Miniaturization of silicon nanopillars below 10 nm by NH 4OH, KOH and HF wet chemical etching for light emission study

Abstract

This paper provides a comparative study of wet etching using NH 4OH, HF and KOH to minimize the nanopillar size down to 10 nm or even lower. The nanopillars were fabricated on the p-Si substrates by deposition of Fe metal clusters using vacuum evaporation method. Subsequent ECR etching of the samples produced 100 nm high and 20 nm thick silicon nanopillars. The results of NH 4OH, HF and KOH chemical wet etching showed that the slow etch rate, 0.7 nm/h can be achieved by 50% HF acid, whereas relatively faster etch rate of 0.7 nm/s can be obtained from 40% KOH solutions. As a result of wet chemical etching, the average pillar diameter was reduced to below 10 nm. The surface morphology of the etched nanostructures was analyzed by SEM and a preliminary PL measurement was performed on the etched samples.