Time evolution of released hole arrays into membranes via vacuum silicon migration

Abstract

This work reports on experimental evaluation of the evolution of suspended silicon hole arrays into membranes through silicon migration in an ultrahigh vacuum (UHV) environment. Multiple identical hole arrays were imaged and measured through scanning electron microscopy after different migration conditions. Many designs of hole arrays eventually progress to continuous membranes, however, despite imperceptible differences in initial geometry the intermediate steps indicate significant non-uniformity of migration. Small deviations from complete volume conservation were observed and evidence of silicon evaporation from the surface supported this volumetric change.