Postannealing Effects on Strain/Crystal Quality of Lateral Source Relaxed/Strained Layer Heterostructures Fabricated by O+ Ion Implantation

Abstract

We have experimentally studied postannealing effects on the relaxation rate of strain and crystal quality of a lateral relaxed/strained heterostructure layer after the O+ ion implantation process. We have demonstrated the critical annealing temperature as well as the critical recoil energy ER of implanted O+ ions for relaxing the strained layers, using UV-Raman spectroscopy. Moreover, we have shown that the crystal quality increases with increasing postannealing temperature, and high-resolution transmission electron microscopy (HRTEM) images of the cross sections and plane views of the O+-ion-implanted strained-Si layers also show the high crystal quality. Moreover, we have observed a threading dislocation of about 15 nm length between high-quality lateral abrupt-relaxed/strained layer heterostuctures, and the threading dislocation area is a stress buffer layer to form the abrupt lateral-strain distribution.