Effects of stress on the microstructure of the corner defect in As+-implanted, two-dimensional amorphized Si

Abstract

The effect of stress induced by a chemical vapor deposited SiO2 film on the microstructure of the corner defects in As+-implanted, two-dimensional amorphized Si hits been studied by transmission electron microscopy. A fine periodic trench structure was used to form two-dimensional amorphous layers and to induce the stress in the Si substrate. As implantation with an energy of 80 keV and a dose of 3 x 10(15)/cm(2) amorphized a 100-nm-thick silicon surface under the trench bottom and produced a sharply curved amorphous/crystalline interface under the bottom corner of the trench. The trench filled with a high-tensile stressed chemical vapor deposited SiO2 film induced a high stress field in the Si substrate. The microstructure of the corner defects was closely related to the stress induced by the trench. In the case of the absence of the stress vacancy-type dislocation half loops were generated on {111} planes after annealing at 650 degreesC or 800 degreesC at the corner of the regrowth regions. While, in the case of the presence of the stress induced by the trench, microtwins were formed on {111} planes after annealing. It was found that the microstructure of the corner defects was determined by the SPE regrowth behavior at intermediate stages of the regrowth process. (C) 2001 Elsevier Science B.V. All rights reserved.