Structures of Thermal Double Donors in Silicon

Local vibrations of thermal double donors in silicon

“…13 In this mode the flanking O i performs asymmetric stretching vibration similar to the mode shown in Fig. 1͑a͒.…”

“…This may be due to the fact that the O i -O 2r 2ϩ chain has about 0.4 eV higher formation energy than the staggered O 3i 0 chain for values of the electron chemical potential above 0.48 eV. 13,31 Hallberg and Lindström find experimentally that TDD1 and TDD2 form bistable systems with a common electrically inactive X-state configuration that has an IR absorption band at 1020 cm Ϫ1 . 30 On the basis of the total-energy calculations we assign the electrically inactive staggered O 4i 0 chain to the X-state configuration.…”

“…The R unit consists of two threefold coordinated O atoms (O r 's) bonded to two common Si atoms. 14 13 We have shown that a rate-equation model for the O chains is able to produce the experimentally observed annealing kinetics of the TDD's. 15,16 However, the agreement may depend on the parameters we use in the kinetic model.…”

“…However, more recent total-energy calculations indicate that oxygen-only structures for TDD's are those energetically most favorable. 8,[11][12][13] On the basis of accurate total-energy calculations we recently put forward an oxygen-chain-like model for TDD's. 13 This consists of adjacent four-member rings ͑R's͒ and flanking interstitial oxygens (O i 's).…”

“…8,[11][12][13] On the basis of accurate total-energy calculations we recently put forward an oxygen-chain-like model for TDD's. 13 This consists of adjacent four-member rings ͑R's͒ and flanking interstitial oxygens (O i 's). The R unit consists of two threefold coordinated O atoms (O r 's) bonded to two common Si atoms.…”