Selective growth of gold nanoparticles on FIB-induced amorphous phase of Si substrate

Abstract

Maskless and electroless patterning of gold was performed by a simple method: 3-mercaptopropyltrimethoxysilane (MPTMS) and an aqueous solution of hydrogen tetrachloroaurate (HAuCl4·4H2O) were reacted, and the obtained solution was dropped onto a silicon substrate processed by a focused ion beam (FIB). This method utilizes the selective growth of gold nanoparticles on an FIB-processed area of a silicon surface. Raman microspectroscopy revealed that gold nanoparticles selectively grew on an FIB-processed area when an amorphous silicon phase was induced by an FIB. Unlike other attempts to fabricate metal patterns with silane coupling agents, MPTMS acts as a reducing agent, not as glue.