Rapid fabrication of high aspect ratio silicon nanopillars for chemical analysis

Abstract

In this study, a method for fabrication of high aspect ratio silicon nanopillars is presented.The method combines liquid flame spray production of silica nanoparticle agglomerateswith cryogenic deep reactive ion etching. First, the nanoparticle agglomerates, having adiameter of about 100 nm, are deposited on a silicon wafer. Then, during the subsequentcryogenic deep reactive ion etching process, the particle agglomerates act as etch masks andsilicon nanopillars are formed. Aspect ratios of up to 20:1 are demonstrated. Themasking process is rapid, cheap and has the potential to be scaled up for largeareas. Three other structured silicon surfaces were fabricated for comparison. Allfour surfaces were utilized as desorption/ionization on silicon (DIOS) sampleplates. The mass spectrometry results indicate that nanopillar surfaces maskedwith the liquid flame spray technique are well suited as DIOS sample plates.