Electron paramagnetic resonance studies were made of the stress-induced alignment and subsequent recovery of the double donor that formed in float-zone material following H-implantation, and annealing for 1200s at above 300C. The activation energy for atomic reorientation of the HDD+ defect was 2.3eV. The reorientation rate was greater than that of the NL8 defect, which formed in Czochralski-type material, by a factor of 104. Both centers had C2v symmetry, and piezo-spectroscopic measurements revealed a large compressional strain along their [001] directions. However, unlike NL8, the core of the present defect also produced a large compressional strain along its one-axis; parallel to the [110] direction. These results unambiguously demonstrated that the 2 centers had differing molecular structures, in spite of their similar electron paramagnetic resonance spectra and electrical properties. It was suggested that the centers had similar core structures, a <001>-oriented self-interstitial complex, with the outer shell structure incorporating H or O atoms, respectively.

Stress-induced alignment and reorientation of hydrogen-associated donors in silicon J.V.Gorelkinskii, N.N.Nevinnyi, K.A.Abdullin: Journal of Applied Physics, 1998, 84[9], 4847-50