Changes in Electronic Device Properties During the Formation of Dislocations

Abstract

ABSTRACTWe describe the results of an investigation into the formation and properties of dislocations in electronic devices. We have made electron transparent specimens from metastable GeSi/Si p-n junction diodes and introduced dislocations into the devices by heatingin situin the electron microscope. A modification made on the specimen holder for our microscope enables us to measure the characteristics of these devices while they remain under observation in the microscope. We can therefore observe the changes in the electrical properties of the devices as dislocations form. We confirm that the introduction of dislocations has a deleterious effect on parameters such as the reverse leakage current through a diode. However the magnitude of the effect we observe can not be explained by a generation-recombination process and instead we suggest a model based on the creation of point defects or the diffusion of metals during the formation of dislocations. We also consider the kinetics of dislocation formation, and in particular how the extent of dislocation formation in a device depends on the subsequent processing steps which it undergoes.