Characterization of Planar Defects in Annealed SiGe/Si Heterostructure

Abstract

Green Ceramics Division, Korea Institute of Ceramic Engineering and Technology, Seoul 153-801(Received October 27, 2009 : Received in revised form November 26, 2009 : Accepted December 1, 2009)ctrastAb Due to the importance of the SiGe/Si heterostructure in the fields of thermoelectric and electronicapplications, SiGe/Si heterostructures have been extensively investigated. For practical applications, thermalstability of the heterost ructure during the the rmoelectric p ower generation or fabricati on process of electronicdevices is of great concern. In this work, we fo cused on the effect of ther mal annealing on the defectconfiguration in the SiGe/Si heterostructure. The formation mechanism of planar defects in an annealed SiGe/Si heterostructure was investigated by transmission electron micr oscopy. Due to the int erdiffusion of Si andGe, interface migration phenomena were observed in annealed heterostructures. Because of the strain gradientin the migrated region between the original interface and the migrated interface, the glide of misfit dislocationwas observed in the region and planar defects were produced by the interaction of the gliding misfitdislocations. The planar de fects were confined to the migrated region, and disl ocation pileup by strain gradientwas the origin of the confinement of the planar defect.Key words SiGe , strain gradient, misfit di slocation, transmission elect ron microscopy, thermoel ectric.