Spectromicroscopic studies of porous silicon oxide on silicon using synchrotron radiation

Abstract

This work is dedicated to microscopic synchrotron studies of the morphology, atomic, and electronic structure of an array of submicron-sized pores in a SiO2 layer on silicon formed with the use of ion-track technology in combination with chemical etching after irradiation. The research method was photoemission electron microscopy using high-intensity synchrotron radiation. The method was used in two modes. The use of chemically selective electron microscopy allowed obtaining morphological information about the studied array of pores. The X-ray spectroscopy mode of the synchrotron radiation of X-rays absorption near-edge fi ne structure spectroscopy allowed us to obtain information about the specifi city of the local surrounding of the given atoms from microscopic regions of nanometer and submicron areas of the obtained microscopic images. The pores had rather sharp boundaries, without a transition layer. The bottom of the pores was a substrate - a crystalline silicon wafer covered with a natural 2-3 nm thick oxide layer. Ion irradiation and chemical etching did not signifi cantly affect the structural and phase characteristics of the porous silicon oxide matrix. There was no signifi cant disordering in the silicon atoms available at the bottom of individual pores. There was no technological contamination. The effi ciency of using ion-track technology in combination with chemical etching after irradiation for the formation of isolated pores arrays with close submicron range sizes was shown. The obtained results demonstrated the effi ciency of the photoemission electron microscopy method using high-intensity synchrotron radiation for the high accuracy microscopic scale study of a wide range of objects with the composite structure-phase nature of the surface.