Electron-paramagnetic-resonance study of silver-induced defects in silicon

Abstract

In this paper two electron-paramagnetic-resonance spectra are reported in silicon doped with silver in a water vapor atmosphere. These centers, labeled Si-NL56 and Si-NL57, show the orthorhombic-I and trigonal symmetries, respectively, and an effective electron spin Sϭ1/2. Based on studies with enriched silver isotopes and analysis of the observed twofold hyperfine splitting, the participation of one silver atom is established for both centers. The Si-NL56 center is identified as an isolated substitutional silver atom. Due to the presence of an additional hyperfine interaction with a nuclear spin Iϭ5/2, the Si-NL57 spectrum is assigned to a complex of silver with another impurity introduced during the diffusion process. Taking into account the sample preparation procedure, the Si-NL57 center is attributed to an Al s -Ag i pair in a negative charge state.

780-meV photoluminescence band in silver-doped silicon: Isotope effect and time-resolved spectroscopy

“…Silver-doped silicon was also thoroughly studied by electron paramagnetic resonance ͑EPR͒; following analyses of the EPR spectra, microscopic models of several Ag-related centers were proposed. 5,6 Also, the photoluminescence ͑PL͒ of silver-doped silicon has been investigated. It has been found that silver doping of silicon crystals results in generation of a characteristic lowtemperature emission spectrum at 780 meV.…”

Lattice location of implanted Ag in Si

“…The Ag(D) level could be assigned by means of photoluminescence (PL) [4,5] and infrared absorption spectroscopy [6] to a defect of C 2v or lower symmetry, and was suggested to be neutral substitutional Ag S 0 . Electron paramagnetic resonance (EPR) measurements have identified at least 8 different Ag-related centers in Si, six of them are supposed to be due to pairs of Ag with other impurities or with itself [7][8][9]. Two centers, however, named NL56 and NL42 have been suggested to consist of substitutional Ag S 0 and tetrahedral interstitial Ag i 0 , respectively.…”