NOVEL-APPROACH TO DEFECT ETCHING IN THIN-FILM SILICON-ON-INSULATOR

A new etch process involving three sequential etch steps was developed to measure low defect densities in a range of about 10(3) - 10(8) cm- 2. The main advantages of this approach as compared to earlier methods are independence from the defect density, improved simplicity, and be tter image contrast. Resulting structures are similar to those obtaine d during defect etching in bulk silicon and allow the application of a utomatic defect measurement tools extending measurement ranges and acc uracies to the bulk technology level. Dependences of defect densities on the implanted oxygen dose and implantation energy have been studied for SIMOX wafers. The experiment shows an increase of defect density with the dose and a decrease of defect density with the implantation e nergy. A comparison with transmission electron microscopy results show s good agreement.