TEM characterization of extended defects induced in Si wafers by H-plasma treatment

Abstract

Silicon hydrogenation is nowadays studied with the aim of developing and improving a technological method known as ‘smart cut’ used in the fabrication of ‘silicon-on-insulator’ devices. The goal of our study is to characterize the defects induced in silicon wafers after exposure to hydrogen RF plasma. Si⟨001⟩ wafers have been treated at 250 °C under hydrogen RF plasma at 110 MHz, for various durations. The main features observed by transmission electron microscopy (TEM) are surface roughening and the presence of three kinds of defects: {1 1 1} planar defects, {1 0 0} planar defects and H bubbles. In this work a study using conventional TEM and high resolution transmission electron microscopy (HRTEM) techniques is presented on H bubbles and {1 0 0} planar defects induced in Si wafers by H-plasma treatment. The strain field around the defects is qualitatively characterized by diffraction contrast analysis and quantitatively by the geometrical phase method, by processing the HRTEM images.