Nature of surface and bulk defect induced by low dose oxygen implantation in separation by implanted oxygen wafers

Two new metrologies have been proposed to characterize unknown surface and bulk defects in separation by implanted oxygen (SIMOX) wafers. They include d the following: i) laser scattering particle counter plus coordinated atom ic force microscope (AFM) and Cu-decoration for defect isolation and ii) cr oss-sectional transmission electron microscope (TEM) foil preparation using focused ion beam (FIB) and TEM investigation for defect morphology observa tion. Three types of surface defects were found and described as follows: i ) a hole with a locally thinned top silicon layer (Park Defect A), ii) a ho le formed locally without either a silicon or a buried oxide layer (Park De fect B), and iii) a hole formed with both a locally thinned top silicon and a buried oxide layer (Park Defect C). In addition, a bulk defect was found to occur as locally distributed square-shaped pits accompanied by the disa ppearance of the buried oxide layer (isolation defect). All surface and bul k defects in SIMOX wafers originate from oxide particle generation by elect rostatic discharge and mechanical abrasion between the wafer and the pin of the wafer holder during oxygen ion implantation.