Electrical observation of the Au-Fe complex in silicon

Abstract

Electron paramagnetic resonance (EPR) and diode capacitance measurements, including deep level transient spectroscopy (DLTS), have been used to identify the levels in the silicon band gap associated with the Au-Fe complex. Two deep levels at Ee -0.354 eV and Ev + 0.434 eV were found with properties consistent with those of the complex; the role of gold in the formation of the complex was confirmed by the observation that during low-temperature annealing ( < 350°C) the changes in the concentration of the center were accompanied by equal and opposite changes in the concentration of the normal gold acceptor and donor levels. PACS numbers: 71.55.Fr 952 J. Appl. Phys. 55 (4). 15 February 1984

Electronic properties and hyperfine parameters of gold–3d-transition-metal impurity pairs in silicon

“…1 This ionic model has been applied to describe some properties of gold-TM centers. [8][9][10][11][12] According to that description, the observed EPR signals come from a magnetic coupling between the angular momenta of the two isolated ions, one centered on the gold and the other on the TM impurity. Therefore, the notation Au s Ϫ TM i ϩ has been currently used to denote the pairs.…”

“…EPR technique was used to determine the effective spin and the structure of Au-TM complex defects. 1,[8][9][10][11] Some complexes are associated with electrically active gap levels that have been characterized by diode capacitance measurements, including deep-level transient spectroscopy ͑DLTS͒. 12,13 EPR experiments showed that the pairs are aligned along the ͗111͘ direction with a trigonal symmetry, indicating that they may consist of a substitutional gold with a TM impurity occupying a nearby interstitial site.…”

“…However, the experimental data pointed only to the existence of goldrelated complexes. 1,[8][9][10][11][12][13][14] Recently, Zeeman studies of the donor and acceptor excitation spectra provided detailed information on the electronic structure of the neutral substitutional gold in silicon. 15,16 The center is paramagnetic (Sϭ1/2) with g ʈ Ϸ2.8 and g Ќ Ϸ0, and has a static ͗100͘ tetragonal distortion (D 2d ).…”

“…[18][19][20] In addition to the fascinating puzzle that isolated gold has provided during all these years, numerous experimental investigations provided a wealth of information on the nature of various centers related to gold in silicon, specifically the gold-transition metal pairs. 1,[8][9][10][11][12][13] The charge states of the pairs have been controlled by the concentration of shallow acceptors or donors present in the sample. EPR technique was used to determine the effective spin and the structure of Au-TM complex defects.…”

Gettering Processes and the Role of Extended Defects

“…The question whether the solubility of M 1 is affected by a second metal impurity M 2 needs to consider (i) the interaction of the two impurities in silicon and the related changes of their chemical potential there, and (ii) their chemical potentials in ternary liquids or silicides. The former may be neglected at high temperatures since, e.g., the formation of M 1 -M 2 pairs usually occurs at quite low temperature (see, e.g., [34]). The latter is related to the respective ternary (or: multinary) phase diagram.…”