MORPHOLOGY OF POROUS SILICON STUDIED BY STM/SEM

The morphology of porous Si layers finds interesting applications in the field of VLSI technology. The study of their structure is, however, difficult due to the small size of pores. In this paper we have used for the first time a scanning tunneling microscope (STM) integrated in a conventional scanning electron microscope (SEM), in order to image the surface microtopography of this material. We have been able to identify the porous structure and to measure its dimensional parameters. We have also examined a cross section of the porous region. The results are briefly discussed in terms of current models of porous formation and growth in silicon. © 1990.