High-pressure oxidation of silicon (HIPOX) is one of various techniques used for electrical-isolation of semiconductor-devices on silicon substrates. The effect of HIPOX-related stresses on isolation structures is of interest because structural-defects, if formed, could electrically degrade devices. The present investigation was performed to study the origin and behavior of defects in recessed HIPOX structures. The structures were exposed to a boron implant. The experimental observations indicate that glide dislocations arise when the following features are present: (i) HIPOX, (ii) recessed edge, (iii) boron implant. The origin and behavior of the defects are modelled and explained in terms of implant-induced dislocation-sources creating glide-dislocations in the structures. The microstructure of the structures described above, and defect-modelling is presented.