surface potential of Si caused by the Dember and Seebeck effects.