The role of hydrogen in the formation of porous structures in silicon

The role of hydrogen in the formation of porous silicon (PS) structures is assumed to passivate dangling bonds of the surface silicon atoms. The forma tion of surface hydride complexes SiHx (x=1,2,3) is well documented using i nfrared absorption spectroscopy and other methods of chemical analysis. In the present work we show by means of infrared spectroscopy of PS films subj ected to different post-anodising chemical treatments that hydrogen atoms a re incorporated into the corroding silicon wafer through easy paths which a re generated in the vicinity of the pore tips as a result of the combined a ction of the electrolyte solution and dynamic mechanical stress generated d uring the dissolution reaction. (C) 1999 Elsevier Science S.A. All rights r eserved.