Elsevier, Microelectronic Engineering, (109), p. 310-313, 2013
DOI: 10.1016/j.mee.2013.03.028
Full text: Download
Using computational modelling we investigate whether Si–H Bonds can serve as precursors for neutral E′E′ centre formation in amorphous silica and at the Si/SiO2 interface. Classical inter-atomic potentials are used to construct models of a-SiO2 containing Si–H bonds. We then investigate the mechanism of dissociation of a Si–H bond to create a neutral E′E′ defect, that is a 3-coordinated silicon with an unpaired electron localised on it. We show that the Si–H bond is extremely stable, but as a result of hole injection it is significantly weakened and may dissociate, creating a neutral E′E′ centre and a proton attached to one of the nearby oxygen atoms. The proton can diffuse around the E′E′ centre and has a profound effect on the defect levels. We show that at a Si/SiO2 interface, the position of the proton can facilitate electron transfer from the Si substrate onto the defect, making it negatively charged.