Oxygen aggregation kinetics, thermal donors and carbon-oxygen defect formation in silicon containing carbon and tin

Abstract

Localized vibrational mode spectroscopy measurements on Czochralski silicon (Cz-Si) samples subjected to isothermal annealing at 450 C are reported. First, we studied the effect of carbon (C) and tin (Sn) isovalent dopants on the aggregation kinetics of oxygen. It is determined that the reduction rate of oxygen is described by the Johnson-Mehl-Avrami equation in accordance with previous reports. The activation energy related with the reaction rate constant of the process is calculated to increase from Cz-Si, to C-doped Cz-Si (CCz-Si), to Sn-doped Cz-Si contained C (SnCz-Si). This is attributed to the presence of the isovalent dopants that may impact both the kinetics of the oxygen atoms and also may lead to the formation of other oxygen-related clusters. Second, we studied the effect of Sn on the formation and evolution of carbon-oxygen (C-O) defects. It was determined that the presence of Sn suppresses the formation of the C-O defects as indicated by the reduction in the strength of the 683, 626, and 586 cm À1 well-known bands of C s O i defect. The phenomenon is attributed to the association of Sn with C atoms that may prevent the pairing of O with C. Third, we investigated the effect of C and Sn on the formation of thermal donors (TDs). Regarding carbon our results verified previous reports that carbon suppresses the formation of TDs. Interestingly, when both C and Sn are present in Si, very weak bands of TDs were observed, although it is known that Sn alone suppress their formation. This may be attributed to the competing strains of C and Sn in the Si lattice. V

Ultrathin Aluminum Oxide Films Induced by Rapid Thermal Annealing for Effective Silicon Surface Passivation

“…The reaction rate (R act ) is strongly dependent on the reaction temperature, and the increase in τ eff during the annealing process can be expressed according to [42]…”

“…The reaction rate ( R act ) is strongly dependent on the reaction temperature, and the increase in τ eff during the annealing process can be expressed according to [ 42 ] where is the measured τ eff at the absolute annealing temperature ( T ) for an isothermal anneal time of t ; is the saturated τ eff for the completely generated Al 2 O 3 passivation films. The R act at different temperatures can be well fitted based on Equation (), as shown in Figure 4.…”

Growth Rate and Temperature Dependence of Oxygen Incorporation in Si1-XGex Thin Films

“…Carbon will typically substitute in a lattice sight and is isovalent. However, its smaller size could preferentially accommodate local oxygen interstitials in the lattice which may act as nucleation sites for oxygen complexes (8,9). This may be a contributing factor to the observed compositional dependence in the activation energy.…”

Tin-based donors in SiSn alloys

“…Donor creation by cluster formation is especially known from oxygen in silicon, which forms thermal donors (TDs) at lower temperatures [27][28][29] and new donors (NDs) after long-time annealing at temperatures above 600 C. [30][31][32][33][34][35]37 The observed admittance spectroscopy peak with an activation energy of 55-70 meV is in agreement with the known energy levels for both TDs (50-150 meV) 38,39 and NDs (30-120 meV). 35 TDs, however, are only stable for annealing temperatures below 600 C, [37][38][39][40] and NDs need very long annealing times in the order of 10 h or more. 30,31,33,37 Furthermore, usually much higher oxygen concentrations than those present here are reported for both TD and ND formation.…”