Composition and microstructures of low dislocation content SIMOX structures

Abstract

Summary form only given. Recent improvements have rendered SIMOX (separation by implanted oxygen) material suitable for direct fabrication of radiation-hard and high-performance CMOS devices in the superficial Si film. A persistent problem is the presence of dislocations with undesirably high densities. These residual dislocations are attributed to the vast amounts of Si point defects that are generated in the collision cascades during the high-dose oxygen implantation. By careful optimization of the implant conditions the dislocation content has been reduced by several orders of magnitude to less than 10/sup 5/ cm/sup -2/. For this low-dislocation-content SIMOX material, the superficial Si film exhibits ordering of the oxide precipitates. In the as-implanted structure the dislocations are confined to the lower part of the superficial Si film, where no oxide precipitate ordering occurred. Precipitate ordering and silicon point defects have been shown to play an important role in the establishment of the final microstructure during oxygen implantation.<>