Using a first-principles approach, we characterize dangling bond defects at Si-SiO2 interfaces by calculating hyperfine parameters for several relaxed structures. Interface models, in which defect Si atoms remain close to crystalline sites of the substrate upon relaxation, successfully describe Pb and Pb0 defects at (111) and (100) interfaces, respectively. On the basis of calculated hyperfine parameters, we discard models of the Pb1 defect containing a first neighbor shell with an O atom or a strained bond. A novel model consisting of an asymmetrically oxidized dimer yields hyperfine parameters in excellent agreement with experiment and is proposed as the structure of the Pb1 center.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)